CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application claims priority to United States Provisional Patent Application Number 63/118,559 entitled “OFFSET FREQUENCY PRE-COMPENSATION FOR HIGH SPEED SCENARIOS UNDER A SIGNLE FREQUENCY NETWORK” and filed on November 25, 2020 for Ahmed Hindy and Vijay Nangia, which application is incorporated herein by reference.

FIELD

[0002] The subject matter disclosed herein relates generally to wireless communications and more particularly relates to offset frequency pre-compensation for high speed Single Frequency Network (“SFN”).

BACKGROUND

[0003] In certain wireless networks, multiple Transmission-Reception Points (“TRPs”) or multi-antenna panels within a TRP may communicate simultaneously with one User Equipment (“UE”) to enhance coverage, throughput, or reliability. High speed rail is expanding in Europe and Asia alongside their number of passengers with smart devices like laptops and mobile phones. Current technologies like GSM for Railways (“GSM-R”), LTE Advanced (“LTE-A”), WiMAX and LTE for Railways (“LTE-R”), support data ranges from tens for kbps to tens of Mbps which will not be enough to handle demand for high-data-rates and increased reliability/latency for on board broadband services.

BRIEF SUMMARY

[0004] Disclosed are procedures for offset frequency pre-compensation for high speed SFN. Said procedures may be implemented by apparatus, systems, methods, or computer program products.

[0005] One method of a UE for offset frequency pre-compensation for high speed SFN includes receiving an indication of a High Speed Train Single Frequency Network (“HST-SFN”) transmission from at least one transmission-reception point (“TRP”) in a network. The method includes receiving a configuration with a plurality of Tracking Reference Signals (“TRSs”), where the plurality of TRSs comprise a first subset of TRSs and a second subset of TRSs. The method includes receiving a downlink scheduling grant containing a Transmission Configuration Indicator (“Tci”) codepoint indicating two TCI states with quasi-co-location (“QCL”) sources configured with respect to the two subsets of TRSs. The method includes transmitting a Sounding Reference Signal (“SRS”) based on received TRSs, where the SRS is associated with the first subset of TRSs via a spatial relation information indication. The method includes receiving a Demodulation Reference Signal (“DMRS”) for at least one of a physical downlink shared channel (“PDSCH”) and a physical downlink control channel (“PDCCH”), where the received DMRS is based on the transmitted SRS.

[0006] One method of a RAN for offset frequency pre-compensation for high speed SFN includes transmitting an indication of an HST-SFN transmission from at least one TRP in a network. The method includes transmitting a configuration with a plurality of TRSs, where the plurality of TRSs comprise a first subset of TRSs and a second subset of TRSs. The method includes transmitting a downlink scheduling grant containing a TCI codepoint indicating two TCI states with QCL sources configured with respect to the two subsets of TRSs. The method includes receiving an SRS based on transmitted TRSs, where the SRS is associated with the first subset of TRSs via a spatial relation information indication. The method includes transmitting a DMRS for at least one of: a PDSCH and a PDCCH, where the transmitted DMRS is based on the received SRS.

BRIEF DESCRIPTION OF THE DRAWINGS

[0007] A more particular description of the embodiments briefly described above will be rendered by reference to specific embodiments that are illustrated in the appended drawings. Understanding that these drawings depict only some embodiments and are not therefore to be considered to be limiting of scope, the embodiments will be described and explained with additional specificity and detail through the use of the accompanying drawings, in which:

[0008] Figure 1 is a block diagram illustrating one embodiment of a wireless communication system for offset frequency pre-compensation for high speed SFN;

[0009] Figure 2A is a diagram illustrating one embodiment of a SFN deployment for High Speed Train (“HST”) scenario;

[0010] Figure 2B is a diagram illustrating one embodiment of a two- tap HST channel model for SFN transmission;

[0011] Figure 3 is a diagram illustrating one example of SFN transmission;

[0012] Figure 4 is a diagram illustrating one example of single Downlink Control Information (“DCI”) for two Physical Downlink Shared Channel (“PDSCH”) multi-TRP transmission; [0013] Figure 5 is a diagram illustrating one example of Abstract Syntax Notation 1 (“ASN.l”) code for PDSCH-Config Information Element (“IE”);

[0014] Figure 6 is a diagram illustrating one example of ASN.l code for DMRS- DownlinkConfig IE;

[0015] Figure 7 is a diagram illustrating one embodiment of ASN.l code for Quasi-Co- Location (“QCL”) information;

[0016] Figure 8 is a diagram illustrating one example of Multi-TRP Ultra-Reliable and Low-Latency Communications (“URLLC”) Spatial Division Multiplexing (“SDM scheme”);

[0017] Figure 9 is a block diagram illustrating one embodiment of a user equipment apparatus that may be used for offset frequency pre-compensation for high speed SFN;

[0018] Figure 10 is a block diagram illustrating one embodiment of a network apparatus that may be used for offset frequency pre-compensation for high speed SFN;

[0019] Figure 11 is a flowchart diagram illustrating one embodiment of a first method for offset frequency pre-compensation for high speed SFN; and

[0020] Figure 12 is a flowchart diagram illustrating one embodiment of a second method for offset frequency pre-compensation for high speed SFN.

DETAILED DESCRIPTION

[0021] As will be appreciated by one skilled in the art, aspects of the embodiments may be embodied as a system, apparatus, method, or program product. Accordingly, embodiments may take the form of an entirely hardware embodiment, an entirely software embodiment (including firmware, resident software, micro-code, etc.) or an embodiment combining software and hardware aspects.

[0022] For example, the disclosed embodiments may be implemented as a hardware circuit comprising custom very-large-scale integration (“VLSI”) circuits or gate arrays, off-the-shelf semiconductors such as logic chips, transistors, or other discrete components. The disclosed embodiments may also be implemented in programmable hardware devices such as field programmable gate arrays, programmable array logic, programmable logic devices, or the like. As another example, the disclosed embodiments may include one or more physical or logical blocks of executable code which may, for instance, be organized as an object, procedure, or function.

[0023] Furthermore, embodiments may take the form of a program product embodied in one or more computer readable storage devices storing machine readable code, computer readable code, and/or program code, referred hereafter as code. The storage devices may be tangible, non- transitory, and/or non-transmission. The storage devices may not embody signals. In a certain embodiment, the storage devices only employ signals for accessing code.

[0024] Any combination of one or more computer readable medium may be utilized. The computer readable medium may be a computer readable storage medium. The computer readable storage medium may be a storage device storing the code. The storage device may be, for example, but not limited to, an electronic, magnetic, optical, electromagnetic, infrared, holographic, micromechanical, or semiconductor system, apparatus, or device, or any suitable combination of the foregoing.

[0025] More specific examples (a non-exhaustive list) of the storage device would include the following: an electrical connection having one or more wires, a portable computer diskette, a hard disk, a random-access memory (“RAM”), a read-only memory (“ROM”), an erasable programmable read-only memory (“EPROM” or Flash memory), a portable compact disc read only memory (“CD-ROM”), an optical storage device, a magnetic storage device, or any suitable combination of the foregoing. In the context of this document, a computer readable storage medium may be any tangible medium that can contain or store a program for use by or in connection with an instruction execution system, apparatus, or device.

[0026] Code for carrying out operations for embodiments may be any number of lines and may be written in any combination of one or more programming languages including an object- oriented programming language such as Python, Ruby, Java, Smalltalk, C++, or the like, and conventional procedural programming languages, such as the "C" programming language, or the like, and/or machine languages such as assembly languages. The code may execute entirely on the user's computer, partly on the user's computer, as a stand-alone software package, partly on the user's computer and partly on a remote computer or entirely on the remote computer or server. In the latter scenario, the remote computer may be connected to the user's computer through any type of network, including a local area network (“LAN”), wireless LAN (“WLAN”), or a wide area network (“WAN”), or the connection may be made to an external computer (for example, through the Internet using an Internet Service Provider (“ISP”)).

[0027] Furthermore, the described features, structures, or characteristics of the embodiments may be combined in any suitable manner. In the following description, numerous specific details are provided, such as examples of programming, software modules, user selections, network transactions, database queries, database structures, hardware modules, hardware circuits, hardware chips, etc., to provide a thorough understanding of embodiments. One skilled in the relevant art will recognize, however, that embodiments may be practiced without one or more of the specific details, or with other methods, components, materials, and so forth. In other instances, well-known structures, materials, or operations are not shown or described in detail to avoid obscuring aspects of an embodiment.

[0028] Reference throughout this specification to “one embodiment,” “an embodiment,” or similar language means that a particular feature, structure, or characteristic described in connection with the embodiment is included in at least one embodiment. Thus, appearances of the phrases “in one embodiment,” “in an embodiment,” and similar language throughout this specification may, but do not necessarily, all refer to the same embodiment, but mean “one or more but not all embodiments” unless expressly specified otherwise. The terms “including,” “comprising,” “having,” and variations thereof mean “including but not limited to,” unless expressly specified otherwise. An enumerated listing of items does not imply that any or all of the items are mutually exclusive, unless expressly specified otherwise. The terms “a,” “an,” and “the” also refer to “one or more” unless expressly specified otherwise.

[0029] As used herein, a list with a conjunction of “and/or” includes any single item in the list or a combination of items in the list. For example, a list of A, B and/or C includes only A, only B, only C, a combination of A and B, a combination of B and C, a combination of A and C or a combination of A, B and C. As used herein, a list using the terminology “one or more of’ includes any single item in the list or a combination of items in the list. For example, one or more of A, B and C includes only A, only B, only C, a combination of A and B, a combination of B and C, a combination of A and C or a combination of A, B and C. As used herein, a list using the terminology “one of’ includes one and only one of any single item in the list. For example, “one of A, B and C” includes only A, only B or only C and excludes combinations of A, B and C. As used herein, “a member selected from the group consisting of A, B, and C,” includes one and only one of A, B, or C, and excludes combinations of A, B, and C.” As used herein, “a member selected from the group consisting of A, B, and C and combinations thereof’ includes only A, only B, only C, a combination of A and B, a combination of B and C, a combination of A and C or a combination of A, B and C.

[0030] Aspects of the embodiments are described below with reference to schematic flowchart diagrams and/or schematic block diagrams of methods, apparatuses, systems, and program products according to embodiments. It will be understood that each block of the schematic flowchart diagrams and/or schematic block diagrams, and combinations of blocks in the schematic flowchart diagrams and/or schematic block diagrams, can be implemented by code. This code may be provided to a processor of a general-purpose computer, special purpose computer, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, create means for implementing the functions/acts specified in the flowchart diagrams and/or block diagrams.

[0031] The code may also be stored in a storage device that can direct a computer, other programmable data processing apparatus, or other devices to function in a particular manner, such that the instructions stored in the storage device produce an article of manufacture including instructions which implement the function/act specified in the flowchart diagrams and/or block diagrams.

[0032] The code may also be loaded onto a computer, other programmable data processing apparatus, or other devices to cause a series of operational steps to be performed on the computer, other programmable apparatus or other devices to produce a computer implemented process such that the code which execute on the computer or other programmable apparatus provide processes for implementing the functions/acts specified in the flowchart diagrams and/or block diagrams.

[0033] The call-flow diagrams, flowchart diagrams and/or block diagrams in the Figures illustrate the architecture, functionality, and operation of possible implementations of apparatuses, systems, methods, and program products according to various embodiments. In this regard, each block in the flowchart diagrams and/or block diagrams may represent a module, segment, or portion of code, which includes one or more executable instructions of the code for implementing the specified logical function(s).

[0034] It should also be noted that, in some alternative implementations, the functions noted in the block may occur out of the order noted in the Figures. For example, two blocks shown in succession may, in fact, be executed substantially concurrently, or the blocks may sometimes be executed in the reverse order, depending upon the functionality involved. Other steps and methods may be conceived that are equivalent in function, logic, or effect to one or more blocks, or portions thereof, of the illustrated Figures.

[0035] Although various arrow types and line types may be employed in the call-flow, flowchart and/or block diagrams, they are understood not to limit the scope of the corresponding embodiments. Indeed, some arrows or other connectors may be used to indicate only the logical flow of the depicted embodiment. For instance, an arrow may indicate a waiting or monitoring period of unspecified duration between enumerated steps of the depicted embodiment. It will also be noted that each block of the block diagrams and/or flowchart diagrams, and combinations of blocks in the block diagrams and/or flowchart diagrams, can be implemented by special purpose hardware-based systems that perform the specified functions or acts, or combinations of special purpose hardware and code. [0036] The description of elements in each figure may refer to elements of proceeding figures. Like numbers refer to like elements in all figures, including alternate embodiments of like elements.

[0037] Generally, the present disclosure describes systems, methods, and apparatus for offset frequency pre-compensation for high speed SFN. In certain embodiments, the methods may be performed using computer code embedded on a computer-readable medium. In certain embodiments, an apparatus or system may include a computer-readable medium containing computer-readable code which, when executed by a processor, causes the apparatus or system to perform at least a portion of the below described solutions.

[0038] Under the offset-frequency pre-compensation scheme, QCL relationships becomes harder - as does triggering the UE. In order for the offset frequency pre-compensation scheme to operate with reasonable gain, partial information related to scheme indication is needed.

