PRIORITY CLAIM

[0001] This application claims priority under 35 USC 1 19(e) to United

States Provisional Patent Application Serial No. 62/401,425, filed September 29, 2016, and under 35 USC 365(a) to PCT Application Serial No.

PCT/CN2016/ 104263, filed November 1 , 2016, which are incorporated herein by reference in their entirety.

TECHNICAL FIELD

[0002] Embodiments pertain to wireless communications. Some embodiments relate to wireless networks including Third Generation Partnership Project (3 GPP) networks, 3 GPP Long Term Evolution (LTE) networks, and 3GPP LTE Advanced (LTE-A) networks. Some embodiments relate to Fifth Generation (5G) networks. Some embodiments relate to New Radio (NR) networks. Some embodiments relate to beamforming at the user device (UE). Some embodiments relate to continuous refinement/adjustment of the UE beam. Some embodiments relate to port specific beam management and port, group specific beam management

BACKGROUND

[0003] Base stations and mobile devices operating in a cellular networks exchange data via RF antenna beams. In some cases path loss occurs, especially in 5G systems. Path loss causes significant issues in quality of communication. Accordingly there is a need for methods of beam management to mitigate path loss and improve quality of communication,

BRIEF DESCRIPTION OF THE DRAWINGS

[0004] FIG. 1 is a functional diagram of an example network in accordance with some embodiments.

[0005] FIG. 2 illustrates a block diagram of an example machine in accordance with some embodiments. [0006] FIG. 3 illustrates a block diagram of an evolved Node-B (eNB) in accordance with some embodiments and a block diagram of a Generation Node- B (gNB) in accordance with some embodiments.

[0007] FIG. 4 A illustrates a block diagram of a User Equipment (UE) in accordance with some embodiments.

[0008] FIG. 4B illustrates examples of multiple beam transmission in accordance with some embodiments.

[0009] FIG. 4C is a diagram illustrating a MIMO transmission scenario utilizing an eNB and a UE, each having multiple antennas according to some embodiments.

[0010] FIG. 5 is a conceptual illustration of codebooks with different resolutions at the user equipment (UE) for hierarchical beam search employing a panel with 4x4 cross polarized antenna elements, according to some

embodiments.

[0011] FIGS. 6A and 6B are illustrations of a set of UE beams for an un- quantized Level 1 codebook for a 4x4 UE array, according to some

embodiments.

[0012] FIGS. 7 A and 7B are illustrations of a set of UE beams for a

Level 2 un-quantized codebook for a 4x4 UE antenna array, according to some embodiments.

[0013] FIG. 8A is an illustration of a difference in response, in dB, to transmit (Tx) beam direction for different codebooks, without tapering, according to some embodiments.

[0014] FIG. 8B is an illustration of a difference in response, in dB, to Tx beam direction for different codebooks, with tapering, according to some embodiments.

[0015] FIG. 9 illustrates an example Media Access Control Element

(MAC-CE) for UE reporting containing a BRS ID (BI), a codebook identifier (CB ID), and an RSRP, according to some embodiments,

[0016] FIG. 1 OA illustrates a scan of 14 beam directions within a single subframe using a cross polarized transmit antenna panel at the eNB, according to some embodiments.

[0017] FIG. 10B illustrates an example beam refinement reference signal

(BRRS), according to some embodiments. [0018] FIG. 11 illustrates a possible timeline of beam refinement using only a beam reference signal (BRS) for a hierarchical beam search, according to some embodiments.

[0019] FIG. 12 illustrates a possible timeline of UE performance of a hierarchical beam search using both a BRS and a BRRS, according to some embodiments.

[0020] FIG. 13 illustrates a MAC-CE for beam change indication containing a BRS ID, a BRRS Resource Indicator (BRRS-RI), and a BRRS Process ID, according to some embodiments.

[0021] FIG. 14 illustrates a single port specific beam, according to some embodiments.

[0022] FIG. 1 5 illustrates an example of a BRRS report, according to some embodiments.

[0023] FIG. 16 illustrates an example of CSIRS, according to some embodiments.

[0024] FIG. 17 is a flow chart that illustrates a hierarchical search, according to some embodiments.

DETAILED DESCRIPTION OF THE DRAWINGS

[0025] To support selection of eNB and UE beam pairs, measurement and reporting of the beam pair, and refinement of the UE beam at the UE side, a UE beam search or beam scanning procedure may be developed internally at the UE in order to locate the best-matching beam pair, one from the UE side and one from the eNB side. A hierarchical UE beam search algorithm may be used for this purpose. The UE may use different implementation-specific codebooks for hierarchical beam search. Hierarchical beam search may result in measured reference signal received power (RSRP) for the same eNB transmitter (Tx) beam direction to vary by several dB depending on the codebook used for

measurement, leading to error. Reporting a codebook identity along with the RSRP report can mitigate this error. Further, both a beam refinement signal (BRS) and a beam refinement reference signal (BRRS) may be used

simultaneously or concurrently for UE beam search for a given transmit (Tx), beam direction, resulting in a faster and therefore more efficient way to support hierarchical beam search at the UE. [0026] Long Term Evolution (LIE) and LTE-advanced are standards for wireless communication of high-speed data for user equipment (UE) such as mobile telephones. LTE, LTE-advanced are leading to and have led to a 5G wireless communication standard. In 5G wireless systems, massive multiple input, multiple output (MEMO) is a technology that uses perhaps hundreds or thousands of antennas operating coherently and adaptively for multipath signal propagation to communicate multiple signals to a plurality of devices. However, in massive MIMO, the transmitting (Tx) beamforming and receiving (Rx) beamforming may be applied simultaneously or concurrently on both the eNB side and the UE side, and can interfere with each other. Consequently there is a need for beam refinement.

[0027] It would be extremely helpful, and at least in some cases even necessary, to design a method of beam refinement. Beam Refinement Reference Signals (BRRS) have been proposed for this purpose. In at least one case, to support a repeated BRRS signal, a wider subcarrier spacing or time domain replica waveform has been proposed. Embodiments described herein provide a method and system for detailed BRRS signal generation, including sequence generation and resource mapping, with the same subcarrier spacing as is used in other physical layer channels that use a time domain replica waveform. Further, the BRRS signal can be generated within one symbol, using frequency domain down-sampling which changes the sampling band edge and scales the amplitude of the sampled signal. By the down-sampling, the number of time-domain samples can be reduced so that the subcarrier spacing can be increased . This BRRS signal generation can operate within the wireless network 100 using standardize communication systems operating according to Third Generation Partnership Project (3GPP) standards such as LTE, LTE-advanced, fifth generation (5G), SI, or other similar or related communication standards for transmitting information.

[0028] FIG. 1 is a functional diagram of an example network in accordance with some embodiments. In some embodiments, the network 100 may be a Third Generation Partnership Project (3 GPP) network. It should be noted that embodiments are not limited to usage of 3 GPP networks, however, as other networks may be used in some embodiments. As an example, a Fifth Generation (5G) network may be used in some cases. As another example, a New Radio (NR) network may be used in some cases. As another example, a wireless local area network (WLAN) may be used in some cases. Embodiments are not limited to these example networks, however, as other networks may be used in some embodiments. In some embodiments, a network may include one or more components shown in FIG. 1. Some embodiments may not necessarily include all components shown in FIG. 1, and some embodiments may include additional components not shown in FIG. 1.

[0029] The network 100 may comprise a radio access network (RAN)

101 and the core network 120 (e.g., shown as an evolved packet core (EPC)) coupled together through an S I interface 1 15. For convenience and brevity sake, only a portion of the core network 120, as well as the RAN 101, is shown. In a non-limiting example, the RAN 101 may be an evolved universal terrestrial radio access network (E-UTRAN). In another non-limiting example, the RAN 101 may include one or more components of a New Radio (NR) network. In another non-limiting example, the RAN 101 may include one or more components of an E-UTRAN and one or more components of another network (including but not limited to an NR network).

[0030] The core network 120 may include a mobility management entity

(MME) 122, a serving gateway (serving GW) 124, and packet data network gateway (PDN GW) 126. In some embodiments, the network 100 may include (and/or support) one or more Evolved Node-B's (eNBs) 104 (which may operate as base stations) for communicating with User Equipment (UE) 102. The eNBs 104 may include macro eNBs and low power (LP) eNBs, in some embodiments.

[0031] In some embodiments, the network 100 may include (and/or support) one or more Generation Node-B's (gNBs) 105. In some embodiments, one or more eNBs 104 may be configured to operate as gNBs 105.

Embodiments are not limited to the number of eNBs 104 shown in FIG. 1 or to the number of gNBs 105 shown in FIG. 1. In some embodiments, the network 100 may not necessarily include eNBs 104. Embodiments are also not limited to the connectivity of components shown in FIG. 1.

[0032] It should be noted that references herein to an eNB 104 or to a gNB 105 are not limiting. In some embodiments, one or more operations, methods and/or techniques (such as those described herein) may be practiced by a base station component (and/or other component), including but not limited to a gNB 105, an eNB 104, a serving cell, a transmit-receive point (TRP) and/or other. In some embodiments, the base station component may be configured to operate in accordance with a New Radio (NR) protocol and/or NR standard, although the scope of embodiments is not limited in this respect. In some embodiments, the base station component may be configured to operate in accordance with a Fifth Generation (5G) protocol and/or 5G standard, although the scope of embodiments is not limited in this respect.

[0033] In some embodiments, one or more of the UEs 102 and/or eNBs

104 may be configured to operate in accordance with an NR protocol and/or NR techniques. References to a LIE 102, eNB 104 and/or gNB 105 as part of descriptions herein are not limiting. For instance, descriptions of one or more operations, techniques and/or methods practiced by an eNB 104 are not limiting. In some embodiments, one or more of those operations, techniques and/or methods may be practiced by a gNB 105 and/or other base station component.

[0034] In some embodiments, the LIE 102 may transmit signals (data, control and/or other) to the gNB 105, and may receive signals (data, control and/or other) from the gNB 105. In some embodiments, the UE 102 may transmit signals (data, control and/or other) to the eNB 104, and may receive signals (data, control and/or other) from the eNB 104. These embodiments will be described in more detail below.

[0035] The MME 122 is similar in function to the control plane of legacy

Serving GPRS Support Nodes (SGSN). The MME 122 manages mobility embodiments in access such as gateway selection and tracking area list management. The serving GW 124 terminates the interface toward the RAN 101, and routes data packets between the RAN 101 and the core network 120. In addition, it may be a local mobility anchor point for inter-eNB handovers and also may provide an anchor for inter-3GPP mobility. Other responsibilities may include lawful intercept, charging, and some policy enforcement. The serving GW 124 and the MME 122 may be implemented in one physical node or separate physical nodes. The PDN GW 126 terminates an SGi interface toward the packet data network (PDN), The PDN GW 126 routes data packets between the EPC 120 and the external PDN, and may be a key node for policy enforcement and charging data collection. It may also provide an anchor point for mobility with non-LTE accesses. The external PDN can be any kind of IP network, as well as an IP Multimedia Subsystem (IMS) domain. The PDN GW 126 and the serving GW 124 may be implemented in one physical node or separated physical nodes.

[0036] In some embodiments, the eNBs 104 (macro and micro) terminate the air interface protocol and may be the first point of contact for a UE 102. In some embodiments, an eNB 104 may fulfill various logical functions for the network 100, including but not limited to RNC (radio network controller functions) such as radio bearer management, uplink and downlink dynamic radio resource management and data packet scheduling, and mobility management.

[0037] In some embodiments, UEs 102 may be configured to

communicate Orthogonal Frequency Division Multiplexing (OFDM) communication signals with an eNB 104 and/or gNB 105 over a multicarrier communication channel in accordance with an Orthogonal Frequency Division Multiple Access (OFDMA) communication technique. In some embodiments, eNBs 104 and/or gNBs 105 may be configured to communicate OFDM communication signals with a UE 102 over a multicarrier communication channel in accordance with an OFDMA communication technique. The OFDM signals may comprise a plurality of orthogonal subcarriers.

[0038] The SI interface 1 15 is the interface that separates the RAN 101 and the EPC 120. It may be split into two parts: the Sl-U, which carries traffic data between the eNBs 104 and the serving GW 24, and the Sl-MME, which is a signaling interface between the eNBs 104 and the MME 122. The X2 interface is the interface between eNBs 104. The X2 interface comprises two parts, the X2-C and X2-U. The X2-C is the control plane interface between the eNBs 104, while the X2-U is the user plane interface between the eNBs 104.

