Techniques for user equipment (UE)-indicated multi-user pairing in wireless communications
By enabling UE reporting of desirable MU pairing metrics, the UE assists the network entity in making dynamic scheduling decisions, reducing interference and maximizing system capacity in MU-MIMO wireless communication systems.
Patent Information
- Application Number
- PCT/CN2024/074856
- Authority / Receiving Office
- WO · WO
- Patent Type
- Applications
- Current Assignee / Owner
- Filing Date
- 2024-01-31
- Publication Date
- 2025-08-07
AI Technical Summary
Existing MU-MIMO scheduling in wireless communication systems, such as 5G NR, often fails to maximize system capacity due to suboptimal UE pairing decisions made by the network entity, leading to increased interference and reduced performance.
User Equipment (UE) is enabled to report desirable MU pairing metrics, allowing the network entity to make dynamic scheduling decisions by measuring and reporting interference levels from configured CSI-RS resources, thereby offloading the complexity of determining co-scheduled UEs to the UE side.
This approach improves MU-MIMO performance by reducing inter-UE interference, enhancing communication efficiency, and maximizing system capacity by pairing UEs with lower interference levels.
Smart Images

Figure CN2024074856_07082025_PF_FP_ABST
Abstract
Description
TECHNIQUES FOR USER EQUIPMENT (UE) -INDICATED MULTI-USER PAIRING IN WIRELESS COMMUNICATIONS
[0001] FIELD OF THE DISCLOSURE
[0002] Aspects of the present disclosure relate generally to wireless communication systems, and more particularly, to multi-input multiple-output (MIMO) wireless communications.
[0003] DESCRIPTION OF RELATED ART
[0004] Wireless communication systems are widely deployed to provide various types of communication content such as voice, video, packet data, messaging, broadcast, and so on. These systems may be multiple-access systems capable of supporting communication with multiple users by sharing the available system resources (e.g., time, frequency, and power) . Examples of such multiple-access systems include code-division multiple access (CDMA) systems, time-division multiple access (TDMA) systems, frequency-division multiple access (FDMA) systems, and orthogonal frequency-division multiple access (OFDMA) systems, and single-carrier frequency division multiple access (SC-FDMA) systems.
[0005] These multiple access technologies have been adopted in various telecommunication standards to provide a common protocol that enables different wireless devices to communicate on a municipal, national, regional, and even global level. For example, a fifth generation (5G) wireless communications technology (which can be referred to as 5G new radio (5G NR) ) is envisaged to expand and support diverse usage scenarios and applications with respect to current mobile network generations. In an aspect, 5G communications technology can include: enhanced mobile broadband addressing human-centric use cases for access to multimedia content, services and data; ultra-reliable-low latency communications (URLLC) with certain specifications for latency and reliability; and massive machine type communications, which can allow a very large number of connected devices and transmission of a relatively low volume of non-delay-sensitive information.SUMMARY
[0006] The following presents a simplified summary of one or more aspects in order to provide a basic understanding of such aspects. This summary is not an extensive overview of all contemplated aspects, and is intended to neither identify key or critical elements of all aspects nor delineate the scope of any or all aspects. Its sole purpose is to present some concepts of one or more aspects in a simplified form as a prelude to the more detailed description that is presented later.
[0007] According to an aspect, an apparatus for wireless communication is provided that includes a transceiver, one or more memories configured to, individually or in combination, store instructions, and one or more processors communicatively coupled with the one or more memories. The one or more processors are, individually or in combination, configured to execute the instructions to cause the apparatus to receive, from a network entity, multiple reference signals that each have a precoder of a different user equipment (UE) applied, and transmit, to the network entity and based on a measurement of each of the multiple reference signals, a multi-user (MU) report indicating at least a portion of the multiple reference signals for MU pairing the UE with one or more of the different UEs.
[0008] In another aspect, an apparatus for wireless communication is provided that includes a transceiver, one or more memories configured to, individually or in combination, store instructions, and one or more processors communicatively coupled with the one or more memories. The one or more processors are, individually or in combination, configured to execute the instructions to cause the apparatus to transmit multiple reference signals that each have a precoder of a different UE applied, receive, from a UE, a MU report indicating at least a portion of the multiple reference signals for MU pairing the UE with one or more of the different UEs, and schedule, based on the MU report, the UE and the one or more different UEs for MU-multiple-input multiple-output (MIMO) communications.
[0009] In another aspect, a method for wireless communications at a UE is provided that includes receiving, from a network entity, multiple reference signals that each have a precoder of a different UE applied, and transmitting, to the network entity and based on a measurement of each of the multiple reference signals, a MU report indicating at least a portion of the multiple reference signals for MU pairing the UE with one or more of the different UEs.
[0010] In another aspect, a method for wireless communications at a network entity is provided that includes transmitting multiple reference signals that each have a precoder of a different UE applied, receiving, from a UE, a MU report indicating at least a portion of the multiple reference signals for MU pairing the UE with one or more of the different UEs, and scheduling, based on the MU report, the UE and the one or more different UEs for MU-MIMO communications.
[0011] In a further aspect, an apparatus for wireless communication is provided that includes a transceiver, a memory configured to store instructions, and one or more processors communicatively coupled with the transceiver and the memory. The one or more processors are configured to execute the instructions to perform the operations of methods described herein. In another aspect, an apparatus for wireless communication is provided that includes means for performing the operations of methods described herein. In yet another aspect, a computer-readable medium is provided including code executable by one or more processors to perform the operations of methods described herein.
[0012] To the accomplishment of the foregoing and related ends, the one or more aspects comprise the features hereinafter fully described and particularly pointed out in the claims. The following description and the annexed drawings set forth in detail certain illustrative features of the one or more aspects. These features are indicative, however, of but a few of the various ways in which the principles of various aspects may be employed, and this description is intended to include all such aspects and their equivalents.BRIEF DESCRIPTION OF THE DRAWINGS
[0013] The disclosed aspects will hereinafter be described in conjunction with the appended drawings, provided to illustrate and not to limit the disclosed aspects, wherein like designations denote like elements, and in which:
[0014] FIG. 1 illustrates an example of a wireless communication system, in accordance with various aspects of the present disclosure;
[0015] FIG. 2 is a diagram illustrating an example of disaggregated base station architecture, in accordance with various aspects of the present disclosure;
[0016] FIG. 3 is a block diagram illustrating an example of a user equipment (UE) , in accordance with various aspects of the present disclosure;
[0017] FIG. 4 is a block diagram illustrating an example of a base station, in accordance with various aspects of the present disclosure;
[0018] FIG. 5 is a flow chart illustrating an example of a method for reporting measurements or reference signals (RSs) or UEs for multi-user (MU) -multiple-input multiple-output (MIMO) scheduling, in accordance with aspects described herein;
[0019] FIG. 6 is a flow chart illustrating an example of a method for scheduling UEs for MU-MIMO communications based on receiving one or more MU reports indicating RS measurements, RSs, or UEs, in accordance with aspects described herein;
[0020] FIG. 7 is a diagram illustrating an example of a wireless communication network including a base station that communicates UEs based on precoders and transmits associated RSs, in accordance with aspects described herein;
[0021] FIG. 8 illustrates an example of a resource allocation showing resources for a network entity to use transmitting the channel state information (CSI) -RSs for MU reporting, in accordance with aspects described herein;
[0022] FIG. 9 illustrates an example of a call flow between a UE and network entity for performing MU reporting and MU-MIMO scheduling, in accordance with aspects described herein; and
[0023] FIG. 10 is a block diagram illustrating an example of a MIMO communication system including a base station and a UE, in accordance with various aspects of the present disclosure.DETAILED DESCRIPTION
[0024] Various aspects are now described with reference to the drawings. In the following description, for purposes of explanation, numerous specific details are set forth in order to provide a thorough understanding of one or more aspects. It may be evident, however, that such aspect (s) may be practiced without these specific details.
[0025] The described features generally relate to devices providing information that can be considered in scheduling the devices for multi-user (MU) communications. For example, in fifth generation (5G) new radio (NR) or other wireless communication technologies, multiple devices (e.g., multiple user equipment (UEs) ) can be scheduled (e.g., by a gNB or other network entity) for performing MU-multiple-input multiple output (MU-MIMO) communications. For example, MU-MIMO can include scheduling multiple UEs to communicate on the same time and / or frequency resources using different precoders. In addition, for example, the co-scheduled UEs can use different orthogonal demodulation reference signal (DMRS) ports to transmit DMRS in the same or different code division multiplexing (CDM) groups. Using the different precoders and / or DMRS ports can allow the network entity scheduling the UEs to distinguish signals received from the UEs. In an example, a given UE may be aware of the co-scheduled UEs (e.g., based on a downlink control information (DCI) indication from the network entity) or may not be aware of the co-scheduled UEs.