[0039] In Third Generation Partnership Project (“3GPP”) release 15 the scheduling downlink grant can indicator only one Transmission Configuration Indicator (“TCI”) state. Thus, for high speed train (“HST”) scenario receiving the same packet from two remote radio heads (“RRHs,” also dubbed Transmission/Reception Point), the PDSCH DMRS can be quasi-co-located (“QCL’ed”) with one tracking reference signal (“TRS”), and the difference in doppler shifts for the channel to RRH1 versus RRH2 would cause intercarrier interference, degrade channel estimation quality, and hence decrease performance.

[0040] In 3GPP Release 16, multi-TRP non-coherent joint transmission (“NCJT”) and ultra-reliable low-latency communication (“URLLC”) schemes enable a two TCI state indication in the transmission configuration indicator (“TCI”) codepoint in the scheduling downlink control information (“DCI”). However, NCJT schemes are designed to increase spectral efficiency, and URLLC schemes are designed to increase reliability. The Doppler variation issue form the two TRPs is not resolved.

[0041] To resolve the Doppler variation and to reduce intercarrier interference, the below described solutions enable the network to configure the offset frequency pre-compensation scheme. The network may indicate a primary TRP (or TRS) that would not be pre-compensated. Also described are QCL relationships between different reference signals.

[0042] Disclosed herein are solutions that address these issues and describe techniques for offset frequency pre-compensation of one or more Reference Signals (“RSs”) is indicated to a UE. Modifications to the underlying QCL relationships between RSs are also proposed to capture the discrepancy in large-scale fading characteristics observed by the RSs due to the offset frequency pre-compensation. Several embodiments and examples therein are provided to explain the proposals and clarify how they can be adopted in practical scenarios.

[0043] Figure 1 depicts a wireless communication system 100 for offset frequency pre compensation for high speed SFN, according to embodiments of the disclosure. In one embodiment, the wireless communication system 100 includes at least one remote unit 105, a radio access network (“RAN”) 120, and a mobile core network 140. The RAN 120 and the mobile core network 140 form a mobile communication network. The RAN 120 may be composed of a base unit 121 with which the remote unit 105 communicates using wireless communication links 123. Even though a specific number of remote units 105, base units 121, wireless communication links 123, RANs 120, and mobile core networks 140 are depicted in Figure 1, one of skill in the art will recognize that any number of remote units 105, base units 121, wireless communication links 123, RANs 120, and mobile core networks 140 may be included in the wireless communication system 100.

[0044] In one implementation, the RAN 120 is compliant with the Fifth-Generation (“5G”) cellular system specified in the Third Generation Partnership Project (“3GPP”) specifications. For example, the RAN 120 may be a Next Generation Radio Access Network (“NG-RAN”), implementing New Radio (“NR”) Radio Access Technology (“RAT”) and/or Long-Term Evolution (“LTE”) RAT. In another example, the RAN 120 may include non-3GPP RAT (e.g., Wi-Fi® or Institute of Electrical and Electronics Engineers (“IEEE”) 802.11-family compliant WLAN). In another implementation, the RAN 120 is compliant with the LTE system specified in the 3GPP specifications. More generally, however, the wireless communication system 100 may implement some other open or proprietary communication network, for example Worldwide Interoperability for Microwave Access (“WiMAX”) or IEEE 802.16-family standards, among other networks. The present disclosure is not intended to be limited to the implementation of any particular wireless communication system architecture or protocol.

[0045] In one embodiment, the remote units 105 may include computing devices, such as desktop computers, laptop computers, personal digital assistants (“PDAs”), tablet computers, smart phones, smart televisions (e.g., televisions connected to the Internet), smart appliances (e.g., appliances connected to the Internet), set-top boxes, game consoles, security systems (including security cameras), vehicle on-board computers, network devices (e.g., routers, switches, modems), or the like. In some embodiments, the remote units 105 include wearable devices, such as smart watches, fitness bands, optical head-mounted displays, or the like. Moreover, the remote units 105 may be referred to as the UEs, subscriber units, mobiles, mobile stations, users, terminals, mobile terminals, fixed terminals, subscriber stations, user terminals, wireless transmit/receive unit (”WTRU”), a device, or by other terminology used in the art. In various embodiments, the remote unit 105 includes a subscriber identity and/or identification module (“SIM”) and the mobile equipment (“ME”) providing mobile termination functions (e.g., radio transmission, handover, speech encoding and decoding, error detection and correction, signaling and access to the SIM). In certain embodiments, the remote unit 105 may include a terminal equipment (“TE”) and/or be embedded in an appliance or device (e.g., a computing device, as described above).

[0046] The remote units 105 may communicate directly with one or more of the base units 121 in the RAN 120 via uplink (“UL”) and downlink (“DL”) communication signals. Furthermore, the UL and DL communication signals may be carried over the wireless communication links 123. Here, the RAN 120 is an intermediate network that provides the remote units 105 with access to the mobile core network 140.

[0047] In some embodiments, the remote units 105 communicate with an application server 151 via a network connection with the mobile core network 140. For example, an application 107 (e.g., web browser, media client, telephone and/or Voice-over-Internet-Protocol (“VoIP”) application) in a remote unit 105 may trigger the remote unit 105 to establish a protocol data unit (“PDU”) session (or other data connection) with the mobile core network 140 via the RAN 120. The mobile core network 140 then relays traffic between the remote unit 105 and the application server 151 in the packet data network 150 using the PDU session. The PDU session represents a logical connection between the remote unit 105 and the User Plane Function (“UPF”) 141.

[0048] In order to establish the PDU session (or PDN connection), the remote unit 105 must be registered with the mobile core network 140 (also referred to as “attached to the mobile core network” in the context of a Fourth Generation (“4G”) system). Note that the remote unit 105 may establish one or more PDU sessions (or other data connections) with the mobile core network 140. As such, the remote unit 105 may have at least one PDU session for communicating with the packet data network 150. The remote unit 105 may establish additional PDU sessions for communicating with other data networks and/or other communication peers.

[0049] In the context of a 5G system (“5GS”), the term “PDU Session” refers to a data connection that provides end-to-end (“E2E”) user plane (“UP”) connectivity between the remote unit 105 and a specific Data Network (“DN”) through the UPF 141. A PDU Session supports one or more Quality of Service (“QoS”) Flows. In certain embodiments, there may be a one-to-one mapping between a QoS Flow and a QoS profile, such that all packets belonging to a specific QoS Flow have the same 5G QoS Identifier (“5QI”). [0050] In the context of a 4G/LTE system, such as the Evolved Packet System (“EPS”), a Packet Data Network (“PDN”) connection (also referred to as EPS session) provides E2E UP connectivity between the remote unit and a PDN. The PDN connectivity procedure establishes an EPS Bearer, i.e., a tunnel between the remote unit 105 and a Packet Gateway (“PGW”, not shown) in the mobile core network 140. In certain embodiments, there is a one-to-one mapping between an EPS Bearer and a QoS profile, such that all packets belonging to a specific EPS Bearer have the same QoS Class Identifier (“QCI”).

[0051] The base units 121 may be distributed over a geographic region. In certain embodiments, a base unit 121 may also be referred to as an access terminal, an access point, a base, a base station, a Node-B (“NB”), an Evolved Node B (abbreviated as eNodeB or “eNB,” also known as Evolved Universal Terrestrial Radio Access Network (“E-UTRAN”) Node B), a 5G/NR Node B (“gNB”), a Home Node-B, a relay node, a RAN node, or by any other terminology used in the art. The base units 121 are generally part of a RAN, such as the RAN 120, that may include one or more controllers communicably coupled to one or more corresponding base units 121. These and other elements of radio access network are not illustrated but are well known generally by those having ordinary skill in the art. The base units 121 connect to the mobile core network 140 via the RAN 120.

[0052] The base units 121 may serve a number of remote units 105 within a serving area, for example, a cell or a cell sector, via a wireless communication link 123. The base units 121 may communicate directly with one or more of the remote units 105 via communication signals. Generally, the base units 121 transmit DL communication signals to serve the remote units 105 in the time, frequency, and/or spatial domain. Furthermore, the DL communication signals may be carried over the wireless communication links 123. The wireless communication links 123 may be any suitable carrier in licensed or unlicensed radio spectrum. The wireless communication links 123 facilitate communication between one or more of the remote units 105 and/or one or more of the base units 121. Note that during NR operation on unlicensed spectrum (referred to as “NR- U”), the base unit 121 and the remote unit 105 communicate over unlicensed (i.e., shared) radio spectrum.

[0053] In one embodiment, the mobile core network 140 is a 5G Core network (“5GC”) or an Evolved Packet Core (“EPC”), which may be coupled to a packet data network 150, like the Internet and private data networks, among other data networks. A remote unit 105 may have a subscription or other account with the mobile core network 140. In various embodiments, each mobile core network 140 belongs to a single mobile network operator (“MNO”) and/or Public Land Mobile Network (“PLMN”). The present disclosure is not intended to be limited to the implementation of any particular wireless communication system architecture or protocol.

[0054] The mobile core network 140 includes several network functions (“NFs”). As depicted, the mobile core network 140 includes at least one UPF 141. The mobile core network 140 also includes multiple control plane (“CP”) functions including, but not limited to, an Access and Mobility Management Function (“AMF”) 143 that serves the RAN 120, a Session Management Function (“SMF”) 145, a Policy Control Function (“PCF”) 147, a Unified Data Management function (“UDM”) and a User Data Repository (“UDR”). In some embodiments, the UDM is co-located with the UDR, depicted as combined entity “UDM/UDR” 149. Although specific numbers and types of network functions are depicted in Figure 1 , one of skill in the art will recognize that any number and type of network functions may be included in the mobile core network 140.

[0055] The UPF(s) 141 is/are responsible for packet routing and forwarding, packet inspection, QoS handling, and external PDU session for interconnecting Data Network (“DN”), in the 5G architecture. The AMF 143 is responsible for termination of Non-Access Spectrum (“NAS”) signaling, NAS ciphering & integrity protection, registration management, connection management, mobility management, access authentication and authorization, security context management. The SMF 145 is responsible for session management (i.e., session establishment, modification, release), remote unit (i.e., UE) Internet Protocol (“IP”) address allocation & management, DL data notification, and traffic steering configuration of the UPF 141 for proper traffic routing.

[0056] The PCF 147 is responsible for unified policy framework, providing policy rules to CP functions, access subscription information for policy decisions in UDR. The UDM is responsible for generation of Authentication and Key Agreement (“AKA”) credentials, user identification handling, access authorization, subscription management. The UDR is a repository of subscriber information and may be used to service a number of network functions. For example, the UDR may store subscription data, policy-related data, subscriber-related data that is permitted to be exposed to third party applications, and the like.

[0057] In various embodiments, the mobile core network 140 may also include a Network Repository Function (“NRF”) (which provides Network Function (“NF”) service registration and discovery, enabling NFs to identify appropriate services in one another and communicate with each other over Application Programming Interfaces (“APIs”)), a Network Exposure Function (“NEF”) (which is responsible for making network data and resources easily accessible to customers and network partners), an Authentication Server Function (“AUSF”), or other NFs defined for the 5GC. When present, the AUSF may act as an authentication server and/or authentication proxy, thereby allowing the AMF 143 to authenticate a remote unit 105. In certain embodiments, the mobile core network 140 may include an authentication, authorization, and accounting (“AAA”) server.

[0058] In various embodiments, the mobile core network 140 supports different types of mobile data connections and different types of network slices, wherein each mobile data connection utilizes a specific network slice. Flere, a “network slice” refers to a portion of the mobile core network 140 optimized for a certain traffic type or communication service. For example, one or more network slices may be optimized for enhanced mobile broadband (“eMBB”) service. As another example, one or more network slices may be optimized for ultra-reliable low- latency communication (“URLLC”) service. In other examples, a network slice may be optimized for machine-type communication (“MTC”) service, massive MTC (“mMTC”) service, Internet- of-Things (“IoT”) service. In yet other examples, a network slice may be deployed for a specific application service, a vertical service, a specific use case, etc.

[0059] A network slice instance may be identified by a single-network slice selection assistance information (“S-NSSAI”) while a set of network slices for which the remote unit 105 is authorized to use is identified by network slice selection assistance information (“NSSAI”). Flere, “NSSAI” refers to a vector value including one or more S-NSSAI values. In certain embodiments, the various network slices may include separate instances of network functions, such as the SMF 145 and UPF 141. In some embodiments, the different network slices may share some common network functions, such as the AMF 143. The different network slices are not shown in Figure 1 for ease of illustration, but their support is assumed.

[0060] While Figure 1 depicts components of a 5G RAN and a 5G core network, the described embodiments for offset frequency pre-compensation for high speed SFN apply to other types of communication networks and RATs, including IEEE 802.11 variants, Global System for Mobile Communications (“GSM”, i.e., a 2G digital cellular network), General Packet Radio Service (“GPRS”), Universal Mobile Telecommunications System (“UMTS”), LTE variants, CDMA 2000, Bluetooth, ZigBee, Sigfox, and the like.