[0039] In some embodiments, similar functionality and/or connectivity described for the eNB 104 may be used for the gNB 105, although the scope of embodiments is not limited in this respect. In a non-limiting example, the S I interface 1 15 (and/or similar interface) may be split into two parts: the Sl -U, which carries traffic data between the gNBs 105 and the serving GW 124, and the Sl-MME, which is a signaling interface between the gNBs 104 and the MME 122. The X2 interface (and/or similar interface) may enable

communication between eNBs 104, communication between gNBs 105 and/or communication between an eNB 104 and a gNB 105. [0040] With cellular networks, LP cells are typically used to extend coverage to indoor areas where outdoor signals do not reach well, or to add network capacity in areas with very dense phone usage, such as train stations. As used herein, the term low power (LP) eNB refers to any suitable relatively low power eNB for implementing a narrower cell (narrower than a macro cell) such as a femtocell, a picocell, or a micro cell, Femtocell eNBs are typically provided by a mobile network operator to its residential or enterprise customers. A femtocell is typically the size of a residential gateway or smaller and generally connects to the user's broadband line. Once plugged in, the femtocell connects to the mobile operator's mobile network and provides extra coverage in a range of typically 30 to 50 meters for residential femtocells. Thus, a LP eNB might be a femtocell eNB since it is coupled through the PDN GW 126. Similarly, a picocell is a wireless communication system typically covering a small area, such as in-building (offices, shopping malls, train stations, etc.), or more recently in-aircraft. A picocell eNB can generally connect through the X2 link to another eNB such as a macro eNB through its base station controller (BSC)

functionality. Thus, LP eNB may be implemented with a picocell eNB since it is coupled to a macro eNB via an X2 interface, Picocell eNBs or other LP eNBs may incorporate some or all functionality of a macro eNB. In some cases, this may be referred to as an access point base station or enterprise femtocell. In some embodiments, various types of gNBs 105 may be used, including but not limited to one or more of the eNB types described above.

[0041] In some embodiments, a downlink resource grid may be used for downlink transmissions from an eNB 104 to a LIE 102, while uplink

transmission from the UE 102 to the eNB 104 may utilize similar techniques. In some embodiments, a downlink resource grid may be used for downlink transmissions from a gNB 05 to a UE 102, while uplink transmission from the UE 102 to the gNB 105 may utilize similar techniques. The grid may be a time- frequency grid, called a resource grid or time-frequency resource grid, which is the physical resource in the downlink in each slot. Such a time-frequency plane representation is a common practice for OFDM systems, which makes it intuitive for radio resource allocation. Each column and each row of the resource grid correspond to one OFDM symbol and one OFDM subearrier, respectively. The duration of the resource grid in the time domain corresponds to one slot in a radio frame. The smallest time-frequency unit in a resource grid is denoted as a resource element (RE), There are several different physical downlink channels that are conveyed using such resource blocks. With particular relevance to this disclosure, two of these physical downlink channels are the physical downlink shared channel and the physical down link control channel.

[0042] As used herein, the term "circuitry" may refer to, be part of or include an Application Specific Integrated Circuit (ASIC), an electronic circuit, a processor (shared, dedicated, or group), and/or memory (shared, dedicated, or group) that execute one or more software or firmware programs, a combinational logic circuit, and/or other suitable hardware components that provide the described functionality. In some embodiments, the circuitry may be

implemented in, or functions associated with the circuitry may be implemented by, one or more software or firmware modules. In some embodiments, circuitry may include logic, at least partially operable in hardware. Embodiments described herein may be implemented into a system using any suitably- configured hardware and/or software.

[0043] FIG. 2 illustrates a block diagram of an example machine in accordance with some embodiments. The machine 200 is an example machine upon which any one or more of the techniques and/or methodologies discussed herein may be performed. In alternative embodiments, the machine 200 may operate as a standalone device or may be connected (e.g., networked) to other machines. In a networked deployment, the machine 200 may operate in the capacity of a server machine, a client machine, or both in server-client network environments. In an example, the machine 200 may act as a peer machine in peer-to-peer (P2P) (or other distributed) network environment. The machine 200 may be a UE 102, eNB 104, gNB 105, access point (AP), station (ST A), mobile device, base station, personal computer (PC), a tablet PC, a set-top box (STB), a personal digital assistant (PDA), a mobile telephone, a smart phone, a web appliance, a network router, switch or bridge, or any machine capable of executing instructions (sequential or otherwise) that specify actions to be taken by that machine. Further, while only a single machine is illustrated, the term "machine" shall also be taken to include any collection of machines that individually or jointly execute a set (or multiple sets) of instructions to perform any one or more of the methodologies discussed herein, such as cloud computing, software as a service (SaaS), other computer cluster configurations.

[0044] Examples as described herein, may include, or may operate on, logic or a number of components, modules, or mechanisms. Modules are tangible entities (e.g., hardware) capable of performing specified operations and may be configured or arranged in a certain manner. In an example, circuits may be arranged (e.g., internally or with respect to external entities such as other circuits) in a specified manner as a module. In an example, the whole or part of one or more computer systems (e.g., a standalone, client or server computer system) or one or more hardware processors may be configured by firmware or software (e.g., instructions, an application portion, or an application) as a module that operates to perform specified operations. In an example, the software may reside on a machine readable medium. In an example, the software, when executed by the underlying hardware of the module, causes the hardware to perform the specified operations.

[0045] Accordingly, the term "module" is understood to encompass a tangible entity, be that an entity that is physically constructed, specifically configured (e.g., hardwired), or temporarily (e.g., transitorily) configured (e.g., programmed) to operate in a specified manner or to perform part or all of any operation described herein. Considering examples in which modules are temporarily configured, each of the modules need not be instantiated at any one moment in time. For example, where the modules comprise a general-purpose hardware processor configured using software, the general-purpose hardware processor may be configured as respective different modules at different times. Software may accordingly configure a hardware processor, for example, to constitute a particular module at one instance of time and to constitute a different module at a different instance of time.

[0046] The machine (e.g., computer system) 200 may include a hardware processor 202 (e.g., a central processing unit (CPU), a graphics processing unit (GPU), a hardware processor core, or any combination thereof), a main memory 204 and a static memory 206, some or all of which may communicate with each other via an interlink (e.g., bus) 208. The machine 200 may further include a display unit 210, an alphanumeric input device 212 (e.g., a keyboard), and a user interface (UI) navigation device 214 (e.g., a mouse). In an example, the display unit 210, input device 212 and UI navigation device 214 may be a touch screen display. The machine 200 may additionally include a storage device (e.g., drive unit) 216, a signal generation device 218 (e.g., a speaker), a network interface device 220, and one or more sensors 221, such as a global positioning system (GPS) sensor, compass, acceierometer, or other sensor. The machine 200 may include an output controller 228, such as a serial (e.g., universal serial bus (USB), parallel, or other wired or wireless (e.g., infrared (IR), near field communication (NFC), etc.) connection to communicate or control one or more peripheral devices (e.g., a printer, card reader, etc).

[0047] The storage device 216 may include a machine readabie medium

222 on which is stored one or more sets of data structures or instructions 224 (e.g., software) embodying or utilized by any one or more of the techniques or functions described herein. The instructions 224 may also reside, completely or at least partially, within the main memory 204, within static memory 206, or within the hardware processor 202 during execution thereof by the machine

200. In an example, one or any combination of the hardware processor 202, the main memory 204, the static memory 206, or the storage device 216 may constitute machine readable media. In some embodiments, the machine readable medium may be or may include a non-transitory computer-readable storage medium.

[0048] While the machine readable medium 222 is illustrated as a single medium, the term "machine readable medium" may include a single medium or multiple media (e.g., a centralized or distributed database, and/or associated caches and servers) configured to store the one or more instructions 224. The term "machine readable medium" may include any medium that is capable of storing, encoding, or carrying instructions for execution by the machine 200 and that cause the machine 200 to perform any one or more of the techniques of the present disclosure, or that is capable of storing, encoding or carrying data structures used by or associated with such instructions. Non-limiting machine readable medium examples may include solid-state memories, and optical and magnetic media. Specific examples of machine readable media may include: non- volatile memory, such as semiconductor memory devices (e.g., Electrically Programmable Read-Only Memory (EPROM), Electrically Erasable

Programmable Read-Only Memory (EEPROM)) and flash memory devices; magnetic disks, such as internal hard disks and removable disks: magneto- optical disks; Random Access Memory (RAM); and CD-ROM and DVD-ROM disks. In some examples, machine readable media may include non-transitory machine readable media. In some examples, machine readable media may include machine readable media that is not a transitory propagating signal.

[0049] The instructions 224 may further be transmitted or received over a communications network 226 using a transmission medium via the network interface device 220 utilizing any one of a number of transfer protocols (e.g., frame relay, internet protocol (IP), transmission control protocol (TCP), user datagram protocol (HDP), hypertext transfer protocol (HTTP), etc.). Example communication networks may include a local area network (LAN), a wide area network (WAN), a packet data network (e.g., the Internet), mobile telephone networks (e.g., cellular networks), Plain Old Telephone (POTS) networks, and wireless data networks (e.g., Institute of Electrical and Electronics Engineers (IEEE) 802. 1 1 family of standards known as Wi-Fi®, IEEE 802.3 6 family of standards known as WiMax®), IEEE 802.1 5.4 fami ly of standards, a Long Term Evolution (LTE) family of standards, a Universal Mobile Telecommunications System (UMTS) family of standards, peer-to-peer (P2P) networks, among others. In an example, the network interface device 220 may include one or more physical jacks (e.g., Ethernet, coaxial, or phone jacks) or one or more antennas to connect to the communications network 226. In an example, the network interface device 220 may include a plurality of antennas to wirelessly communicate using at least one of single-input multiple-output (SIMO), multiple-input multiple-output (MIMO), or multiple-input single-output (MI SO) techniques. In some examples, the network interface device 220 may wirelessly communicate using Multiple LJser MIMO techniques. The term "transmission medium" shall be taken to include any intangible medium that is capable of storing, encoding or carrying instructions for execution by the machine 200, and includes digital or analog communications signals or other intangible medium to facilitate communication of such software.

[0050] The eNB described above operates by use of layer protocols,

FIG. 3 is an illustration of eNB protocol functions that may be implemented in a wireless communication device according to some embodiments. In some embodiments, protocol layers may include one or more of physical layer (PHY) 310, medium access control layer (MAC) 320, radio link control layer (RLC) 330, packet data convergence protocol layer (PDCP) 340, service data adaptation protocol (SDAP) layer 347, radio resource control layer (RRC) 355, and non- access stratum (NAS) layer 357, in addition to other higher layer functions not illustrated.

[0051] According to some embodiments, protocol layers may include one or more service access points that may provide communication between two or more protocol layers.

[0052] According to some embodiments, PHY 310 may transmit and receive physical layer signals 305 that may be received or transmitted respectively by one or more other communication devices. According to some embodiments, physical layer signals 305 may comprise one or more physical channels.

[0053] According to some embodiments, an instance of PHY 310 may process requests from and provide indications to an instance of MAC 320 via one or more physical layer service access points (PHY-SAP) 315. According to some embodiments, requests and indications communicated via PHY-SAP 315 may comprise one or more transport channels.

[0054] According to some embodiments, an instance of MAC 310 may process requests from and provide indications to an instance of RLC 330 via one or more medium access control service access points (MAC-SAP) 325.

According to some embodiments, requests and indications communicated via

MAC-SAP 325 may comprise one or more logical channels.

[0055] According to some embodiments, an instance of RLC 330 may process requests from and provide indications to an instance of PDCP 340 via one or more radio link control service access points (RLC-SAP) 335. According to some embodiments, requests and indications communicated via RLC-SAP

335 may comprise one or more RLC channels.

[0056] According to some embodiments, an instance of PDCP 340 may process requests from and provide indications to one or more of an instance of RRC 355 and one or more instances of SDAP 347 via one or more packet data convergence protocol service access points (PDCP-SAP) 345. According to some embodiments, requests and indications communicated via PDCP-SAP 345 may comprise one or more radio bearers. [0057] According to some embodiments, an instance of SDAP 3 7 may process requests from and provide indications to one or more higher layer protocol entities via one or more service data adaptation protocol service access points (SDAP-SAP) 349. According to some embodiments, requests and indications communicated via SDAP-SAP 349 may comprise one or more quality of service (QoS) flows.