[0026] In some examples, a UE in 5G NR can be configured to report MU channel state information (CSI) for assisting the network entity in performing MU precoding when UE is configured with additional non-zero-power (NZP) CSI-reference signal (CSI-RS) resources for interference measurement (IM) . For example, each NZP-CSI-RS port can correspond to an interference transmission layer from a co-scheduled UE. For interference measurement on NZP-CSI-RS, the UE may assume all interference layers are presented (e.g., no dynamic selection) . In this example, the UE may also perform inter-cell interference measurement based on the configured CSI-IM resource and can determine CSI considering both intra-cell (MU) interference measured on NZP-CSI-RS and inter-cell interference on CSI-IM. Conventionally, in the MU-MIMO framework, the gNB pre-programs MU pairing of UEs and minimizes the potential MU interference via precoding based on MU-CSI reporting. That is, for example, MU pairing is currently based on gNB implementation (e.g., based on sounding reference signals (SRS) in time division duplexing (TDD) ) and it is possible that gNB may not provide the best MU pairing decision. In such case, system capacity may not be maximized even with MU-CSI reporting from UE.
[0027] In 5G NR, a cross-link interference (CLI) framework is also supported where, for UE-centric CLI-RS framework for CLI coordination, gNB can configure SRS resource pool for UE to discovery neighbor cells which create large CLI. The UE can report discovery results to gNB, and based on the results, the gNB can make the dynamic TDD scheduling decision for the UE, which can include avoiding mutually jamming users to be simultaneously scheduled.
[0028] Aspects described herein relate to improving MU-MIMO scheduling by enabling the UE to report a desirable MU pairing, or metrics for determining a desirable MU pairing, to allow the network entity (e.g., gNB) to make dynamic MU scheduling decision. For example, the network entity (e.g., gNB) can configure, for a UE to be scheduled, a CSI-RS resource pool where each NZP-CSI-RS resource / port in the pool can correspond to an interference transmission layer from a potentially co-scheduled UE. The network entity can transmit the CSI-RS using a precoder selected by the co-scheduled UE. The UE to be scheduled can measures the CSI-RS resource in the pool and report a list of desirable CSI-RS resources to the network entity (e.g., in terms of the resource having the lowest energy or interference level) . In another example, the UE can sort the list of CSI-RS from low interference to high interference with some threshold interference level or signal-to-interference-and-noise ratio (SINR) level. In yet another example, the UE may report the interference level as well, which can be used by network entity for modulation and coding scheme (MCS) determination for MU-MIMO. After receiving the report, the network entity can pair the UE to be scheduled with other co-scheduled UEs that are reported as low interference level. In one example, the network entity can use the same precoder when interference level of the co-scheduled UE is lower than a threshold.
[0029] In this regard, for example, the network node can schedule UEs without pre-programming the pairing and measurement, and instead can offload the complexity of determining the co-scheduled UEs to UE side. The UE may need to perform some measurements, but this can be limited if there is a framework to simplify each measurement. In addition, receiving the information from the UE for scheduling UEs in MU-MIMO may be useful for the network entity to perform or update MU pairing decision with no need to change the user precoder to minimize inter-UE interference. Pairing UEs that experience low levels of interference between one another can improve performance and experience when communicating with the network entity using MU-MIMO.
[0030] The described features will be presented in more detail below with reference to FIGS. 1-10.
[0031] As used in this application, the terms “component, ” “module, ” “system” and the like are intended to include a computer-related entity, such as but not limited to hardware, firmware, a combination of hardware and software, software, or software in execution. For example, a component may be, but is not limited to being, a process running on a processor, a processor, an object, an executable, a thread of execution, a program, and / or a computer. By way of illustration, both an application running on a computing device and the computing device can be a component. One or more components can reside within a process and / or thread of execution and a component can be localized on one computer and / or distributed between two or more computers. In addition, these components can execute from various computer readable media having various data structures stored thereon. The components can communicate by way of local and / or remote processes such as in accordance with a signal having one or more data packets, such as data from one component interacting with another component in a local system, distributed system, and / or across a network such as the Internet with other systems by way of the signal.
[0032] As used herein, a processor, at least one processor, and / or one or more processors, individually or in combination, configured to perform or operable for performing a plurality of actions is meant to include at least two different processors able to perform different, overlapping or non-overlapping subsets of the plurality actions, or a single processor able to perform all of the plurality of actions. In one non-limiting example of multiple processors being able to perform different ones of the plurality of actions in combination, a description of a processor, at least one processor, and / or one or more processors configured or operable to perform actions X, Y, and Z may include at least a first processor configured or operable to perform a first subset of X, Y, and Z (e.g., to perform X) and at least a second processor configured or operable to perform a second subset of X, Y, and Z (e.g., to perform Y and Z) . Alternatively, a first processor, a second processor, and a third processor may be respectively configured or operable to perform a respective one of actions X, Y, and Z. It should be understood that any combination of one or more processors each may be configured or operable to perform any one or any combination of a plurality of actions.
[0033] As used herein, a memory, at least one memory, and / or one or more memories, individually or in combination, configured to store or having stored thereon instructions executable by one or more processors for performing a plurality of actions is meant to include at least two different memories able to store different, overlapping or non-overlapping subsets of the instructions for performing different, overlapping or non-overlapping subsets of the plurality actions, or a single memory able to store the instructions for performing all of the plurality of actions. In one non-limiting example of one or more memories, individually or in combination, being able to store different subsets of the instructions for performing different ones of the plurality of actions, a description of a memory, at least one memory, and / or one or more memories configured or operable to store or having stored thereon instructions for performing actions X, Y, and Z may include at least a first memory configured or operable to store or having stored thereon a first subset of instructions for performing a first subset of X, Y, and Z (e.g., instructions to perform X) and at least a second memory configured or operable to store or having stored thereon a second subset of instructions for performing a second subset of X, Y, and Z (e.g., instructions to perform Y and Z) . Alternatively, a first memory, and second memory, and a third memory may be respectively configured to store or have stored thereon a respective one of a first subset of instructions for performing X, a second subset of instruction for performing Y, and a third subset of instructions for performing Z. It should be understood that any combination of one or more memories each may be configured or operable to store or have stored thereon any one or any combination of instructions executable by one or more processors to perform any one or any combination of a plurality of actions. Moreover, one or more processors may each be coupled to at least one of the one or more memories and configured or operable to execute the instructions to perform the plurality of actions. For instance, in the above non-limiting example of the different subset of instructions for performing actions X, Y, and Z, a first processor may be coupled to a first memory storing instructions for performing action X, and at least a second processor may be coupled to at least a second memory storing instructions for performing actions Y and Z, and the first processor and the second processor may, in combination, execute the respective subset of instructions to accomplish performing actions X, Y, and Z. Alternatively, three processors may access one of three different memories each storing one of instructions for performing X, Y, or Z, and the three processor may in combination execute the respective subset of instruction to accomplish performing actions X, Y, and Z. Alternatively, a single processor may execute the instructions stored on a single memory, or distributed across multiple memories, to accomplish performing actions X, Y, and Z.
[0034] Techniques described herein may be used for various wireless communication systems such as CDMA, TDMA, FDMA, OFDMA, single carrier-FDMA, and other systems. The terms “system” and “network” may often be used interchangeably. A CDMA system may implement a radio technology such as CDMA2000, Universal Terrestrial Radio Access (UTRA) , etc. CDMA2000 covers IS-2000, IS-95, and IS-856 standards. IS-2000 Releases 0 and A are commonly referred to as CDMA2000 1X, 1X, etc. IS-856 (TIA-856) is commonly referred to as CDMA2000 1xEV-DO, High Rate Packet Data (HRPD) , etc. UTRA includes Wideband CDMA (WCDMA) and other variants of CDMA. A TDMA system may implement a radio technology such as Global System for Mobile Communications (GSM) . An OFDMA system may implement a radio technology such as Ultra Mobile Broadband (UMB) , Evolved UTRA (E-UTRA) , IEEE 802.11 (Wi-Fi) , IEEE 802.16 (WiMAX) , IEEE 802.20, Flash-OFDMTM, etc. UTRA and E-UTRA are part of Universal Mobile Telecommunication System (UMTS) . 3GPP Long Term Evolution (LTE) and LTE-Advanced (LTE-A) are new releases of UMTS that use E-UTRA. UTRA, E-UTRA, UMTS, LTE, LTE-A, and GSM are described in documents from an organization named “3rd Generation Partnership Project” (3GPP) . CDMA2000 and UMB are described in documents from an organization named “3rd Generation Partnership Project 2” (3GPP2) . The techniques described herein may be used for the systems and radio technologies mentioned above as well as other systems and radio technologies, including cellular (e.g., LTE) communications over a shared radio frequency spectrum band. The description below, however, describes an LTE / LTE-Asystem for purposes of example, and LTE terminology is used in much of the description below, although the techniques are applicable beyond LTE / LTE-Aapplications (e.g., to fifth generation (5G) new radio (NR) networks or other next generation communication systems) .
