[0001] * Recite information identifying related applications, if any *,

FIELD OF THE INVENTION

[0002] The described embodiments are related to interactions between a user equipment (UE) and an evolved Node B (eNB) in a Long Term Evolution (LTE) wireless communication system,

BACKGROUND

[0003] The 3rd Generation Partnership Project (3GPP) is the organization responsible for the standardization of the Universal Mobile Telecommunication System (UMTS) and Long Term Evolution (LTE). For many years wireless communication has been continuously evolving. Every year or two or more, new standards are released, that include new capabilities based on select newly developed technologies, preferably while maintaining interoperability with previously released standards. Different equipment manufacturers can then make devices in compliance with the new standards that can interoperate and that have new features not found in older- standards compliant devices, and yet can still interoperate with those older devices. For example, a release 8 compliant UE will still work in a release 10 compliant network, but cannot use the new functionality introduced after release 8. Conversely, a release 10 compliant UE can use all functionality introduced through release 10, and can also communicate with a release 8 compliant UE.

[0004] The so-called evolved UMTS Terrestrial Radio Access (e-UTRA) is the air interface of BGPP's Long Term Evolution (LTE) upgrade path for mobile networks. It is a radio access network standard meant to replace UMTS, and High-Speed Downlink / Uplink Packet Access (HSDPA/HSUPA) technologies specified in 3GPP releases beginning with release 5. In 3GPP network parlance, a mobile user device such as a cell phone or the like is referred to as a User Equipment (UE). The UE has a radio frequency (RF) transmitter and receiver, and communicates directly with an evolved Node B (eNodeB, or eNB). The eNB also contains RF transmitters and receivers that can communicate directly and simultaneously with a plurality of UEs as they move within the service area of the eNB. An evolved UMTS Terrestrial Radio Access Network (e- UTRAN) is a network in which UEs and eNBs communicate with each other using the E- UTRA air interface.

[0005] Existing 3GPP standards include e-UTRAN Release 8, established in 2008, specified the first LTE standard. Release 9, established in 2009, included additions to the physical layer like dual layer multiple-input/multiple-output (MIMO) beam-forming transmission and positioning support. Release 10, established in 2011, introduces certain LTE Advanced features like carrier aggregation, uplink single user (SU)-MIMO or relays, and increasing a UE's peak data rate.

[0006] Thus, many types of new and advanced technology equipment are regularly being introduced into new releases of the 3GPP standards that can provide services that were not possible previously. Such advanced technology equipment might include improvements or new features, for example, for use in a UE, an eNB, or other systems and devices. The improvements and new features are deemed more highly "evolved" than the corresponding equipment in a prior release compliant telecommunications system.

[0007] Terms that may be used herein when describing current standards, or advanced or next generation equipment, may include High Speed Packet Access (HSPA), LTE, and E-UTRAN. In particular, LTE is a technology that can reach high data rates both in the downlink and in the uplink, and allows for a system bandwidth of 20 MHz, or up to 100 MHz with certain features.

[0008] Mobile telephones, handheld devices, devices embedded in laptop computers, Machine-2-Machine (M2M) devices and the like, that have wireless communication capabilities are all referred to herein as UEs or wireless devices. [0009] A network that includes infrastructure points that use a plurality of wireless access technologies, each of them having different capabilities, constraints, and operating functionalities, is referred to as a heterogeneous network (HetNet). For example, a HetNet may include a mix of macrocells, remote radio heads, and low- power nodes such as picocells, femtoce!!s, and relays.