[0061] Moreover, in an LTE variant where the mobile core network 140 is an EPC, the depicted network functions may be replaced with appropriate EPC entities, such as a Mobility Management Entity (“MME”), a Serving Gateway (“SGW”), a PGW, a Home Subscriber Server (“F1SS”), and the like. For example, the AMF 143 may be mapped to an MME, the SMF 145 may be mapped to a control plane portion of a PGW and/or to an MME, the UPF 141 may be mapped to an SGW and a user plane portion of the PGW, the UDM/UDR 149 may be mapped to an HSS, etc.

[0062] In the following descriptions, the term “gNB” is used for the base station/ base unit, but it is replaceable by any other radio access node, e.g., RAN node, ng-eNB, eNB, Base Station (“BS”), Access Point (“AP”), Integrated Access-and-BackhauI (“IAB”) node, Radio Head (“RH”), etc. Additionally, the term “UE” is used for the mobile station/ remote unit, but it is replaceable by any other remote device, e.g., remote unit, MS, ME, Customer Premise Equipment (“CPE”), etc. Further, the operations are described mainly in the context of 5G NR. However, the below described solutions/methods are also equally applicable to other mobile communication systems for offset frequency pre-compensation for high speed SFN.

[0063] High speed rail is expanding in Europe and Asia alongside their number of passengers with smart devices like laptops and mobile phones. Current technologies like GSM- R, LTE-A, WiMAX and LTE-R, support data ranges from tens for kbps to tens of Mbps which will not be enough to handle demand for high-data-rates and increased reliability/latency for on board broadband services.

[0064] In SFN deployment scenario that was defined in 3GPP (i.e., all cells are operating at the same frequency), multiple remote radio heads are located along the railway and connected to a central unit usually via fiber. They also share the same cell ID. When the transmission from the Transmit-Receive Points (“TRPs”) within a cell are synchronized, SFN deployment can enlarge the cell coverage, reduce the frequency of handovers, and achieve transmission diversity and power gain. A typical 4GHz deployment is shown in Figure 1. Based on a 6dB pathloss difference between any two TRPs, we expect the train would take advantage of simultaneous two TRP transmissions for sessions of at least 4 seconds long, assuming a train speed of 500 km/hr.

[0065] For SFN transmission (NR Release 15), the PDSCH is repeated from two TRPs using a single scheduling DCI indicating a single DMRS port and a single TCI state. Consider the example in Figure 1. Clearly the doppler shift for the transmission from TRP1 (also dubbed RRH1) is different than the doppler shift from TRP2 (also dubbed RRH2). When the receiver uses the long-term channel statistics, e.g., Doppler shift, Doppler spread, average delay, and delay spread, associated with the indicated TCI state, to estimate the aggregate channel. Obviously, this may lead to estimation errors and performance degradation.

[0066] A single DCI muIti-TRP transmission can be instead used (for example muIti-TRP URFFC SDM repetition scheme - scheme la in NR Rel. 16). The DCI will indicate DMRS ports from different CDM groups along with a TCI codepoint indicating two TCI states. Some layers of the transmitted Transport Block (“TB”) will be sent from TRP1 and some layers from TRP2. This causes interlayer interference and does not achieve a power gain, hence no increase in cell coverage. Also, due to the varying proximity of the two TRPs to the UE, the Signal-to-Noise Ratio ("SNR”) gap between the signals from the two TRPs can lead to constraining the Modulation Coding Scheme (“MCS”) level (via Channel Quality Indicator (“CQI”)) to the worse of both transmissions, assuming a single codeword (“CW”).

[0067] This disclosure addresses a few aspects, including methods of indication of an offset frequency-pre-compensation to a TRS under HST-SFN transmission, in addition to the indication of the TRP whose Doppler shift value is used as a reference value for transmission, and finally discuss QCL relationships between TRS, PDSCH and DMRS for PDCCH, as well as the possibility of introducing QCL relationships between UL and DL RSs. In the following, a TRS is equivalent to a Channel State Information Reference Signal (“CSI-RS”) resource in an NZP-CSI- RS-ResourceSet configured with higher layer parameter trs-Info.

[0068] Figure 2A is a diagram illustrating one embodiment of a SFN deployment 200 for High Speed Train (“HST”). The SFN deployment comprises a plurality of Transmit/Receive Points (“TRPs”) along the route of a high-speed train 201 (i.e., deployed near a high-speed rail line). In a traditional cellular network deployment, a UE 205 would need to be handed over from one network node (i.e., TRP supporting a cell) to another as the high-speed train 201 moves along the rail. However, this type of deployment would result in a large number of handovers for each UE on the train 201 and therefore would result in poor network performance and poor resource efficiency due to the overhead of a high volume of handovers.

[0069] To minimize handovers along the UEs’ route, a Single Frequency Network (“SFN”) is deployed along the route. The multiple TRPs along the train route transmit the same Transport Block (“TB”), also referred to as “packet,” using the same frequency so that the UE 205 perceives a single transmitter (even if multiple transmission paths are detected). In essence, the multiple TRPs are to form one “virtual” transmitter.

[0070] However, due to the high-speed of the train 201 (e.g., speeds up to 500km/hour), the frequency drift from doppler shift at the UE 205 is large, and hence the channel is time-varying - meaning that time-averaging cannot improve estimation accuracy. However, the direction and velocity of the train 201 do not change rapidly, at least during the transmission duration/occasion, allowing for better prediction algorithms at the transceiver. The Doppler shift of the signal from the nearest TRP/RRH can be considered as a single tap channel where the doppler shift is calculated as:

Equation 1 where f is the carrier frequency, v is the train speed, c is the speed of light and Q is the angle between the line-of-sight (“LOS”) direction and the moving direction. At 4 GHz, this doppler shift of transmissions 207 ranges from 0 Hz to lKHz when the train 201 is halfway between TRPs/RRHs.

[0071] Note that Figure 2 A depicts example distances between the TRPs and the railway/track. These distances are for illustration only and may vary from one HST-SFN deployment to another and within a given HST-SFN the TRPs may not always be evenly spaced from each other and/or from the railway/track.

[0072] Figure 2B is a diagram illustrating one embodiment of a delay profile for a two-tap HST channel model for SFN transmission. To model an SFN transmission from two TRPs/RRHs, a two-tap channel model can be used. The channel model takes into consideration the two strongest paths corresponding to two nearest TRPs, i.e., with tap ti corresponding to a closest TRP and tap U corresponding to a second-closest TRP, and it captures dynamic propagation condition, including dynamic Doppler shift, channel tap delay, and channel tap power.

[0073] Because the train is moving farther away from one of the TRPs and moving closer to the next TRP (along direction of travel), the Doppler spread can be as significant as 2 KHz, meaning a coherence time of 0.5ms (duration of 1 slot at subcarrier spacing ("SCS”) = 30 KHz). The Doppler spread causes a carrier frequency offset (“CFO”). Another source of CFO can be caused by the frequency mismatch between the transmitter and the receiver (usually in the order of lOOKhz at 5GHz for 20ppm handsets). CFO usually causes:

• the phase rotation common to all carriers

• the signal amplitude distortion common to all carriers

• interference of each carrier on the symbols located on its neighboring carriers

[0074] CFO caused by oscillator imperfections can be better estimated and corrected. In contrast, CFO from Doppler spread is harder to compensate for. While High-Speed Train is the primary example in the below embodiments, the solutions described herein are also applicable to other high speed scenarios, i.e., where UE velocity causes a significant doppler shift which is corrected in the SFN using pre-compensation, such as UEs in vehicles traveling on a highway, UEs in aircraft, etc.

[0075] Figure 3 is a diagram illustrating one example scenario 300 of SFN transmission from two TRPs, i.e., first TRP 401 (denoted “TRP-1”) and a second TRP 303 (denoted “TRP-2”), to the high-speed UE 305. For the case of two TRP transmission from two TRPs to the high-speed UE 305, a Single-Frequency Network (“SFN”) transmission is used, where the same packet is sent with exactly the same resource block from multiple TRPs. The downlink scheduling grant (i.e., PDCCH #1) indicates the DL antenna ports along with single TCI state just as for regular single TRP transmission. In the time a UE can be configured with two TRSs, one from TRP-A 301 and one from TRP-B 303, the TCI state would point to only one of them.

[0076] However, where the UE velocity is significant, the Doppler spread/shift could degrade performance, i.e., due to intercarrier interference as well as poor channel estimation. To mitigate the effects of Doppler shift due to high UE velocity, the TRP-A 301 and the TRP-B 303 may use offset frequency pre-compensation when transmitting to the UE 305, as described in greater detail below.

[0077] Figure 4 is a diagram illustrating one example scenario 400 of single DCI for two PDSCH multi-TRP transmission, i.e., first TRP 401 (denoted “TRP-1”) and a second TRP 403 (denoted “TRP-2”), to the high-speed UE 405. The downlink scheduling grant (i.e., PDCCH #1) indicates the DL antenna ports along with a TCI codepoint indicating two TCI states. In the two PDSCH multi-TRP transmission scheme, each TRP transmits a different PDSCH to the UE 405 (denoted PDSCH #1 and PDSCH #2).

[0078] However, where the UE velocity is significant, the Doppler spread/shift could degrade performance, i.e., due to intercarrier interference as well as poor channel estimation. To mitigate the effects of Doppler shift due to high UE velocity, the TRP-A 401 and the TRP-B 403 may use offset frequency pre-compensation when transmitting to the UE 405, as described in greater detail below.

[0079] Figures 3 and 4 depict examples of joint transmission from two nodes (i.e., TRPs) where a relative frequency drift occurs due to the speed/mobility of a UE. At high speeds, the relative frequency drift becomes significant which results in the signals from each TRP not aligning in frequency. Note that in conventional systems, frequency drift values are not reported to the network. Rather, references signals are transmitted with data signals to link them together, so that parameters used to compensate for imperfections in the received reference signal can also be applied to the received data signals.

[0080] Several solutions for offset frequency pre-compensation for high speed SFN are described below. An objective of the below solutions is to enable alignment of signals from the two (or more) RAN nodes for seamless reception of the joint transmission at the UE. According to a possible embodiment, one or more elements or features from one or more of the described embodiments may be combined. While the below solutions are described as the network resolving the frequency drift (i.e., by performing offset frequency pre-compensation), in other embodiments the UE quantifies the frequency drift and pre-compensates the quantified frequency drift. [0081] The pre-compensation scheme involves multiple steps for resolving the frequency drift in a SFN due to high UE speeds. In the following descriptions, it is assumed that the UE is served by only two nodes (i.e., two TRPs); however, the below pre-compensation scheme also applies to scenarios where the UE receives signals from more than two network nodes.

[0082] At Step 1, the two nodes each transmit a pilot signal, e.g., a Tracking Reference Signal (“TRS”)· Here, the pilot/TRS from the first TRP is referred to as TRS-1, while the pilot/TRS from the second TRP is referred to as TRP-2.

[0083] At Step 2, the UE receives and estimates the pilot signals (TRSs) to measure the frequency drift. Here, the frequency drift of TRS-1 is referred to as Afl and the frequency drift of TRS -2 is referred to as Af2.

[0084] At Step 3, the UE reports the frequency drift values to the network. To do so, the UE generates and transmits its own pilot signal (e.g., a Sounding Reference Signal (“SRS”) or another uplink reference signal) based on the TRS frequencies. In other words, the UE applies a frequency shift - g(Afl, Af2) - to its SRS. Various aspects of the below solutions describe how to map the SRS to which frequency drift (i.e., which of Afl, Af2).

[0085] At Step 4, the network receives the SRS from the UE and quantifies the frequency drift - h(Afl, Af2) - as perceived at the UE. In certain embodiments, the network additionally estimates the SRS to measure a frequency drift of uplink transmissions.

[0086] At Step 5, the network pre-compensates the frequency drift from one node, e.g., add a frequency drift for transmission of the second node to align signals from the two nodes for seamless reception of the joint transmission at the UE. In one embodiment, the adjusted frequency drift is based on the difference between Afl and Af2. Various aspects of the below solutions describe which node pre-compensates transmission.

[0087] According to embodiments of a first solution, the network indicates a high speed SFN transmission (e.g., HST-SFN transmission) by configuring a UE with multi-TRP transmission under HST-SFN mode via a combination of one or more or the following embodiments.

[0088] In a first embodiment of the first solution, the network may introduce one or more higher-layer parameters to indicate HST-SFN transmission, e.g., highSpeedFlag, which if configured (i.e., set to on), then the UE would be configured for HST-SFN transmission. In one example, the higher-layer parameter appears in DMRS-DownlinkConfig IE, or DownlinkConfigCommon IE, or ServingCellConfig IE, or PDSCH-Config IE, or PDSCH- ServingCellConfig IE, or BWP-DownlinkDedicated IE. In such embodiments, the contents of the above listed IEs may be modified to include an indication of a high speed SFN transmission (e.g., HST-SFN transmission), such as the highSpeedFlag parameter, mentioned above, or similar parameter. Details on the other contents of the above listed IEs may be found in Clause 6.3.2 of 3GPP TS 38.331.

