Joint channel state information of virtual user equipment

Abstract

A base station (BS) communicatively connected to a group including a first user equipment (UE) and a second UE may implement a method. The method includes determining (316 or 416), by processing hardware of the base station, a channel state information (CSI) process configuration for the group. The method also includes sending (318) a control signal including the CSI process configuration to the group, and sending (336) a reference signal to the group based on the CSI process configuration. The method also includes, in response to sending the reference signal to the group, receiving (354) an indication of a joint channel state of the group from at least one UE of the group.

Description

Technical Field

[0001] The present disclosure relates generally to wireless communications, and more particularly, to a grouping strategy for coordinating user equipment in a wireless communication system. Background Art

[0002] In wireless communication systems, such as fifth generation (5G) radio access ("NR") networks, a base station (e.g., gNB) must configure downlink transmissions to and uplink transmissions from user equipment within the coverage area of ​​the base station. To perform such configuration, the base station transmits control information indicating random access channel information, scheduling grants, power control commands, coding information, etc. via a control channel. However, processing the configuration of a large number of user equipments may require a large amount of control channel overhead (e.g., time and frequency resources), resulting in reduced network efficiency.

[0003] In addition, the signal strength at the location of a particular user device (commonly referred to as user equipment ("UE")) and / or the reception capability of a particular UE may be poor. For example, the UE may be located at the edge of a cell, or experience fading effects due to Doppler shift, multipath propagation, or shadowing. The base station may have difficulty establishing communication with the UE, further reducing overall network efficiency.

[0004] To address some of these issues, various schemes for coordination (or "grouping") between different UEs have been proposed. Despite these different schemes, there are more opportunities to gain more network efficiency improvements that UE grouping can provide, and to flexibly adjust the coordination scheme to better utilize larger UE group sizes. Summary of the invention

[0005] According to the techniques of the present disclosure, multiple UEs form a group (referred to herein as a "UE coordination set" or "UECS") that the base station treats as a single UE or "virtual" UE in at least some aspects and some protocol stack layers. Although in previously proposed UE grouping schemes, the base station of the serving cell is unaware of changes in the joint reception capabilities of the UE group (or UECS, as referred to herein as the UE group) over time (e.g., when a particular UE experiences poor channel conditions), the techniques of the present disclosure provide the base station with feedback that the base station can use to quickly adjust downlink transmissions to adapt to the current capabilities of the UECS.

[0006] Specifically, the coordinating or "master" UE of the UECS collects individual receive capability information from each UE in the UECS. The capability information may indicate how many multiple-input multiple-output (MIMO) layers the UE can process, as well as possible other information (e.g., whether the UE can perform nonlinear processing on received MIMO signals). For example, a UE with two antennas may report 2-layer, 2x2 MIMO processing capabilities. The master UE analyzes the individual UE capabilities to determine the joint capabilities of the UECS, which the master UE reports to the base station. For example, if the UECS includes two UEs, each of which supports 2-layer MIMO processing under current channel conditions, the master UE may report the 4-layer MIMO processing capability of the UECS. As another example, the same two UEs may only be able to support single-input single-output (SISO) processing under their current channel conditions, and therefore, the master UE reports the 2-layer MIMO processing capability of the UECS. The master UE then distributes the joint capability information to other UEs in the UECS to enable joint transmission from the UECS to the base station.

[0007] Based on the received joint capability information of the UECS, the base station defines / determines a channel state information (CSI) process configuration specific to the UECS. The CSI process configuration includes, for example, timing and frequency information of a reference signal (e.g., CSI-RS) that the base station will send to the UECS. The CSI process configuration may also include other information required for the CSI process, such as code domain information (e.g., for signal precoding). The base station sends a control signal (e.g., a radio resource control (RRC) message or a lower layer message) including the CSI process configuration to the UECS. The UECS receives the control signal jointly, and the UE processes the CSI process configuration, for example, to identify the time and frequency resources on which the UE will receive the reference signal. In some implementations and / or scenarios, the base station defines resources for multiple reference signals and sends multiple reference signals (e.g., one for each base station antenna).

[0008] Later, the base station sends a reference signal to the UECS, and each of the UEs performs measurements on the received reference signal to determine the UE-specific channel quality and generate a UE-specific CSI report. Each UE-specific CSI report may include parameters such as a channel quality indicator (CQI), a precoding matrix indicator (PMI), a rank indicator (RI), and / or a modulation and coding scheme (MCS) index. The UEs in the UECS forward their respective individual CSI reports to the master UE, which then calculates a joint CSI report for the UECS as a whole. For example, a joint CSI report may include parameters of the same type as a separate CSI report. In some implementations, the parameters include parameters indicating how many streams or MIMO layers the base station should use. In addition, one or more parameters in the joint CSI report may depend on the specific joint processing capabilities of the UECS. For example, if the UECS includes only UEs capable of linear joint processing, the master UE will report a lower / worse joint CQI (in the joint CSI report) than if at least one UE is capable of nonlinear joint processing.

[0009] An example embodiment of these techniques is a method in a base station communicatively connected to a group including a first UE and a second UE. The method includes determining, by processing hardware of the base station, a CSI process configuration for the group and sending a control signal including the CSI process configuration to the group. The method also includes sending a reference signal to the group according to the CSI process configuration. The method also includes, in response to sending the reference signal to the group, receiving an indication of a joint channel state of the group from at least one UE of the group.

[0010] Another example embodiment of the techniques is a base station comprising hardware and configured to implement the above method.

[0011] An additional embodiment of these techniques is a method in a first UE of a group including a first UE and a second UE. The method includes receiving a reference signal from a base station, and determining, by processing hardware of the first UE, a first indication of a UE-specific channel state based on the reference signal. The method also includes receiving, from a second UE via a local wireless network, a second indication of a UE-specific channel state determined by the second UE based on the reference signal. The method also includes determining, by the processing hardware and based on at least the first indication of the UE-specific channel state and the second indication of the UE-specific channel state, an indication of a joint channel state. The method also includes sending the indication of the joint channel state to the base station.

[0012] Another example embodiment of the techniques is a UE including hardware and configured to implement the above methods.

[0013] An additional embodiment of these techniques is a method in a first UE of a group including a first UE and a second UE. The method includes receiving a reference signal from a base station, and determining, by processing hardware of the first UE, an indication of a UE-specific channel state based on the reference signal. The method also includes sending the indication of the UE-specific channel state to the second UE via a local wireless network. The method also includes receiving an indication of a joint channel state from the second UE via the local wireless network, and sending the indication of the joint channel state to the base station.

[0014] Another example embodiment of the techniques is a UE including hardware and configured to implement the above methods. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 An example communication system is shown in which the joint channel state feedback technique of a user equipment coordination set (UECS) of the present disclosure may be implemented;

[0016] Figure 2 An example antenna arrangement to support multiple-input multiple-output (MIMO) communications between a UE and a base station is shown;

[0017] Figure 3A and Figure 3B is a message diagram of an example scenario in which a UE of a UECS sends joint reception capability and status information of the UECS to a base station;

[0018] Figure 4 is a message diagram for a more specific example scenario in which one UE of the UECS reports a poor channel quality indicator (CQI) to a primary UE;

[0019] Figure 5 is a flow chart of an example method for providing an indication of a joint channel state to a base station, which example method may be performed by a UE acting as a master UE. Figure 1 Implementation in UE;

[0020] Figure 6 is a flow chart of another example method for providing an indication of a joint channel state to a base station, which example method may be used in a UE that is not acting as a master UE. Figure 1 Implementation in UE;

[0021] Figure 7 is a flow chart of an example method for obtaining joint channel state feedback from a UECS, which example method may be used in Figure 1 is implemented in the base station. DETAILED DESCRIPTION

[0022] Figure 1An example communication system 100 is shown in which the joint channel state feedback techniques of a user equipment coordination set (UECS) of the present disclosure may be implemented. Communication system 100 includes a plurality of user equipments (UEs), including UE 102, UE 104, and UE 106. Each of UE 102, 104, and 106 may be any suitable device capable of wireless communication (e.g., any of the exemplary user equipment discussed below following the description of the figures). In the depicted scenario, UE 102, 104, and 106 form a UE group 108, also referred to herein as UECS 108. Although Figure 1 Three UEs are depicted, but the UECS 108 may include any number (greater than one) of UEs. The UECS 108 may locally coordinate uplink (UL) transmissions and downlink (DL) receptions to and from the base station 114 using techniques described in further detail below.