[0035] The following description provides examples, and is not limiting of the scope, applicability, or examples set forth in the claims. Changes may be made in the function and arrangement of elements discussed without departing from the scope of the disclosure. Various examples may omit, substitute, or add various procedures or components as appropriate. For instance, the methods described may be performed in an order different from that described, and various steps may be added, omitted, or combined. Also, features described with respect to some examples may be combined in other examples.
[0036] Various aspects or features will be presented in terms of systems that can include a number of devices, components, modules, and the like. It is to be understood and appreciated that the various systems can include additional devices, components, modules, etc. and / or may not include all of the devices, components, modules etc. discussed in connection with the figures. A combination of these approaches can also be used.
[0037] FIG. 1 is a diagram illustrating an example of a wireless communications system and an access network 100. The wireless communications system (also referred to as a wireless wide area network (WWAN) ) can include base stations 102, UEs 104, an Evolved Packet Core (EPC) 160, and / or a 5G Core (5GC) 190. The base stations 102 may include macro cells (high power cellular base station) and / or small cells (low power cellular base station) . The macro cells can include base stations. The small cells can include femtocells, picocells, and microcells. In an example, the base stations 102 may also include gNBs 180, as described further herein. In one example, some nodes of the wireless communication system may have a modem 340 and UE communicating component 342 for reporting measurements of reference signals associated with different UEs, in accordance with aspects described herein. In addition, some nodes may have a modem 440 and BS communicating component 442 for scheduling a UE for MU-MIMO communications based on measurements of reference signals associated with different UEs, in accordance with aspects described herein. Though a UE 104 is shown as having the modem 340 and UE communicating component 342 and a base station 102 / gNB 180 is shown as having the modem 440 and BS communicating component 442, this is one illustrative example, and substantially any node or type of node may include a modem 340 and UE communicating component 342 and / or a modem 440 and BS communicating component 442 for providing corresponding functionalities described herein.
[0038] The base stations 102 configured for 4G LTE (which can collectively be referred to as Evolved Universal Mobile Telecommunications System (UMTS) Terrestrial Radio Access Network (E-UTRAN) ) may interface with the EPC 160 through backhaul links 132 (e.g., using an S1 interface) . The base stations 102 configured for 5G NR (which can collectively be referred to as Next Generation RAN (NG-RAN) ) may interface with 5GC 190 through backhaul links 184. In addition to other functions, the base stations 102 may perform one or more of the following functions: transfer of user data, radio channel ciphering and deciphering, integrity protection, head compression, mobility control functions (e.g., handover, dual connectivity) , inter-cell interference coordination, connection setup and release, load balancing, distribution for non-access stratum (NAS) messages, NAS node selection, synchronization, radio access network (RAN) sharing, multimedia broadcast multicast service (MBMS) , subscriber and equipment trace, RAN information management (RIM) , paging, positioning, and delivery of warning messages. The base stations 102 may communicate directly or indirectly (e.g., through the EPC 160 or 5GC 190) with each other over backhaul links 134 (e.g., using an X2 interface) . The backhaul links 134 may be wired or wireless.
[0039] The base stations 102 may wirelessly communicate with one or more UEs 104. Each of the base stations 102 may provide communication coverage for a respective geographic coverage area 110. There may be overlapping geographic coverage areas 110. For example, the small cell 102' may have a coverage area 110' that overlaps the coverage area 110 of one or more macro base stations 102. A network that includes both small cell and macro cells may be referred to as a heterogeneous network. A heterogeneous network may also include Home Evolved Node Bs (eNBs) (HeNBs) , which may provide service to a restricted group, which can be referred to as a closed subscriber group (CSG) . The communication links 120 between the base stations 102 and the UEs 104 may include uplink (UL) (also referred to as reverse link) transmissions from a UE 104 to a base station 102 and / or downlink (DL) (also referred to as forward link) transmissions from a base station 102 to a UE 104. The communication links 120 may use multiple-input and multiple-output (MIMO) antenna technology, including spatial multiplexing, beamforming, and / or transmit diversity. The communication links may be through one or more carriers. The base stations 102 / UEs 104 may use spectrum up to Y MHz (e.g., 5, 10, 15, 20, 100, 400, etc. MHz) bandwidth per carrier allocated in a carrier aggregation of up to a total of Yx MHz (e.g., for x component carriers) used for transmission in the DL and / or the UL direction. The carriers may or may not be adjacent to each other. Allocation of carriers may be asymmetric with respect to DL and UL (e.g., more or less carriers may be allocated for DL than for UL) . The component carriers may include a primary component carrier and one or more secondary component carriers. A primary component carrier may be referred to as a primary cell (PCell) and a secondary component carrier may be referred to as a secondary cell (SCell) .
[0040] In another example, certain UEs 104 may communicate with each other using device-to-device (D2D) communication link 158. The D2D communication link 158 may use the DL / UL WWAN spectrum. The D2D communication link 158 may use one or more sidelink channels, such as a physical sidelink broadcast channel (PSBCH) , a physical sidelink discovery channel (PSDCH) , a physical sidelink shared channel (PSSCH) , and a physical sidelink control channel (PSCCH) . D2D communication may be through a variety of wireless D2D communications systems, such as for example, FlashLinQ, WiMedia, Bluetooth, ZigBee, Wi-Fi based on the IEEE 802.11 standard, LTE, or NR.
[0041] The wireless communications system may further include a Wi-Fi access point (AP) 150 in communication with Wi-Fi stations (STAs) 152 via communication links 154 in a 5 GHz unlicensed frequency spectrum. When communicating in an unlicensed frequency spectrum, the STAs 152 / AP 150 may perform a clear channel assessment (CCA) prior to communicating in order to determine whether the channel is available.
[0042] The small cell 102' may operate in a licensed and / or an unlicensed frequency spectrum. When operating in an unlicensed frequency spectrum, the small cell 102' may employ NR and use the same 5 GHz unlicensed frequency spectrum as used by the Wi-Fi AP 150. The small cell 102', employing NR in an unlicensed frequency spectrum, may boost coverage to and / or increase capacity of the access network.
[0043] A base station 102, whether a small cell 102' or a large cell (e.g., macro base station) , may include an eNB, gNodeB (gNB) , or other type of base station. Some base stations, such as gNB 180 may operate in a traditional sub 6 GHz spectrum, in millimeter wave (mmW) frequencies, and / or near mmW frequencies in communication with the UE 104. When the gNB 180 operates in mmW or near mmW frequencies, the gNB 180 may be referred to as an mmW base station. Extremely high frequency (EHF) is part of the RF in the electromagnetic spectrum. EHF has a range of 30 GHz to 300 GHz and a wavelength between 1 millimeter and 10 millimeters. Radio waves in the band may be referred to as a millimeter wave. Near mmW may extend down to a frequency of 3 GHz with a wavelength of 100 millimeters. The super high frequency (SHF) band extends between 3 GHz and 30 GHz, also referred to as centimeter wave. Communications using the mmW / near mmW radio frequency band has extremely high path loss and a short range. The mmW base station 180 may utilize beamforming 182 with the UE 104 to compensate for the extremely high path loss and short range. A base station 102 referred to herein can include a gNB 180.
[0044] The EPC 160 may include a Mobility Management Entity (MME) 162, other MMEs 164, a Serving Gateway 166, a Multimedia Broadcast Multicast Service (MBMS) Gateway 168, a Broadcast Multicast Service Center (BM-SC) 170, and a Packet Data Network (PDN) Gateway 172. The MME 162 may be in communication with a Home Subscriber Server (HSS) 174. The MME 162 is the control node that processes the signaling between the UEs 104 and the EPC 160. Generally, the MME 162 provides bearer and connection management. All user Internet protocol (IP) packets are transferred through the Serving Gateway 166, which itself is connected to the PDN Gateway 172. The PDN Gateway 172 provides UE IP address allocation as well as other functions. The PDN Gateway 172 and the BM-SC 170 are connected to the IP Services 176. The IP Services 176 may include the Internet, an intranet, an IP Multimedia Subsystem (IMS) , a PS Streaming Service, and / or other IP services. The BM-SC 170 may provide functions for MBMS user service provisioning and delivery. The BM-SC 170 may serve as an entry point for content provider MBMS transmission, may be used to authorize and initiate MBMS Bearer Services within a public land mobile network (PLMN) , and may be used to schedule MBMS transmissions. The MBMS Gateway 168 may be used to distribute MBMS traffic to the base stations 102 belonging to a Multicast Broadcast Single Frequency Network (MBSFN) area broadcasting a particular service, and may be responsible for session management (start / stop) and for collecting eMBMS related charging information.