[0010] One approach to provide a significant performance leap in wireless networks is to decrease the distance between the access network and the UEs. This approach leverages the existing network infrastructure, and adds net elements to it in a manner that can improve spatial spectrum reuse and enhance indoor coverage. [0011] Different UEs may use different types of radio access technology (RAT) to access a wireless communications network. So-called multi-mode UEs are capable of using more than one RAT. For example, a multi-mode UE may obtain service from one or more modes of UMTS, and one or more other technologies such as GSM (Global System for Mobile Communications) or other radio systems. Multi-mode UEs referred to herein may be of various types specified in the 3GPP document Technical Specification Group (TSG) Terminals, Multi-Mode UE Issues, Categories, Principles and Procedures (3G TR 21.910), the entirety of which is included herein by reference. Examples of RATs, or network technologies that may use different types of RATs, include UTRAN, GSM, GSM Enhanced Data rates for Global Evolution (EDGE) Radio Access Network (GERAN), Wireless Fidelity (WiFi), General Packet Radio Service (GPRS), High-Speed Downlink Packet Access (H5DPA), HSPA, and LTE. Other RATs, or other network technologies based on these RATs, also exist in the prior art.

[0012] The 3GPP standards for the UE and other devices include performance requirements. For example, in order to guarantee that a UE supporting a particular functionality, such as MIMO, exhibits good performance in practice, the specified performance requirements may be verified through conformance testing, as specified in the relevant 3GPP standard. With regard to the UE, performance requirements may be divided into so-called "conducted" performance requirements and "radiated" performance requirements. [0013] The conducted performance requirements are normally defined at the antenna connector of the UE. To verify these requirements, tests are performed by setting up a test system that emulates an eNB, in a controlled environment. The antenna connector of the device under test (DUT) is operatively coupled to the test equipment. The test equipment may comprise model channel, radio environment, or other conditions required for testing and utilizing faders, signal generators, etc. The conducted performance requirements cover radio, baseband, and radio resource management (RRM) requirements. The radio requirements can be classified as RF receiver or transmitter requirements. The baseband requirements can be classified as performance that is obtained after demodulating the received signal. Baseband performance may be expressed as achievable throughput, for example. And, RRM can be classified as mobility performance of the UE, and can include measurement reporting, for example. The performance is expressed and verified using the specified conducted performance requirements for UEs. [0014] Multiple antennas may be arranged in a so-called Multiple Input Multiple

Output (MIMO) configuration for both transmission and reception. MIMO antennas may be used for enhancing throughput of the UE, the eNB, or both. Communication using MIMO antennas is an important factor behind the high performance offered by

LTE. [0015] In addition, the LTE standard defines entities called antenna "ports" (APs) that may be used for reference signaling, for example. APs are logical entities, and do not necessarily correspond to physical antennas. For example, multiple antenna port signals can be transmitted on a single transmit antenna, such as a single antenna element 295 illustrated in FIG. 2B. Conversely, a single antenna port can be spread across multiple transmit antennas, such as the group of antenna elements 290 in FIG. 2B. Any number of antenna elements, operated as groups in any arrangement, may be used. UEs can be configured to use multiple ports to improve diversity gain and/or multiplexing gain. And, new LTE releases can introduce changes to port definitions and usage. [0016] For example, antenna ports used for Physical Downlink Shared Channel (PDSCH) transmit allocations were supported in LTE Release 8 on AP 0, (0 and 1), (0, 1, 2), or (0, 1, 2, 3). Accordingly, these ports are designated "cell-specific reference signal" (C-RS) APs. Various configurations are defined that use C-RS antenna ports, including 2- or 4-port Transmit Diversity and 2-, 3-, or 4- port Spatial Multiplexing.

[0017] Beamforming support was introduced later, and single-layer PDSCH transmit allocations support on AP 5 was added. LTE Release 9 added Transmission Mode 8 (i.e., dual-layer beamforming), in which the eNB weighs two layers individually at the antennas to combine beamforming with spatial multiplexing for one or more UEs. In Rel 9, PDSCH may be transmitted using APs 7 and 8; and single-layer beamforming can use APs 7 and 8 in addition to AP 5. LTE Release 10 introduced transmission mode 9 (TM9), which adds up to 8-layer transmissions using APs 7-14.