[0058] According to some embodiments, RRC entity 355 may configure, via one or more management service access points (M-SAP), embodiments of one or more protocol layers, which may include one or more instances of PHY 310, MAC 320, RLC 330, PDCP 340 and SDAP 347. According to some embodiments, an instance of RRC 355 may process requests from and provide indications to one or more NAS entities via one or more RRC service access points (RRC- SAP) 356.

[0059] For a control command exchange between a UE and the network in LTE, there are several communication paths at the MAC layer. Consequently, there is a MAC structure that carries special control information. The MAC structure carrying the control information is called the MAC Control Element (MAC CE). The MAC CE may be implemented as a special bit string in the Local Channel ID (LCID) field of the MAC header.

[0060] FIG. 4A illustrates a block diagram of a User Equipment (UE) in accordance with some embodiments. The UE 400 may be suitable for use as a UE 102 as depicted in FIG. 1. In some embodiments, the UE 400 may include application circuitry 402, baseband circuitry 404, Radio Frequency (RF) circuitry 406, front-end module (FEM) circuitry 408 and one or more antennas 410, coupled together at least as shown. In some embodiments, other circuitry or arrangements may include one or more elements and/or components of the application circuitry 402, the baseband circuitry 404, the RF circuitry 406 and/or the FEM circuitry 408, and may also include other elements and/or components in some cases. As an example, "processing circuitry" may include one or more elements and/or components, some or ail of which may be included in the application circuitry 402 and/or the baseband circuitry 404. As another example, a "transceiver" and/or "transceiver circuitry" may include one or more elements and/or components, some or all of which may be included in the RF circuitry 406 and/or the FEM circuitry 408. These examples are not limiting, however, as the processing circuitry, transceiver and/or the transceiver circuitry may also include other elements and/or components in some cases. It should be noted that in some embodiments, a UE or other mobile device may include some or all of the components shown in either FIG. 2 or FIG. 4A or both.

[0061] The application circuitry 402 may include one or more application processors. For example, the application circuitry 402 may include circuitry such as, but not limited to, one or more single-core or multi-core processors. The processors) may include any combination of general-purpose processors and dedicated processors (e.g., graphics processors, application processors, etc.). The processors may be coupled with and/or may include memory/storage and may be configured to execute instructions stored in the memory/storage to enable various applications and/or operating systems to run on the system.

[0062] The baseband circuitry 404 may include circuitry such as, but not limited to, one or more single-core or multi-core processors. The baseband circuitry 404 may include one or more baseband processors and/or control logic to process baseband signals received from a receive signal path of the RF circuitry 406 and to generate baseband signals for a transmit signal path of the RF circuitry 406. Baseband processing circuitry 404 may interface with the application circuitry 402 for generation and processing of the baseband signals and for controlling operations of the RF circuitry 406. For example, in some embodiments, the baseband circuitry 404 may include a second generation (2G) baseband processor 404a, third generation (3G) baseband processor 404b, fourth generation (4G) baseband processor 404c, and/or other baseband processor(s) 404d for other existing generations, generations in development or to be developed in the future (e.g., fifth generation (5G), 6G, etc.). The baseband circuitry 404 (e.g., one or more of baseband processors 404a-d) may handle various radio control functions that enable communication with one or more radio networks via the RF circuitry 406. The radio control functions may include, but are not limited to, signal modulation/demodulation,

encoding/decoding, radio frequency shifting, etc. In some embodiments, modulation/demodulation circuitry of the baseband circuitry 404 may include Fast-Fourier Transform (FFT), precoding, and/or constellation

mapping/demapping functionality. In some embodiments, encoding/decoding circuitry of the baseband circuitry 404 may include convolution, tail-biting convolution, turbo, Viterbi, and/or Low Density Parity Check (LDPC) encoder/decoder functionality. Embodiments of modulation/demodulation and encoder/decoder functionality are not limited to these examples and may include other suitable functionality in other embodiments.

[0063] In some embodiments, the baseband circuitry 404 may include elements of a protocol stack such as, for example, elements of an evolved universal terrestrial radio access network (EUTRAN) protocol including, for example, physical (PHY), media access control (MAC), radio link control (RLC), packet data convergence protocol (PDCP), and/or radio resource control (RRC) elements. A central processing unit (CPU) 404e of the baseband circuitry 404 may be configured to run elements of the protocol stack for signaling of the PHY, MAC, RLC, PDCP and/or RRC layers. In some embodiments, the baseband circuitry may include one or more audio digital signal processor(s) (DSP) 404f. The audio DSP(s) 404f may be include elements for

compression/decompression and echo cancellation and may include other suitable processing elements in other embodiments. Components of the baseband circuitry may be suitably combined in a single chip, a single chipset, or disposed on a same circuit board in some embodiments. In some embodiments, some or all of the constituent components of the baseband circuitry 404 and the application circuitry 402 may be implemented together such as, for example, on a system on a chip (SoC).

[0064] In some embodiments, the baseband circuitry 404 may provide for communication compatible with one or more radio technologies. For example, in some embodiments, the baseband circuitry 404 may support communication with an evolved universal terrestrial radio access network (EUTRAN) and/or other wireless metropolitan area networks (WMAN), a wireless local area network (WLAN), a wireless personal area network (WPAN). Embodiments in which the baseband circuitry 404 is configured to support radio communications of more than one wireless protocol may be referred to as multi- mode baseband circuitry.

[0065] RF circuitry 406 may enable communication with wireless networks using modulated electromagnetic radiation through a non-solid medium. In various embodiments, the RF circuitry 406 may include switches, filters, amplifiers, etc. to facilitate the communication with the wireless network. RF circuitry 406 may include a receive signal path which may include circuitry to down-convert RF signals received from the FEM circuitry 408 and provide baseband signals to the baseband circuitry 404. RF circuitry 406 may also include a transmit signal path which may include circuitry to up-convert baseband signals provided by the baseband circuitry 404 and provide RF output signals to the FEM circuitry 408 for transmission.

[0066] In some embodiments, the RF circuitry 406 may include a receive signal path and a transmit signal path. The receive signal path of the RF circuitry 406 may include mixer circuitry 406a, amplifier circuitry 406b and filter circuitry 406c. The transmit signal path of the RF circuitry 406 may include filter circuitry 406c and mixer circuitry 406a. RF circuitry 406 may also include synthesizer circuitry 406d for synthesizing a frequency for use by the mixer circuitry 406a of the receive signal path and the transmit signal path. In some embodiments, the mixer circuitry 406a of the receive signal path may be configured to down-convert RF signals received from the FEM circuitry 408 based on the synthesized frequency provided by synthesizer circuitry 406d. The amplifier circuitry 406b may be configured to amplify the down-converted signals and the filter circuitry 406c may be a low-pass filter (LPF) or band-pass filter (BPF) configured to remove unwanted signals from the down-converted signals to generate output baseband signals. Output baseband signals may be provided to the baseband circuitry 404 for further processing. In some embodiments, the output baseband signals may be zero-frequency baseband signals, although this is not a requirement. In some embodiments, mixer circuitry 406a of the receive signal path may comprise passive mixers, although the scope of the embodiments is not limited in this respect. In some embodiments, the mixer circuitry 406a of the transmit signal path may be configured to up-convert input baseband signals based on the synthesized frequency provided by the synthesizer circuitry 406d to generate RF output signals for the FEM circuitry 408. The baseband signals may be provided by the baseband circuitry 404 and may be filtered by filter circuitry 406c, The filter circuitry 406c may include a low-pass filter (LPF), although the scope of the embodiments is not limited in this respect . [0067] In some embodiments, the mixer circuitry 406a of the receive signal path and the mixer circuitry 406a of the transmit signal path may include two or more mixers and may be arranged for quadrature downconversion and/or upconversion respectively. In some embodiments, the mixer circuitry 406a of the receive signal path and the mixer circuitry 406a of the transmit signal path may include two or more mixers and may be arranged for image rejection (e.g., Hartley image rejection). In some embodiments, the mixer circuitry 406a of the receive signal path and the mixer circuitry 406a may be arranged for direct downconversion and/or direct upconversion, respectively. In some embodiments, the mixer circuitry 406a of the receive signal path and the mixer circuitry 406a of the transmit signal path may be configured for super-heterodyne operation.

[0068] In some embodiments, the output baseband signals and the input baseband signals may be analog baseband signals, although the scope of the embodiments is not limited in this respect. In some alternate embodiments, the output baseband signals and the input baseband signals may be digital baseband signals. In these alternate embodiments, the RF circuitry 406 may include analog-to-digital converter (ADC) and digitai-to-analog converter (DAC) circuitry and the baseband circuitry 404 may include a digital baseband interface to communicate with the RF circuitry 406. In some dual-mode embodiments, a separate radio IC circuitry may be provided for processing signals for each spectrum, although the scope of the embodiments is not limited in this respect.

[0069] In some embodiments, the synthesizer circuitry 406d may be a fractional-N synthesizer or a fractional N/N+l synthesizer, although the scope of the embodiments is not limited in this respect as other types of frequency synthesizers may be suitable. For example, synthesizer circuitry 406d may be a delta-sigma synthesizer, a frequency multiplier, or a synthesizer comprising a phase-locked loop with a frequency divider. The synthesizer circuitry 406d may be configured to synthesize an output frequency for use by the mixer circuitry 406a of the RF circuitry 406 based on a frequency input and a divider control input. In some embodiments, the synthesizer circuitry 406d may be a fractional N/N+l synthesizer. In some embodiments, frequency input may be provided by a voltage controlled oscillator (VCO), although that is not a requirement. Divider control input may be provided by either the baseband circuitry 404 or the applications processor 402 depending on the desired output frequency. In some embodiments, a divider control input (e.g., N) may be determined from a lookup table based on a channel indicated by the applications processor 402.

[0070] Synthesizer circuitry 406d of the RF circuitry 406 may include a divider, a delay-locked loop (DLL), a multiplexer and a phase accumulator. In some embodiments, the divider may be a dual modulus divider (DMD) and the phase accumulator may be a digital phase accumulator (DP A). In some embodiments, the DMD may be configured to divide the input signal by either N or N+l (e.g., based on a carry out) to provide a fractional division ratio. In some example embodiments, the DLL may include a set of cascaded, tunable, delay elements, a phase detector, a charge pump and a D-type flip-flop. In these embodiments, the delay elements may be configured to break a VCO period up into Nd equal packets of phase, where Nd is the number of delay elements in the delay line. In this way, the DLL provides negative feedback to help ensure that the total delay through the delay line is one VCO cycle.

[0071] In some embodiments, synthesizer circuitry 406d may be configured to generate a carrier frequency as the output frequency, while in other embodiments, the output frequency may be a multiple of the carrier frequency (e.g., twice the carrier frequency, four times the carrier frequency) and used in conjunction with quadrature generator and divider circuitry to generate multiple signals at the carrier frequency with multiple different phases with respect to each other. In some embodiments, the output frequency may be a LO frequency (fjLo). In some embodiments, the RF circuitry 406 may include an IQ/polar converter.

[0072] FEM circuitry 408 may include a receive signal path which may include circuitry configured to operate on RF signals received from one or more antennas 410, amplify the received signals and provide the amplified versions of the received signals to the RF ^' circuitry 406 for further processing. FEM circuitry 408 may also include a transmit signal path which may include circuitry configured to amplify signals for transmission provided by the RF circuitry 406 for transmission by one or more of the one or more antennas 410.

[0073] In some embodiments, the FEM circuitry 408 may include a

TX/RX switch to switch between transmit mode and receive mode operation. The FEM circuitry may include a receive signal path and a transmit signal path. The receive signal path of the FEM circuitry may include a low-noise amplifier (LNA) to amplify received RF signals and provide the amplified received RF signals as an output (e.g., to the RF circuitry 406). The transmit signal path of the FEM circuitry 408 may include a power amplifier (PA) to amplify input RF signals (e.g., provided by RF circuitry 406), and one or more filters to generate RF signals for subsequent transmission (e.g., by one or more of the one or more antennas 410. In some embodiments, the LIE 400 may include additional elements such as, for example, memory/storage, display, camera, sensor, and/or input/output (I/O) interface.