[0089] Additionally, or alternatively, in a second embodiment of the first solution, the network may modify the DCI to indicate whether HST-SFN transmission is activated. In one implementation, the network introduces a 1-bit field in the DCI to indicate whether HST-SFN transmission is activated. In another implementation, this indication may be indicated in DCI using an existing field, as described below.

[0090] Additionally, or alternatively, in a third embodiment of the first solution, the network may modify CSI-ReportConfig Reporting Setting to indicate whether HST-SFN transmission is activated, e.g., introducing new possible values to the higher-layer parameter reportQuantity reporting quantities indicated in CSI reporting setting, e.g., ‘cri-RI-PMI-CQTDI,’ where DI is a new quantity representing Doppler Indication.

[0091] Additionally, or alternatively, in a fourth embodiment of the first solution, the network may introduce new QCF relationship types between different Reference Signals (“RSs”) including but not limited to QCF relationship between TRS and Synchronization Signal Block (“SSB”), or between DMRS for PDSCH and TRS. An example of an additional QCF relationship type would be a new QCF type other than ‘TypeA,’ ‘TypeB,’ ‘TypeC’ or ‘TypeD.’ The new QCF type, referred to herein as ‘TypeE,’ may have the two RSs of interest not being QCF’ed with one or more of Doppler shift and Doppler spread.

[0092] According to embodiments of a second solution, the network implements an offset frequency pre-compensation scheme, wherein a UE is configured with one or more TRSs and one DMRS port per PDSCH layer. A TRS (tracking reference signal) is transmitted for establishing fine time and frequency synchronization at the UE to aid in demodulation of PDSCH, particularly for higher order modulations. A TRS is an NZP-CSI-RS resource set with trs-Info set to true. Here, the element trs-Info indicates that the antenna port for all NZP-CSI-RS resources in the CST RS resource set is same.

[0093] The TRS may be configured using the element trs-Info, as described above. The TRS contains either 2 or 4 periodic CSI-RS resources with periodicity 2 ^m x Xp slots where Xp = 10, 20, 40, or 80 and where m is related to the SCS, i.e. m = 0, 1, 2, 3, 4 for 15, 30, 60, 120, 240 kHz, respectively. The slot offsets for the 2 or 4 CSI-RS resources are configured such that the first pair of resources are transmitted in one slot, and the 2nd pair (if configured) are transmitted in the next (adjacent) slot. All four resources are single port with density 3. [0094] The two CSI-RS within a slot are always separated by four symbols in the time domain. This time-domain separation sets a limit for the maximum frequency error that can be compensated. Therefore:

• At SCS = 15 KHz, CFO_max = 1750 KHz

• At SCS = 30 KHz, CFO_max = 3500 KHz

[0095] Likewise, the frequency-domain separation of four subcarriers sets a limit for the maximum timing error that can be compensated. The maximum number of TRS a UE can be configured with is a UE capability:

• The maximum number of TRS resource sets (per CC) UE is able to track simultaneously: Candidate value set { 1 to 8 }

• The maximum number of TRS resource sets configured to UE per component carrier (“CC”): Candidate value set: { 1 to 64}. UE is mandated to report at least 8 for Frequency Range #1 (“FR1”, i.e., frequencies from 410 MHz to 7125 MHz) and 16 for Frequency Range #2 (“FR2”, i.e., frequencies from 24.25 GHz to 52.6 GHz).

• The maximum number of TRS resource sets configured to UE across CCs: Candidate value set: { 1 to 256}. UE is mandated to report at least 16 for FR1 and 32 for FR2

[0096] Furthermore, an aperiodic TRS is a set of aperiodic CSI-RS for tracking that is optionally configured, but a periodic TRS must always be configured, and its time and frequency domain configurations (except for the periodicity) must match those of the periodic TRS. The UE may assume that the aperiodic TRS resources are quasi-co-located with the periodic TRS resources.

[0097] In one embodiment of the second solution, the SRS transmitted from the UE is used to provide an estimate of the Doppler shift for each UE-TRP channel link (e.g., the local oscillator (“LO”) in the UE is frequency-locked to the received DL transmission (e.g., SSB, TRS that are not Doppler shift pre-compensated etc.) from the TRP which includes the Doppler shift, and is used for generating the UL SRS transmission). Let the Doppler shift computed at TRP k be \fk. Since Doppler shift is reciprocal, i.e., the Doppler shift between two transceivers (e.g., UE and TRP, or Tx and Rx for Time Division Duplex (“TDD”) and approximately same for Frequency Division Duplex (“FDD”) (e.g., carrier frequency much larger than the duplex spacing)) is the same regardless of which node is transmitting, TRP k can use the Doppler shift computed for the Uplink (“UL”) to pre-compensate the Downlink (“DL”) Doppler shift, for instance via applying a frequency offset of -Afk prior to the transmitting the DL RSs as well as the data/control signaling over the PDSCH/PDCCH. [0098] In another embodiment of the second solution, TRP k would pre-compensate the DL Doppler shift via applying a frequency offset of Afj -Afk, i.e., aligning its offset with that of another TRPj, prior to the transmitting the DL RSs, e.g., TRS, DMRS for PDSCH as well as the data/control signaling over the PDSCH/PDCCH.

[0099] Note that for such Doppler reciprocity to hold, it would be required that the spatial- domain transmit filter used for the transmission of the SRS is similar to the spatial-domain filter used for the reception of one or more of the prior or subsequent TRS, DMRS for PDSCH and DMRS for PDCCH, which may be applied when the UE is configured with HST-SFN transmission via one or more of the indications discussed in the first solution. Other indications are not precluded.

[0100] In one embodiment of the second solution, an equation or criteria is introduced to indicate the validity of this spatial relation, e.g., if the UE receives the DCI triggering the (e.g., aperiodic) SRS in slot n, the spatial-domain filter used for transmitting the target SRS at slot n+kO is the same as the receive spatial filter used for the TRS that is received in the time window from slot n+kl up to slot n+k2, where kO, kl and k2 are arbitrary positive integer values that are either set by a rule or are higher-layer configured, and satisfy W<kl<k2.

[0101] In another embodiment of the second solution, an equation is introduced to indicate the validity of this spatial relation, e.g., if the UE transmits the SRS in slot n, the spatial-domain filter used for receiving the TRS for up to slot n+k3 is the same as the spatial-domain filter used for transmitting the target SRS, where k3 is a positive integer value.

[0102] In yet another embodiment of the second solution, no equation is introduced, the spatial-domain filter for TRS reception is the same as the spatial-domain filter of prior SRS transmission whenever the UE is configured with HST-SFN transmission, as discussed in the first solution. Other indications are not precluded. Note that the same spatial relation info may apply to all SRS resources in the same SRS Resource Set.

[0103] According to embodiments of a third solution, the network may send to the UE an indication of offset frequency pre-compensation. In one embodiment, a higher-layer parameter is introduced to configure the offset frequency pre-compensation scheme, e.g., offset-frequency- Precompensation, which when configured/set to true, the offset frequency of one or more of the TRS, DMRS for PDSCH and DMRS for PDCCH would be pre-compensated with a value that may be based on the Doppler shift value(s) at one or more TRP. The higher-layer parameter may appear in DMRS-DownlinkConfig IE, or DownlinkConfig Common IE, or ServingCellConfig IE, or PDSCH-Config IE, or PDSCPl-ServingCellConfig IE, or BWP-DownlinkDedicated IE. Also, configuring this higher-layer parameter may be dependent on the indication of the HST-SFN transmission scheme as discussed in the first solution. More details about these IEs can be found in Clause 6.3.2 of 3GPP TS 38.331.

[0104] Figure 5 depicts one example of ASN.l code for PDSCH-Config information element. The PDSCH-Config IE is used to configure the UE specific PDSCH parameters. As depicted, the PDSCH-Config IE may include the parameter offset-frequency-Precompensation, or similar parameter, used to indicate that one or more of the TRS, DMRS for PDSCH and DMRS for PDCCH is to be pre-compensated with a value based on the Doppler shift value(s) at one or more TRP.

[0105] Additionally, the PDSCH-Config IE may include the parameter highSpeedFlag, or similar parameter, used to indicate a high speed SFN transmission (e.g., HST-SFN transmission).

[0106] Figure 6 depicts one example of ASN.l code for DMRS-DownlinkConfig information element. The DMRS-DownlinkConfig IE is used to configure downlink demodulation reference signals for PDSCH. As depicted, the DMRS-DownlinkConfig IE may include the parameter offset-frequency-Precompensation, or similar parameter, used to indicate that one or more of the TRS, DMRS for PDSCH and DMRS for PDCCH is to be pre-compensated with a value based on the Doppler shift value(s) at one or more TRP.

[0107] Additionally, the DMRS-DownlinkConfig IE may include the parameter highSpeedFlag, or similar parameter, used to indicate a high speed SFN transmission (e.g., HST- SFN transmission). Note that the configuration of the DMRS Type is provided through higher- layer signaling independently for each PDSCH and Physical Uplink Shared Channel (“PUSCH”), each mapping Type (A or B) and each bandwidth part (“BWP”) independently (e.g., as illustrated in Figure 6).

[0108] In a second embodiment of the third solution, an additional bit in the DCI field or an additional parameter may be indicated by an existing field in DCI (e.g., DCI field 'Transmission Configuration Indication' may indicate the TCI state(s) and whether offset frequency pre compensation is applied) is introduced (e.g., by configuring a higher layer parameter, e.g., offset- frequency-Precompensation-PresentlnDCI) that indicates whether offset frequency pre compensation is applied to one or more of TRS, DMRS for PDSCH and DMRS for PDCCH. Also, configuring the DCI to include the presence of the additional bit may be dependent on the indication of the HST-SFN transmission scheme as discussed in the first solution.

[0109] In some of the embodiments of the third solution, the configuration or presence of offset frequency pre-compensation indication (e.g., higher-layer parameter, bit field) may implicitly indicate the use of HST-SFN transmission scheme. [0110] In some of the embodiments of the third solution, the use of HST-SFN transmission scheme and application of offset frequency pre-compensation to one or more of TRS, DMRS for PDSCH and DMRS for PDCCH may be jointly indicated. For example, the joint indication may be a higher-layer parameter (e.g., may appear in DMRS-DownlinkConfig IE, or DownlinkConfigCommon IE or ServingCellConfig or PDSCH-Config or PDSCH- ServingCellConfig or BWP-DownlinkDedicated), or an additional bit or additional parameter. In some examples, the indication (if present) may indicate one of HST-SFN with offset frequency pre-compensation, and HST-SFN without offset frequency pre-compensation.

[0111] In a third embodiment of the third solution, offset frequency pre-compensation would be implied whenever a UE is configured with a TCI state that indicates a TRS is quasi-co located with a DMRS for PDSCH and/or DMRS for PDCCH via one or more QCL types that do not include either Doppler shift or Doppler spread. In one example, a new QCL type ‘QCL-TypeE’ is introduced that indicates the TRS is QCL’ed with a DMRS for PDSCH and/or a DMRS for PDCCH in terms of one of the following four sets of large-scale parameters ({Average Delay, Delay spread}, [Average Delay}, [Delay Spread}, {None}) and ‘QCL-TypeD,’ if applicable.

[0112] In a fourth embodiment of the third solution, the offset frequency pre-compensation is UE-triggered, e.g., based on UE signaling to the network or a UE capability.

[0113] Figure 7 depicts one embodiment of ASN.1 code for QCL information. A TCI state (see below and as configured by Radio Resource Control (“RRC”)) will have two Quasi- Colocation (“QCL”) types (i.e. two reference signals) with the second QCL type only for operation in FR2. For the reception of PDCCH/DMRS for PDSCH, QCL TypeA properties (i.e., Doppler shift, Doppler spread, average delay, delay spread) can be inferred from a periodic TRS. In turn for periodic TRS, QCL TypeC properties (i.e., Average delay, Doppler shift) can be inferred from an SSB block.

[0114] According to embodiments of a fourth solution, the network may transmit to the UE an indication of the reference TRS for offset frequency pre-compensation. In a first embodiment of the fourth solution, for high-speed train communication. For example, when offset frequency pre-compensation is configured/indicated/provided), a TCI state indicates that a DMRS for PDSCH (or DMRS for PDCCH) is quasi-co-located with a TRS with ‘QCL-TypeA’ and, when applicable, 'QCL-TypeD', if the TRS index is configured within the spatialrelationinfo of the SRS triggering or SRS transmission (e.g., latest SRS transmission prior to the PDSCH reception (or corresponding PDCCH reception in another example) by a minimum time-offset.

[0115] In a second embodiment of the fourth solution, for high-speed train communication, a TCI state indicates that a DMRS for PDSCH (or DMRS for PDCCH) is quasi-co-located with a TRS with ‘QCL-TypeE’ and, when applicable, 'QCL-TypeD', if the TRS index is not configured within the spatialrelationinfo of the SRS triggering or SRS transmission.

[0116] In a third embodiment of the fourth solution, for high-speed train communication, a TCI state cannot indicate that a DMRS for PDSCH (or DMRS for PDCCH) is quasi-co-located with a TRS with any of ‘QCL-TypeA’ or ‘QCL-TypeB’ or ‘QCL-TypeC’ if the TRS index is not configured within the spatialrelationinfo of the SRS triggering or SRS transmission.