[0045] The 5GC 190 may include a Access and Mobility Management Function (AMF) 192, other AMFs 193, a Session Management Function (SMF) 194, and a User Plane Function (UPF) 195. The AMF 192 may be in communication with a Unified Data Management (UDM) 196. The AMF 192 can be a control node that processes the signaling between the UEs 104 and the 5GC 190. Generally, the AMF 192 can provide QoS flow and session management. User Internet protocol (IP) packets (e.g., from one or more UEs 104) can be transferred through the UPF 195. The UPF 195 can provide UE IP address allocation for one or more UEs, as well as other functions. The UPF 195 is connected to the IP Services 197. The IP Services 197 may include the Internet, an intranet, an IP Multimedia Subsystem (IMS) , a PS Streaming Service, and / or other IP services.
[0046] The base station may also be referred to as a gNB, Node B, evolved Node B (eNB) , an access point, a base transceiver station, a radio base station, a radio transceiver, a transceiver function, a basic service set (BSS) , an extended service set (ESS) , a transmit reception point (TRP) , or some other suitable terminology. The base station 102 provides an access point to the EPC 160 or 5GC 190 for a UE 104. Examples of UEs 104 include a cellular phone, a smart phone, a session initiation protocol (SIP) phone, a laptop, a personal digital assistant (PDA) , a satellite radio, a global positioning system, a multimedia device, a video device, a digital audio player (e.g., MP3 player) , a camera, a game console, a tablet, a smart device, a wearable device, a vehicle, an electric meter, a gas pump, a large or small kitchen appliance, a healthcare device, an implant, a sensor / actuator, a display, or any other similar functioning device. Some of the UEs 104 may be referred to as IoT devices (e.g., parking meter, gas pump, toaster, vehicles, heart monitor, etc. ) . IoT UEs may include machine type communication (MTC) / enhanced MTC (eMTC, also referred to as category (CAT) -M, Cat M1) UEs, NB-IoT (also referred to as CAT NB1) UEs, as well as other types of UEs. In the present disclosure, eMTC and NB-IoT may refer to future technologies that may evolve from or may be based on these technologies. For example, eMTC may include FeMTC (further eMTC) , eFeMTC (enhanced further eMTC) , mMTC (massive MTC) , etc., and NB-IoT may include eNB-IoT (enhanced NB-IoT) , FeNB-IoT (further enhanced NB-IoT) , etc. The UE 104 may also be referred to as a station, a mobile station, a subscriber station, a mobile unit, a subscriber unit, a wireless unit, a remote unit, a mobile device, a wireless device, a wireless communications device, a remote device, a mobile subscriber station, an access terminal, a mobile terminal, a wireless terminal, a remote terminal, a handset, a user agent, a mobile client, a client, or some other suitable terminology.
[0047] Deployment of communication systems, such as 5G new radio (NR) systems, may be arranged in multiple manners with various components or constituent parts. In a 5G NR system, or network, a network node, a network entity, a mobility element of a network, a radio access network (RAN) node, a core network node, a network element, or a network equipment, such as a base station (BS, e.g., BS 102) , or one or more units (or one or more components) performing base station functionality, may be implemented in an aggregated or disaggregated architecture. For example, a BS (such as a Node B (NB) , evolved NB (eNB) , NR BS, 5G NB, access point (AP) , a transmit receive point (TRP) , or a cell, etc. ) may be implemented as an aggregated base station (also known as a standalone BS or a monolithic BS) or a disaggregated base station.
[0048] An aggregated base station may be configured to utilize a radio protocol stack that is physically or logically integrated within a single RAN node. A disaggregated base station may be configured to utilize a protocol stack that is physically or logically distributed among two or more units (such as one or more central or centralized units (CUs) , one or more distributed units (DUs) , or one or more radio units (RUs) ) . In some aspects, a CU may be implemented within a RAN node, and one or more DUs may be co-located with the CU, or alternatively, may be geographically or virtually distributed throughout one or multiple other RAN nodes. The DUs may be implemented to communicate with one or more RUs. Each of the CU, DU and RU also can be implemented as virtual units, i.e., a virtual central unit (VCU) , a virtual distributed unit (VDU) , or a virtual radio unit (VRU) .
[0049] Base station-type operation or network design may consider aggregation characteristics of base station functionality. For example, disaggregated base stations may be utilized in an integrated access backhaul (IAB) network, an open radio access network (O-RAN (such as the network configuration sponsored by the O-RAN Alliance) ) , or a virtualized radio access network (vRAN, also known as a cloud radio access network (C-RAN) ) . Disaggregation may include distributing functionality across two or more units at various physical locations, as well as distributing functionality for at least one unit virtually, which can enable flexibility in network design. The various units of the disaggregated base station, or disaggregated RAN architecture, can be configured for wired or wireless communication with at least one other unit.
[0050] In an example, BS communicating component 442 of a base station 102 or gNB 180 can transmit, to a UE 104, multiple reference signals (RSs) each having a precoder of a different UE applied. In this example, UE communicating component 342 can receive and / or perform a measurement of the multiple RSs, and report the measurements of the RSs or an indication of the RSs or associated UEs for which MU-MIMO pairing is desirable back to the bae station 102 or gNB 180. For example, the BS communicating component 442 can accordingly determine UE pairings for co-scheduling UEs for MU-MIMO communications based on the reported measurements or RS or UE indications, as described herein.
[0051] FIG. 2 shows a diagram illustrating an example of disaggregated base station 200 architecture. The disaggregated base station 200 architecture may include one or more central units (CUs) 210 that can communicate directly with a core network 220 via a backhaul link, or indirectly with the core network 220 through one or more disaggregated base station units (such as a Near-Real Time (Near-RT) RAN Intelligent Controller (RIC) 225 via an E2 link, or a Non-Real Time (Non-RT) RIC 215 associated with a Service Management and Orchestration (SMO) Framework 205, or both) . A CU 210 may communicate with one or more distributed units (DUs) 230 via respective midhaul links, such as an F1 interface. The DUs 230 may communicate with one or more radio units (RUs) 240 via respective fronthaul links. The RUs 240 may communicate with respective UEs 104 via one or more radio frequency (RF) access links. In some implementations, the UE 104 may be simultaneously served by multiple RUs 240.
[0052] Each of the units, e.g., the CUs 210, the DUs 230, the RUs 240, as well as the Near-RT RICs 225, the Non-RT RICs 215 and the SMO Framework 205, may include one or more interfaces or be coupled to one or more interfaces configured to receive or transmit signals, data, or information (collectively, signals) via a wired or wireless transmission medium. Each of the units, or an associated processor or controller providing instructions to the communication interfaces of the units, can be configured to communicate with one or more of the other units via the transmission medium. For example, the units can include a wired interface configured to receive or transmit signals over a wired transmission medium to one or more of the other units. Additionally, the units can include a wireless interface, which may include a receiver, a transmitter or transceiver (such as a radio frequency (RF) transceiver) , configured to receive or transmit signals, or both, over a wireless transmission medium to one or more of the other units.
[0053] In some aspects, the CU 210 may host one or more higher layer control functions. Such control functions can include radio resource control (RRC) , packet data convergence protocol (PDCP) , service data adaptation protocol (SDAP) , or the like. Each control function can be implemented with an interface configured to communicate signals with other control functions hosted by the CU 210. The CU 210 may be configured to handle user plane functionality (i.e., Central Unit –User Plane (CU-UP) ) , control plane functionality (i.e., Central Unit –Control Plane (CU-CP) ) , or a combination thereof. In some implementations, the CU 210 can be logically split into one or more CU-UP units and one or more CU-CP units. The CU-UP unit can communicate bidirectionally with the CU-CP unit via an interface, such as the E1 interface when implemented in an O-RAN configuration. The CU 210 can be implemented to communicate with the DU 230, as necessary, for network control and signaling.