[0018] Thus, with multiple receivers (Rx) 235, such as a plurality of antenna elements 295 operated as receivers, a system can support multiple layer spatial multiplexing. With multiple Rx APs a system with multiple layer spatial multiplexing is capable of utilizing both beamforming and diversity gain. These layers can be combined through dynamic beamforming and MIMO receiver processing to increase communication reliability and range. The use of 4 Rx APs enables even higher UE data rates in a broad range of usage scenarios, and can enhance receiver sensitivity. Depending on the transmission scheme used in the eNB and the channel conditions, 4

Rx APs may enable peak throughput to be doubled compared to dual layer multiplexing by virtue of additional diversity gain and/or multiplexing gain. The same or other antenna elements 295 may also be operated as transmitters, and may thereby provide transmit diversity and spatial multiplexing [0019] Further improvements and features in communication network capabilities will require new capabilities to be developed and deployed. SUMMARY

[0020] Methods and apparatuses are disclosed for use in an evolved UMTS Terrestrial Radio Access Network (e-UTRAN) communication network, in which an enhanced Node B (eNB) obtains information related to the receiver antenna ports characteristics of a user equipment (UE). Based on the obtained information, the eNB determines network radio resources and/or UE configuration parameters to use for communication between the eNB and the UE. The eNB then uses the determined radio resources, and/or sends to the UE the determined UE configuration parameters, which the UE then uses. [0021] It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory and are intended to provide further explanation of the invention as claimed.

BRIEF DESCRIPTION OF THE DRAWINGS

[0022] The accompanying drawings are included to provide a further understanding of the invention, and are incorporated in and constitute a part of this specification. The drawings, which are not necessarily drawn to scale, illustrate disclosed embodiments and/or aspects, and together with the description serve to explain the principles of the invention. The protected scope of the invention is not limited to the described exemplary embodiments. Rather, it is determined by the appended claims.

[0023] In the drawings:

[0024] FIG. 1 is a block diagram of a portion of a wireless communications system according to the disclosure. [0025] FIG. 2A is a diagram of the control-plane protocol stack defined in 3GPP TS

36.300, the entirety of which is included by reference as if fully set forth herein.

[0026] FIG. 2B is a simplified block diagram of a UE and an eNB in which the disclosed methods may be used. [0027] FIG. 3 is a flow chart illustrating an exemplary method performed in an eNB for obtaining and using a UE's receiver antenna ports declaration information.

[0028] FIG. 4 is a flow chart illustrating an exemplary method performed in the UE for providing its receiver antenna ports declaration information to the eNB. [0029] FIG.5 illustrates the procedure for the network eNB to obtain information of a UE's receiver antenna ports characteristics.

[0030] FIG. 6 illustrates radio resource control information elements used to specify UE receiver antenna ports characteristics.

[0031] FIG. 7 illustrates the radio resource control information elements used to specify two groups of UE receiver antenna ports characteristics, designated as primary and secondary.

DETAILED DESCRIPTION

[0032] The figures and descriptions provided herein may have been simplified to illustrate aspects of the described embodiments that are relevant for a clear understanding of the disclosed methods, devices, and/or systems, while eliminating for the purpose of clarity other aspects that may be found in typical methods, devices, and/or systems. Thus, those of ordinary skill in the relevant arts may recognize that other elements and/or steps may be desirable and/or necessary to implement the methods, devices, and systems described herein. Because such elements and steps are well known in the art, and because they do not facilitate a better understanding of the described embodiments, a discussion of such elements and steps may not be provided herein. However, the present disclosure is deemed to inherently include all such elements, variations, and modifications to the described aspects that would be known to those of ordinary skill in the pertinent art.