[0023] For example, the base station 114 is communicatively connected to the core network (CN) 110 via an NG interface. In some implementations, the base station 114 is a 5G new radio (NR) base station operating as a gNodeB (gNB), and the CN 110 is a 5G core network (5GC). However, in other implementations, the communication system 100 may include one or more base stations operating according to other types of radio access technologies (RATs) besides NR, and these base stations may be connected to other types of CNs. The CN 110 may be, for example, a 5G core network (5GC), a less advanced core network (e.g., an evolved packet core (EPC)), or conversely, a more advanced core network.

[0024] Base station 114 is associated with RAN 112 and provides coverage for cell 116. Figure 1 Base station 114 is depicted as being associated with only one cell 116, but it should be understood that base station 114 may also cover cells not in the Figure 1 1. In addition, the RAN 112 may include any suitable number of base stations that jointly support one or more RATs. When operating within the cell 116, each UE (such as UE 102) may be communicatively connected to the RAN 112 via the base station 114, and in turn may be communicatively connected to the CN 110 via the RAN 112.

[0025] UE 102 is equipped with at least processing hardware 130, a UE group management unit 136, at least one antenna 140, and a local wireless network interface 150. Figure 1Only UE 102 is depicted as including processing hardware 130, UE group management unit 136, antenna 140, and local wireless network 150, but it should be understood that each of UE 104 and UE 106 also includes the same or similar elements. Processing hardware 130 may include one or more general-purpose processors (e.g., CPUs) and at least one non-transitory computer-readable memory storing instructions executable on one or more general-purpose processors and / or special-purpose processing units (such as wireless communication chipsets).

[0026] The processing hardware 130 includes a physical (PHY) layer controller 132. The PHY layer controller 132 is responsible for internal processes at the PHY layer 182 of the wireless communication protocol stack 180, such as demodulating and decoding downlink control and data signals received from a base station (e.g., base station 114), encoding and modulating uplink control and data signals, and so on. In addition, the PHY layer controller 132 includes a channel state information (CSI) controller 133. As referred to herein, the CSI may conform to the CSI defined by a current standard (e.g., 3GPP Technical Specifications 36.312 and / or 38.312), or may more generally correspond to channel state information. The CSI controller 133 supports functionality related to determining receive capability information, joint receive capability information, CSI reporting, and / or joint CSI reporting, as described below with reference to Figure 3A-Figure 4 described.

[0027] The processing hardware 130 also includes an upper layer controller 134. The upper layer controller 134 is responsible for internal processes at the corresponding upper layer 184 above the PHY layer 182 of the protocol stack 180, such as aggregating uplink data of the UECS 108 and deaggregating downlink data of the UECS 108. The upper layer 184 can be, for example, a medium access control (MAC) layer, a packet data convergence protocol (PDCP) layer, or a radio link control (RLC) layer. For example, the upper layer controller 134 can support channel access, addressing, quality of service (QoS) and other functions of the MAC layer, user plane data transmission, control plane data transmission, integrity protection and other functions of the PDCP layer, or segmentation and other functions of the RLC layer. Although not described in detail, the upper layer controller 134 may be a plurality of layers including ... Figure 1 , but the processing hardware 130 may also include controllers for each of a plurality of other layers, such as a radio resource control (RRC) controller and an MM controller associated with the RRC and mobility management (MM) layers of the protocol stack 180, respectively.

[0028] The UE group management unit 136 of the UE 102 is generally responsible for functions related to UE grouping functions, such as sharing signals with other UEs (e.g., UE 104 and UE 106) of the UECS 108, as discussed further below. The UEs of the UECS 108 can communicate with each other through at least one local wireless network, which is not described in detail in the following description. Figure 1 The local wireless network can correspond to a personal area network (PAN), near field communication (NFC), Bluetooth TM , wireless local area network (WLAN), or any other suitable communication standard or protocol. The local wireless network interface 150 of the UE 102 generally facilitates communication with other UEs of the UECS 108 on the local wireless network. The UE group management unit 136 may be implemented jointly by the processing hardware 130 and the local wireless network interface 150, or may be implemented by a processor not in the local wireless network. Figure 1 102 is implemented by another controller of the UE 102 shown in FIG.

[0029] The base station 114 includes at least one antenna 170 for communicating with other elements of the communication system 100. The base station 114 also includes processing hardware 160, which may include one or more general purpose processors (e.g., CPUs) and at least one non-transitory computer-readable memory storing instructions executable on one or more general purpose processors and / or special purpose processing units (such as wireless communication chipsets). Similar to the processing hardware 130 of the UE 102, the processing hardware 160 may include a PHY layer controller 162 and an upper layer controller 164 corresponding to the PHY layer 182 and the upper layer 184 of the protocol stack 180, respectively. The controllers 162 and 164 may perform functions similar to or corresponding to the controllers 132 and 134, but from the perspective of the base station 114 rather than the UE 102. For example, the PHY layer controller 162 may encode and modulate downlink control and data signals sent to the UECS 108, and the upper layer controller 164 may aggregate downlink data of the UECS 108 and deaggregate uplink data received from the UECS 108.

[0030] In addition, PHY layer controller 162 includes CSI process controller 163. CSI process controller 163 may perform similar functions as CSI controller 133, but from the perspective of base station 114 rather than UE 102. For example, CSI process controller 163 defines the CSI process configuration that base station 114 will send to UECS 108, as described below with reference to Figure 3B and Figure 4 Descriptive.

[0031] The upper layer controllers 134 and 164, the PHY layer controllers 132 and 162, the CSI controller 133 and the CSI process controller 163, and the UE group management unit 136 can all be implemented using any suitable combination of hardware, software, and / or firmware. In an example implementation, the controllers 132, 133, 134, 162, 163, and 164 and / or the UE group management unit 136 are instruction sets that the corresponding processing hardware 130 or 160 runs to perform the various functions described herein.

[0032] As described above, the UE 102 includes at least one antenna 140 for receiving signals transmitted to the UE 102 and transmitting signals from the UE 102. The UE 102 may be equipped with multiple antennas 140 to support multiple-input multiple-output (MIMO) communications, or may be equipped with only a single antenna 140. For example, the UE 102 may have two transmit-receive antennas to support two simultaneous transmit / receive paths, or may have separate transmit and receive antennas, etc. Figure 2 MIMO communications between the base station 114 and the UEs 102, 104 are discussed. Additionally, as discussed further below, the base station 114 (eg, the PHY controller 162) can determine an antenna port for each physical antenna 140 of the UE 102 at the PHY layer 182.