[0074] One or more of the antennas 230, 301, 351 , 410 may comprise one or more directional or omnidirectional antennas, including, for example, dipole antennas, monopole antennas, patch antennas, loop antennas, microstrip antennas or other types of antennas suitable for transmission of RF signals. In some multiple-input multiple-output (MIMO) embodiments, one or more of the antennas 230, 301 , 351, 410 may be effectively separated to take advantage of spatial diversity and the different channel characteristics that may result.

[0075] In some embodiments, the LIE 400 and/or the eNB 300 and/or gNB 350 may be a mobile device and may be a portable wireless communication device, such as a personal digital assistant (PDA), a laptop or portable computer with wireless communication capability, a web tablet, a wireless telephone, a smartphone, a wireless headset, a pager, an instant messaging device, a digital camera, an access point, a television, a wearable device such as a medical device (e.g., a heart rate monitor, a blood pressure monitor, etc.), or other device that may receive and/or transmit information wireiessly. In some embodiments, the LIE 400 and/or eNB 300 and/or gNB 350 may be configured to operate in accordance with 3 GPP standards, although the scope of the embodiments is not limited in this respect. Mobile devices or other devices in some embodiments may be configured to operate according to other protocols or standards, including IEEE 802. 1 1 or other IEEE standards. In some embodiments, the UE 400, eNB 300, gNB 350 and/or other device may include one or more of a keyboard, a display, a non- volatile memory port, multiple antennas, a graphics processor, an application processor, speakers, and other mobile device elements. The display may be an LCD screen including a touch screen.

[0076] Although the LIE 400, the eNB 300 and the gNB 350 are each illustrated as having several separate functional elements, one or more of the functional elements may be combined and may be implemented by combinations of software-configured elements, such as processing elements including digital signal processors (DSPs), and/or other hardware elements. For example, some elements may comprise one or more microprocessors, DSPs, field- programmable gate arrays (FPGAs), application specific integrated circuits (ASICs), radio-frequency integrated circuits (RFICs) and combinations of various hardware and logic circuitry for performing at least the functions described herein. In some embodiments, the functional elements may refer to one or more processes operating on one or more processing elements.

[0077] Embodiments may be implemented in one or a combination of hardware, firmware and software. Embodiments may also be implemented as instructions stored on a computer-readable storage device, which may be read and executed by at least one processor to perform the operations described herein. A computer-readable storage device may include any non- transitory mechanism for storing information in a form readable by a machine (e.g., a computer). For example, a computer-readable storage device may include readonly memory (ROM), random-access memory (RAM), magnetic disk storage media, optical storage media, flash-memory devices, and other storage devices and media. Some embodiments may include one or more processors and may be configured with instructions stored on a computer-readable storage device.

[0078] It should be noted that in some embodiments, an apparatus used by the UE 400 and/or eNB 300 and/or gNB 350 and/or machine 200 may include various components of the UE 400 and/or the eNB 300 and/or the gNB 350 and/or the machine 200 as shown in FIGs. 2-4. Accordingly, techniques and operations described herein that refer to the UE 400 (or 102) may be applicable to an apparatus for a UE. In addition, techniques and operations described herein that refer to the eNB 300 (or 104) may be applicable to an apparatus for an eNB. In addition, techniques and operations described herein that refer to the gNB 350 (or 105) may be applicable to an apparatus for a gNB.

[0079] In accordance with some embodiments, the UE 102 may receive downlink control information (DO) that indicates a configurable first physical resource block (PRB) for an allocation of PRBs for new radio (NR) physical uplink control channel (PUCCH) transmissions in a control region of a slot. The control region may include one or more symbol periods. The UE 102 may store at least a portion of the DCI in memory. The UE 102 may determine a frequency separation parameter that is based at least partly on an identifier of the LIE 102. The UE 102 may determine, based on the first PRE and the frequency separation parameter, a second PRB that is allocated for the NR PUCCH transmissions in the control region. The UE 102 may transmit an NR PUCCH in the first and second PRBs in the control region. These embodiments are described in more detail below.

[0080] FIG. 4B illustrates examples of multiple beam transmission in accordance with some embodiments, FIG. 4C illustrates examples of multiple beam transmission in accordance with some embodiments. Although the example scenarios 401 and 450 depicted in FIG. 413 may illustrate some aspects of techniques disclosed herein, it will be understood that embodiments are not limited by example scenarios 401 and 450. Embodiments are not limited to the number or type of components shown in FIG. 4B and are also not limited to the number or arrangement of transmitted beams shown in FIG. 4B.

[0081] In example scenario 401 of FIG. 4B, the eNB 104 may transmit a signal on multiple beams 405-420, any or all of which may be received at the UE 102. It should be noted that the number of beams or transmission angles as shown are not limiting. As the beams 420-435 may be directional, transmitted energy from the beams 405-420 may be concentrated in the direction shown. Therefore, the UE 102 may not necessarily receive a significant amount of energy from beams 420 and 425 in some cases, due to the relative location of the UE 102.

[0082] UE 102 may receive a significant amount of energy from the beams 430 and 435 as shown. As an example, the beams 405-420 may be transmitted using different reference signals, and the LIE 102 may determine channel-state information (CSI) feedback or other information for beams 420 and 435. In some embodiments, each of beams 420-435 are configured as CSI reference signals (CSIRS). In related embodiments, the CSIRS signal is a part of the discovery reference signaling (DRS) configuration. The DRS configuration may- serve to inform the UE 102 about the physical resources (e.g., subframes, subcarriers) on which the CSIRS signal will be found. In related embodiments, the UE 102 is further informed about any scrambling sequences that are to be applied for CSIRS. [0083] In some embodiments, up to 2 MEMO layers may be transmitted within each beam by using different polarizations. More than 2 MIMO layers may be transmitted by using multiple beams. In related embodiments, the UE is configured to discover the available beams and report those discovered beams to the eNB prior to the MIMO data transmissions using suitable reporting messaging, such as channel-state reports (CSR), for example. Based on the reporting messaging, the eNB 104 may determine suitable beam directions for the MIMO layers to be used for data communications with the UE 102. In various embodiments, there may be up to 2, 4, 8, 16, 32, or more MIMO layers, depending on the number of MIMO layers that are supported by the eNB 104 and UE 102. In a given scenario, the number of MIMO layers that may actually be used will depend on the quality of the signaling received at the UE 102, and the availability of reflected beams arriving at diverse angles at the UE 102 such that the UE 102 may discriminate the data carried on the separate beams.

[0084] In the example scenario 450, the UE 102 may determine angles or other information (such as CSI feedback, channel-quality indicator (CQI) or other) for the beams 465 and 470. The UE 102 may also determine such information when received at other angles, such as the illustrated beams 475 and 480. The beams 475 and 480 are demarcated using a dotted line configuration to indicate that they may not necessarily be transmitted at those angles, but that the UE 102 may determine the beam directions of beams 475 and 480 using such techniques as receive beam-forming, as receive directions. This situation may occur, for example, when a transmitted beam reflects from an object in the vicinity of the UE 102, and arrives at the UE 102 according to its reflected, rather than incident, angle.

[0085] In some embodiments, the UE 102 may transmit one or more channel state information (CSI) messages to the eNB 104 as reporting messaging. Embodiments are not limited to dedicated CSI messaging, however, as the UE 102 may include relevant reporting information in control messages or other types of messages that may or may not be dedicated for communication of the CSI-type information,

[0086] As an example, the first signal received from the first eNB 104 may include a first directional beam based at least partly on a first CSIRS signal and a second directional beam based at least partly on a second CSIRS signal. The UE 102 may determine a rank indicator (RI) for the first CSIRS and an RI for the second CSIRS, and may transmit both RIs in the CSI messages. In addition, the LIE 102 may determine one or more RIs for the second signal, and may also include them in the CSI messages in some cases. In some embodiments, the UE 02 may also determine a CQI, a preceding matrix indicator (PMI), receive angles or other information for one or both of the first and second signals. Such information may be included, along with one or more RIs, in the one or more CSI messages. In some embodiments, the UE 102 performs reference signal receive power (RSRP) measurement, received signal strength indication (RSSI) measurement, reference signal receive quality (RSRQ) measurement, or some combination of these using CSIRS signals,

[0087] FIG. 4C is a diagram illustrating a ΜΪΜΌ transmission scenario utilizing an eNB and a UE, each having multiple antennas according to some embodiments. eNB 403 has multiple antennas, as depicted, which may be used in various groupings, and with various signal modifications for each grouping, to effectively produce a plurality of antenna ports P1-P4. In various embodiments within the framework of the illustrated example, each antenna port P1-P4 may be defined for 1, 2, 3, or 4 antennas. Each antenna port 1-P4 may correspond to a different transmission signal direction. Using the different antenna ports, eNB 403 may transmit multiple layers with codebook-based or non-codebook- based preceding techniques. According to some embodiments, each antenna port corresponds to a beam antenna port-specific CSIRS signals are transmitted at via respective antenna port. In other embodiments, there may be more, or fewer, antenna ports available at the eNB than the four antenna ports as illustrated in FIG. 4C.

[0088] On the UE 405 side, there are a plurality of receive antennas. As illustrated in the example of FIG. 4C, there four receive antennas, A1 -A4. The multiple receive antennas may be used selectively to create receive beam forming. Receive beam forming may be used advantageously to increase the receive antenna gain for the direction(s) on which desired signals are received, and to suppress interference from neighboring cells, provided of course that the interference is received along different directions than the desired signals. Hierarchical User Equipment (UE) beam search for beamforming systems ia 5G

[0089] In the description below, certain wireless communication terms will be used. These terms can be found in the publication Verizon 5G TF (Technical Forum) Release 1. These terms are:

BRS - Beam reference signals; BRS can be one type of Synchronization Signal Block (SSB) or CSI-RS.

BRRS - Beam refinement reference signals; BRRS can be one type of CSI-RS.

B SI - Beam state information

BRI - Beam refinement information

RSRP - Reference signal received power.

Generally, "beam" means an SSB/CSIRS resource.

[00901 In millimeter wave (mm Wave) frequencies, beamforming at the UE, or other mobile device, side is highly important to overcome the higher path loss and to provide better coverage and capacity performance. In addition to that, of course, all the reasons for beamforming at, for example, Wi-Fi frequencies, NT frequencies, and other related frequencies, still exist. In addition, a new reason at 5G is to compensate for path loss. The beamforming architecture may include both radio frequency (RF) and baseband components but, at the least, RF beamforming is considered highly important to allow a low cost solution for forming narrow beams using up to 4, 8 or 16 radiating elements in an array. In one embodiment discussed below, RF beamforming is described using 4 radiating elements. In order to integrate RF beamforming at the UE side into the air interface, procedures that are used comprise a) selection of a beam pair, comprising an evolved Node-B (eNB) beam and a UE beam, that allow communication, b) measurement and reporting the strength, in terms of power received, of beam pairs comprising an eNB beam and a UE beam, that allows the network to be aware of the UE environment, and c) for a given eNB beam, the continuous refinement /adjustment of the paired eNB beam and UE beam for maintaining the communication link between the eNB and the UE.

[0091] In order to support the procedures described in a), b) and c), above, at the UE side, a UE beam search or a beam scanning procedure may be developed internally at the UE in order to locate the best-matching beam pair, one from the UE side and one from the e B side. In order to provide a trade-off between latency of beam search and the achievable gains due to beamforming, hierarchical UE beam search algorithms are described in some embodiments. In a hierarchical bean search, a UE may use different implementation-specific codebooks for hierarchical beam search that vary in terms of resolution, beam- width, side-lobe levels, and related parameters. A codebook is a pre-determined and finite set of beam weights. A codebook can be identified by a codebook identity. Each beam weight is a complex set of coefficients which when applied to a set of antenna elements forms a beam in the spatial domain. A particular beam weight can be associated with the codebook that it belongs to. In some embodiments, a particular beam weight can be a particular codebook identity.

[0092] The difference in measured reference signal received power

(RSRP) for the same eNB transmitter (Tx) beam direction can range from 1.2 dB to3.5 dB depending on the codebook used for measurement. This variation in RSRP can mislead a serving eNB into making incorrect decisions. Multi- resolution codebooks or hierarchical codebooks, not specified in the LTE or related standards, that are resident in the UE, and not necessarily resident in the eNB, can be used for hierarchical beam searching in some embodiments. In some embodiments, the codebooks could be different for different UEs. Beams in codebooks that specify beams that have larger beam widths are referred to as a coarse codebook beam and beams in codebooks that have much finer beam widths and are specified in codebooks are referred to as fine codebook beams. Fine codebook beams result in high resolution searches. There can also be omnidirectional beams in the codebook which search three dimensional space. Another embodiment of the codebook is to associate one beam with other beams. For example, one coarse beam can be associated with a number of finer beams, which in some embodiments may be eight finer beams. A Level 1, one coarse beam can be associated with 8 finer beams in level 2. Association helps in search. In some embodiments, the UE first searches the Level 1 beams and, having found best Level 1 beam pair, refines the search by searching the Level 2 beams for the best beam pair, but only those Level 2 beams associated with the best Level 1 beam.