[0117] According to the first, second, and/or third embodiments of the fourth solution, the TRS may be configured for at least one SRS resource within spatialrelationinfo as a source reference signal for the target SRS transmission.

[0118] In a fourth embodiment of the fourth solution, for high-speed train communication, a TCI state indicates that a DMRS for PDSCH (or DMRS for PDCCH) is quasi-co-located with a TRS with ‘QCL-TypeE’ and, when applicable, 'QCL-TypeD', based on one or more CSI-RS configurations that are assigned to high-speed train communication, e.g., one or more of TRS periodicity, number of CSI-RS per slot.

[0119] In a fifth embodiment of the fourth solution, for high-speed train communication, a TCI state indicates that a DMRS for PDSCH (or DMRS for PDCCH) is quasi-co-located with a TRS with ‘QCL-TypeE’ and, when applicable, 'QCL-TypeD', based on the RSRP of the TRS, e.g., when the RSRP of a TRS is less than that of another reference signal, e.g., TRS, indicated in the TCI state).

[0120] Ligure 8 is a diagram illustrating one example of Multi-TRP URLLC SDM scheme. The same scheme was agreed for multi-TRP URLLC SDM transmission as for single DCI multi- TRP transmission. A single codeword with one RV is used across all spatial layers or layer sets. Lrom the UE perspective, different coded bits are mapped to different layers or layer sets with the same mapping rule as in Rel-15. Each layer set is associated with one TCI and one set of DMRS port(s) (2 CDM groups are used). The first TCI state corresponds to the CDM group of the first antenna port indicated by the antenna port indication table. Note that a group of Resource Elements (“REs”) for which time and/or frequency direction Orthogonal Cover Code (“OCC”) is applied is called a Code Division Multiplexing (“CDM”) group. For DMRS Type 1 and 2 there are two and three CDM groups, respectively.

[0121] Moreover, it was agreed in Release 16 that when 2 TCI states are indicated by a TCI code point, for DMRS type 1 and type 2 for eMBB and URLLC scheme- la, if indicated DMRS ports are from two CDM groups, the first TCI state corresponds to the CDM group of the first antenna port indicated by the antenna port indication table. The second TCI state is applied to the second indicated CDM group. Therefore, each TCI state could point to a different TRS signal configured for the UE. With the transmission ports belonging to different CDM groups, the UE could estimate the channel from TRP A and TRP B. However, the scheme suffers from interlayer interference, and does not achieve a power gain like the SFN transmission essential for increasing coverage. Hereafter, TRS refers to a CSI-RS or non-zero power (“NZP”) CSI-RS configured with higher-layer parameter trs-info.

[0122] In some embodiments of the fourth solution, for high-speed communication, the UE expects to be configured with an SRS configuration comprising at least one SRS resource with spatialrelationinfo including a source reference signal (e.g., TRS); the same source reference signal (e.g., the TRS) also configured as a QCL reference signal for which quasi-collocation information (e.g., with ‘QCL-TypeA’ and, when applicable, 'QCL-TypeD') is provided in at least one TCI state (for DMRS for PDSCH or DMRS for PDCCH).

[0123] Note here that ‘QCL-TypeE’ can refer to one of the following large-scale parameters:

1. 'QCL-TypeE': [average delay, delay spread}

2. 'QCL-TypeE': [average delay}

3. 'QCL-TypeE': [delay spread}

4. 'QCL-TypeE': none

[0124] According to embodiments of the fifth solution, QCL relationships may be based on offset frequency pre-compensation. According to one embodiment of the fifth solution, for high-speed train communication, a TCI state indicates that a DMRS for PDSCH (or DMRS for PDCCH) is quasi-co-located with an SRS with ‘QCL-TypeD,’ when applicable.

[0125] In a second embodiment of the fifth solution, for high-speed communication, a TCI state indicates that a TRS is quasi-co-located with an SRS with ‘QCL-TypeD,’ when applicable.

[0126] In a third embodiment of the fifth solution, for high-speed communication, a TCI state indicates that a TRS is quasi-co-located with an SRS with ‘QCL-TypeA’ and, when applicable, 'QCL-TypeD', when the TRS index is configured within the spatialrelationinfo of the SRS triggering or SRS transmission.

[0127] In a fourth embodiment of the fifth solution, for high-speed communication, a TCI state indicates that a DMRS for PDSCH (or DMRS for PDCCH) is quasi-co-located with an SRS with ‘QCL-TypeA’ and, when applicable, 'QCL-TypeD', when a TRS index is configured within the spatialrelationinfo of the SRS triggering, and wherein this TRS is quasi-co-located with ‘QCL- TypeA’ and, when applicable, ‘QCL-TypeD’, with the DMRS for PDSCH (or DMRS for PDCCH). [0128] The DMRS is used to estimate channel coefficients for coherent detection of the physical channels. For downlink, the DMRS is subject to the same precoding as the PDSCH. NR first defines two time-domain structures for DMRS according to the location of the first DMRS symbol:

• Mapping Type A, where the first DMRS is located in the second and the third symbol of the slot and the DMRS is mapped relative to the start of the slot boundary, regardless of where in the slot the actual data transmission occurs.

• Mapping Type B, where the first DMRS is positioned in the first symbol of the data allocation, that is, the DMRS location is not given relative to the slot boundary, rather relative to where the data are located.

[0129] The mapping of PDSCH transmission can be dynamically signaled as part of the downlink control information (“DCI”). Moreover, the DMRS has two types: that is, Types 1 and 2, which are distinguished in frequency-domain mapping and the maximum number of orthogonal reference signals.

[0130] The DMRS Type 1 can provide up to four orthogonal signals using a single-symbol DMRS and up to eight orthogonal reference signals using a double-symbol DMRS. For four orthogonal signals, ports 1000 and 1001 use even-numbered subcarriers and are separated in the code domain within the CDM group (length-2 orthogonal sequences in the frequency domain). Antenna ports 1000 and 1001 belong to CDM group 0, since they use the same subcarriers. Similarly, ports 1002 and 1003 belong to CDM group 1 and are generated in the same way using odd-numbered subcarriers.

[0131] The DMRS Type 2 has a similar structure to Type 1 but Type 2 can provide 6 and 12 patterns depending on the number of symbols. Four subcarriers are used in each resource block and in each CDM group defining three CDM groups.

[0132] The time domain mapping of the DMRS patterns can be decomposed to two parts: the first part defines the DMRS pattern used for the front-load DMRS, and then the second part defines a set of additional DMRS symbols inside the scheduled data channel duration which are either single-symbols, or double-symbols depending on the length of the front-load DMRS. Inside the scheduled time-domain allocation of a PDSCH, the UE may expect up to 4 DMRS symbols.

[0133] The location of the DMRS is defined by both higher-layer configuration and dynamic (DCI-based) signaling:

• dmrs-TypeA-Position

• maxLength • dmrs-AdditionalPosition

[0134] In NR Rel-15, in the absence of CSI-RS configuration, and unless otherwise configured, the UE may assume PDSCH DMRS and Synchronization Signal Physical Broadcast Channel (“SS/PBCH”) block antenna ports be quasi co-located with respect to Doppler shift, Doppler spread, average delay, delay spread, and spatial Rx parameters (if applicable). However, a CSI-RS for tracking can be used as a QCL reference (e.g., larger bandwidth than an SS/ PBCH block).

[0135] Furthermore, the UE may assume that the PDSCH DMRS within the same CDM group are quasi co-located with respect to Doppler shift, Doppler spread, average delay, delay spread, and spatial Rx. The UE may then perform a joint estimation of DMRS ports which are CDM’ed using the same long-term statistics, and it is not required to measure, or use, different long-term statistics for different DMRS ports of the same PDSCH.

[0136] In some embodiments, the terms antenna, panel, and antenna panel are used interchangeably. An antenna panel may be a hardware that is used for transmitting and/or receiving radio signals at frequencies lower than 6GHz, e.g., frequency range 1 (FR1), or higher than 6GHz, e.g., frequency range 2 (FR2) or millimeter wave (mmWave). In some embodiments, an antenna panel may comprise an array of antenna elements, wherein each antenna element is connected to hardware such as a phase shifter that allows a control module to apply spatial parameters for transmission and/or reception of signals. The resulting radiation pattern may be called a beam, which may or may not be unimodal and may allow the device (e.g., UE, node) to amplify signals that are transmitted or received from spatial directions.

[0137] In some embodiments, an antenna panel may or may not be virtualized as an antenna port in the specifications. An antenna panel may be connected to a baseband processing module through a radio frequency (RF) chain for each of transmission (egress) and reception (ingress) directions. A capability of a device in terms of the number of antenna panels, their duplexing capabilities, their beamforming capabilities, and so on, may or may not be transparent to other devices. In some embodiments, capability information may be communicated via signaling or, in some embodiments, capability information may be provided to devices without a need for signaling. In the case that such information is available to other devices, it can be used for signaling or local decision making.

[0138] In some embodiments, a device (e.g., UE, node) antenna panel may be a physical or logical antenna array comprising a set of antenna elements or antenna ports that share a common or a significant portion of an RF chain (e.g., in-phase/quadrature (I/Q) modulator, analog to digital (A/D) converter, local oscillator, phase shift network). The device antenna panel or “device panel” may be a logical entity with physical device antennas mapped to the logical entity. The mapping of physical device antennas to the logical entity may be up to device implementation. Communicating (receiving or transmitting) on at least a subset of antenna elements or antenna ports active for radiating energy (also referred to herein as active elements) of an antenna panel requires biasing or powering on of the RF chain which results in current drain or power consumption in the device associated with the antenna panel (including power amplifier/low noise amplifier (LNA) power consumption associated with the antenna elements or antenna ports). The phrase " active for radiating energy, " as used herein, is not meant to be limited to a transmit function but also encompasses a receive function. Accordingly, an antenna element that is active for radiating energy may be coupled to a transmitter to transmit radio frequency energy or to a receiver to receive radio frequency energy, either simultaneously or sequentially, or may be coupled to a transceiver in general, for performing its intended functionality. Communicating on the active elements of an antenna panel enables generation of radiation patterns or beams.

[0139] In some embodiments, depending on device’s own implementation, a “device panel” can have at least one of the following functionalities as an operational role of Unit of antenna group to control its Tx beam independently, Unit of antenna group to control its transmission power independently, Unit of antenna group to control its transmission timing independently. The “device panel” may be transparent to gNB. For certain condition(s), gNB or network can assume the mapping between device’s physical antennas to the logical entity “device panel” may not be changed. For example, the condition may include until the next update or report from device or comprise a duration of time over which the gNB assumes there will be no change to the mapping. A Device may report its capability with respect to the “device panel” to the gNB or network. The device capability may include at least the number of “device panels.” In one implementation, the device may support UL transmission from one beam within a panel; with multiple panels, more than one beam (one beam per panel) may be used for UL transmission. In another implementation, more than one beam per panel may be supported/used for UL transmission.

[0140] In some of the embodiments described, an antenna port is defined such that the channel over which a symbol on the antenna port is conveyed can be inferred from the channel over which another symbol on the same antenna port is conveyed.

[0141] Two antenna ports are said to be quasi co-located (QCL) if the large-scale properties of the channel over which a symbol on one antenna port is conveyed can be inferred from the channel over which a symbol on the other antenna port is conveyed. The large-scale properties include one or more of delay spread, Doppler spread, Doppler shift, average gain, average delay, and spatial Rx parameters. Two antenna ports may be quasi-located with respect to a subset of the large-scale properties and different subset of large-scale properties may be indicated by a QCL Type. The QCL Type can indicate which channel properties are the same between the two reference signals (e.g., on the two antenna ports). Thus, the reference signals can be linked to each other with respect to what the device can assume about their channel statistics or QCL properties. For example, QCL-Type may take one of the following values:

• 'QCL-TypeA': {Doppler shift, Doppler spread, average delay, delay spread}

• 'QCL-TypeB': {Doppler shift, Doppler spread}

• 'QCL-TypeC: {Doppler shift, average delay}

• ' QCL-T ypeD ' : { Spatial Rx parameter } .

[0142] Other QCL-Types may be defined based on combination of one or large-scale properties.

[0143] Spatial Rx parameters may include one or more of: angle of arrival (“AoA”) Dominant AoA, average AoA, angular spread, Power Angular Spectrum (PAS) of AoA, average angle of departure (“AoD”), PAS of AoD, transmit/receive channel correlation, transmit/receive beamforming, spatial channel correlation etc.

[0144] The QCL-TypeA, QCL-TypeB and QCL-TypeC may be applicable for all carrier frequencies, but the QCL-TypeD may be applicable only in higher carrier frequencies (e.g., mmWave, FR2 and beyond), where essentially the device may not be able to perform omni directional transmission, i.e. the device would need to form beams for directional transmission. A QCL-TypeD between two reference signals A and B, the reference signal A is considered to be spatially co-located with reference signal B and the device may assume that the reference signals A and B can be received with the same spatial filter (e.g., with the same Rx beamforming weights).