[0033] Initially, as described above, UEs 102, 104, and 106 and those not in Figure 1 108. The UECS 108 may be formed in a variety of ways depending on the implementation and / or scenario. For example, in some implementations, the UEs may coordinate with each other locally to form the UECS 108 with little or no input from the base station 114. The UEs 102, 104, and 106 may choose to coordinate with each other based on, for example, their respective distances from each other and / or based on other suitable factors. For example, based on the relative processing capabilities of the UEs 102, 104, and 106 and / or other factors (e.g., proximity to the base station 114), the UEs 102, 104, and 106 may jointly select a coordination or "master" UE from the UEs 102, 104, and 106.

[0034] In other implementations, the base station 114 directs or partially directs the formation of the UECS 108. For example, the base station 114 detects the UEs 102, 104, and 106 within the cell 116 and assigns each UE to the UECS 108. The base station 114 may also request the UEs 102, 104, and 106 to form the UECS 108, and only assign the specific UE to the UECS 108 if the specific UE responds with a confirmation and / or approval of the request. The base station 114 may select the UEs for the UECS 108 based on the location of each UE relative to the base station 114 and other UEs and / or other factors. The base station 114 may also select specific UEs for the UECS 108 depending on beam scheduling, for example, the base station 114 only selects UEs in the same beam. The base station 114 may also select which single UE will serve as the master UE of the UECS 108.

[0035] Grouping UEs into the UECS 108 can provide various benefits. For example, in some implementations, the UECS 108 can jointly receive downlink control and data signals from the base station 114, and jointly send uplink control and data signals to the base station 114. Because each UE of the UECS 108 is equipped with at least one antenna (e.g., the antenna 140 of the UE 102), the UECS 108 can utilize the antennas of the various UEs as a distributed antenna arrangement for both reception and transmission. Therefore, the UECS 108 can have reception and transmission capabilities that exceed the individual UEs 102, 104, and 106. In addition, if one UE of the UECS 108 experiences poor reception, the UE can rely on other UEs of the UECS 108 to receive information from the base station 114 and forward the information to the UE with poor reception. In addition, the UECS 108 can utilize the combined processing power of the UEs 102, 104, and 106 to demodulate data and control signals, thereby improving the reception of the UECS 108 as a whole.

[0036] The master UE may act as a "joint receiver" UE for performing the functions necessary to facilitate joint reception, or the master UE may delegate this responsibility by assigning another UE as the joint receiver UE. In some implementations, the base station 114 instructs the master UE to select a joint receiver UE, or directly assigns a joint receiver UE. In other implementations, the master UE selects a joint receiver UE with little or no input from the base station. The master UE may change which UE acts as the joint receiver UE depending on changing power and reception conditions and / or capabilities of the UEs in the UECS 108. Regardless of how the joint receiver UEs are selected or reallocated, the joint receiver UEs may use the following references to Figure 3B-Figure 4 Any of the various techniques described may be used to facilitate joint reception.

[0037] In some implementations of the communication system 100, the UECS 108 and the base station 114 utilize the distributed antenna arrangement of the UE by implementing multiple-input multiple-output (MIMO) communication for uplink and / or downlink. For both uplink and downlink, MIMO communication can increase the data rate (by utilizing spatial multiplexing, i.e., sending different data from different antennas) or the error rate (by utilizing spatial diversity, i.e., sending redundant data on different antennas).

[0038] exist Figure 2 In the example antenna arrangement 200 of FIG. 1 , the base station 114 includes four transmit-receive antennas 202, 204, 206, and 208, each antenna having its own transmit / receive circuitry in a radio frequency (RF) front end, the UE 102 includes two transmit-receive antennas 210 and 212, each antenna having its own transmit / receive circuitry in the RF front end, and the UE 104 also includes two transmit-receive antennas 214 and 216, each antenna having its own transmit / receive path in the RF front end. Therefore, each of the UEs 102 and 104 can support two downlink streams and two uplink streams, corresponding to two MIMO layers (2x2 MIMO communication). The base station 114 using its four transmit-receive antennas can support four MIMO layers. Although a single UE of the UEs 102 and 104 is only capable of 2x2 MIMO communication with the base station 114, the UEs 102 and 104 are combined as the UECS 108 and are capable of 4x4 communication with the base station 114. It should be understood that UEs 102 and 104 and / or base station 114 may instead have Figure 2 More or fewer antennas are shown, thereby supporting more or fewer MIMO layers.

[0039] In order to configure MIMO communication with UECS 108, base station 114 first determines the total number of antennas available to UECS 108 (i.e., UEs 102 and 104), as well as the signal quality of different streams between UECS 108 and base station 114. It should be understood that the number of different antennas of a UE or base station mentioned herein may refer to the number of physical antennas, or may refer to the number of antennas or antenna sets coupled to different RF front ends. Thus, for example, if both antennas are coupled to the same RF front end (e.g., for the purpose of generating a specific antenna radiation pattern), the combination of a patch antenna and a monopole antenna at a UE or base station may be "counted" as only one antenna.

[0040] In general, for the downlink, the base station 114 determines how to configure MIMO communications with a UE (e.g., UE 102) based on the CSI received from the UE 102. The base station 114 similarly defines a CSI process configuration that indicates the time and frequency resources that the base station 114 will use to send reference signals (e.g., CSI-RS) to the UECS 108. In some implementations, the UE 102 can use the reference signals (e.g., perform measurements on them) to estimate various parameters related to channel quality and estimate an appropriate MIMO or SISO configuration for the downlink, and send this information to the base station 114 in a CSI report.

[0041] The parameters included in the CSI report indicate how well the UE 102 (and more specifically, the antennas of the UE 102) is currently able to receive from the base station 114 (i.e., as a result of the channel conditions currently experienced at the antennas of the UE 102). For example, the CSI report may include an indication of how many streams or MIMO layers the UE 102 can currently process, thereby indicating the number of antennas available for reception in the UE 102. Examples of parameters that the UE 102 may include in the CSI report include a channel quality indicator (CQI), a rank indicator (RI), and a precoding matrix indicator (PMI). The CQI may indicate a modulation and coding scheme (MCS) (e.g., by including an MCS index).

[0042] For example, the RI specifies the number of recommended MIMO layers that the base station 114 should use when transmitting to the UE 102, and is based on the number of antennas available to the UE 102 for receiving MIMO streams. The PMI may suggest a suitable MIMO precoding matrix for the specified RI, and the CQI may specify a modulation and coding scheme (MCS) suitable for the specified PMI. In addition, the CSI report may also include a CSI-RS resource indicator (CRI) for identifying the beam on which the CSI report is based (e.g., if the base station 114 transmits reference signals on multiple beams). In an implementation where the base station 114 is a gNB, the UE 102 may also include in the CSI report a layer indicator (LI) for notifying the base station 114 which MIMO layer the UE 102 has identified as the best layer, as well as a synchronization signal block (SSB) physical broadcast channel (PBCH) block resource indicator (SSBRI) and layer 1 reference signal received power (L1-RSRP), which the base station 114 may use in beam management and mobility procedures.

[0043] if Figure 2108, the base station 114 may transmit a reference signal to each of the UEs 102 and 104 according to a CSI process configuration defined by the base station 114 for each of the UEs 102 and 104 (i.e., where different time / frequency resources are used for the two reference signals). Each of the UEs 102 and 104 receives its respective reference signal, processes the respective reference signal, and transmits a UE-specific CSI report to the base station 114 (i.e., corresponding only to the individual UE). However, if the UEs 102 and 104 are included in the UECS 108, the base station 114 may define a single CSI process configuration for the UECS 108 as a whole, and transmit reference signals according to the CSI process configuration defined for the group. The UECS 108 may jointly receive and process control signals including the CSI process configuration, and each UE may receive and process the reference signal (e.g., perform measurements on it). Based on the CSI reports generated by the individual UEs of UECS 108, UECS 108 determines a joint CSI report that may (depending on the current channel conditions of each UE) reflect a greater reception capability than that possible for any individual UE.