[0093] To determine that one beam is better than another, use can be made of the beam reference signal (BRS) that is transmitted from eNB side. In some embodiments the BRS is used for measurements and those measurements determine whether one beam is better than another beam. In some embodiments the BRS is used to measure coarse beams. The BRS is universally transmitted periodically in time and in frequency for all UEs in a cell to use and can therefore be viewed as an "always on" signal. In some embodiments, a BRS can be used for both Level 1 and Level 2 measurements in a hierarchical search to determine the best Tx-Rx beam pair.

[0094] Beam refinement reference signals (BRRS) are reference signals that are not transmitted all the time but are sent specifically to one or two particular UEs, perhaps on demand, and are intended in some embodiments to further refine Level 2 beams. In some embodiments both the BRS and a Beam Refinement Reference Signal (BRRS) can simultaneously or concurrently be used for a UE beam search for a given Tx, beam direction, which is a faster and therefore more efficient way to support hierarchical beam search at the UE. In some embodiments a BRRS is associated with a BRS via a Media Access Control Element (MAC-CE), to enable searching using both the BRS and the BRRS, for a faster hierarchical search. There may be other examples for beam refinement, and in a hierarchical search other reference signals may be used. In other words, the BRS and the BRRS are examples of reference signals used for refinement.

[0095] In some embodiments, a UE may use different implementation- specific codebooks that vary in terms of resolution, beam- width, side-lobe levels, and related parameters for hierarchical beam search. Because the difference in measured RSRP for the same eNB Tx beam direction can range from 1.2-3.5 dB depending on the codebook used for measurement, codebook identity may be reported along with the RSRP reports to mitigate this issue.

[0096] Some embodiments utilize both BRS and BRRS simultaneously for UE beam search for a given Tx beam direction as an efficient way to support hierarchical beam search at the UE.

Codebooks for hierarchical UE beam refinement

[0097] In some embodiments, for UE beamforming both at the Tx and at the Rx, a UE would typically make use of multiple codebooks. As discussed above, an important reason for using multiple codebooks is to enable hierarchical beam search. FIG. 5 illustrates codebooks for a 2 level hierarchical beam search. In this case sets of 8 Level-2 beams 512, one set enumerated 1-8 in FIG. 3, is associated with a Level- 1 anchor beam 504. A set of 8 Level-2 beams is used in some embodiments for beam refinement in directions that are spatially around the Level- 1 anchor beam (in both azimuth and elevation).

[0098] FIG. 5 is a conceptual illustration of codebooks with different resolutions that are used at the UE for hierarchical beam search employing a panel with 4x4 cross polarized antenna elements, according to some

embodiments. An omnidirectional beam 502 is used for synchronization and broadcast channel reception for minimizing access latency. A coarse codebook, called a Level 1 codebook, here has 4 beam directions 504, 506, 508, 510 and is used in some embodiments for a quick beam search using the BRS information. In some embodiments, a fine codebook, here with 32 beams, the first 8 beams illustrated as beams 1-8, may be used for high resolution beam search using either the BRS information for the second level search, or using BRRS information for a faster second level search.

[0099] FIGS. 6 A and 6B are illustrations of a set of UE beams for an un- quantized Level 1 codebook for a 4x4 UE array, according to some

embodiments. FIGS. 6 A and 6B illustrate example coarse codebooks for the Level- 1 beam search shown in FIG. 5. FIGS. 6 A and 6B endeavor to design beam weights that can create such waves. In FIG. 6A there are digital Fourier transform weights for the beams. FIG. 6B introduces tapering that suppresses side lobes as indicated in the figure, to create desired beams. Tapering is well- known in the literature. The x-axis in FIGS. 6A and 6B is the azimuth angle in degrees and the y-axis is the composite gain in dB. A composite antenna gain may be plotted including both the array gain and the gain of a radiating element. Th radiating element pattern (in dB) is assumed to follow Equation (1):

Equation (1) [00100] In FIG. 6A, beams can be compared. Beam 602A had less gain than beam 604 A, but has wider coverage than beam 604 A. Side lobes can be seen in each of the beams. For example, beam 602A has side lobes 602B, and 602C, which can be compared to side lobes 604B and 604C of beam 604 A. Other beams can be similarly compared. The tapering introduced in FIG. 6B can be seen to reduce the amplitude of side lobes and improve coverage of the tapered beams. Comparison can be made between the beams of FIG. 6B and similarly numbered beams of FIG. 6A. For example, beams 602 A', 602B, 602 { ^" of FIG. 6B can be compared in coverage and side lobe amplitude with the un-tapered beams 602 A, 602B, 602C of FIG. 6 A. All such beams of FIGS. 6 A and 6B can be compared in this manner to see the effect of tapering.

[0100] FIGS. 7A and 7B are illustrations of a set of UE beams for a

Level 2 unquantized codebook for a 4x4 UE antenna array, according to some embodiment s. The set of UE beam s for a Level-2 codebook (unquantized) for a 4x4 UE array is illustrated in FIG. 7A has no tapering. The codebook of FIG. 7B includes tapering used for targeting 20 dB side lobes. As with FIGS. 6 A and 6B, the x-axis is the azimuth angle in degrees and the y-axis is the composite gain in dB. FIGS. 7 A and 7B provide examples of beam weights for Level 2 beams, where tapering reduces side lobes on FIG. 7B, Tapering is applied in FIG 7, meaning a different set of beam weights is applied. In the case under discussion Tchebychev tapering is used. In this example of tapering, the beam is broadened by five percent (5%) or less. If criteria other than a small beam broadening result is desired, for example if larger beam broadening is desired, a different type of tapering, well known in the literature, may be used. As with FIGS. 6 A and 6B, the beams of FIG. 7 A (702 A, 702B) can be compared with the tapered beams of FIG. 7B (702A', 702B') for difference in coverage and side lobe amplitude. Other corresponding beams in the two figures can be similarly compared.

[0101] FIG. 8A is an illustration of a difference in response, in dB, to transmit (Tx) beam direction for different codebooks, without tapering, according to some embodiments. FIG. 8B is an illustration of a difference in response, in dB, to Tx beam direction for different codebooks, with tapering, according to some embodiments. The measured RSRP for a particular Tx beam direction depends on the codebook that is used at the UE side for measurement. This is shown in FIGS. 8A and 8B where additional RSRP gains ranging from 1.2 dB to 3.5 dB can be obtained when a Levei-2 codebook is used, compared to a Level- 1 codebook. FIG. 8A has no tapering. A Level-2 codebook with 32 beam directions can provide a gain between 1.6 - 3.5 dB as seen in FIG. 8 A for some embodiments, depending on the type of Level ! codebook used. The waveform for 32 beams is seen at 8 to give maximum gain in this plot and to give good coverage. Waveforms 4A-4E with 4 beams gives good gain but less coverage than wave 8. Waveforms 6A-6D illustrates reduced coverage. FIG. 8B, with tapering, illustrates a difference in response (in dB) to the Tx beam direction for different codebooks. A Level-2 codebook with 32 beam directions can provide a gain between 1.2 - 2.7 dB depending on the type of Level 2 codebook used. As seen at 8, FIG. 8B provides an illustration of a similar result but with tapering added. For example, in FIG. 8B there is a difference from between 1.2 dB and 2.7 dB depending on the type of Level 2 code book that is used. Like numbered beams of FIGS. 8 A. and 813 can be compared for coverage and amplitude differences. As discussed above, hierarchical beam search may result in measured reference signal received power (RSRP) for the same eNB transmitter (Tx) beam direction to vary by several dB depending on the codebook used for measurement, leading to error. Reporting a codebook identity along with the RSRP report can mitigate this error. Hence, a feedback identity of the codebook used for measuring the beams, for example, whether it is a Level 1 codebook or a Level 2 codebook that is used, is provided in an uplink in some embodiments.

[0102] In some embodiments, a codebook ID may be indicated along with, or in, an RSRP report that reports the measurements under discussion. This would lower the probability that an eNB is misled by the RSRP variation caused by different codebooks used for measurement. This will allow the eNB to consider only reported RSRP measurements associated with the same codebook ID for comparison purposes. The eNB will generally not be able to recreate the beam at the eNB because it does not have the code book, but it will be able to associate measurements with a codebook ID. In other words the eNB does not compare measurements across codebook IDs, [0103] FIG. 9 illustrates an example MAC-CE for UE reporting containing a BRS ID (BI), a codebook identifier (CB ID), and an RSRP, according to some embodiments. The MAC-CE of FIG. 9, here associating a measurement with a code book, illustrates reporting both the beam search result and the ID of the codebook used, to the eNB by the UE. FIG. 9 is drawn with the segments stacked vertically. The Octaves (Octave 1 , Octave 2, Octave 3) show the sequence of each 8 bits (or Octave). The eNB would then consider only measurements associated with the same codebook to be comparabies when the eNB attempts to determine the best direction for transmission. The eNB may also request the UE to perform a measurement with a selected codebook by indicating the codebook ID in a downlink request for a particular measurement. For example, the eNB can send the BRS to the UE for use in a Level 1 beam scan, in this example the BRS sub frame could be .2 ms duration and would include 14 OFDM symbols in time. For each OFDM symbol, a different direction is indicated from the same antenna panel. This illustrates a manner in which the eNB can help the UE beam scan by transmitting the BRS for different directions.

[0104] Further, given that the eNB receives the codebook IDs via the

MAC-CE of FIG. 9, the eNB may in some embodiments also request a UE to perform an RSRP measurement with a selected codebook where in this case a codebook ID is included with the RSRP measurement request to the UE.

eNB Tx beam scanning

[0105] In the following description, a Tx beam scanning scheme using a cross polarization (XP) panel at the eNB as shown in FIG. 1 I with a BRS subframe periodicity of 5ms and a 20 millisecond (ms) duration for scanning 56 Tx beams sent by the eNB, in some embodiments. FIG. 11 illustrates a time line for a process in which a BRRS signal is used that provides 8 beams are scanned at Level 2 (where 8 is merely an example of the number of beams in a Level 2 beam scan) in the embodiment under discussion, giving the UE an opportunity for scanning different directions of beams. Assume a 20 millisecond (ms) time for the eNB to transmit the beams in all indicated directions. The first 20 ms is for a single UE beam to scan all the measurements using a BRS. For four Level 1 beams as illustrated in FIG. 5, above, the time taken for the scan is 4 x 20 = 80 ms. At that point, then, the UE finds the best UE Level 1 beam, and can further scan 8 UE Level 2 beams using the BRS which, as indicated above, is transmitted periodically by the e ^' NB. This second, or Level 2, scan will take another 160 ms, namely 20 ms for each of the 8 level 2 beams, to find the strongest Level 2 beam pair. In some embodiments, the strongest Level 2 beam pair is the beam pair that includes the beam the strongest received power at the UE. In some embodiments the received power can be determined by measuring a beam resource such as a reference signal. In some embodiments the measurement is RSRP. This is an example where the BRS is used for both Level 1 and Level 2 beam scans. Therefore the time to arrive at the best beam pair is 80 + 160 = 240 ms in this example. A second example will shorten the time for arriving at best beam to less than 240 ms. Here, the Level 1 search uses a BRS. When the best Level 1 beam pair is found, the Level 2 search is based on a BRRS waveform in which two OFDM symbols can switch its beam 8 times. Switching 4 beams within the same OFDM symbol is not available in other cases. Usually beams are switchable once every other OFDM symbol.