[0145] An “antenna port” according to an embodiment may be a logical port that may correspond to a beam (resulting from beamforming) or may correspond to a physical antenna on a device. In some embodiments, a physical antenna may map directly to a single antenna port, in which an antenna port corresponds to an actual physical antenna. Alternately, a set or subset of physical antennas, or antenna set or antenna array or antenna sub-array, may be mapped to one or more antenna ports after applying complex weights, a cyclic delay, or both to the signal on each physical antenna. The physical antenna set may have antennas from a single module or panel or from multiple modules or panels. The weights may be fixed as in an antenna virtualization scheme, such as cyclic delay diversity (CDD). The procedure used to derive antenna ports from physical antennas may be specific to a device implementation and transparent to other devices. [0146] In some of the embodiments described, a TCI-state (Transmission Configuration Indication) associated with a target transmission can indicate parameters for configuring a quasi collocation relationship between the target transmission (e.g., target RS of DMRS ports of the target transmission during a transmission occasion) and a source reference signal(s) (e.g., SSB/CSI-RS/SRS) with respect to quasi co-location type parameter(s) indicated in the corresponding TCI state. The TCI describes which reference signals are used as QCL source, and what QCL properties can be derived from each reference signal. A device can receive a configuration of a plurality of transmission configuration indicator states for a serving cell for transmissions on the serving cell. In some of the embodiments described, a TCI state comprises at least one source RS to provide a reference (device assumption) for determining QCL and/or spatial filter.

[0147] In some of the embodiments described, a spatial relation information associated with a target transmission can indicate parameters for configuring a spatial setting between the target transmission and a reference RS (e.g., SSB/CSI-RS/SRS). For example, the device may transmit the target transmission with the same spatial domain filter used for reception the reference RS (e.g., DL RS such as SSB/CSI-RS). In another example, the device may transmit the target transmission with the same spatial domain transmission filter used for the transmission of the reference RS (e.g., UL RS such as SRS). A device can receive a configuration of a plurality of spatial relation information configurations for a serving cell for transmissions on the serving cell.

[0148] Figure 9 depicts a user equipment apparatus 900 that may be used for offset frequency pre-compensation for high speed SFN, according to embodiments of the disclosure. In various embodiments, the user equipment apparatus 900 is used to implement one or more of the solutions described above. The user equipment apparatus 900 may be one embodiment of the remote unit 105, the UE 205, the high speed UE 305, and/or the high speed UE 405, described above. Furthermore, the user equipment apparatus 900 may include a processor 905, a memory 910, an input device 915, an output device 920, and a transceiver 925.

[0149] In some embodiments, the input device 915 and the output device 920 are combined into a single device, such as a touchscreen. In certain embodiments, the user equipment apparatus 900 may not include any input device 915 and/or output device 920. In various embodiments, the user equipment apparatus 900 may include one or more of: the processor 905, the memory 910, and the transceiver 925, and may not include the input device 915 and/or the output device 920.

[0150] As depicted, the transceiver 925 includes at least one transmitter 930 and at least one receiver 935. In some embodiments, the transceiver 925 communicates with one or more cells (or wireless coverage areas) supported by one or more base units 121. In various embodiments, the transceiver 925 is operable on unlicensed spectrum. Moreover, the transceiver 925 may include multiple UE panels supporting one or more beams. Additionally, the transceiver 925 may support at least one network interface 940 and/or application interface 945. The application interface(s) 945 may support one or more APIs. The network interface(s) 940 may support 3GPP reference points, such as Uu, Nl, PC5, etc. Other network interfaces 940 may be supported, as understood by one of ordinary skill in the art.

[0151] The processor 905, in one embodiment, may include any known controller capable of executing computer-readable instructions and/or capable of performing logical operations. For example, the processor 905 may be a microcontroller, a microprocessor, a central processing unit (“CPU”), a graphics processing unit (“GPU”), an auxiliary processing unit, a field programmable gate array (“FPGA”), or similar programmable controller. In some embodiments, the processor 905 executes instructions stored in the memory 910 to perform the methods and routines described herein. The processor 905 is communicatively coupled to the memory 910, the input device 915, the output device 920, and the transceiver 925.

[0152] In various embodiments, the processor 905 controls the user equipment apparatus 900 to implement the above described UE behaviors. In certain embodiments, the processor 905 may include an application processor (also known as “main processor”) which manages application-domain and operating system (“OS”) functions and a baseband processor (also known as “baseband radio processor”) which manages radio functions.

[0153] In various embodiments, the processor 905 controls the transceiver 925 to receive an indication of a high speed SFN transmission (e.g., HST-SFN transmission) from at least one TRP in the RAN and to receive a configuration with a plurality of TRSs (e.g., denoted as TRS1, TRS2, TRS3, etc.). Here, the TRSs enable fine frequency synchronization for two channels with different doppler shifts. Additionally, the plurality of TRSs is decomposed into a first subset of TRSs and a second subset of TRSs.

[0154] Via the transceiver 925, the processor 905 receives a downlink scheduling grant containing a TCI codepoint indicating two TCI states with QCL sources configured with respect to the two subsets of TRSs. Moreover, via the transceiver 925, the processor 905 transmits an SRS to the TRP based on the received TRSs, where the SRS is associated with the first subset of TRSs via a spatial relation information indication. Via the transceiver 925, the processor 905 receives a DMRS for at least one of: a PDSCH and a PDCCH, where the received DMRS is based on the transmitted SRS, i.e., the DMRS is transmitted with a frequency shift that resembles the frequency shift measured for the received SRS at the network due to Doppler shift. [0155] In some embodiments, the HST-SFN transmission indication includes at least one of: a higher-layer parameter, a field in DCI containing the downlink scheduling grant, a CSI reporting setting, and a QCL relationship type (i.e., an indication as described above in the first and/or third solutions). In one embodiment, the field in DCI indicating the HST-SFN transmission is a 1-bit field. In another embodiment, the HST-SFN transmission indication may be indicated in an existing field in DCI.

[0156] In some embodiments, the indication of an HST-SFN transmission is implied when the UE is configured with a TCI state that indicates a TRS is quasi-co-located with at least one of a DMRS for PDSCH and a DMRS for PDCCH via one or more QCL types that do not include either Doppler shift or Doppler spread. In some embodiments, the first subset of the TRSs and the second subset of TRSs each contain a single TRS.

[0157] In some embodiments, the DMRS for physical downlink channel ports (e.g., PDSCH/PDCCH ports) corresponding to each layer of a downlink data transmission are quasi-co- located (i.e., coupled/paired) with the second subset of TRSs based on a QCL relationship (e.g., QCL-TypeE) that links average delay parameters, and delay spread parameters. In certain embodiments, the DMRS are further quasi-co-located with the second subset of TRSs based on a QCL-TypeD relationship that links Spatial Rx parameters.

[0158] In some embodiments, the DMRS for physical downlink channel ports (e.g., PDSCH/PDCCH ports) corresponding to each layer of a downlink data transmission are quasi-co- located (i.e., coupled/paired) with the first subset of TRSs based on a QCL-TypeA relationship that links Doppler shift parameters, Doppler spread parameters, average delay parameters, and delay spread parameters. In certain embodiments, the DMRS are further quasi-co-located with the first subset of TRSs based on a QCL-TypeD relationship that links Spatial Rx parameters.

[0159] In some embodiments, the TCI codepoint points to a TCI state that indicates that the SRS and the first subset of TRSs are coupled via a QCL-TypeA relationship that links Doppler shift parameters, Doppler spread parameters, average delay parameters, and delay spread parameters. In certain embodiments, the TCI state further indicates that the SRS and the first subset of TRSs are coupled via a QCL-TypeD relationship that links Spatial Rx parameters.

[0160] In some embodiments, the TCI codepoint points to a TCI state that indicates that the SRS and the DMRS (e.g., for PDSCH and/or PDCCH) are coupled via a QCL-TypeA relationship that links Doppler shift parameters, Doppler spread parameters, average delay parameters, and delay spread parameters. In certain embodiments, the TCI state further indicates that the SRS and the DMRS are coupled via a QCL-TypeD relationship that links Spatial Rx parameters. [0161] The memory 910, in one embodiment, is a computer readable storage medium. In some embodiments, the memory 910 includes volatile computer storage media. For example, the memory 910 may include a RAM, including dynamic RAM (“DRAM”), synchronous dynamic RAM (“SDRAM”), and/or static RAM (“SRAM”). In some embodiments, the memory 910 includes non-volatile computer storage media. For example, the memory 910 may include a hard disk drive, a flash memory, or any other suitable non-volatile computer storage device. In some embodiments, the memory 910 includes both volatile and non-volatile computer storage media.

[0162] In some embodiments, the memory 910 stores data related to offset frequency pre compensation for high speed SFN and/or mobile operation. For example, the memory 910 may store various parameters, panel/beam configurations, resource assignments, policies, and the like as described above. In certain embodiments, the memory 910 also stores program code and related data, such as an operating system or other controller algorithms operating on the apparatus 900.

[0163] The input device 915, in one embodiment, may include any known computer input device including a touch panel, a button, a keyboard, a stylus, a microphone, or the like. In some embodiments, the input device 915 may be integrated with the output device 920, for example, as a touchscreen or similar touch-sensitive display. In some embodiments, the input device 915 includes a touchscreen such that text may be input using a virtual keyboard displayed on the touchscreen and/or by handwriting on the touchscreen. In some embodiments, the input device 915 includes two or more different devices, such as a keyboard and a touch panel.

[0164] The output device 920, in one embodiment, is designed to output visual, audible, and/or haptic signals. In some embodiments, the output device 920 includes an electronically controllable display or display device capable of outputting visual data to a user. For example, the output device 920 may include, but is not limited to, a Liquid Crystal Display (“LCD”), a Light- Emitting Diode (“LED”) display, an Organic LED (“OLED”) display, a projector, or similar display device capable of outputting images, text, or the like to a user. As another, non-limiting, example, the output device 920 may include a wearable display separate from, but communicatively coupled to, the rest of the user equipment apparatus 900, such as a smart watch, smart glasses, a heads-up display, or the like. Further, the output device 920 may be a component of a smart phone, a personal digital assistant, a television, a table computer, a notebook (laptop) computer, a personal computer, a vehicle dashboard, or the like.

[0165] In certain embodiments, the output device 920 includes one or more speakers for producing sound. For example, the output device 920 may produce an audible alert or notification (e.g., a beep or chime). In some embodiments, the output device 920 includes one or more haptic devices for producing vibrations, motion, or other haptic feedback. In some embodiments, all or portions of the output device 920 may be integrated with the input device 915. For example, the input device 915 and output device 920 may form a touchscreen or similar touch-sensitive display. In other embodiments, the output device 920 may be located near the input device 915.

[0166] The transceiver 925 communicates with one or more network functions of a mobile communication network via one or more access networks. The transceiver 925 operates under the control of the processor 905 to transmit messages, data, and other signals and also to receive messages, data, and other signals. For example, the processor 905 may selectively activate the transceiver 925 (or portions thereof) at particular times in order to send and receive messages.

[0167] The transceiver 925 includes at least transmitter 930 and at least one receiver 935. One or more transmitters 930 may be used to provide UL communication signals to a base unit 121, such as the UL transmissions described herein. Similarly, one or more receivers 935 may be used to receive DL communication signals from the base unit 121, as described herein. Although only one transmitter 930 and one receiver 935 are illustrated, the user equipment apparatus 900 may have any suitable number of transmitters 930 and receivers 935. Further, the transmitter(s) 930 and the receiver(s) 935 may be any suitable type of transmitters and receivers. In one embodiment, the transceiver 925 includes a first transmitter/receiver pair used to communicate with a mobile communication network over licensed radio spectrum and a second transmitter/receiver pair used to communicate with a mobile communication network over unlicensed radio spectrum.

[0168] In certain embodiments, the first transmitter/receiver pair used to communicate with a mobile communication network over licensed radio spectrum and the second transmitter/receiver pair used to communicate with a mobile communication network over unlicensed radio spectrum may be combined into a single transceiver unit, for example a single chip performing functions for use with both licensed and unlicensed radio spectrum. In some embodiments, the first transmitter/receiver pair and the second transmitter/receiver pair may share one or more hardware components. For example, certain transceivers 925, transmitters 930, and receivers 935 may be implemented as physically separate components that access a shared hardware resource and/or software resource, such as for example, the network interface 940.

[0169] In various embodiments, one or more transmitters 930 and/or one or more receivers 935 may be implemented and/or integrated into a single hardware component, such as a multi transceiver chip, a system-on-a-chip, an Application-Specific Integrated Circuit (“ASIC”), or other type of hardware component. In certain embodiments, one or more transmitters 930 and/or one or more receivers 935 may be implemented and/or integrated into a multi-chip module. In some embodiments, other components such as the network interface 940 or other hardware components/circuits may be integrated with any number of transmitters 930 and/or receivers 935 into a single chip. In such embodiment, the transmitters 930 and receivers 935 may be logically configured as a transceiver 925 that uses one more common control signals or as modular transmitters 930 and receivers 935 implemented in the same hardware chip or in a multi-chip module.