[0054] The DU 230 may correspond to a logical unit that includes one or more base station functions to control the operation of one or more RUs 240. In some aspects, the DU 230 may host one or more of a radio link control (RLC) layer, a medium access control (MAC) layer, and one or more high physical (PHY) layers (such as modules for forward error correction (FEC) encoding and decoding, scrambling, modulation and demodulation, or the like) depending, at least in part, on a functional split, such as those defined by the third Generation Partnership Project (3GPP) . In some aspects, the DU 230 may further host one or more low PHY layers. Each layer (or module) can be implemented with an interface configured to communicate signals with other layers (and modules) hosted by the DU 230, or with the control functions hosted by the CU 210.
[0055] Lower-layer functionality can be implemented by one or more RUs 240. In some deployments, an RU 240, controlled by a DU 230, may correspond to a logical node that hosts RF processing functions, or low-PHY layer functions (such as performing fast Fourier transform (FFT) , inverse FFT (iFFT) , digital beamforming, physical random access channel (PRACH) extraction and filtering, or the like) , or both, based at least in part on the functional split, such as a lower layer functional split. In such an architecture, the RU (s) 240 can be implemented to handle over the air (OTA) communication with one or more UEs 104. In some implementations, real-time and non-real-time aspects of control and user plane communication with the RU (s) 240 can be controlled by the corresponding DU 230. In some scenarios, this configuration can enable the DU (s) 230 and the CU 210 to be implemented in a cloud-based RAN architecture, such as a vRAN architecture.
[0056] The SMO Framework 205 may be configured to support RAN deployment and provisioning of non-virtualized and virtualized network elements. For non-virtualized network elements, the SMO Framework 205 may be configured to support the deployment of dedicated physical resources for RAN coverage requirements which may be managed via an operations and maintenance interface (such as an O1 interface) . For virtualized network elements, the SMO Framework 205 may be configured to interact with a cloud computing platform (such as an open cloud (O-Cloud) 290) to perform network element life cycle management (such as to instantiate virtualized network elements) via a cloud computing platform interface (such as an O2 interface) . Such virtualized network elements can include, but are not limited to, CUs 210, DUs 230, RUs 240 and Near-RT RICs 225. In some implementations, the SMO Framework 205 can communicate with a hardware aspect of a 4G RAN, such as an open eNB (O-eNB) 211, via an O1 interface. Additionally, in some implementations, the SMO Framework 205 can communicate directly with one or more RUs 240 via an O1 interface. The SMO Framework 205 also may include a Non-RT RIC 215 configured to support functionality of the SMO Framework 205.
[0057] The Non-RT RIC 215 may be configured to include a logical function that enables non-real-time control and optimization of RAN elements and resources, Artificial Intelligence / Machine Learning (AI / ML) workflows including model training and updates, or policy-based guidance of applications / features in the Near-RT RIC 225. The Non-RT RIC 215 may be coupled to or communicate with (such as via an A1 interface) the Near-RT RIC 225. The Near-RT RIC 225 may be configured to include a logical function that enables near-real-time control and optimization of RAN elements and resources via data collection and actions over an interface (such as via an E2 interface) connecting one or more CUs 210, one or more DUs 230, or both, as well as an O-eNB, with the Near-RT RIC 225.
[0058] In some implementations, to generate AI / ML models to be deployed in the Near-RT RIC 225, the Non-RT RIC 215 may receive parameters or external enrichment information from external servers. Such information may be utilized by the Near-RT RIC 225 and may be received at the SMO Framework 205 or the Non-RT RIC 215 from non-network data sources or from network functions. In some examples, the Non-RT RIC 215 or the Near-RT RIC 225 may be configured to tune RAN behavior or performance. For example, the Non-RT RIC 215 may monitor long-term trends and patterns for performance and employ AI / ML models to perform corrective actions through the SMO Framework 205 (such as reconfiguration via O1) or via creation of RAN management policies (such as A1 policies) .
[0059] Turning now to FIGS. 3-10, aspects are depicted with reference to one or more components and one or more methods that may perform the actions or operations described herein, where aspects in dashed line may be optional. Although the operations described below in FIGS. 5 and 6 are presented in a particular order and / or as being performed by an example component, it should be understood that the ordering of the actions and the components performing the actions may be varied, depending on the implementation. Moreover, it should be understood that the following actions, functions, and / or described components may be performed by a specially programmed processor, a processor executing specially programmed software or computer-readable media, or by any other combination of a hardware component and / or a software component capable of performing the described actions or functions.
[0060] Referring to FIG. 3, one example of an implementation of UE 104 may include a variety of components, some of which have already been described above and are described further herein, including components such as one or more processors 312 and one or more memories 316 and one or more transceivers 302 in communication via one or more buses 344. For example, the one or more processors 312 can include a single processor or multiple processors configured to perform one or more functions described herein. For example, the multiple processors can be configured to perform a certain subset of a set of functions described herein, such that the multiple processors together can perform the set of functions. Similarly, for example, the one or more memories 316 can include a single memory device or multiple memory devices configured to store instructions or parameters for performing one or more functions described herein. For example, the multiple memory devices can be configured to store the instructions or parameters for performing a certain subset of a set of functions described herein, such that the multiple memory devices together can store the instructions or parameters for the set of functions. The one or more processors 312, one or more memories 316, and one or more transceivers 302 may operate in conjunction with modem 340 and / or UE communicating component 342 for reporting measurements of reference signals associated with different UEs, in accordance with aspects described herein.
[0061] In an aspect, the one or more processors 312 can include a modem 340 and / or can be part of the modem 340 that uses one or more modem processors. Thus, the various functions related to UE communicating component 342 may be included in modem 340 and / or processors 312 and, in an aspect, can be executed by a single processor, while in other aspects, different ones of the functions may be executed by a combination of two or more different processors. For example, in an aspect, the one or more processors 312 may include any one or any combination of a modem processor, or a baseband processor, or a digital signal processor, or a transmit processor, or a receiver processor, or a transceiver processor associated with transceiver 302. In other aspects, some of the features of the one or more processors 312 and / or modem 340 associated with UE communicating component 342 may be performed by transceiver 302.
[0062] Also, memory / memories 316 may be configured to store data used herein and / or local versions of applications 375 or UE communicating component 342 and / or one or more of its subcomponents being executed by at least one processor 312. Memory / memories 316 can include any type of computer-readable medium usable by a computer or at least one processor 312, such as random access memory (RAM) , read only memory (ROM) , tapes, magnetic discs, optical discs, volatile memory, non-volatile memory, and any combination thereof. In an aspect, for example, memory / memories 316 may be a non-transitory computer-readable storage medium that stores one or more computer-executable codes defining UE communicating component 342 and / or one or more of its subcomponents, and / or data associated therewith, when UE 104 is operating at least one processor 312 to execute UE communicating component 342 and / or one or more of its subcomponents.
[0063] Transceiver 302 may include at least one receiver 306 and at least one transmitter 308. Receiver 306 may include hardware, firmware, and / or software code executable by a processor for receiving data, the code comprising instructions and being stored in a memory (e.g., computer-readable medium) . Receiver 306 may be, for example, a radio frequency (RF) receiver. In an aspect, receiver 306 may receive signals transmitted by at least one base station 102. Additionally, receiver 306 may process such received signals, and also may obtain measurements of the signals, such as, but not limited to, Ec / Io, signal-to-noise ratio (SNR) , signal-to-interference-and-noise ratio (SINR) , reference signal received power (RSRP) , reference signal received quality (RSRQ) , received signal strength indicator (RSSI) , etc. Transmitter 308 may include hardware, firmware, and / or software code executable by a processor for transmitting data, the code comprising instructions and being stored in a memory (e.g., computer-readable medium) . A suitable example of transmitter 308 may including, but is not limited to, an RF transmitter.
[0064] Moreover, in an aspect, UE 104 may include RF front end 388, which may operate in communication with one or more antennas 365 and transceiver 302 for receiving and transmitting radio transmissions, for example, wireless communications transmitted by at least one base station 102 or wireless transmissions transmitted by UE 104. RF front end 388 may be connected to one or more antennas 365 and can include one or more low-noise amplifiers (LNAs) 390, one or more switches 392, one or more power amplifiers (PAs) 398, and one or more filters 396 for transmitting and receiving RF signals.
[0065] In an aspect, LNA 390 can amplify a received signal at a desired output level. In an aspect, each LNA 390 may have a specified minimum and maximum gain values. In an aspect, RF front end 388 may use one or more switches 392 to select a particular LNA 390 and its specified gain value based on a desired gain value for a particular application.