[0033] In an LTE communication network, the radio resource control (RRC) function handles signaling between the UE and the eNB. In embodiments, the RRC is also responsible for determining and reporting to the eNB the state of the UE receiver ports. RRC functions pertain generally to establishing and terminating communication connections, conveying system information, establishing, reconfiguring and releasing radio bearer resources, and handling connection mobility procedures. In doing so, the RRC takes into account the state of certain network resources. FIG. 1 illustrates a usage scenario that may arise as low-power, micro scale nodes such as picocells and femtocells are introduced into an e-UTRAN, in which the disclosed methods may be used. In particular, FiG. 1 illustrates a situation in which UE antenna ports state, measurements, and RRC reporting of the UE ports state might occur. As shown, e- UTRAN 100 comprises an elSIodeB (eNB) 140 that is part of macro technology portion 150 of the e-UTRAN. The e-UTRAN also comprises UE 110, shown moving from the eNB's service area (macro cell) toward the micro technology network (e.g., pico cell) service area. The UE may be engaged, for example, in an activity in which the macro technology network is running an application on or via the eNB. As shown, the eNB is transmitting data or is otherwise in communication with the UE. For example, in an exemplary operation the eNB 140 is responsible not only for determining the macro resources to use and how to use them when communicating with the UE, but is also responsible for determining the preferred UE configuration parameters and sending them to the UE. Communication data 120 is shown being sent from the eNB to the UE, for example, to convey the configuration parameters to the UE, which the UE then uses. Communication between the UE 110 and the micro network 130 is also shown, for example to maintain communication with the macro network 150 from within the micro network service area. In addition, communication directly between the eNB and the micro network (not shown) may occur, in which the eNB and the micro network operate in conjunction to provide service to the UE when it is in the micro network service area, for example.

[0034] FIG. 2A illustrates an embodiment of the control-plane protocol stack 200 used in exemplary embodiments, and FIG. 2B is a simplified block diagram of exemplary UE 110 and eNB 140. FIG. 2A includes protocols by which the UE 110, the eNB 140, and a mobility management entity (MME) 220 communicate. The MME is responsible for network functions such as paging, tagging, and retransmissions. It plays a part in the bearer activation/deactivation process, and is also responsible for choosing a gateway for the UE to communicate with the core network (not shown) when the UE attaches to the network for communications services, and during handover from one macro cell to another. [0035] The protocol layers enable the UE, the eNB, and the MME to communicate with each other. In particular with regard to the disclosed apparatus and methods, UE 110 and eNB 140 communicate with each other over an air interface via respective transmitters (215, 225) and respective receivers (235, 245). Various operations are performed under the control of respective processors (255, 265), each accessing instructions and data stored in respective storage devices (275, 285), such as solid state memories, for example.

[0036] In operation, each of the protocol layers terminates in two communicating devices. In addition to their respective protocol layer functions, each layer that is disposed between two other layers operates as an interface between those two other layers. The protocol layers shown begin with the physical layer (PHY) 230, which operates in the circuitry required to implement physical layer functions. A PHY connects a link layer device to a physical medium such as an air interface, and typically includes a Physical Coding Sublayer (PCS) and a Physical Medium Dependent (PMD) layer. The PCS encodes and decodes the data that is transmitted and received. [0037] The PHY is operatively coupled to a link layer device called a media access controller, and uses a protocol layer referred to as the media access control (MAC) layer 240. The MAC protocol layer provides addressing and channel access control mechanisms that make it possible for a plurality of terminals and other network nodes to communicate concurrently via a shared medium. Functions performed by the MAC layer include frame delimiting and recognition, destination addressing, conveying source addressing information, and controlling access to the physical transmission medium. The MAC layer is operatively coupled to the PHY and to a radio link control (RLC) layer 250. [0038] The RLC layer is used for error recovery and flow control. RLC parameters include transmit window size, receiving window size, and poll timers, and it functions to ensure that radio resources are fully utilized, The RLC layer is operatively coupled to the MAC layer and to a packet data convergence protocol (PDCP) layer 260.

[0039] The PDCP layer 260 performs communication packet header compression and decompression, transfer of user data, and maintenance of sequence numbers for radio bearers during handover as the UE moves from one serving cell to another. The PDCP layer is operatively coupled to the RLC layer and to a radio resource control (RRC) protocol layer 270.

[0040] The RRC protocol layer 270 functions include connection establishment and release functions, broadcast of system information, radio bearer establishment, reconfiguration and release, and RRC connection mobility procedures. The RRC layer is operatively coupled to the PDCP layer and to a non access stratum (NAS) layer 280.

[0041] The NAS 280 layer signaling is used in communications between the UE and the MME. It is used in assigning temporary identities to UEs, and enforces UE roaming restrictions. The MME also provides the control plane functionality needed for 4G LTE and 2G/3G access networks (not shown) to intercommunicate, among other things.