[0170] Figure 10 depicts a network apparatus 1000 that may be used for offset frequency pre-compensation for high speed SFN, according to embodiments of the disclosure. In one embodiment, network apparatus 1000 may be one implementation of a RAN device, such as the base unit 121, the TRP-1 211, the TRP-2213, the TRP-3215, the TRP-A 301, the TRP-B 303, the TRP-A 401, and/or the TRP-B 403, as described above. Furthermore, the network apparatus 1000 may include a processor 1005, a memory 1010, an input device 1015, an output device 1020, and a transceiver 1025.

[0171] In some embodiments, the input device 1015 and the output device 1020 are combined into a single device, such as a touchscreen. In certain embodiments, the network apparatus 1000 may not include any input device 1015 and/or output device 1020. In various embodiments, the network apparatus 1000 may include one or more of: the processor 1005, the memory 1010, and the transceiver 1025, and may not include the input device 1015 and/or the output device 1020.

[0172] As depicted, the transceiver 1025 includes at least one transmitter 1030 and at least one receiver 1035. Flere, the transceiver 1025 communicates with one or more remote units 105. Additionally, the transceiver 1025 may support at least one network interface 1040 and/or application interface 1045. The application interface(s) 1045 may support one or more APIs. The network interface(s) 1040 may support 3GPP reference points, such as Uu, Nl, N2 and N3. Other network interfaces 1040 may be supported, as understood by one of ordinary skill in the art.

[0173] The processor 1005, in one embodiment, may include any known controller capable of executing computer-readable instructions and/or capable of performing logical operations. For example, the processor 1005 may be a microcontroller, a microprocessor, a CPU, a GPU, an auxiliary processing unit, a FPGA, or similar programmable controller. In some embodiments, the processor 1005 executes instructions stored in the memory 1010 to perform the methods and routines described herein. The processor 1005 is communicatively coupled to the memory 1010, the input device 1015, the output device 1020, and the transceiver 1025.

[0174] In various embodiments, the network apparatus 1000 is a RAN node (e.g., gNB) that communicates with one or more UEs, as described herein. In such embodiments, the processor 1005 controls the network apparatus 1000 to perform the above described RAN behaviors. When operating as a RAN node, the processor 1005 may include an application processor (also known as “main processor”) which manages application-domain and operating system (“OS”) functions and a baseband processor (also known as “baseband radio processor”) which manages radio functions.

[0175] In various embodiments, the processor 1005 controls the transceiver 1025 to send an indication of a high speed SFN transmission (e.g., HST-SFN transmission) from at least one TRP in a network (i.e., the RAN) and to send a configuration with a plurality of TRSs (e.g., denoted as TRS1, TRS2, TRS3, etc.). Here, the TRSs enable fine frequency synchronization for two channels with different doppler shifts. Additionally, the plurality of TRSs is decomposed into a first subset of TRSs and a second subset of TRSs.

[0176] Via the transceiver 1025, the processor 1005 sends a downlink scheduling grant containing a TCI codepoint indicating two TCI states with QCL sources configured with respect to the two subsets of TRSs and receives a SRS based on transmitted TRSs, where the SRS is associated with the first subset of TRSs via a spatial relation information indication. Via the transceiver 1025, the processor 1005 transmits a DMRS for at least one of: a PDSCH and a PDCCH, where the transmitted DMRS is based on the received SRS.

[0177] In some embodiments, the HST-SFN transmission indication includes at least one of: a higher-layer parameter, a field in DCI containing the downlink scheduling grant, a CSI reporting setting, and a QCL relationship type (i.e., an indication as described above in the first and/or third solutions). In one embodiment, the field in DCI indicating the HST-SFN transmission is a 1-bit field. In another embodiment, the HST-SFN transmission indication may be indicated in an existing field in DCI.

[0178] In some embodiments, the indication of an HST-SFN transmission is implied when the UE is configured with a TCI state that indicates a TRS is quasi-co-located with at least one of a DMRS for PDSCH and a DMRS for PDCCH via one or more QCL types that do not include either Doppler shift or Doppler spread. In some embodiments, the first subset of the TRSs and the second subset of TRSs each contain a single TRS.

[0179] In some embodiments, the DMRS for physical downlink channel ports (e.g., PDSCH/PDCCH ports) corresponding to each layer of a downlink data transmission are quasi-co- located (i.e., coupled/paired) with the second subset of TRSs based on a QCL relationship (e.g., QCL-TypeE) that links average delay parameters, and delay spread parameters. In certain embodiments, the DMRS are further quasi-co-located with the second subset of TRSs based on a QCL-TypeD relationship that links Spatial Rx parameters. [0180] In some embodiments, the DMRS for physical downlink channel ports (e.g., PDSCH/PDCCH ports) corresponding to each layer of a downlink data transmission are quasi-co located (i.e., coupled/paired) with the first subset of TRSs based on a QCL-TypeA relationship that links Doppler shift parameters, Doppler spread parameters, average delay parameters, and delay spread parameters. In certain embodiments, the DMRS are further quasi-co-located with the first subset of TRSs based on a QCL-TypeD relationship that links Spatial Rx parameters.

[0181] In some embodiments, the TCI codepoint points to a TCI state that indicates that the SRS and the first subset of TRSs are coupled via a QCL-TypeA relationship that links Doppler shift parameters, Doppler spread parameters, average delay parameters, and delay spread parameters. In certain embodiments, the TCI state further indicates that the SRS and the first subset of TRSs are coupled via a QCL-TypeD relationship that links Spatial Rx parameters.

[0182] In some embodiments, the TCI codepoint points to a TCI state that indicates that the SRS and the DMRS (e.g., for PDSCH and/or PDCCH) are coupled via a QCL-TypeA relationship that links Doppler shift parameters, Doppler spread parameters, average delay parameters, and delay spread parameters. In certain embodiments, the TCI state further indicates that the SRS and the DMRS are coupled via a QCL-TypeD relationship that links Spatial Rx parameters.

[0183] The memory 1010, in one embodiment, is a computer readable storage medium. In some embodiments, the memory 1010 includes volatile computer storage media. For example, the memory 1010 may include a RAM, including dynamic RAM (“DRAM”), synchronous dynamic RAM (“SDRAM”), and/or static RAM (“SRAM”). In some embodiments, the memory 1010 includes non-volatile computer storage media. For example, the memory 1010 may include a hard disk drive, a flash memory, or any other suitable non-volatile computer storage device. In some embodiments, the memory 1010 includes both volatile and non-volatile computer storage media.

[0184] In some embodiments, the memory 1010 stores data related to offset frequency pre compensation for high speed SFN and/or mobile operation. For example, the memory 1010 may store parameters, configurations, resource assignments, policies, and the like, as described above. In certain embodiments, the memory 1010 also stores program code and related data, such as an operating system or other controller algorithms operating on the apparatus 1000.

[0185] The input device 1015, in one embodiment, may include any known computer input device including a touch panel, a button, a keyboard, a stylus, a microphone, or the like. In some embodiments, the input device 1015 may be integrated with the output device 1020, for example, as a touchscreen or similar touch-sensitive display. In some embodiments, the input device 1015 includes a touchscreen such that text may be input using a virtual keyboard displayed on the touchscreen and/or by handwriting on the touchscreen. In some embodiments, the input device 1015 includes two or more different devices, such as a keyboard and a touch panel.

[0186] The output device 1020, in one embodiment, is designed to output visual, audible, and/or haptic signals. In some embodiments, the output device 1020 includes an electronically controllable display or display device capable of outputting visual data to a user. For example, the output device 1020 may include, but is not limited to, an LCD display, an LED display, an OLED display, a projector, or similar display device capable of outputting images, text, or the like to a user. As another, non-limiting, example, the output device 1020 may include a wearable display separate from, but communicatively coupled to, the rest of the network apparatus 1000, such as a smart watch, smart glasses, a heads-up display, or the like. Further, the output device 1020 may be a component of a smart phone, a personal digital assistant, a television, a table computer, a notebook (laptop) computer, a personal computer, a vehicle dashboard, or the like.

[0187] In certain embodiments, the output device 1020 includes one or more speakers for producing sound. For example, the output device 1020 may produce an audible alert or notification (e.g., a beep or chime). In some embodiments, the output device 1020 includes one or more haptic devices for producing vibrations, motion, or other haptic feedback. In some embodiments, all or portions of the output device 1020 may be integrated with the input device 1015. For example, the input device 1015 and output device 1020 may form a touchscreen or similar touch-sensitive display. In other embodiments, the output device 1020 may be located near the input device 1015.

[0188] The transceiver 1025 includes at least transmitter 1030 and at least one receiver 1035. One or more transmitters 1030 may be used to communicate with the UE, as described herein. Similarly, one or more receivers 1035 may be used to communicate with network functions in the Public Land Mobile Network (“PLMN”) and/or RAN, as described herein. Although only one transmitter 1030 and one receiver 1035 are illustrated, the network apparatus 1000 may have any suitable number of transmitters 1030 and receivers 1035. Further, the transmitter(s) 1030 and the receiver(s) 1035 may be any suitable type of transmitters and receivers.

[0189] Figure 11 depicts one embodiment of a method 1100 for offset frequency pre compensation for high speed SFN, according to embodiments of the disclosure. In various embodiments, the method 1100 is performed by a UE device, such as the remote unit 105, the UE 205, the high-speed UE 305, the high speed UE 405, and/or the user equipment apparatus 900, described above as described above. In some embodiments, the method 1100 is performed by a processor, such as a microcontroller, a microprocessor, a CPU, a GPU, an auxiliary processing unit, a FPGA, or the like. [0190] The method 1100 begins and receives 1105 an indication of a high speed SFN transmission (e.g., HST-SFN transmission) from at least one TRP in a network. The method 1100 includes receiving 1110 a configuration with a plurality of TRSs, where the plurality of TRSs comprise a first subset of TRSs and a second subset of TRSs. The method 1100 includes receiving 1115 a downlink scheduling grant containing a TCI codepoint indicating two TCI states with QCL sources configured with respect to the two subsets of TRSs. The method 1100 includes transmitting 1120 an SRS based on received TRSs, where the SRS is associated with the first subset of TRSs via a spatial relation information indication. The method 1100 includes 1125 receiving a DMRS for at least one of a PDSCH and a PDCCH, where the received DMRS is based on the transmitted SRS. The method 1100 ends.

[0191] Figure 12 depicts one embodiment of a method 1200 for offset frequency pre compensation for high speed SFN, according to embodiments of the disclosure. In various embodiments, the method 1200 is performed by a RAN entity, such as the base unit 121, the gNB 210, the TRP-1 211, the TRP-2 213, the TRP-3 215, the TRP-A 301, the TRP-B 303, the TRP-A 401, the TRP-B 403, and/or the network apparatus 1000, described above as described above. In some embodiments, the method 1200 is performed by a processor, such as a microcontroller, a microprocessor, a CPU, a GPU, an auxiliary processing unit, a FPGA, or the like.

[0192] The method 1200 begins and transmits 1205 an indication of a high speed SFN transmission (e.g., HST-SFN transmission) from at least one TRP in a network. The method 1200 includes transmitting 1210 a configuration with a plurality of TRSs, where the plurality of TRSs comprise a first subset of TRSs and a second subset of TRSs. The method 1200 includes transmitting 1215 a downlink scheduling grant containing a TCI codepoint indicating two TCI states with QCL sources configured with respect to the two subsets of TRSs. The method 1200 includes receiving 1220 an SRS based on transmitted TRSs, where the SRS is associated with the first subset of TRSs via a spatial relation information indication. The method 1200 includes transmitting 1225 a DMRS for at least one of: a PDSCH and a PDCCH, where the transmitted DMRS is based on the received SRS. The method 1200 ends.

[0193] Disclosed herein is a first apparatus for offset frequency pre-compensation for high speed SFN, according to embodiments of the disclosure. The first apparatus may be implemented by a UE device, such as the remote unit 105, the UE 205, the high speed UE 305, the high speed UE 405, and/or the user equipment apparatus 900, described above. The first apparatus includes a processor and a transceiver that communicates with a RAN. Via the transceiver, the processor receives an indication of a high speed SFN transmission (e.g., HST-SFN transmission) from at least one TRP in the RAN and receives a configuration with a plurality of TRSs, e.g., that enable fine frequency synchronization for two channels with different doppler shifts. Here, the plurality of TRSs comprise a first subset of TRSs and a second subset of TRSs.

[0194] The processor receives a downlink scheduling grant containing a TCI codepoint indicating two TCI states with QCL sources configured with respect to the two subsets of TRSs and transmits a SRS based on the received TRSs, where the SRS is associated with the first subset of TRSs via a spatial relation information indication. Via the transceiver, the processor receives a DMRS for at least one of: a PDSCH and a PDCCH, where the received DMRS is based on the transmitted SRS.

[0195] In some embodiments, the HST-SFN transmission indication includes at least one of: a higher-layer parameter, a field in DCI containing the downlink scheduling grant, a CSI reporting setting, and a QCL relationship type. In one embodiment, the field in DCI indicating the HST-SFN transmission is a 1-bit field. In another embodiment, the HST-SFN transmission indication may be indicated in an existing field in DCI.

[0196] In some embodiments, the indication of an HST-SFN transmission is implied when the UE is configured with a TCI state that indicates a TRS is quasi-co-located with at least one of a DMRS for PDSCH and a DMRS for PDCCH via one or more QCL types that do not include either Doppler shift or Doppler spread. In some embodiments, the first subset of the TRSs and the second subset of TRSs each contain a single TRS.