[0066] Further, for example, one or more PA (s) 398 may be used by RF front end 388 to amplify a signal for an RF output at a desired output power level. In an aspect, each PA 398 may have specified minimum and maximum gain values. In an aspect, RF front end 388 may use one or more switches 392 to select a particular PA 398 and its specified gain value based on a desired gain value for a particular application.
[0067] Also, for example, one or more filters 396 can be used by RF front end 388 to filter a received signal to obtain an input RF signal. Similarly, in an aspect, for example, a respective filter 396 can be used to filter an output from a respective PA 398 to produce an output signal for transmission. In an aspect, each filter 396 can be connected to a specific LNA 390 and / or PA 398. In an aspect, RF front end 388 can use one or more switches 392 to select a transmit or receive path using a specified filter 396, LNA 390, and / or PA 398, based on a configuration as specified by transceiver 302 and / or processor 312.
[0068] As such, transceiver 302 may be configured to transmit and receive wireless signals through one or more antennas 365 via RF front end 388. In an aspect, transceiver may be tuned to operate at specified frequencies such that UE 104 can communicate with, for example, one or more base stations 102 or one or more cells associated with one or more base stations 102. In an aspect, for example, modem 340 can configure transceiver 302 to operate at a specified frequency and power level based on the UE configuration of the UE 104 and the communication protocol used by modem 340.
[0069] In an aspect, modem 340 can be a multiband-multimode modem, which can process digital data and communicate with transceiver 302 such that the digital data is sent and received using transceiver 302. In an aspect, modem 340 can be multiband and be configured to support multiple frequency bands for a specific communications protocol. In an aspect, modem 340 can be multimode and be configured to support multiple operating networks and communications protocols. In an aspect, modem 340 can control one or more components of UE 104 (e.g., RF front end 388, transceiver 302) to enable transmission and / or reception of signals from the network based on a specified modem configuration. In an aspect, the modem configuration can be based on the mode of the modem and the frequency band in use. In another aspect, the modem configuration can be based on UE configuration information associated with UE 104 as provided by the network during cell selection and / or cell reselection.
[0070] In an aspect, UE communicating component 342 can optionally include a RS processing component 352 for receiving and / or processing one or more RSs received from a network entity, a measuring component 354 for performing or determining a measurement associated with the one or more RSs, and / or a MU reporting component 356 for generating a MU report (or measurement report) indicating the measurements of the RSs or an indication of the RSs or associated UEs that are desirable (or are not desirable) for pairing in MU-MIMO communications, in accordance with aspects described herein.
[0071] In an aspect, the processor (s) 312 may correspond to one or more of the processors described in connection with the UE in FIG. 10. Similarly, the memory / memories 316 may correspond to the one or more memories described in connection with the UE in FIG. 10.
[0072] Referring to FIG. 4, one example of an implementation of base station 102 (e.g., a base station 102 and / or gNB 180, as described above) may include a variety of components, some of which have already been described above, but including components such as one or more processors 412 and one or more memories 416 and one or more transceivers 402 in communication via one or more buses 444. For example, the one or more processors 412 can include a single processor or multiple processors configured to perform one or more functions described herein. For example, the multiple processors can be configured to perform a certain subset of a set of functions described herein, such that the multiple processors together can perform the set of functions. Similarly, for example, the one or more memories 416 can include a single memory device or multiple memory devices configured to store instructions or parameters for performing one or more functions described herein. For example, the multiple memory devices can be configured to store the instructions or parameters for performing a certain subset of a set of functions described herein, such that the multiple memory devices together can store the instructions or parameters for the set of functions. The one or more processors 412, one or more memories 416, and one or more transceivers 402 may operate in conjunction with modem 440 and / or BS communicating component 442 for scheduling a UE for MU-MIMO communications based on measurements of reference signals associated with different UEs, in accordance with aspects described herein.
[0073] The transceiver 402, receiver 406, transmitter 408, one or more processors 412, memory / memories 416, applications 475, buses 444, RF front end 488, LNAs 490, switches 492, filters 496, PAs 498, and one or more antennas 465 may be the same as or similar to the corresponding components of UE 104, as described above, but configured or otherwise programmed for base station operations as opposed to UE operations.
[0074] In an aspect, BS communicating component 442 can optionally include a RS component 452 for transmitting multiple RSs each using a precoder associated with a different UE, a report processing component 454 for receiving and / or processing a MU report from a UE that indicates measurements of the RSs or indicates the RSs or associated UEs for which MU pairing is desirable (or is not desirable) , and / or a scheduling component 456 for scheduling multiple UEs for MU-MIMO communications based on one or more MU reports, in accordance with aspects described herein.
[0075] In an aspect, the processor (s) 412 may correspond to one or more of the processors described in connection with the base station in FIG. 10. Similarly, the memory / memories 416 may correspond to the one or more memories described in connection with the base station in FIG. 10.
[0076] FIG. 5 illustrates a flow chart of an example of a method 500 for reporting measurements or RSs or UEs for MU-MIMO scheduling, in accordance with aspects described herein. FIG. 6 illustrates a flow chart of an example of a method 600 for scheduling UEs for MU-MIMO communications based on receiving one or more MU reports indicating RS measurements, RSs, or UEs, in accordance with aspects described herein. In an example, a UE 104 can perform the functions described in method 500 shown in FIG. 5 using one or more of the components described in FIGS. 1 and / or 3. In an example, a node scheduling the UE 104 with communication resources, such as a base station 102 or gNB 180, a monolithic base station or gNB, a portion of a disaggregated base station or gNB, a UE in sidelink communication, etc., can perform the functions described in method 600 shown in FIG. 6 using one or more of the components described in FIGS. 1 and / or 4. Methods 500 and 600 are described in conjunction with one another for ease of explanation; however, the methods 500 and 600 are not required to be performed together and indeed can be performed independently using separate devices.
[0077] In method 600, at Block 602, multiple RSs that each of a precoder of a different UE applied can be transmitted. In an aspect, RS component 452, e.g., in conjunction with processor (s) 412, memory / memories 416, transceiver 402, BS communicating component 442, etc., can transmit (e.g., to one or more UEs) the multiple RSs that each have a precoder of a different UE applied. For example, the different UEs can communicate with the network entity using a precoder, which the different UEs may indicate to the network entity as part of a configuration process for the precoder or associated beam and / or the network entity may select for the different UEs as part of the configuration process for the precoder or associated beam. In any case, the network entity may know the precoder used for communication with each of the different UEs, and can accordingly transmit a RS using each precoder. For example, RS component 452 can transmit the RSs in a resource pool, as described herein, to allow a UE 104 to receive the RSs and report measurements for the RSs or otherwise determine which RSs or associated UEs would be desirable (or not desirable) for pairing with the UE 104 in scheduling MU-MIMO communications. In an example, the RSs can include CSI-RSs or other RSs, and each CSI-RS (or other RS) resource or port in the resource pool can correspond to an interference transmission layer from a potentially co-scheduled UE.
[0078] In method 500, at Block 502, multiple RSs that each of a precoder of a different UE applied can be received from a network entity. In an aspect, RS processing component 352, e.g., in conjunction with processor (s) 312, memory / memories 316, transceiver 302, UE communicating component 342, etc., can receive, from the network entity, the multiple RSs that each have a precoder of a different UE applied. For example, RS processing component 352 can receive each of the multiple RSs over different resources of a resource pool configured for the network entity to use in transmitting the multiple RSs.
[0079] In method 500, at Block 504, a MU report indicating at least a portion of the multiple RSs for MU pairing the UE with the one or more different UEs can be transmitted to the network entity based on a measurement of each of the multiple RSs. In an aspect, MU reporting component 356, e.g., in conjunction with processor (s) 312, memory / memories 316, transceiver 302, UE communicating component 342, etc., can transmit, to the network entity and based on the measurement of each of the multiple RSs, the MU report indicating at least the portion of the multiple RSs for MU pairing the UE with one or more different UEs. For example, MU reporting component 356 can transmit the MU report over resources indicated by the network entity, such as using uplink channel resources (e.g., physical uplink control channel (PUCCH) or physical uplink shared channel (PUSCH) resources scheduled by the network entity for transmitting uplink control information (UCI) ) . Transmitting the MU report is also referred to herein as MU pairing reporting.
[0080] In method 500, optionally at Block 506, measurement of each of the multiple RSs can be performed. In an aspect, measuring component 354, e.g., in conjunction with processor (s) 312, memory / memories 316, transceiver 302, UE communicating component 342, etc., can perform the measurement of each of the multiple RSs. For example, measuring component 354 can measure a signal energy or quality (e.g., RSSI, RSRP, RSRQ, SINR, etc. ) over the resources in the resource pool.