[0044] Use the following reference Figure 3A-Figure 7 According to the discussed techniques, the UEs of the UECS 108 may determine a joint CSI report based on the joint reception capability of the group and send the joint CSI report together to the base station 114. Figure 3A-Figure 7 and the accompanying description specifically relates to Figure 1 UE 102, 104, 106, UECS 108 and base station 114, but it should be understood that other components and / or in addition to Figure 1 The following technology is implemented in a system other than the communication system 100.

[0045] Figure 3A and Figure 3B 1 and 1 , a message diagram of a first example scenario 300 in which a UE of the UECS 108 sends joint reception capability and status information of the UECS 108 to the base station 114. In the example scenario 300, the UE 102 acts as a master UE of the UECS 108, the UE 104 acts as a joint receiver UE 104 of the UECS 108, and the UE 106 is another UE in the UECS 108 that is neither a master UE nor a joint receiver. It should be understood that in some scenarios and / or implementations, the UEs 102, 104, and / or 106 may have other roles in the UECS 108. Furthermore, in some scenarios and / or implementations, the master UE 102 is not assigned a joint receiver UE, but performs a joint reception function.

[0046] When a UE in UECS 108 (such as joint receiver UE 104) receives a signal via a local wireless network (e.g., the above combined Figure 1 The example scenario 300 begins when a master UE 102 (e.g., a local wireless network discussed above) sends 302 its own UE-specific receive capability information to a master UE 102. For each UE, the UE-specific receive capability information may indicate, for example, how many MIMO layers the UE can process or how many MIMO layers can currently be processed under current channel conditions. For example, a UE with two antennas may report a 2-layer, 2x2 MIMO processing capability. In some cases, the UE-specific receive capability information indicates that the corresponding UE only supports SISO processing. In some implementations, the UE-specific receive capability information also indicates whether the UE can perform linear or nonlinear processing on a received MIMO (or SISO) signal. More generally, the UE-specific receive capability information may indicate the number of antennas of the UE or include an indication of the number of antenna ports that the base station 114 can determine for the UE. In addition, the UE-specific receive capability information reported by each UE may be specific to each of one or more carrier frequency bands. For example, a UE may report a first number of MIMO layers that can be used to process signals carried on a first frequency band (e.g., a low frequency band), and a different second number of MIMO layers that can be used to process signals carried on a different second frequency band (e.g., a mid frequency band).

[0047] Another UE (such as UE 106) may also send 304 its UE-specific reception capability information to the primary UE 102 via the local wireless network. Figure 3A UE 106 is depicted as transmitting 304 its UE-specific reception capability information after joint receiver UE 104, but the relative timing of the transmission is different than shown. For example, UE 106 may transmit 304 its information before or at the same time as joint receiver UE 104 transmits 302 its information. Furthermore, although in scenario 300 UE 104 and UE 106 transmit 302, 304 their UE-specific reception capability information directly to master UE 102, master UE 102 may instead receive UE-specific reception capability information from UE 104 and UE 106 in other ways. For example, in some scenarios, UE 106 may first transmit its UE-specific reception capability information to joint receiver UE 104 or another UE of UECS 108, and joint receiver UE 104 or other UE may forward information corresponding to UE 106 to master UE 102 (e.g., only the information, or the information combined with the UE-specific reception capability information of the forwarding UE). For example, if UE 106 has a poor wireless local connection to primary UE 102, but can use a different wireless local communication technology (such as Bluetooth TM) to better communicate with the joint receiver UE 104 or another UE of the UECS 108. Depending on the channel conditions and the capabilities of the individual UEs, the UE-specific reception capability information of a particular UE may be sent through several UEs of the UECS 108 before reaching the master UE 102.

[0048] By analyzing the UE-specific receive capability information received from other UEs of the UECS 108, as well as its own UE-specific receive capability, the master UE 102 determines 306 joint receive capability information corresponding to the receive capability of the UECS 108 as a whole (i.e., when jointly receiving signals from the BS 114). In at least some scenarios, the joint receive capability of the UECS 108 is different from the receive capability of any individual UE in the UECS 108. For example, the number of MIMO layers that the UECS 108 can process may be proportional to the number of UEs (and possibly UE antennas) in the UECS 108. For example, if the information received from the joint receiver UE 104 and UE 106 at events 302 and 304 indicates that each of the UE 104 and UE 106 currently supports 2-layer MIMO processing under current channel conditions, and if the master UE 102 itself supports 2-layer processing, the master UE 102 determines that the UECS 108 supports 6-layer MIMO processing.

[0049] Furthermore, in some implementations, the master UE 102 may delegate the task of determining 306 the joint reception capability information to the joint receiver UE 104 or another designated UE of the UECS 108. In such implementations, the master UE 102 collects the various UE-specific reception capability information and forwards the grouped information to the joint receiver UE 104 or other designated UEs, or informs other UEs of the UECS 108 to send their UE-specific reception capability information directly to the joint receiver UE 104 or other designated UEs.

[0050] In some implementations (not in Figure 3A ), after determining 306 the joint reception capability information, only the primary UE 102 sends an indication of the joint reception capability information to the base station 114. Alternatively, as Figure 3AAs shown, the master UE 102 can utilize the joint transmission capability of the UECS 108 to provide joint reception capability information to the base station 114. In such an implementation, the master UE 102 sends 308 an indication of the joint reception capability information to the UE 104 and the UE 106. The master UE 102 can select a joint transmission scheme and coordinate the joint transmission from the group in any suitable manner. For example, the master UE 102 can generate I / Q samples corresponding to the indication of the joint channel state and send these I / Q samples to the UE 104 and the UE 106 to facilitate the joint transmission. Then, the UEs of the UECS 108 (i.e., UE 102, UE 104, and UE 106) can act as distributed antenna transmitters and jointly send 310 an indication of the joint reception capability information to the base station 114. For the joint transmission 310, the UEs use their respective antennas to send the indication of the joint reception capability information to the base station 114 in a time-aligned, signal-aligned manner. Events 308 and 310 are in Figure 3A These incidents are collectively referred to as Incident 315.

[0051] The base station 114 then defines 316 a CSI process configuration for the UECS 108 based on the received joint receive capability information, such that the CSI process configuration is a joint CSI process configuration for the UECS 108 as a whole. To define the CSI process configuration, the base station 114 allocates resource elements for a reference signal (e.g., CSI-RS) that the base station 114 will later send to the UECS 108. More specifically, the CSI process configuration includes time domain and frequency domain information that the UECS 108 can use to prepare to receive the reference signal. The CSI process configuration may also include other information, such as an indication of what information the base station 114 wants to receive from the UECS 108 when the UECS 108 provides a joint CSI report in response to the reference signal. For example, the CSI process configuration may include an indication of a PHY layer 182 parameter that the base station 114 seeks from the UECS 108.