Switching four times within the same OFDM symbol allows the UE to search through 8 beams in 2 OFDM symbols, which improves speed and efficiency of the search and leads to an improvement in the underlying technology of the UE. An assumption used for beam switching is that the eNB Tx is transmitting the best Tx beam, based on the Level 1 beam scan, that it can transmit. So the total time required is 80 ms plus an extra__2 OFDM symbols which much shorter than the 240 ms for the two BRS search. In other words, based on the Level 1 report the eNB transmits a BRRS waveform, and the UE measures 8 Level 2 waveforms using the BRRS information, for example, the RSRP information. In summary, in the embodiments discussed, the MAC CE of FIG. 9 is sent from the eNB to the UE. The MAC-CE from the eNB to the UE informs the UE that the BRRS is sent using the reported best transmit beam based on the last BSI report from the UE, which was itself based on the Level 1 search. The UE then knows it is to scan the Level 2 beams using the BRRS information in the MAC-CE because the Level 1 beams do not need to be scanned again, assuming no reorientation from the last BSI report. Determination of beam weight begins with determining what the antenna array is. Here it is a 4x4 array, with 16 antenna elements. Based on those antenna positions, an algorithm is run to determine the weights that gives a desired beam properties in one direction, for example the boresight. Given desired properties like beam width, side lobes, and the like, the algorithm would determine that one beam. Then in a second step, that beam is translated by the algorithm to other angles for example, every plus and minus 10 degrees to create a set of beams.

[0106] FIG. 10A illustrates a scan of 14 beam directions within a single subframe using a cross polarized transmit antenna panel at the eNB, according to some embodiments. The 14 beam directions are scanned within a single BRS subframe using a XP Tx panel at the eNB. Two XP ports may be aggregated in a single beam direction in each symbol. The 14 beam reference signal received power (BRSRP) measurements can be made by a UE from a BRS subframe.

[0107] FIG. 10B illustrates an example beam refinement reference signal

(BRRS), according to some embodiments. Fig 10B shows an example BRRS waveform 1000 and related expected behavior from a eNB and UE. Here a eNB uses a fixed transmit beam in one BRRS symbol (one OFDM symbol). Within a single BRRS symbol, the same waveform is repeated 4 times (#0, #1, $2, #3) in the time-domain. The repetition of a single waveform (eNB Tx BEAM

SWITCHING) ensures that a single cyclic prefix (CP) is sufficient for the BRRS symbol. A UE may switch its receive beam four times (#( ⁾ ', #1 ', #2', #3 ') within a single BRRS (OFDM) symbol. The switching instants corresponds to the boundaries of the time- waveform that is repeated 4 times within a symbol. This enables the UE to measure power from 4 transmit-receive beam pair

combinations within a single BRRS symbol. A second BRRS symbol may also be transmitted where the eNB could switch the transmit beam. BRS based hierarchical UE beam refinement

[0108] FIG. 9 illustrates an example Media Access Control Element

(MAC-CE) for UE reporting containing a BRS ID (BI), a codebook identifier (CB ID), and an RSRP, according to some embodiments. In the case of BRS based hierarchical beam refinement, following the MAC-CE of FIG. 9, it is clear that 80ms is needed for UE beam search using a Level- 1 coarse codebook (4 beams) as shown in FIG. 5. Following a selected Level- anchor beam, further UE beam refinement is accomplished using a set of 8 Level-2 beams (where 8 used as the example under discussion), and this can be can be performed in 160 ms, using the 20 ms BRS duration described above for beam scanning. This is illustrated in FIG . 1 1. FIG. 1 1 illu strates a possible timeline of beam refinement using only a beam reference signal (BRS) for a hierarchical beam search, according to some embodiments. Using a hierarchical beam search, a UE can perform beam refinement (select from 32 beams) in 80+160=240 ms using two BRS, one for the Level 1 search and one for the Level 2 search. A brute-force search from 32 Level-2 beams would, in contrast, need 640ms. Note that Level- 1 and Level-2 beam search is applied to the BRS port as indicated by a BRS Beam Change Indication (BCI) MAC-CE. When to apply Level-2 beam search and transition between Level- 1 and Level-2 beam search for a certain BRS port is managed by a UE implementation.

BRS mid BRRS based hierarchical U E beam refinement:

[0109] Hierarchical UE beam refinement can be made to work more efficiently if both BRS and BRRS can be utilized. This can be accomplished by depending on the BRS for the coarse Level- 1 beam search and depending on the BRRS for the fine Level-2 beam search. This is shown in FIG. 12. FIG. 12 illustrates a possible timeline of UE performance of a hierarchical beam search using both a BRS and a BRRS, according to some embodiments. In FIG. 12 the Level- 1 beam search is based on the BRS (80ms for 4 Level- 1 beams), and the BSI reports are based on Level 1 beams. The Level-2 beam search is then based on the BRRS (2 BRRS symbols for 8 Level-2 beams), and the BRI reports are based on Level 2 beams. In one embodiment, the sequence described in FIG. 12 is as follows. At 1210, the UE reports to the eNB the best of the L I beam pairs, where in some embodiments "best" means the beam received with the highest power, which may be indicated by the RSRP. Time T is a bounded time, as the system designer' s choice, during which the eNB, after reception of the UE report at 1210 can transmit a MAC-CE based on that report. At 1220 the UE receives a MAC-CE, such as that illustrated in FIG. 13, from the eNB, wherein the MAC- CE associates the UE report in step 1 to a BR Process 0. In other words, the association between the Level 1 beams and the Level 2 beams is indicated by a BR process 0. This is enabled by the MAC-CE of FIG. 13 where the beam indicator (ΒΪ) is obtained from the report in 1210 that is associated with a BRS process or BRRS process and a BRRS-RI. At 1230 the UE performs beam refinement based on the Level 2 beam by searching for the best Level 2 beam pair which the UE reports to the eNB via a report such as that described above with respect to FIG. 9.

[0110] In order to enable the above sequence, a B S port is associated with a BRRS process ID and a BRRS resource ID. This can be specified by a MAC-CE containing a BRS ID or BI, a BRRS process ID and a BRRS resource ID (BRRS-RI). This is seen in FIG. 13. FIG. 113 illustrates an example MAC- CE providing a BRRS for Level-2 beam scanning, according to some

embodiments. The MAC-CE in FIG. 13 is used in the two level (BRS-BRRS) beam search of FIG. 12 discussed above,

Single port specific and port group specific beam management

[0111] Analog beam forming is currently planned for 5G. Consequently, for BRS and BRRS related beam management, the antenna ports can have the same beam weight but will have different polarizations. In other words, a single port is independent and can support a beam that has independent beam weights. So single ports can be grouped and the corresponding beam management, such as beam acquisition, beam refinement, beam measurement, beam switching, and reporting, can be performed on the group. Beam management for a port groups may have less overhead than beam management for single ports because two ports are combined into a group. While the single port case is more flexible because each port can utilize an optimized beam weight, beam management overhead may be larger for the single port case than for port group case, because of the number of single ports. Embodiments below clarify whether beam related information is for the single port case or for the group port case, and the impact of single port operation on beam management and reporting; and the impact of port group operation on beam management and reporting.

[0112] For beam management CSI-RS, NR supports higher layer configuration of a set of single-symbol CSI-RS resources where the set configuration contains an information element (IE) indicating whether repetition is "on/off." This does not necessarily mean that the CSIRS resources in a set occupy adjacent symbols. Generally, one CSI-RS resource set can be viewed as multiple 1-port CSI-RS. As used in the foregoing context, "on/off means:

"On": The UE may assume that the gNB maintains a fixed Tx beam. "Off : The UE may not assume that the gNB maintains a fixed Tx beam. Support for the following for group based beam reporting, if group based beam reporting is configured;

[0113] In a beam reporting instance, a UE can be configured to report N different Tx beams that can be received simultaneously.

10114 f The UE may report N or fewer beams in a given reporting instance.

N is configured by the gNB where N<= Nmax

Nmax depends on UE capability

FFS: how to define the UE capabi lity

N =2 is supported. Further study {4,8}

Notes; Information indicating group is not required to be reported in Rel-15

By agreement, a group of beams can indicate the beams received from different UE panels, which beams can be received simultaneously.

[0115] Embodiments below may be used to mitigate 5G self-interference

(SI). In a currently agreed antenna virtualization assumption, the antenna elements with the same polarization will be virtualized into one transmit/receive unit transmit-receive unit (TXRU). In order to achieve sufficient beam forming gain, and in an effort to guarantee the coverage area, the beam weight can be applied at both the eNB and the UE side, as discussed above. Since the arrival angle of different polarizations at the UE side is different, so different beams can be applied on different TXRUs, in order to improve the channel quality and blockage robustness. Some embodiments provide the following.

• Single port specific BRS and port group specific BRS

measurement and reporting

• Single port specific CSIRS and port group specific CSIRS

• Single port specific BRRS and port group specific BRRS

• Single port specific and port group specific beam management In high band systems such as 5G, hybrid beam forming is adopted to obtain attractive beam forming gain at acceptable cost. Different procedures are introduced to refine the analog beam, e.g. BRRS, BRS. As a matter of clarification, BRS can be one type of Synchronization Signal Block (SSB) or Channel State Information Reference Signal (CSI-RS) for beam management. Also, BRRS can be one type of CSI-RS for beam management. [0116] In one embodiment, the beam of each port can be managed independently to achieve the flexibility, e.g. different beams can be

implemented, and updated on each port flexibly to realize beam diversity transmission, and/or align the direction of beam weight with the

arrival/departure direction of wave as much as possible. In this way, the beams can be managed in a single port specific way.

[0117] In one embodiment, to save the related control overhead of single port management, more than one port can be grouped, where the beams within one group are refined or managed at the same time. In this way, the beams can be managed in a port group specific way.

[0118] To clarify the different procedures, e.g., beam acquisition, refinement, measurement, beam switching will be involved in the single port specific way and the port group specific way, in accordance with the four embodiments recited above.

[0119] In one embodiment, in order to achieve a tradeoff between performance and cost, analog beam forming can be performed at both the eNB/UE side, which enables them to compensate for severe pathioss at 5G frequencies. According to the agreed the antenna virtualization assumption at a recent RANI committee meeting, the antenna elements of one or multiple panels with the same polarization will be virtualized into one transmit-receive unit TXRUs. While after virtualization, different ports may prefer different beams, then in order to support port specific beam forming, the following procedures may be used. In one embodiment of an eFD-ΜΓΜΟ system, an example of port specific codebooks for 4 ports is illustrated in equation (1 ), where ii and are port selection index, and range from {0, 1 } .

(i)

[0120] The embodiments discussed below for the new radio (NR.) system comprise ways to flexibly support port specific and beam specific operation for beam management, especially analog beam weight.

Smg!e Port specific BRS & port groep specific BRS measurement ¾md report

[0121] In one embodiment, a beam reference signal (BRS) is transmitted by the eNB to enable beam sweeping and choosing the optimal network-UE (NW/UE) beam pair, where the same beam is transmitted by different polarization in a FDMed or TDMed way.

[0122] FIG. 14 illustrates a single port specific beam, according to some embodiments. The illustrated beam comprises both horizontal and vertical polarization, where beam weight set 1 is applicable to the beam polarized as VI and H2, and beam weight set 2 is applicable to the beam polarized as HI and V2. To support more beams at one time, two ports with different polarization are utilized to transmit different beam weights. For instance, in a 4 panel

embodiment, with each panel having two ports, 8 beams can be scanned at one time instance. At the next time instance for BRS transmission, the polarization is changed. The first transmission can be at subframe zero (SF 0), while the secondary transmission can be at subframe twenty-fi ve (SF 25) of the relevant radio frame. In various embodiments, the BRS-RP can be measured and reported either by a single port specific procedure or a port group specific procedure, for use by the eNB for possible beam refinement or beam switching, where during the port group specific BRS-RP procedure, the reported BRS-RP is averaged based on the different port polarizations and different resource blocks (RBs), and during the port, specific BRS-RP procedure, the reported value is averaged based on the same polarization, as seen in in FIG. 14.

01 2 ;;3 ^' In some 5G embodiments, because of legacy from earlier systems, there is one subframe per BRS transition. In one embodiment, the BRS-RP of a series of specific subframes can be measured and reported independently. For instance, the BRS of even subframes can be measured and/or averaged to derive a BRS-PR value, i.e. BRSRPeven, while the BRS of odd subframes can be measured and/or averaged to derive a BRS-RP value, i.e.

BRSRPodd. The UE may pick up the strongest BRSRP based on BRSRPeven and BRSRPodd, and report it to the eNB. When reporting the BRSRP in a single port specific BRS report through xPUSCH or xPUCCH, a subframe index, which is utilized to distinguish the odd/even subframes should be reported.