[0042] FIG. 3 is a flow diagram illustrating an exemplary method performed in the eNB for obtaining and using a UE's antenna ports declaration information. In step 310, the eN B sends a request to the UE for its receiver antenna ports declaration information, which the UE sends. The eNB receives the requested receiver antenna ports declaration information from the UE, 320. Finally, the eNB uses the received UE antenna ports declaration information for operations, 330.

[0043] FIG. 4 is a flow diagram illustrating an exemplary method performed in the UE for providing its receiver antenna ports declaration information to the eNB. In step 410, the UE receives from an eNB a request for the UE's receiver antenna ports declaration information. Responsive to the request, the UE obtains its receiver antenna ports declaration information and sends it to the eNB. [0044] FIG. 5 also illustrates the procedure for the network eNB to obtain information related to the UE receiver antenna ports characteristics. In step 410, the eNB sends a request to the UE for its receiver (Rx) antenna ports (AP) declaration information. The UE responds by sending its Rx AP information to the eNB.

[0045] FIG. 6 and FIG. 7 illustrate embodiments of the radio resource control information elements for a plurality of antenna ports. In FIG. 6, the antenna ports are not operated as primary and secondary groups. In FIG. 7 however, the radio resource control information elements for the UE receiver antenna ports are operated as primary and secondary groups.

[0046] Thus, the exemplary methods and embodiments described are used with an eNB in communication with a user equipment (UE) that has multiple receiver antenna ports, operating in a wireless communication network. The eNB requests and obtains from the UE information related to characteristics of the UE receiver antenna ports. Based on the obtained information, the network eNB determines radio resources and/or UE configuration parameters to use for communication with the UE. The determined radio resources and/or configuration parameters are then used for the communications between the eNB and the UE.

[0047] In an embodiment, the UE is a multi-mode UE within communication range of the eNB as a serving cell. The network may also comprise at least one Neighbor cell, which may use the same mode or a different mode as the serving cell.

[0048] In embodiments, the described methods employ a control-plane protocol stack of the communication network. The radio resource control (RRC) function may perform UE measurement reporting, and/or may initiate control functions that are terminated in or through the eNB on the network side.

[0049] In disclosed exemplary embodiments, the network eNB transmits a request to the UE to send its receiver antenna ports declaration information. In response, the UE sends the requested information to the eNB.

[0050] In an exemplary operation of disclosed embodiments, the UE receives the request from the network eNB for the UE receiver antenna ports declaration information. The UE may respond to the request by sending to the eNB the requested UE receiver antenna ports declaration information.

[0051] In embodiments, the UE response to the network eNB request may include the number of antenna ports supported by the UE. The UE receiver antenna ports may be characterized as primary ports and secondary ports in the UE response to the network eNB request.

[0052] In an exemplary operation, the network eNB determines the radio resources to use for communication with the UE based on the information obtained from the UE. in another exemplary operation, the network eNB determines the configuration parameters for the UE to use, and sends the determined parameters to the UE.

[0053] in an aspect of the disclosed embodiments, the determined UE configuration parameters are received by the UE and used at least in part by the UE for communication with the eNB. [0054] The foregoing can _. be utilized, for example, upon initial connection of the UE with the eNB; or as the UE moves from a first serving cell to a second serving cell. Moreover, after the eNB obtains the UE's antenna ports information and determines and sends configuration parameters to the UE, the eNB may thereafter determine and send to the UE reconfiguration parameters determined as a result of network operations that did not involve the UE, In order to better utilize radio resources and/or other network resources. For example, the reconfiguration parameters may be redetermined in response to a change in network radio resource usage, or intermittently or at regular intervals.

Although the invention has been described and illustrated in exemplary forms with a certain degree of particularity, it is noted that the description and illustrations have been made by way of example only. Numerous changes in the details of construction, combination, and arrangement of parts and steps may be made. Accordingly, such changes are intended to be included within the subject matter of the disclosure, the protected scope of which is defined by the claims.