[0052] After defining 316 the CSI process configuration for the UECS 108, the base station 114 sends 318 a control signal including the CSI process configuration to the UECS 108, such as Figure 3B As shown. In some implementations, the base station 114 sends 318 a control signal to the UECS 108 via a single control channel (e.g., PDCCH) specific to the UECS 108. The control signal including the CSI process configuration may be an RRC message or a higher level message such as a MAC message, an RLC message, or a PDCP message. In some implementations and scenarios, the base station 114 includes the CSI process configuration in downlink control information (DCI) included in the control signal.

[0053] Each UE of the UECS 108 can receive the same control signal (channel conditions permitting), so that the UECS 108 effectively operates as a distributed antenna receiver. If a particular UE encounters problems receiving signals from the base station 114, but can still communicate with one or more other UEs in the UECS 108, the other UEs of the UECS 108 can receive the control signal, process the control signal in a manner discussed below, and forward the processed control information to the UE using the wireless local connection.

[0054] In the example scenario 300, all UEs 102, UE 104, and UE 106 receive a control signal sent 318 by base station 114. Thus, each of UE 106, UE 104, and master UE 102 generates (respectively 320, 322, and 324) corresponding I / Q samples by demodulating the received control signal. The I / Q samples represent the control signal after the RF signal is down-converted and demodulated into in-phase (I) and quadrature (Q) components. In the example scenario 300, UE 104 acts as a joint receiver UE that performs joint processing. Thus, via the local wireless network, UE 106 sends 328 its I / Q samples to the joint receiver UE 104, and master UE 102 sends 326 its I / Q samples to the joint receiver UE 104.

[0055] After the joint receiver UE 104 receives the I / Q samples from the UE 102, UE 106, the joint receiver UE 104 decodes 330 the CSI process configuration by processing the I / Q samples received from the UE 102, UE 106 and the I / Q samples generated 322 by the joint receiver UE 104 itself. To decode 330 the CSI process configuration, the joint receiver UE 104 first time-aligns and combines (e.g., sums) the I / Q samples of the UEs 102, 104, and 106. By combining the I / Q samples, the joint receiver UE 104 produces a linear power gain and can obtain a stronger signal than that received by any individual UE, thereby increasing the likelihood that the joint receiver UE 104 will be able to successfully decode 330 the CSI process configuration (and the DCI as a whole, if the CSI process configuration is included in the DCI).

[0056] exist Figure 3BIn the illustrated implementation, the joint receiver UE 104 then distributes the decoded CSI process configuration by sending (332, 334) the CSI process configuration to other UEs (106, 102) in the UECS 108 via the local wireless network. In other implementations and / or scenarios, the joint receiver UE 104 sends 334 the CSI process configuration to the master UE 102 but not to the UE 106, and the master UE 102 then sends the CSI process configuration to each UE in the UECS 108 (possibly excluding the joint receiver UE 104) or to at least one other UE in the UECS 108, which then further distributes the CSI process configuration (e.g., forming part of a transmission chain within the local wireless network). Events 320 to 336 are described in detail in detail in detail. Figure 3B These incidents were collectively referred to as Incident 337.

[0057] After receiving the CSI process configuration, each of the UE 102, UE 104, and UE 106 can configure itself according to the information in the CSI process configuration in order to prepare to receive the reference signal from the base station 114. That is, when the base station 114 sends 336 a reference signal (e.g., CSI-RS) to the UECS 108 at some later point, the UE 102, UE 104, and UE 106 know the timing and frequency of the reference signal and can therefore detect and measure the reference signal. For ease of explanation, this discussion refers to the base station 114 sending 336 a single "reference signal". However, it should be understood that the base station 114 can send a collection of multiple reference signals to the UECS 108 as a whole. For example, the base station 114 can send a different reference signal from each antenna of the base station 114 (e.g., of the multiple antennas 170).

[0058] Each UE that detects / receives the reference signal (i.e., UE 106, joint receiver UE 104, and master UE 102 in scenario 300) determines (338, 340, and 342, respectively) a UE-specific CSI report based on the reference signal. Figure 2 As discussed, the UE-specific CSI report includes various information estimated by the UE based on how well the UE is able to receive a reference signal. For example, the UE-specific CSI report may include a CQI, PMI, and / or RI determined by an individual UE based on its measurements of a reference signal, where the CQI indicates an MCS supported by the individual UE. The information in the UE-specific CSI report indicates how many MIMO layers the individual UE can process and / or how many antennas the UE has available for reception.

[0059] UE 104 and UE 106 send (344, 346) their respective UE-specific CSI reports to master UE 102, which processes the UE-specific CSI reports to determine 348 a joint CSI report for UECS 108. Alternatively, master UE 102 may assign another UE (e.g., joint receiver UE 104) of UECS 108 to perform the processing to determine the joint CSI report. For example, if master UE 102 assigns joint receiver UE 104 to determine the joint CSI report, UE 106 and master UE 102 send their respective UE-specific CSI reports to joint receiver UE 104.

[0060] The joint CSI report may include the same type of parameters as the individual, UE-specific CSI reports, but the values ​​of these parameters reflect the current channel quality and current reception capabilities of the UECS 108 as a whole. In some implementations and scenarios, the joint CSI report is different from the UE-specific CSI report of any individual UE. In some implementations, the parameters of the joint CSI report indicate how many streams or MIMO layers the base station 114 should use to send to the UECS 108. One or more parameters in the joint CSI report may depend on the joint processing capabilities of the UECS 108 (e.g., determined 306 by the master UE 102). For example, if the UECS 108 only includes UEs capable of linear joint processing, the master UE 102 may determine a lower / worse joint CQI for the joint CSI report than if at least one UE is capable of nonlinear joint processing. In some implementations, the master UE 102 determines the joint CQI specifically based on the processing capabilities of the current joint receiver UE (i.e., in this example, based on whether the UE 104 is capable of nonlinear joint processing). Furthermore, the master UE 102 may select a particular UE as a joint receiver UE based at least in part on the UE being capable of non-linear joint processing, particularly if other available UEs of the UECS 108 are only capable of linear joint processing.

[0061] As another example, the joint CSI report may also include (e.g., within the CQI of the joint CSI report) a recommended MCS that may be supported by the UECS 108 during joint reception, and / or otherwise indicate a suitable MCS for the UECS 108. The recommended MCS generally depends on the joint reception capability information of the UECS 108. That is, in at least some scenarios, the UECS 108 may successfully (jointly) receive signals from the base station 114 using the recommended MCS, but each individual UE of the UECS 108 may not be able to do so.

[0062] In some implementations (not in Figure 3B), after the master UE 102 (or another UE of the UECS 108, if the master UE 102 has delegated the determination of the joint CSI report) determines 348 the joint CSI report, only the master UE 102 sends the joint CSI report to the base station 114. Alternatively, as Figure 3B As depicted in FIG. 1 , the primary UE 102 may utilize the joint transmission capability of the UECS 108 to provide a joint CSI report to the base station 114 (e.g., similar to Figure 3A 315). In such an implementation, master UE 102 first sends 350 a joint CSI report to UE 104 and UE 106. As discussed with reference to event 308, master UE 102 can facilitate the joint transmission by generating I / Q samples corresponding to the joint CSI report and sending these I / Q samples to UE 104 and UE 106. Then, the UEs of UECS 108 (i.e., UE 102, UE 104, and UE 106) act as distributed antenna transmitters to jointly send 352 the joint CSI report to base station 114. Events 350 and 352 are Figure 3B These incidents are collectively referred to as Incident 355.

[0063] In some implementations, each time the base station 114 defines a new CSI process configuration for the UECS 108, Figure 3B For example, the sequence of events may be repeated because base station 114 has received a new indication of joint receive capability information from UECS 108 (e.g., similar to event 310), which may reflect a new UECS composition of the UE, or because the base station has received a joint CSI report from UECS 108 for a channel configuration that requires an update (e.g., similar to event 352).