[0197] In some embodiments, the DMRS for physical downlink channel ports (e.g., PDSCH/PDCCH ports) corresponding to each layer of a downlink data transmission are quasi-co- located (i.e., coupled/paired) with the second subset of TRSs based on a QCL relationship (e.g., QCL-TypeE) that links average delay parameters, and delay spread parameters. In certain embodiments, the DMRS are further quasi-co-located with the second subset of TRSs based on a QCL-TypeD relationship that links Spatial Rx parameters.

[0198] In some embodiments, the DMRS for physical downlink channel ports (e.g., PDSCH/PDCCH ports) corresponding to each layer of a downlink data transmission are quasi-co- located (i.e., coupled/paired) with the first subset of TRSs based on a QCL-TypeA relationship that links Doppler shift parameters, Doppler spread parameters, average delay parameters, and delay spread parameters. In certain embodiments, the DMRS are further quasi-co-located with the first subset of TRSs based on a QCL-TypeD relationship that links Spatial Rx parameters.

[0199] In some embodiments, the TCI codepoint points to a TCI state that indicates that the SRS and the first subset of TRSs are coupled via a QCL-TypeA relationship that links Doppler shift parameters, Doppler spread parameters, average delay parameters, and delay spread parameters. In certain embodiments, the TCI state further indicates that the SRS and the first subset of TRSs are coupled via a QCL-TypeD relationship that links Spatial Rx parameters.

[0200] In some embodiments, the TCI codepoint points to a TCI state that indicates that the SRS and the DMRS (e.g., for PDSCH and/or PDCCH) are coupled via a QCL-TypeA relationship that links Doppler shift parameters, Doppler spread parameters, average delay parameters, and delay spread parameters. In certain embodiments, the TCI state further indicates that the SRS and the DMRS are coupled via a QCL-TypeD relationship that links Spatial Rx parameters.

[0201] Disclosed herein is a first method for offset frequency pre-compensation for high speed SFN, according to embodiments of the disclosure. The first method may be performed by a UE device, such as the remote unit 105, the UE 205, the high speed UE 305, the high speed UE 405, and/or the user equipment apparatus 900, described above. The first method includes receiving an indication of a high speed SFN transmission (e.g., HST-SFN transmission) from at least one TRP in a network and receiving a configuration with a plurality of TRSs (e.g., that enable fine frequency synchronization for two channels with different doppler shifts), where the plurality of TRSs comprises a first subset of TRSs and a second subset of TRSs. The first method includes receiving a downlink scheduling grant containing a TCI codepoint indicating two TCI states with QCL sources configured with respect to the two subsets of TRSs and transmitting a SRS based on received TRSs, where the SRS is associated with the first subset of TRSs via a spatial relation information indication. The first method includes receiving a DMRS for at least one of a PDSCH and a PDCCH, where the received DMRS is based on the transmitted SRS.

[0202] In some embodiments, the HST-SFN transmission indication includes at least one of: a higher-layer parameter, a field in DCI containing the downlink scheduling grant, a CSI reporting setting, and a QCL relationship type. In one embodiment, the field in DCI indicating the HST-SFN transmission is a 1-bit field. In another embodiment, the HST-SFN transmission indication may be indicated in an existing field in DCI.

[0203] In some embodiments, the indication of an HST-SFN transmission is implied when the UE is configured with a TCI state that indicates a TRS is quasi-co-located with at least one of a DMRS for PDSCH and a DMRS for PDCCH via one or more QCL types that do not include either Doppler shift or Doppler spread. In some embodiments, the first subset of the TRSs and the second subset of TRSs each contain a single TRS.

[0204] In some embodiments, the DMRS for physical downlink channel ports (e.g., PDSCH/PDCCH ports) corresponding to each layer of a downlink data transmission are quasi-co- located (i.e., coupled/paired) with the second subset of TRSs based on a QCL relationship (e.g., QCL-TypeE) that links average delay parameters, and delay spread parameters. In certain embodiments, the DMRS are further quasi-co-located with the second subset of TRSs based on a QCL-TypeD relationship that links Spatial Rx parameters.

[0205] In some embodiments, the DMRS for physical downlink channel ports (e.g., PDSCH/PDCCH ports) corresponding to each layer of a downlink data transmission are quasi-co- located (i.e., coupled/paired) with the first subset of TRSs based on a QCL-TypeA relationship that links Doppler shift parameters, Doppler spread parameters, average delay parameters, and delay spread parameters. In certain embodiments, the DMRS are further quasi-co-located with the first subset of TRSs based on a QCL-TypeD relationship that links Spatial Rx parameters.

[0206] In some embodiments, the TCI codepoint points to a TCI state that indicates that the SRS and the first subset of TRSs are coupled via a QCL-TypeA relationship that links Doppler shift parameters, Doppler spread parameters, average delay parameters, and delay spread parameters. In certain embodiments, the TCI state further indicates that the SRS and the first subset of TRSs are coupled via a QCL-TypeD relationship that links Spatial Rx parameters.

[0207] In some embodiments, the TCI codepoint points to a TCI state that indicates that the SRS and the DMRS (e.g., for PDSCH and/or PDCCH) are coupled via a QCL-TypeA relationship that links Doppler shift parameters, Doppler spread parameters, average delay parameters, and delay spread parameters. In certain embodiments, the TCI state further indicates that the SRS and the DMRS are coupled via a QCL-TypeD relationship that links Spatial Rx parameters.

[0208] Disclosed herein is a second apparatus for offset frequency pre-compensation for high speed SLN, according to embodiments of the disclosure. The second apparatus may be implemented by a RAN entity, such as the base unit 121, the gNB 210, the TRP-1 211, the TRP- 2 213, the TRP-3 215, the TRP-A 301, the TRP-B 303, the TRP-A 401, the TRP-B 403, and/or the network apparatus 1000, described above. The second apparatus includes a processor and a transceiver that communicates with a UE. Via the transceiver, the processor sends an indication of a high speed SLN transmission (e.g., HST-SLN transmission) from at least one TRP in a network and sends a configuration with a plurality of TRSs, e.g., that enable fine frequency synchronization for two channels with different doppler shifts. Here, the plurality of TRSs comprise a first subset of TRSs and a second subset of TRSs.

[0209] The processor sends a downlink scheduling grant containing a TCI codepoint indicating two TCI states with QCL sources configured with respect to the two subsets of TRSs and receives a SRS based on transmitted TRSs, where the SRS is associated with the first subset of TRSs via a spatial relation information indication. Via the transceiver, the processor transmits a DMRS for at least one of: a PDSCH and a PDCCH, where the transmitted DMRS is based on the received SRS.

[0210] In some embodiments, the HST-SFN transmission indication includes at least one of: a higher-layer parameter, a field in DCI containing the downlink scheduling grant, a CSI reporting setting, and a QCL relationship type. In one embodiment, the field in DCI indicating the HST-SFN transmission is a 1-bit field. In another embodiment, the HST-SFN transmission indication may be indicated in an existing field in DCI.

[0211] In some embodiments, the indication of an HST-SFN transmission is implied when the UE is configured with a TCI state that indicates a TRS is quasi-co-located with at least one of a DMRS for PDSCH and a DMRS for PDCCH via one or more QCL types that do not include either Doppler shift or Doppler spread. In some embodiments, the first subset of the TRSs and the second subset of TRSs each contain a single TRS.

[0212] In some embodiments, the DMRS for physical downlink channel ports (e.g., PDSCH/PDCCH ports) corresponding to each layer of a downlink data transmission are quasi-co- located (i.e., coupled/paired) with the second subset of TRSs based on a QCL relationship (e.g., QCL-TypeE) that links average delay parameters, and delay spread parameters. In certain embodiments, the DMRS are further quasi-co-located with the second subset of TRSs based on a QCL-TypeD relationship that links Spatial Rx parameters.

[0213] In some embodiments, the DMRS for physical downlink channel ports (e.g., PDSCH/PDCCH ports) corresponding to each layer of a downlink data transmission are quasi-co- located (i.e., coupled/paired) with the first subset of TRSs based on a QCL-TypeA relationship that links Doppler shift parameters, Doppler spread parameters, average delay parameters, and delay spread parameters. In certain embodiments, the DMRS are further quasi-co-located with the first subset of TRSs based on a QCL-TypeD relationship that links Spatial Rx parameters.

[0214] In some embodiments, the TCI codepoint points to a TCI state that indicates that the SRS and the first subset of TRSs are coupled via a QCL-TypeA relationship that links Doppler shift parameters, Doppler spread parameters, average delay parameters, and delay spread parameters. In certain embodiments, the TCI state further indicates that the SRS and the first subset of TRSs are coupled via a QCL-TypeD relationship that links Spatial Rx parameters.

[0215] In some embodiments, the TCI codepoint points to a TCI state that indicates that the SRS and the DMRS (e.g., for PDSCH and/or PDCCH) are coupled via a QCL-TypeA relationship that links Doppler shift parameters, Doppler spread parameters, average delay parameters, and delay spread parameters. In certain embodiments, the TCI state further indicates that the SRS and the DMRS are coupled via a QCL-TypeD relationship that links Spatial Rx parameters.

[0216] Disclosed herein is a second method for offset frequency pre-compensation for high speed SFN, according to embodiments of the disclosure. The second method may be performed by a RAN entity in a source RAN, such as the base unit 121, the gNB 210, the TRP-1 211, the TRP-2 213, the TRP-3 215, the TRP-A 301, the TRP-B 303, the TRP-A 401, the TRP-B 403, and/or the network apparatus 1000, described above. The second method includes transmitting an indication of a high speed SFN transmission (e.g., FiST-SFN transmission) from at least one TRP in a network and transmitting a configuration with a plurality of TRSs, where the plurality of TRSs comprise a first subset of TRSs and a second subset of TRSs. The second method includes transmitting a downlink scheduling grant containing a TCI codepoint indicating two TCI states with QCL sources configured with respect to the two subsets of TRSs and receiving a SRS based on transmitted TRSs, where the SRS is associated with the first subset of TRSs via a spatial relation information indication. The second method includes transmitting a DMRS for at least one of: a PDSCF1 and a PDCCF1, wherein the transmitted DMRS is based on the received SRS.

[0217] In some embodiments, the FIST-SFN transmission indication includes at least one of: a higher-layer parameter, a field in DCI containing the downlink scheduling grant, a CSI reporting setting, and a QCL relationship type. In one embodiment, the field in DCI indicating the FIST-SFN transmission is a 1-bit field. In another embodiment, the FIST-SFN transmission indication may be indicated in an existing field in DCF

[0218] In some embodiments, the indication of an FIST-SFN transmission is implied when the UE is configured with a TCI state that indicates a TRS is quasi-co-located with at least one of a DMRS for PDSCF1 and a DMRS for PDCCF1 via one or more QCL types that do not include either Doppler shift or Doppler spread. In some embodiments, the first subset of the TRSs and the second subset of TRSs each contain a single TRS.

[0219] In some embodiments, the DMRS for physical downlink channel ports (e.g., PDSCFI/PDCCF1 ports) corresponding to each layer of a downlink data transmission are quasi-co- located (i.e., coupled/paired) with the second subset of TRSs based on a QCL relationship (e.g., QCL-TypeE) that links average delay parameters, and delay spread parameters. In certain embodiments, the DMRS are further quasi-co-located with the second subset of TRSs based on a QCL-TypeD relationship that links Spatial Rx parameters.

[0220] In some embodiments, the DMRS for physical downlink channel ports (e.g., PDSCFI/PDCCF1 ports) corresponding to each layer of a downlink data transmission are quasi-co- located (i.e., coupled/paired) with the first subset of TRSs based on a QCL-TypeA relationship that links Doppler shift parameters, Doppler spread parameters, average delay parameters, and delay spread parameters. In certain embodiments, the DMRS are further quasi-co-located with the first subset of TRSs based on a QCL-TypeD relationship that links Spatial Rx parameters.

[0221] In some embodiments, the TCI codepoint points to a TCI state that indicates that the SRS and the first subset of TRSs are coupled via a QCL-TypeA relationship that links Doppler shift parameters, Doppler spread parameters, average delay parameters, and delay spread parameters. In certain embodiments, the TCI state further indicates that the SRS and the first subset of TRSs are coupled via a QCL-TypeD relationship that links Spatial Rx parameters.

[0222] In some embodiments, the TCI codepoint points to a TCI state that indicates that the SRS and the DMRS (e.g., for PDSCH and/or PDCCH) are coupled via a QCL-TypeA relationship that links Doppler shift parameters, Doppler spread parameters, average delay parameters, and delay spread parameters. In certain embodiments, the TCI state further indicates that the SRS and the DMRS are coupled via a QCL-TypeD relationship that links Spatial Rx parameters. [0223] Embodiments may be practiced in other specific forms. The described embodiments are to be considered in all respects only as illustrative and not restrictive. The scope of the invention is, therefore, indicated by the appended claims rather than by the foregoing description. All changes which come within the meaning and range of equivalency of the claims are to be embraced within their scope.