[0124] FIG. 15 illustrates an example of a BRRS report, according to some embodiments. An example of a BRS report entity is illustrated at 1500 in FIG. 15, where the beams with the same index cannot be transmitted at the same time. The Simultaneous Indication field is an indication of beam polarization and the Port Specific Indication field is an indication of the port the report is intended for. The single port specific beam index represents that the preferred beam at one specific polarization is measured, e.g. "0" for the polarization at SF 0, or " 1 " at SF 25. In other words, the beam has one polarization at SF 0 and switches polarization at SF 25.

[0125] In another embodiment, the BRS of ail subframes can be measured and averaged to derive the BRSRP. In this case, the subframe index can be omitted. For instance, the RRC layer of the BRSRP filter to combine measurement results can be introduced. Suppose the previous BRSRP is y _n -i corresponding to a specific beam, and the instantaneous measured value at the current time is the x _n , then the averaged BRSRP at the current stage can be equal to:

y„ = (l-l/N)y„.] + l./N; xn

where N is the averaging weight, which can be defined by high layer signalling. [0126] In one embodiment, the BRS beam pattern indicator can be configured by the eNB through downlink control information, high layer signalling, e.g., RRC, xSIB, xMIB. This beam pattern indicator is utilized to inform whether the LIE measures BRS and reports the BRSRP based on all subframes, or a series of specific subframes.

[0127] In another embodiment, the single port indication can be reported implicitly, e.g. the first half BRSRPs correspond to the polarization of SFO, and the second half BRSRPs correspond to the polarization of SF 25. Single port specific CSIRS & port group specific CSIRS

[0128] FIG. 16 illustrates an example of CSIRS, according to some embodiments. In one embodiment, the CSIRS can be configured either in a single port specific way, or a port group specific way. Two examples of CSIRS are illustrated in FIG. 16, where, in Example (A), one pair of CSIRS contains two ports with different polarization and the same beam weight, at beams #0 through #3; in Example (B), each CSIRS port is transmitted by one different beam, beams #15-#22. Both examples can be utilized for beam selection with/without CQI. Example (A) can have reduced report overhead, while Example (B) can provide more beams for selection.

[0129] In one embodiment, a I bit indicator can be configured by the eNB to inform the UE whether a port group specific CSIRS port or a single port specific CSIRS port is configured, e.g. 0 for port group specific CSIRS, I for single port specific CSIRS.

[0130] FIG. 17 is a flow chart that illustrates a hierarchical search, according to some embodiments. At 1710, a plurality of antenna beams are received from the eNB from different directions. The antenna beams in some embodiments include signal (RS) in at least one subframe of a radio frame. At 1720 the UE determines the strongest received antenna beam by searching the received antenna beams in directions indicated by coarse codebook-generated antenna beams that are generated at the apparatus. At 1730, the UE transmits report, which in some embodiments may be a beam state information (BSI), to the eNB on a xPUSCH or a xPUCCH. The report, in some embodiments includes identity of the strongest received antenna beam, identity of a coarse codebook used to determine the direction of the strongest received antenna beam, an indication of RS received power (RSRP) of the strongest received antenna beam. The report may also include a subframe index to distinguish subframes of the report. At 1740, the UE refines the strongest received antenna beam by searching antenna beams received from the eNB in response to the report, the searching being in directions indicated by fine codebook-generated antenna beams that are generated at the apparatus and that are associated with the coarse codebook-generated antenna beam in the direction of the strongest received antenna beam, to determine the a strongest antenna beam pair.

[0131] In another embodiment, the single port specific CSI measurement can be reported based on the port group specific CSIRS, where the reported entities are:

® one or two CQIs for one or two codebooks

® two CSIRS resource indexes (CSIRS-RI) where one CRI corresponds to one port

® PMI based on selected ports

• RI

[0132] In one embodiment, two CRI indexes #0 and #2 are reported, which can be interpreted as port 15 and port 20, are selected, then 2x1 or 2x2 precoding can be applied on those two beams for data transmission.

[0133] In another embodiment, the single port specific CSI measurement can be reported, where the reported entities contain:

• one or two CQIs for one or two codebooks

® a bit map for beam selection, e.g., 8 bit map in Example (B) of FIG. 16, where 1 represents selected this port, and 0 represents do not select this port

® PMI based on selected ports

• RI

SiiigSe port specific BRRS & port group specific BRRS

[0134] In one embodiment, the BRRS can be configured either in a single port specific way, or a port group specific way. In the port group specific way, two adjacent BRRS ports are paired and transmitted with the same network

(NW) beam, where one port has a vertically polarized beam and the other port has a horizontally polarized beam. In the single port specific way, the NW beam for each BRRS port can be independently maintained,

[0135] In one embodiment, the BRRS port pair information can be configured by the eNB or can be pre-defined, and the configuration can apply to two ports (i.e., a pair of ports) at the same time.

[0136] For instance, suppose there are eight antenna ports for BRRS, e.g.

(600, 601 ... 607}, and then two BRRS ports are paired, e.g., {600, 601 ), {602, 603 }, (604, 605}, (606, 607}. In this embodiment, when the eNB configures the BRRS for beam sweeping, the related information will be applicable for two paired BRRS ports at the same time, e.g. the BRRS symbol or the format configuration.

[0137] In one embodiment, the configuration of each BRRS port is independent. For example, the candidate NW beam is carried by one BRRS port, and the active NW ⁷ beam can be carried by the other BRRS port. Then the UE can use one port for active NW beam sweeping, and the other port for candidate NW beam sweeping.

[0138] In one embodiment, the BRRS of a single port can be refined, then the UE need refine only the Rx beam of one specific port, instead of a two port refinement, resulting in lower complexity and more flexibility.

Single port specific & port group specific beam management

[0139] In one embodiment of a beam formed system, for example, two ports may be paired for data transmission, where the beams on two ports may be different for beam diversity.

[0140] In one embodiment, when reporting the beam index for beam switching, the port indication is reported at the same time, so that the eNB can distinguish the beam of which port is required to be switched, where the beam index refers to beam weight which will be reported to the UE, which can then apply the beam weight associated with the beam index to perform downlink and uplink transmission for beam switching and beam acquisition.

[0141] In another embodiment, two beam indexes for beam switching can be reported at the same time. When reporting the beam indexes for beam switching, the preferred beam can be arranged in the order of port indexes, e.g., the beam index related to the port with the smaller slant angle can be

concatenated with the beam index related to the port with the larger slant angle.

EXAMPLES

[0142] Example 1 is an apparatus of a user equipment (UE), comprising: memory; and processing circuitry configured to: decode a plurality of antenna beams received from an evolved Node B (eNB) at different directions, each of the antenna beams including a reference signal (RS) in at least one subfranie of a radio frame of the antenna beam; determine the strongest of the received antenna beams by search in directions indicated by coarse codebook-generated antenna beams; encode a beam state information (BSI) report for transmission to an eNB on a xPUSCH or a xPUCCH, the report comprising identity of the strongest received antenna beam, identity of a coarse codebook used to determine the strongest received antenna beam, an indication of RS received power (RSRP) of the strongest received antenna beam, and a subfranie index to distinguish subframes of the report; and refine the strongest received antenna beam by search of antenna beams received in response to the BSI report, the search being in directions indicated by fine codebook-generated antenna beams that are associated with the coarse codebook-generated antenna beam in the direction of the strongest received antenna beam, to determine the a strongest antenna beam pair.

[0143] In Example 2, the subject matter of Example I optionally includes wherein coarse codebook-generated antenna beams are generated at the UE.

[0144] In Example 3, the subject matter of any one or more of Examples

1-2 optionally include wherein the report comprises a media access control element (MAC-CE) that includes, the identity of a coarse codebook used to determine the strongest antenna beam, a beam reference signal (BRS) identifier (BRSID), and an RSRP.

[0145] In Example 4, the subject matter of any one or more of Examples

1-3 optionally include wherein the strongest received antenna beam pair is determined by measurement of a plurality of BRS received in directions indicated by the plurality of coarse codebook-generated antenna beams, and by measurement of a plurality of BRS received in directions indicated by the fine codebook-generated antenna beams.

[0146] In Example 5, the subject matter of any one or more of Examples

1-4 optionally include wherein the strongest received antenna beam pair is determined by measurement of a plurality of BRS received in directions indicated by the plurality of coarse codebook-generated antenna beams, and by measurement of a plurality of BRRS received in directions indicated by the fine codebook-generated antenna beams.

[0147] In Example 6, the subject matter of any one or more of Examples 3-5 optionally include wherein the BRS is periodically received apparatus from the eNB.

[0148] In Example 7, the subject matter of any one or more of Examples

5-6 optionally include wherein the BRRS is transmitted via a MAC-CE that includes a BRS ID, a BRRS-RI, and a BRRS process ID.

[0149] In Example 8, the subject matter of any one or more of Examples

1-7 optionally include wherein the coarse codebook-generated antenna beams and the fine codebook-generated antenna beams comprise respective sets of beam weight vectors specified in codebooks at the apparatus.

[0150] In Example 9, the subject matter of Example 8 optionally includes wherein the beam weights are known at the apparatus and not known at the eNB.

[0151] Example 10 is a non-transitory computer-readable storage medium that stores instructions for execution by processing circuitry of a user equipment (UE) to: decode a plurality of antenna beams received from an eNB at different directions, each of the antenna beams including a reference signal (RS) in at least one subframe of a radio frame of the antenna beam, determine the strongest of the received antenna beams by search in directions indicated by coarse codebook-generated antenna: encode a beam state information (BSI) report for transmission to an eNB on a xPUSCH or a xPUCCH, the report comprising identity of the strongest received antenna beam, identity of a coarse codebook used to determine the strongest received antenna beam, an indication of RS received power (RSRP) of the strongest received antenna beam, and a subframe index to distinguish subframes of the report; and refine the strongest received antenna beam by search of antenna beams received in response to the BSI report, the search being in directions indicated by fine codebook-generated antenna beams and that are associated with the coarse codebook-generated antenna beam in the direction of the strongest received antenna beam, to determine the a strongest antenna beam pair,

In Example 11, the subject matter of Example 10 optionally includes wherein the coarse codebook-generated antenna beams are generated at the UE.

[0152] In Example 12, the subject matter of any one or more of

Examples 10-11 optionally include wherein the report comprises a media access control element (MAC-CE) that includes, the identity of a coarse codebook used to determine the strongest antenna beam, a beam reference signal (BRS) identifier (BRSID), and an RSRP.

[0153] In Example 13, the subject matter of any one or more of

Examples 10-12 optionally include wherein the strongest received antenna beam pair is determined by measurement of a plurality of B RS received in directions indicated by the plurality of coarse codebook-generated antenna beams, and by measurement of a plurality of BRS received in directions indicated by the fine codebook-generated antenna beams.

[0154] In Example 14, the subject matter of any one or more of

Examples 10-13 optionally include wherein the strongest received antenna beam pair is determined by measurement of a plurality of BRS received in directions indicated by the plurality of coarse codebook-generated antenna beams, and by measurement of a plurality of BRRS received in directions indicated by the fine codebook-generated antenna beams.

[0155] In Example 15, the subject matter of any one or more of

Examples 13- 4 optionally include wherein the BRS is periodically received from the eNB.

[0156] In Example 16, the subject matter of any one or more of

Examples 14-15 optionally include wherein the BRRS is transmitted via a MAC-CE that includes a BRS ID, a BRRS-RI, and a BRRS process ID.

[0157] In Example 17, the subject matter of any one or more of

Examples 10-16 optionally include wherein the coarse codebook-generated antenna beams and the fine codebook-generated antenna beams comprise respective sets of beam weight vectors specified in codebooks at the apparatus. [0158] In Example 18, the subject matter of Example 17 optionally includes wherein the beam weights are known at the apparatus and not know at the eNB.

[0159] In Example 19, the subject matter of any one or more of

Examples 10-18 optionally include wherein the strongest received beam is determined by measuring the received power of a received antenna beam ,

[0160] Example 20 is an apparatus of user equipment (UE) comprising: memory; and processing circuitry to: decode a plurality of different antenna beams on each of a plurality of antenna ports; and select a first procedure to implement and update different antenna beams on each of a plurality of antenna ports individually, or when the antenna beams are not to be implemented and updated on each of a plurality of antenna ports individually, select a second procedure to implement and update antenna beams on each of a plurality of antenna ports concurrently, for BRS management comprising BRS received power measurement, CSIRS management comprising beam preceding for data transmission, and BRRS management comprising BRSRP beam averaging wherein the BRS, CSIRS, and BRRS are received in one or a series of subframes, and wherein the first procedure and the second procedure further comprise encoding a single port specific report or a group port specific report for transmission to an extended Node B (eNB), on a xPUSCH or a xPUCCH, the report comprising the result of the antenna beam management and a subframe index to distinguish subframes of the report.