[0064] Figure 4 4 is a message diagram for a more specific example scenario in which one UE (UE 106) of UECS 108 reports a poor CQI to master UE 102. In example scenario 400, UECS 108 includes master UE 102, joint receiver UE 104, and UE 106. As previously described, although joint receiver UE 104 is shown as a separate UE, in other scenarios, master UE 102 also performs the function of a joint receiver, and thus UE 104 does not exist or behaves similarly to a non-master, non-joint receiver UE 106. Similar to 302, scenario 400 begins when UE 104 sends 402 its UE-specific reception capability information to master UE 102. In scenario 400, UE 104 has two transmit-receive antennas and an RF front end (e.g., as shown in FIG. 4 ). Figure 2), and thus its UE-specific reception capability information indicates that UE 104 can support 2-layer (2x2) MIMO. Similar to 304, UE 106 also sends 404 its UE-specific reception capability information to primary UE 102. In scenario 400, UE 106 also has two transmit-receive antennas (e.g., Figure 2 108 ), and its UE-specific reception capability information similarly indicates that UE 106 can support 2-layer MIMO. Master UE 102 analyzes the UE-specific reception capability information received from UE 104 and UE 106 to determine 406 joint reception capability information of UECS 108. Combining the capabilities of UE 104 and UE 106 with its own 2-layer reception capability, master UE 102 determines 406 joint reception capability information indicating 6-layer (6x6) MIMO capability.

[0065] At event 415, UECS 108 then distributes the 6x6 joint reception capability information within the group and jointly sends an indication of the 6x6 joint reception capability information to base stations 114. For example, event 415 may be similar to Figure 3A 315. The base station 114 then defines 416 a CSI process configuration for the UECS 108 based on the 6x6 joint reception capability reported by the UECS 108, and sends 418 the CSI process configuration to the UECS 108. At event 437, the UEs of the UECS 108 jointly receive the CSI process configuration, prepare to receive reference signals using the CSI process configuration, and receive the reference signals according to the CSI process configuration. For example, event 437 may be similar to Figure 3A Event 337.

[0066] UE 106, UE 104, and UE 102 use (e.g., measure) the reference signal to determine (438, 440, and 442, respectively) their respective UE-specific CSI reports. In scenario 400, UE 106 is experiencing poor channel conditions (e.g., due to fading, multipath, distance from base station 114, etc.), and therefore determines 438 a CSI report that includes a poor CQI. For example, UE 106 may measure a weak / noisy reference signal on either of its two antennas (e.g., due to a low signal-to-noise ratio (SNR) or signal-to-interference-plus-noise ratio (SINR)). In contrast, in scenario 400, UE 104 is not experiencing poor channel conditions, and therefore determines 440 a CSI report that includes a better CQI.

[0067] UE 104 and UE 106 send (444, 446) their respective UE-specific CSI reports to master UE 102, which processes the received UE-specific CSI reports and its own CSI report to determine 448 a joint CSI report for UECS 108. Because UE 106's CSI report indicates a poor CQI, the joint CSI report indicates that UECS 108 has only 4-layer (4x4) MIMO reception capability, even though (under better conditions) UECS 108 theoretically has 6-layer MIMO reception capability, as indicated by the joint reception capability information previously determined 406 by master UE 102.

[0068] At event 455, primary UE 102 distributes a joint CSI report to UECS 108, and UECS 108 jointly sends a joint CSI report indicating 4-layer MIMO reception capability to base station 114. For example, event 455 may be similar to Figure 3B The base station 114 may then adjust 456 any future transmissions and / or resource allocations of the UECS 106 to reflect the 4-layer MIMO reception capability of the UECS 108. In some implementations, the base station 114 may define a new CSI process configuration based on the received joint CSI report and send the new CSI process configuration to the UECS 108, which may be similar to Figure 3A and Figure 3B Events 316 and 318.

[0069] For example, based on the received joint CSI report, base station 114 may send 458 a signal (which may be a control signal or a data signal) to UECS 108 based on the current 4-layer MIMO reception capability of UECS 108. Due to its poor CQI, UE 106 cannot effectively participate in the joint reception. Instead, UE 104 and UE 102 jointly receive 4x4 MIMO transmissions by operating as distributed antenna receivers with a smaller number of antenna elements. Therefore, only UE 104 and UE 102 generate (462, 464) I / Q samples by demodulating the signals. If UE 104 acts as a joint receiver UE 104, as is the case in scenario 400, UE 102 sends 466 its I / Q samples to the joint receiver UE 104. Similar to Figure 3A At event 330, the joint receiver UE 104 may then decode the signal content (control information or data, depending on the signal type) by processing the I / Q samples. The joint receiver UE 104 may then send (470, 472) the control information or data to UE 106 and UE 102.

[0070] Figure 5is a flow chart of an example method 500 for sending an indication of a joint channel state to a base station (eg, base station 114), which example method may be performed at Figure 1 The UE executing method 500 may act as a master UE of the UECS (e.g., Figure 3A-Figure 4 In some implementations, the UE may also act as a joint receiver UE. The method 500 begins at block 502, where the UE receives a reference signal (e.g., Figure 3B At block 504, based on the reference signal, the UE determines a first indication of a UE-specific channel state (e.g., Figure 3B Event 342 or Figure 4 Next, at block 506, the UE receives a second indication of a UE-specific channel state from a second UE (eg, Figure 3B Event 344 or 346, or Figure 4 event 444 or 446).

[0071] At block 508, the UE determines an indication of a joint channel state (eg, Figure 3B Event 348 or Figure 4 Event 448 of UECS). At block 510, the UE sends an indication of a joint channel state to the base station. The UE may send the indication of a joint channel state to the base station itself (e.g., a joint CSI report) or may distribute the indication of a joint channel state to other UEs of the UECS, which jointly send the indication of a joint channel state to the base station (e.g., a joint CSI report). Figure 3B Event 355 or Figure 4 Event 455).

[0072] Figure 6 is a flow chart of an example method 600 for sending an indication of a joint channel state to a base station (eg, base station 114), which example method may be performed at Figure 1 The UE executing method 600 may act as a joint receiver UE of UECS 108 (e.g., Figure 3A and Figure 3B 104) or another UE that is not a joint receiver UE or a master UE acting as a UECS 108 (e.g., Figure 3A and Figure 3B UE 106).

[0073] Method 600 begins at block 602, where a UE receives a reference signal (e.g., Figure 3BAt block 604, based on the reference signal, the UE determines an indication of a UE-specific channel state based on the reference signal (e.g., Figure 3B Event 340 or Figure 4 In some implementations, blocks 602 and 604 include receiving and processing, respectively, a set of multiple reference signals (e.g., one reference signal per base station antenna, etc.). Next, at block 606, the UE sends an indication of a UE-specific channel state to a second UE (e.g., Figure 3B Event 344 or Figure 4 Event 444).

[0074] At block 608, the UE receives an indication of the joint channel state from the second UE (eg, Figure 3B At block 610, the UE sends an indication of the joint channel state to the base station (e.g., Figure 3B Event 352).