[0081] In method 500, optionally at Block 508, the MU report can be generated to one of include an indication of the multiple RSs having the measurement less than a threshold, to include indications of the UEs associated with the multiple RSs having the measurement less than the threshold, sort indications of the multiple RSs by a level of energy or interference, to include measurements of the RSs, etc. In an aspect, MU reporting component 356, e.g., in conjunction with processor (s) 312, memory / memories 316, transceiver 302, UE communicating component 342, etc., can generate the MU report to one of include an indication of the multiple RSs having the measurement less than a threshold, to include indications of the UEs associated with the multiple RSs having the measurement less than the threshold, sort indications of the multiple RSs by a level of energy or interference, to include measurements of the RSs, etc.
[0082] For example, MU reporting component 356 can include, in the MU report, the indication of one or more of the multiple RSs (or associated UEs) having a lowest energy or interference level (or energy or interference level less than a threshold) . In another example, MU reporting component 356 can sort the list of CSI-RS from low interference to high interference with some threshold interference level or SINR level. In yet another example, MU reporting component 356 can report (e.g., include in the MU report) the interference level as well, which can be used by the network entity for MCS determination for MU-MIMO.
[0083] In method 600, at Block 604, a MU report indicating at least a portion of the multiple RSs for MU pairing the UE with one or more different UEs can be received from the UE. In an aspect, report processing component 454, e.g., in conjunction with processor (s) 412, memory / memories 416, transceiver 402, BS communicating component 442, etc., can receive, from the UE, the MU report indicating at least the portion of the multiple RSs for MU pairing the UE (e.g., UE 104) with the one or more different UEs. Indicating the UEs for MU pairing can include indicating, to the network entity, that the UEs could be co-scheduled for MU-MIMO communications without their respective communications significantly interfering with one another. As described, for example, the MU report can one of include an indication of the multiple RSs having the measurement less than a threshold, to include indications of the UEs associated with the multiple RSs having the measurement less than the threshold, sort indications of the multiple RSs by a level of energy or interference, to include measurements of the RSs, etc. Report processing component 454 can process the report to determine one or more of the different UEs with which the UE 104 can be paired for MU-MIMO communications to decrease likelihood of interference between the UEs transmitting or receiving MU-MIMO communications to or from the network entity.
[0084] In method 600, at Block 606, the UE and the one or more different UEs can be scheduled, based on the MU report, for MU-MIMO communications. In an aspect, scheduling component 456, e.g., in conjunction with processor (s) 412, memory / memories 416, transceiver 402, BS communicating component 442, etc., can schedule, based on the MU report, the UE (e.g., UE 104) and the one or more different UEs for MU-MIMO communications. In one example, scheduling component 456 can determine the UEs indicated in the MU report, or the UEs associated with RSs indicated in the MU report, for pairing the UE 104 with one or more different UEs for MU-MIMO communications. For example, scheduling component 456 can determine which of the one or more different UEs are desirable for pairing with the UE 104 from which the MU report is received. In one example, the MU report can indicate the desirable (or non-desirable) different UE (s) , or an identifier of RS (s) related to desirable (or non-desirable) different UE (s) s, and scheduling component 456 can determine the different UEs based on the indications. In another example, the MU report can include measurements of RSs, and scheduling component 456 can determine the different UE (s) based on determining a lowest measurement and / or one or more measurements that are less than a threshold, etc., as described further herein.
[0085] In one specific example, for the case of multiple UEs reporting, scheduling component 456 may determine the MU scheduling decision based on a common list from all the co-scheduled UEs. For example, where UE1 reports UE2, UE3, UE4 with low interference level, UE 2 reports UE1, UE3 with low interference level, and UE3 reports UE1 with low interference level, based on reporting, scheduling component 456 may co-schedule UE1 and UE2 or UE1 and UE3, but scheduling component 456 may not schedule UE1 and UE2 and UE3, as UE3 does not report a low interference level from UE2.
[0086] In accordance with some examples, the network entity can configure the resource pool for the UE. In method 600, optionally at Block 608, a configuration indicating a RS resource pool over which the multiple RSs are transmitted by the network entity can be transmitted to the UE. In an aspect, scheduling component 456, e.g., in conjunction with processor (s) 412, memory / memories 416, transceiver 402, BS communicating component 442, etc., can transmit, to the UE the configuration indicating the RS resource pool over which the multiple RSs are transmitted by the network entity. For example, scheduling component 456 can transmit the RS resource pool as an indication of a set of resources over which RSs are transmitted. In an example, the indication can include a RS or UE identifier corresponding to the RS to be transmitted in one or more resource of the RS resource pool, which the UE 104 can use in generating the MU report. In another example, the UE 104 can report an index of a resource associated with an RS in generating the MU report (e.g., to include measurements of the RSs by index or to identify desirable RSs by index, etc. ) . For example, scheduling component 456 can transmit the RS resource pool configuration to the UE 104 in downlink control information (DCI) (e.g., over physical downlink control channel (PDCCH) or physical downlink shared channel (PDSCH) resources configured by the network entity.
[0087] In this example, in method 500, optionally at Block 510, a configuration indicating a RS resource pool over which the multiple RSs are transmitted by the network entity can be received from the network entity. In an aspect, RS processing component 352, e.g., in conjunction with processor (s) 312, memory / memories 316, transceiver 302, UE communicating component 342, etc., can receive, from the network entity, the configuration indicating the RS resource pool over which the multiple RSs are transmitted by the network entity. As described, the RS resource pool configuration can indicate resources over which the RSs are transmitted, and the RS processing component 352 can accordingly receive and / or measure RSs transmitted over the resources of the RS resource pool configuration for reporting to the network entity in the MU report.
[0088] In one example, the measurement resource for determining a best (or desirable) MU pairing can be based on CSI-IM resources configured by the network entity. For example, each CSI-IM resource can correspond to an interference layer or all interference layers from a potentially co-scheduled UE, and as such, RS component 452 can transmit a CSI-RS on each CSI-IM resource configured by the network entity, where the CSI-RSs can be transmitted using a precoder configured for a different UE. When multiplexing all layers in one CSI-IM resource, RS component 452 can use random data for each layer to avoid cancellation. In one example, measuring component 354 can measure L1-SINR for use by MU reporting component 356 in generating the MU report. For example, MU reporting component 356 can use L1-SINR as the metric for MU pairing reporting. In this example, measuring component 354 can measure the signal power based on a measured channel power from a separate NZP CSI-RS resource (with the precoding selected by the UE) or from DMRS in PDSCH scheduled and / or can measure interference and noise power on the resource elements carrying the CSI-IM. In some examples, scheduling component 456 can configure NZP CSI-RS resource for channel measurement in a different CSI reporting setting.
[0089] In this example, the configuration indicating the RS resource pool transmitted at Block 608 can include the CSI-IM configuration, and in method 600, optionally at Block 610, a resource for measuring a NZP CSI-RS from the network entity can be configured for the UE. In an aspect, scheduling component 456, e.g., in conjunction with processor (s) 412, memory / memories 416, transceiver 402, BS communicating component 442, etc., can configure, for the UE (e.g., UE 104) , the resource for measuring the NZP CSI-RS from the network entity. In this example, the network entity can transmit the separate NZP CSI-RS resource, as described above, and measuring component 354 of the UE can measure the signal power (e.g., at Block 506) based on the measured channel power from the NZP CSI-RS.
[0090] In another example, the measuring component 354 can measure, and the MU reporting component 356 can use, the measured interference and noise power from CSI-IM as the metric. In this example, MU reporting component 356 can generate the MU report (e.g., at Block 508) to include a list of CSI-IM resources with low interference level and / or to indicate the corresponding interference power level. In one example, to reduce the overhead and skip reporting of the absolute interference power level, the network entity may configure one CSI-IM resource as a reference resource that corresponds to inter-cell interference only or the current MU interference. In this example, in method 600, optionally at Block 612, a reference resource for measuring a reference CSI-IM signal can be configured for the UE. In an aspect, scheduling component 456, e.g., in conjunction with processor (s) 412, memory / memories 416, transceiver 402, BS communicating component 442, etc., can configure, for the UE (e.g., UE 104) , the reference resource for measuring the reference CSI-IM signal.
[0091] For example, measuring component 354 can measure the interference and noise power on the reference CSI-IM resource, and MU reporting component 356 may use this measured power as a threshold for selecting CSI-IM resources (e.g., MU reporting component 356 may only report the CSI-IM resources with lower interference power than the reference CSI-IM) . In this example, MU reporting component 356 can generate the report (e.g., at Block 508) to include only the index of the selected “good” CSI-IM resources. In an example, MU reporting component 356 may also include, in the MU report, a power difference to the reference CSI-IM (e.g., which may use a smaller number of bits compared to reporting the absolute interference power level, thus conserving radio resources and processing) .