[0161] In Example 21, the subject matter of Example 20 optionally includes wherein during a port group specific procedure the BRSRP is averaged and reported based on beams having different port polarization or different RBs, and during a port specific procedure the BRSRP is averaged and reported based on beams having the same polarization.

[0162] In Example 22, the subject matter of any one or more of

Examples 20-21 optionally include wherein the BRSRP of a series of specific subframes is measured and reported independently, the BRS of even subframes being measured and averaged to derive a BRSRP for the even subframes (BRSRPeven,) and the BRS of odd subframes being measured and averaged to derive a BRSRP for the odd subframes (BRSRPodd). [0163] In Example 23, the subject matter of any one or more of

Examples 20-22 optionally include wherein the UE detects the strongest BRSRP based on BRSRPeven and BRSRPodd and the report comprises the strongest BRSRP.

[0164] In Example 24, the subject matter of any one or more of

Examples 20-23 optionally include wherein when reporting the BRSRP as a single port specific BRS report through xPUSCH or xPUCCH, a subframe index is reported to distinguish the odd/even subframes.

[0165] In Example 25, the subject matter of any one or more of

Examples 20-24 optionally include wherein the BRS of ail subframes are measured and averaged to derive the BRSRP and no subframe index is reported, [0166] In Example 26, the subject matter of Example 25 optionally includes wherein the averaged BRSRP at a current time is equal to: yn ^:: = (1- 1/N)yn-1 + 1/N xn where the averaged BRSRP of a previous time is yn-1 and corresponds to a specific beam, the instantaneous averaged BRSRP at the current time is xn, and N is the averaging weight, the average weight being defined by high layer signaling.

[0167] In Example 27, the subject matter of any one or more of

Examples 20-26 optionally include wherein a BRS beam pattern indicator is received by the apparatus through downlink control information by high layer signaling comprising RRC, xSIB, or xMIB, and the beam pattern indicator informs the UE whether to measure the BRS and report the BRSRP based on all subframes, or based on a series of specific subframes.

[0168] In Example 28, the subject matter of any one or more of

Examples 20-27 optionally include wherein a first part of the BRSRP

corresponds to polarization of a first subframe, and a second part of the BRSRS corresponds to polarization of a second subframe.

[0169] In Example 29, the subject matter of any one or more of

Examples 20-28 optionally include wherein the CSIRS is configured either for a single port specific procedure, or for a port group specific procedure.

[0170] In Example 30, the subject matter of any one or more of

Examples 20-29 optionally include wherein a subframe received by the apparatus includes an indicator to inform the UE whether a port group specific CSIRS or a single port specific CSIRS is configured. [0171] In Example 31, the subject matter of any one or more of

Examples 20-30 optionally include wherein a single port specific CSI measurement is reported based on a port group specific CSIRS procedure, and the report includes one or two CQIs for one or two codebooks, two CSIRS resource indexes (CSIRS-RI) where one CSIRS-RI corresponds to one port, a PMI based on selected ports, or a RI.

[0172] In Example 32, the subject matter of any one or more of

Examples 20-31 optionally include wherein the report comprises a port specific CSI measurement and the report includes one or two CQIs for one or two codebooks, a bit map for beam selection, a PMI based on selected ports, or a RI.

[0173] In Example 33, the subject matter of any one or more of

Examples 20-32 optionally include wherein the procedure for BRRS

management in a port group comprises two adjacent paired BRRS ports transmitted with the same NW beam, and wherein the procedure for BRS management in the single port comprises the NW beam for each BRRS port being independently maintained.

[0174] In Example 34, the subject matter of Example 33 optionally includes wherein the BRRS of only a single port is refined by the apparatus.

[0175] In Example 35, the subject matter of any one or more of

Examples 33-34 optionally include wherein the antenna beams on the two adjacent paired BRRS ports are paired for data transmission, and the antenna beams on the two ports are different.

[0176] In Example 36, the subject matter of any one or more of

Examples 20-35 optionally include wherein a port indication is reported concurrently with a beam index for beam switching, and the report is configured to distinguish the beam of the port that is to be switched.

[0177] In Example 37, the subject matter of any one or more of

Examples 20-36 optionally include wherein two beam indexes for switching two beams are reported concurrently, the beam index of a beam that is preferred for switching being arranged such that the beam index related to a port with a smaller slant angle is concatenated with a beam index related to a port with a larger slant angle.

[0178] Example 38 is a non-transitory computer-readable storage medium that stores instaictions for execution by processing circuitry to: decode a plurality of different antenna beams on each of a plurality of antenna ports; and select a first procedure to implement and update different antenna beams on each of a plurality of antenna ports individually, or when the antenna beams are not to be implemented and updated on each of a plurality of antenna ports individually, select a second procedure to implement and update antenna beams on each of a plurality of antenna ports concurrently, for BRS management comprising BRS received power measurement, CSIRS management comprising beam preceding for data transmission, and BRRS management comprising BRSRP beam averaging wherein the BRS, CSIRS, and BRRS are received in one or a series of subframes, and wherein the procedure further comprise encoding a single port specific report or a group port specific report for transmission to an extended Node B (eNB), on a xPUSCH or a xPUCCH, the report comprising the result of the antenna beam management and a subfrarne index to distinguish subframes of the report.

[0179] In Example 39, the subject matter of Example 38 optionally includes wherein during a port group specific procedure the BRSRP is averaged and reported based on beams having different port polarization or different RBs, and during a port specific procedure the BRSRP is averaged and reported based on beams having the same polarization.

[0180] In Example 40, the subject matter of any one or more of

Examples 38-39 optionally include wherein the BRSRP of a series of specific subframes is measured and reported independently, the BRS of even subframes being measured and averaged to derive a BRSRP for the even subframes (BRSRPeven,) and the BRS of odd subframes being measured and averaged to derive a BRSRP for the odd subframes (BRSRPodd).

[0181] In Example 41 , the subject matter of Example 40 optionally includes wherein the IJE detects the strongest BRSRP based on BRSRPeven and BRSRPodd and the report comprises the strongest BRSRP.

[0182] In Example 42, the subject matter of any one or more of

Examples 40-41 optionally include wherein when reporting the BRSRP as a single port specific BRS report through xPUSCH or xPUCCH, a subfrarne index is reported to distinguish the odd/even subframes. [0183] In Example 43, the subject matter of any one or more of

Examples 38-42 optionally include wherein the BRS of all subframes are measured and averaged to derive the BRSRP and no subframe index is reported.

[0184] In Example 44, the subject matter of Example 43 optionally includes wherein the averaged BRSRP at a current time is equal to: yn = (1- 1/N)yn-1 + I IN xn where the averaged BRSRP of a previous time is yn-1 and corresponds to a specific beam, the instantaneous averaged BRSRP at the current time is xn, and N is the averaging weight, the average weight being defined by high layer signaling.

[0185] In Example 45, the subject matter of any one or more of

Examples 38-44 optionally include wherein a first part of the BRSRP

corresponds to polarization of a first subframe, and a second part of the BRSRS corresponds to polarization of a second subframe,

[0186] In Example 46, the subject matter of any one or more of

Examples 38-45 optionally include wherein the CSIRS is configured either for a single port specific procedure, or for a port group specific procedure.

[0187] In Example 47, the subject matter of any one or more of

Examples 38-46 optionally include wherein a subframe received by the apparatus includes an indicator to inform the UE whether a port group specific CSIRS or a single port specific CSIRS is configured.

[0188] In Example 48, the subject matter of any one or more of

Examples 38-47 optionally include wherein a single port specific CSI measurement is reported based on a port group specific CSIRS procedure, and the report includes one or two CQIs for one or two codebooks, two CSIRS resource indexes (CSIRS-Ri) where one CSIRS-RI corresponds to one port, a PMI based on selected ports, or a RI.

[0189] In Example 49, the subject matter of any one or more of

Examples 38-48 optionally include wherein the report comprises a port specific CSI measurement and the report includes one or two CQIs for one or two codebooks, a bit map for beam selection, a PMI based on selected ports, or a RI.

[0190] In Example 50, the subject matter of any one or more of

Examples 38-49 optionally include wherein the procedure for BRRS

management in a port group comprises two adjacent paired BRRS ports transmitted with the same NW beam, and wherein the procedure for BRS management in the single port comprises the NW beam for each BRRS port being independently maintained.

[0191] In Example 51, the subject matter of any one or more of

Examples 38-50 optionally include wherein the apparatus receives a BRRS port pair in a pre-defined configuration that applies to the port pair concurrently.

[0192] In Example 52, the subject matter of any one or more of

Examples 38-5 1 optionally include wherein the configuration of the BRRS at a first port is independent of the BRRS configuration at a second port, the candidate NW beam is carried by the first port, and the active NW beam is carried by the second port, and the apparatus uses the second port for active NW beam sweeping and the first port for candidate NW beam sweeping.

[0193] In Example 53, the subject matter of any one or more of

Examples 51-52 optionally include wherein the BRRS of only a single port is refined by the apparatus.

[0194] In Example 54, the subject matter of any one or more of

Examples 51-53 optionally include wherein the antenna beams on the two ports are paired for data transmission, and the antenna beams on the two ports are different.

[0195] In Example 55, the subject matter of any one or more of

Examples 38-54 optionally include wherein a port indication is reported concurrently with a beam index for beam switching, and the report is configured to distinguish the beam of the port that is to be switched and wherein two beam indexes for switching two beams are reported concurrently, the beam index of a beam that is preferred for switching being arranged such that the beam index related to a port with a smaller slant angle is concatenated with a beam index related to a port with a larger slant angle.

[0196] Example 56 can comprise, or can optionally be combined with any portion or combination of any portions of any one or more of Examples 1 through 55 to include subject matter that can comprise means for performing any one or more of the functions of Examples 1 through 55, or a machine-readable medium including instructions that, when performed by a machine, cause the machine to perform any one or more of the functions of Examples 1 through 55.

[0197] The above detailed description includes references to the accompanying drawings, which form a part of the detailed description. The drawings show, by way of illustration, specific embodiments in which the invention can be practiced. These embodiments are also referred to herein as "examples." All publications, patents, and patent documents referred to in this document are incorporated by reference herein in their entirety, as though individually incorporated by reference. In the event of inconsistent usages between this document and those documents so incorporated by reference, the usage in the incorporated reference(s) should be considered supplementary to that of this document; for irreconcilable inconsistencies, the usage in this document controls.

[0198] In this document, the terms "a" or "an" are used, as is common in patent documents, to include one or more than one, independent of any other instances or usages of "at least one" or "one or more." In this document, the term "or" is used to refer to a nonexclusive or, such that "A or B" includes "A but not B," "B but not A," and "A and B," unless otherwise indicated. In the appended claims, the terms "including" and "in which" are used as the plain- English equivalents of the respective terms "comprising" and "wherein." Also, in the following claims, the terms "including" and "comprising" are open-ended, that is, a system, device, article, or process that includes elements in addition to those listed after such a term in a claim are still deemed to fall within the scope of that claim. Moreover, in the following claims, the terms "first," "second," and "third," etc. are used merely as labels, and are not intended to impose numerical requirements on their objects,

[0199] The above description is intended to be illustrative, and not restrictive. For example, the above-described examples (or one or more aspects thereof) may be used in combination with each other. Other embodiments can be used, such as by one of ordinary skill in the art upon reviewing the above description. Also, in the above Detailed Description, various features may be grouped together to streamline the disclosure. This should not be interpreted as intending that an unclaimed disclosed feature is essential to any claim. Rather, inventive subject matter may lie in less than all features of a particular disclosed embodiment. Thus, the following claims are hereby incorporated into the Detailed Description, with each claim standing on its own as a separate embodiment. The scope of the invention should be determined with reference to the appended claims, along with the full scope of equivalents to which such claims are entitled.

[0200] The Abstract is provided to allow the reader to ascertain the nature and gist of the technical disclosure. It is submitted with the understanding that it will not be used to limit or interpret the scope or meaning of the claims. The following claims are hereby incorporated into the detailed description, with each claim standing on its own as a separate embodiment.