[0075] Figure 7 is a flow chart of an example method 700 for sending a CSI process configuration to a UECS (e.g., UECS 108) and receiving an indication of a joint channel state from the UECS, which example method may be performed at a base station (e.g., Figure 1 Method 700 begins at block 702, where the base station determines a CSI process configuration for a UECS (e.g., Figure 3A Event 316 or Figure 4 At block 704, the base station sends a control signal including a CSI process configuration to the UECS (e.g., Figure 3B Event 318 or Figure 4 Next, at block 706, the base station sends a reference signal to the UECS according to the CSI process configuration (e.g., Figure 3B Event 336 or Figure 4 In some implementations, block 706 includes sending a set of multiple reference signals (e.g., one reference signal per base station antenna, etc.). At block 708, the base station receives an indication of a joint channel state of the UECS from at least one UE in the group of UEs (e.g., Figure 3B Event 354 or Figure 4 Event 455).

[0076] All aspects

[0077] Aspect 1 - A method in a base station communicatively connected to a group including a first user equipment (UE) and a second UE, the method comprising: determining, by processing hardware of the base station, a channel state information (CSI) process configuration for the group; sending a control signal including the CSI process configuration to the group; sending a reference signal to the group according to the CSI process configuration; and receiving an indication of a joint channel state of the group from at least one UE of the group in response to sending the reference signal to the group.

[0078] Aspect 2-The method of Aspect 1, wherein the indication of the joint channel state indicates at least a multiple-input multiple-output (MIMO) reception capability of the group.

[0079] Aspect 3 - The method of any of aspects 1-2, wherein the indication of the joint channel state indicates at least antenna availability of the group.

[0080] Aspect 4 - the method of any one of Aspects 1-3, wherein the indication of the joint channel state comprises at least one of a precoding matrix indicator (PMI), a rank indicator (RI), or a modulation and coding scheme (MCS) index.

[0081] Aspect 5 - the method of any one of Aspects 1-4, wherein sending a reference signal according to the CSI process configuration includes sending a reference signal according to one or both of (i) time domain information included in the CSI process configuration and (ii) frequency domain information included in the CSI process configuration.

[0082] Aspect 6 - the method of any one of Aspects 1-5, wherein sending the control signal comprises sending a medium access control (MAC) layer message, a radio link control (RLC) layer message, or a packet data convergence protocol (PDCP) layer message.

[0083] Aspect 7 - The method of any one of Aspects 1-5, wherein sending the control signal comprises sending a radio resource control (RRC) layer message.

[0084] Aspect 8 - The method of any one of Aspects 1-7 further includes: before sending the control signal, receiving joint reception capability information of the group from at least one UE of the group, wherein determining the CSI process configuration is at least partially based on the joint reception capability information.

[0085] Aspect 9-The method of Aspect 8, wherein the joint reception capability information indicates how many multiple-input multiple-output (MIMO) layers the group supports.

[0086] Aspect 10 - The method of any one of aspects 1-9, wherein receiving the indication of the joint channel state comprises receiving a joint channel quality indicator (CQI) for the group.

[0087] Aspect 11 - A base station comprising hardware and configured to perform the method of any of aspects 1-10.

[0088] Aspect 12 - A method in a first user equipment (UE) of a group including a first user equipment (UE) and a second UE, the method comprising: receiving a reference signal from a base station; determining, by processing hardware of the first UE, a first indication of a UE-specific channel state based on the reference signal; receiving, from a second UE via a local wireless network, a second indication of a UE-specific channel state determined by the second UE based on the reference signal; determining, by processing hardware, an indication of a joint channel state based on at least the first indication of the UE-specific channel state and the second indication of the UE-specific channel state; and sending an indication of the joint channel state to the base station.

[0089] Aspect 13-The method of Aspect 12, wherein sending an indication of the joint channel state to the base station includes: sending an indication of the joint channel state to the second UE via the local wireless network to send to the base station.

[0090] Aspect 14 - A method according to any one of Aspects 12-13, wherein the first indication of the UE-specific channel state, the second indication of the UE-specific channel state and the indication of the joint channel state respectively indicate at least the antenna availability of the first UE, the second UE and the group.

[0091] Aspect 15 - The method of any one of Aspects 12-14, wherein the indication of the joint channel state indicates at least the joint MIMO reception capability of the group.

[0092] Aspect 16 - the method of any one of Aspects 12-15, wherein the indication of the joint channel state comprises at least one of a precoding matrix indicator (PMI), a rank indicator (RI), or a modulation and coding scheme (MCS) index.

[0093] Aspect 17 - The method of any one of Aspects 12-16 also includes: before receiving the reference signal, receiving a control signal including a channel state information (CSI) process configuration from a base station, wherein the CSI process configuration includes one or both of (i) time domain information and (ii) frequency domain information of the reference signal.

[0094] The method of Aspect 18-Aspect 17 also includes: generating a first I / Q sample by the processing hardware by demodulating a received control signal; receiving a second I / Q sample corresponding to the control signal received by the second UE from the second UE via the local wireless network; and decoding the CSI process configuration by the processing hardware by processing at least the first I / Q sample and the second I / Q sample.

[0095] The method of Aspect 19-Aspect 17 also includes: generating I / Q samples by demodulating a received control signal by processing hardware; sending the I / Q samples to a second UE or a third UE of the group via a local wireless network; and receiving a decoded CSI process configuration from the second UE or the third UE via the local wireless network.

[0096] Aspect 20 - The method of any one of Aspects 17-19, wherein receiving the control signal comprises receiving a medium access control (MAC) layer message, a radio link control (RLC) layer message, or a packet data convergence protocol (PDCP) layer message.

[0097] Aspect 21 - The method of any one of Aspects 17-19, wherein receiving the control signal comprises receiving a radio resource control (RRC) layer message.

[0098] Aspect 22 - The method of any one of Aspects 17-21 also includes: before receiving the control signal, receiving UE-specific receiving capability information from a second UE via a local wireless network; determining, by processing hardware, joint receiving capability information of the group based at least on (i) the UE-specific receiving capability information from the second UE and (ii) the UE-specific receiving capability information of the first UE; and sending the joint receiving capability information to the base station.

[0099] Aspect 23-The method of Aspect 22, wherein sending the joint reception capability information to the base station includes: sending the joint reception capability information to the second UE via the local wireless network, so as to send it to the base station.

[0100] Aspect 24 - the method of any one of Aspects 22-23, wherein the joint reception capability information indicates how many multiple-input multiple-output (MIMO) layers the group supports.

[0101] Aspect 25 - A method of any one of Aspects 12-24, wherein determining an indication of a joint channel state comprises determining a joint channel quality indicator (CQI) based on (i) a first CQI included in a first indication of a UE-specific channel state and (ii) a second CQI included in a second indication of a UE-specific channel state.

[0102] Aspect 26-The method of Aspect 25, wherein determining the joint CQI is also based on whether at least one UE in the group supports non-linear joint processing.

[0103] Aspect 27 - A user equipment (UE), comprising hardware and configured to perform the method of any one of aspects 12-26.

[0104] Aspect 28 - A method in a first UE of a group including a first user equipment (UE) and a second UE, the method comprising: receiving a reference signal from a base station; determining, by processing hardware of the first UE, an indication of a UE-specific channel state based on the reference signal; sending an indication of the UE-specific channel state to the second UE via a local wireless network; receiving an indication of a joint channel state from the second UE via the local wireless network; and sending an indication of the joint channel state to the base station.

[0105] Aspect 29-The method of Aspect 28, wherein the indication of the UE-specific channel state indicates at least the antenna availability of the first UE, and the indication of the joint channel state indicates at least the antenna availability of the group.

[0106] Aspect 30 - The method of any one of Aspects 28-29, wherein the indication of the joint channel state indicates at least a joint MIMO reception capability of the group.

[0107] Aspect 31 - the method of any one of Aspects 28-30, wherein the indication of the joint channel state comprises at least one of a precoding matrix indicator (PMI), a rank indicator (RI), or a modulation and coding scheme (MCS) index.

[0108] The method of any one of Aspect 32-Aspects 28-31 further includes: before receiving the reference signal, receiving a control signal including a channel state information (CSI) process configuration from a base station, wherein the CSI process configuration includes one or both of (i) time domain information and (ii) frequency domain information of the reference signal.

[0109] The method of Aspect 33-Aspect 32 also includes: generating a first I / Q sample by the processing hardware by demodulating a received control signal; receiving a second I / Q sample corresponding to the control signal received by the second UE from the second UE via the local wireless network; and decoding the CSI process configuration by the processing hardware by processing at least the first I / Q sample and the second I / Q sample.

[0110] The method of Aspect 34-Aspect 32 also includes: generating I / Q samples by demodulating a received control signal by processing hardware; sending the I / Q samples to a second UE or a third UE of the group via a local wireless network; and receiving a decoded CSI process configuration from the second UE or the third UE via the local wireless network.

[0111] Aspect 35 - The method of any one of Aspects 32-34, wherein receiving the control signal comprises receiving a medium access control (MAC) layer message, a radio link control (RLC) layer message, or a packet data convergence protocol (PDCP) layer message.

[0112] Aspect 36 - The method of any one of Aspects 32-34, wherein receiving the control signal comprises receiving a radio resource control (RRC) layer message.

[0113] The method of any one of Aspect 37-Aspects 32-36 also includes: before receiving the control signal, sending UE-specific receiving capability information to the second UE via the local wireless network; receiving joint receiving capability information of the UE group from the second UE via the local wireless network; and sending the joint receiving capability information to the base station.

[0114] Aspect 38-The method of Aspect 37, wherein sending the joint reception capability information to the base station includes: sending the joint reception capability information to the second UE via the local wireless network to send to the base station.

[0115] Aspect 39 - the method of any one of Aspects 37-38, wherein the joint reception capability information indicates how many multiple-input multiple-output (MIMO) layers the group supports.

[0116] Aspect 40 - The method of any of Aspects 28-40, wherein receiving the indication of the joint channel state comprises receiving a joint channel quality indication (CQI).

[0117] Aspect 41 - A user equipment (UE) comprising hardware and configured to perform the method of any of aspects 28-40.

[0118] Additional considerations

[0119] The user equipment (e.g., UE 102) in which the technology of the present disclosure can be implemented can be any suitable device capable of wireless communication, such as a smart phone, a tablet computer, a laptop computer, a mobile game console, a point of sale (POS) terminal, a health monitoring device, a drone, a camera, a media streaming software dog (dongle) or another personal media device, a wearable device (such as a smart watch), a wireless hotspot, a femtocell base station or a broadband router. In addition, in some cases, the user equipment can be embedded in an electronic system (such as a head unit of a vehicle or an advanced driver assistance system (ADAS)). In addition, the user equipment can be operated as an Internet of Things (IoT) device or a mobile Internet device (MID). Depending on the type, the user equipment may include one or more general-purpose processors, a computer-readable memory, a user interface, one or more network interfaces, one or more sensors, etc.

[0120] Specific embodiments described in the present disclosure include logic or multiple components or modules. A module can be a software module (e.g., a code or machine-readable instruction stored on a non-transitory machine-readable medium) or a hardware module. A hardware module is a tangible unit that is capable of performing a specific operation and can be configured or arranged in a specific manner. A hardware module can include a dedicated circuit or logic that is permanently configured to perform a specific operation (e.g., as a dedicated processor, such as a field programmable gate array (FPGA) or an application-specific integrated circuit (ASIC), a digital signal processor (DSP), etc.). A hardware module can also include programmable logic or circuits (e.g., contained in a general-purpose processor or other programmable processor) that are temporarily configured by software to perform a specific operation. The decision to implement a hardware module in a dedicated and permanently configured circuit or in a temporarily configured circuit (e.g., configured by software) can be driven by cost and time considerations.

[0121] When implemented in software, the techniques may be provided as part of an operating system, a library used by multiple applications, a specific software application, etc. The software may be executed by one or more general-purpose processors or one or more special-purpose processors.

Claims

1. A method in a base station communicatively connected to a group comprising a first user equipment UE and a second UE, the method comprising: receiving, from at least one UE of the group, joint reception capability information of the group; determining, by the base station, a channel state information (CSI) process configuration for the group based at least in part on the joint receive capability information; sending a control signal including the CSI process configuration to the group; sending a reference signal to the group according to the CSI process configuration; as well as In response to sending the reference signal to the group, an indication of a joint channel state of the group is received from at least one UE of the group.

2. The method according to claim 1, wherein: The indication of the joint channel state indicates at least a multiple-input multiple-output (MIMO) receive capability of the group.

3. The method according to claim 1, wherein: The indication of the joint channel status indicates at least antenna availability of the group.

4. The method according to claim 1, wherein: The joint reception capability information indicates how many multiple-input multiple-output MIMO layers the group supports.

5. The method according to claim 1, wherein: Receiving the indication of the joint channel state includes receiving a joint channel quality indicator (CQI) for the group.

6. A base station comprising hardware and configured to perform the method according to any one of claims 1 to 5.

7. A method in a first UE of a group including a first user equipment UE and a second UE, the method comprising: sending the joint receiving capability information of the group to the base station; receiving, from the base station, a control signal including a channel state information (CSI) process configuration of the group; receiving a reference signal from the base station; determining, by the first UE based on the reference signal, a first indication of a UE-specific channel state; receiving, from the second UE via a local wireless network, a second indication of a UE-specific channel state determined by the second UE based on the reference signal; determining, by the first UE, an indication of a joint channel state based at least on the first indication of the UE-specific channel state and the second indication of the UE-specific channel state; as well as Sending an indication of the joint channel state to the base station.

8. The method according to claim 7, wherein: Sending an indication of a joint channel state to the base station includes: An indication of the joint channel state is sent to the second UE via a local wireless network for sending to the base station.

9. The method according to claim 7, wherein: The first indication of the UE-specific channel state, the second indication of the UE-specific channel state, and the indication of the joint channel state indicate at least antenna availability of the first UE, the second UE, and the group, respectively.

10. The method according to claim 7, wherein: The CSI process configuration includes one or both of (i) time domain information or (ii) frequency domain information of the reference signal.

11. The method according to claim 10, further comprising: Before receiving the control signal, receiving UE-specific receiving capability information from the second UE via a local wireless network; as well as The joint reception capability information of the group is determined by the first UE based at least on (i) UE-specific reception capability information from the second UE and (ii) UE-specific reception capability information of the first UE.

12. A method in a first UE of a group including a first user equipment UE and a second UE, the method comprising: sending the joint receiving capability information of the group to the base station; receiving, from the base station, a control signal including a channel state information (CSI) process configuration of the group; receiving a reference signal from the base station; determining, by the first UE, an indication of a UE-specific channel state based on the reference signal; sending an indication of the UE-specific channel state to the second UE via a local wireless network; receiving an indication of a joint channel state from the second UE via a local wireless network; and Sending an indication of the joint channel state to the base station.

13. The method according to any one of claims 7 to 12, wherein: The indication of the joint channel state indicates at least a joint MIMO reception capability of the group.

14. A user equipment UE, comprising hardware and configured to execute the method according to any one of claims 7 to 13.

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