[0092] In one example, the measurement resource for determining a best (or desirable) MU pairing can be based on NZP CSI-RS resources configured by the network entity. For example, each CSI-RS port of the one or more NZP CSI-RS resources can correspond to an interference layer from a potentially co-scheduled UE, and as such, RS component 452 can transmit a CSI-RS on each NZP CSI-RS resource configured by the network entity, where the CSI-RSs can be transmitted using a precoder configured for a different UE. In this example, measuring component 354 can measure the channel of each NZP CSI-RS port and estimate the power of the corresponding interference layer. In one example, measuring component 354 can measure L1-RSRP of the CSI-RSs as the metric for best (or desirable) MU pairing reporting. In an example, MU reporting component 356 can generate the MU report (e.g., at Block 508) to indicate NZP CSI-RS ports / resources with large signal power. In this example, report processing component 454 and / or scheduling component 456 can assume the unreported CSI-RS ports to be good or desirable MU pairing candidates for the UE 104 transmitting the MU report. This may be because when interference is weak and UE 104 may not accurately estimate channel from NZP CSI-RS, the estimated signal power may not be accurate. In another example, MU reporting component 356 may decide reporting NZP CSI-RS resources with high or low signal power based on feedback overhead associated with the resources.
[0093] In another example, UE 104 or the network entity can configure a RSRP threshold, which can be based on a measured channel power from a separate NZP CSI-RS resource (with the precoding selected by the UE) or from DMRS in PDSCH scheduled. In an example, scheduling component 456 can configure this resource (e.g., in Block 610) , as described above. In an example, MU reporting component 356 may also generate the MU report (e.g., at Block 508) to indicate the power difference to the threshold for the reported NZP CSI-RS resources / ports to assist the MU-MIMO scheduling by the network entity.
[0094] In another example, measuring component 354 can measure, and / or MU reporting component 356 can use, L1-SINR for best (or desirable) MU pairing determination and / or reporting. For example, the SINR can be defined by the signal power of the NZP CSI-RS port divided by the averaged inter-cell interference and noise power from all NZP CSI-RS ports / resources. In an example, measuring component 354 can estimate the channel from the signal part of the NZP CSI-RS, cancel the channel, estimate the interference part of the NZP CSI-RS, and then average the measured inter-cell interference and noise power across all NZP CSI-RS resources / ports. In this example, L1-SINR can represent the ratio of the potential MU interference over inter-cell interference and noise power. MU reporting component 356 can generate the MU report to include the L1-SINR or otherwise use the L1-SINR to determine desirable (or non-desirable) RSs or associated UEs for co-scheduling and indicating in the MU report.
[0095] In one example, the network entity can configure, for the UE, MU reporting and CSI reporting in the same reporting setting configuration. For example, as legacy, CSI reporting includes NZP CSI-RS resources for channel measurement and NZP CSI-RS / CSI-IM for interference measurement, scheduling component 456 can use the legacy CSI reporting configuration for also configuring the resources for MU reporting (e.g., in transmitting the configuration at Block 608) . In this example, measuring component 354 can compute, and / or MU reporting component 356 can report, CSI without considering, or regardless of, MU pairing reporting.
[0096] In another example, scheduling component 456 can configure additional CSI-RS resource pool (NZP CSI-RS or CSI-IM) for MU pairing reporting (e.g., at Block 608) . In one example, measuring component 354 can use a precoding matrix indicator (PMI) reported based on legacy CSI-RS to estimate the signal power of the serving channel, and MU reporting component 356 can accordingly determine the CSI-RS resources for best (or desirable) MU pairing based on the signal power established from PMI. That is, for example, MU pairing reporting may be dependent on the CSI. In addition, for example, MU reporting component 356 can jointly report (e.g., at Block 504) the wideband best (or desirable) MU pairing reporting with PMI, channel quality indicator (CQI) , rank indicator (RI) , etc., or separately report the MU report. In another example, MU reporting component 356 can transmit the MU report (e.g., at Block 504) as a periodic, semi-persistent, or aperiodic report –e.g., meaning that the MU reporting component 356 can transmit the MU report periodically (e.g., based on a period of time resource) , semi-persistently (e.g., based on semi-persistent scheduled resources) , or aperiodically (e.g., not based on periodic time resources and / or as dynamically scheduled by the network entity) .
[0097] In another example, scheduling component 456 can configure the MU report (e.g., the best or desirable MU pairing reporting) and CSI reporting in different reporting setting configuration. In this example, for MU report, scheduling component 456 can include, in the reporting setting configuration, only the CSI-RS resources for MU pairing measurement. In such case, for example, measuring component 354 can use the signal power from DMRS in latest scheduled PDSCH as a reference channel power for MU pairing reporting (e.g., for determining desirable UEs for pairing or for otherwise reporting RSs or RSs relative to the reference channel power, etc., as described above) .
[0098] In accordance with some examples described herein, the configured CSI-RS resources for MU reporting may be expected to be occupied; otherwise, the UE 104 may generate the MU report for RS resources over which CSI-RS is not received. For example, if the network entity is not sending CSI-RS, but UE is configured to monitor the resources for CSI-RS, measuring component 354 may measure inter-cell interference on the resources and may wrongly consider the resources as a good candidate for MU pairing. In one example, the RS component 452 can ensure that all of the configured CSI-RS resources include CSI-RSs transmitted with precoder used by interfering UE. In an example, if there is no interfering UE, the RS component 452 can use a dummy or generic precoder (e.g., a precoder not used by the interfering UEs) , which can be repeated over multiple CSI-RS resources if needed. In this case, measuring component 354 may measure multiple good CSI-RSs, and MU reporting component 356 can separately report the CSI-RSs, but report processing component 454 can know that these CSI-RSs may be for the same interferer, and can accordingly process the MU report for determining the MU-MIMO scheduling.
[0099] In another example, the RS component 452 can transmit, to the UE 104, a n indication (e.g., a dynamic indication) of which CSI-RS resources are occupied (e.g., used to transmit CSI-RS with different UE precoders) for MU pairing measurement. In an example, in method 600, optionally at Block 614, a configuration indicating which of the multiple RSs are activated for measurement can be transmitted to the UE. In an aspect, RS component 452, e.g., in conjunction with processor (s) 412, memory / memories 416, transceiver 402, BS communicating component 442, etc., can transmit, to the UE (e.g., UE 104) , the configuration indicating which of the multiple RSs are activated for measurement. For example, RS component 452 can transmit the indication in DCI (e.g., in a group common (GC) -DCI) , which can be for one (or more) CSI-RS resource pools. For example, each bit in the GC-DCI can correspond to one CSI-RS resource or port of the CSI resource pool. In an example, the DCI may be used to indicate available CSI-RS. In one example, BS communicating component 442 can use the remaining resources, not occupied by CSI-RS, for data transmission. In addition, in this example, the CSI-RS resource pool for MU pairing may be aperiodic. In an example, the GC-DCI can also trigger aperiodic MU pairing reporting.
[0100] In this example, in method 500, optionally at Block 512, a configuration indicating which of the multiple RSs are activated for measurement can be received from the network entity. In an aspect, RS processing component 352, e.g., in conjunction with processor (s) 312, memory / memories 316, transceiver 302, UE communicating component 342, etc., can receive, from the network entity, the configuration indicating which of the multiple RSs are activated for measurement. For example, RS processing component 352 can receive the configuration and determine which RSs to receive (e.g., at Block 502) and / or measure for generating the MU report, as described above. In one example, UE communicating component 342 may receive data communications from the network entity over the remaining resources.
[0101] In another example, the different UEs may have a rank greater than one (e.g., the UEs can transmit using more than one layer) , and it may be desirable for the MU report to report the multiple layers of a given different UE together. In one example, when measuring component 354 measures CSI-IM for MU pairing measurement, RS component 452 may multiplex all the layers from the same interfering UE to the same CSI-IM resource (e.g., in transmitting the CSI-RS using the associated precoder over the CSI-IM resource) . In an example, a selection of the CSI-IM resource (e.g., an indication of the CSI-IM resource in the MU report) can be associated with a selection of all layers for a given UE. In another example, when measuring component 354 measures NZP CSI-RS for MU pairing measurement and each NZP CSI-RS port corresponds to an interference transmission layer, RS component 452 can use a dummy precoder and repeat it over the unused CSI-RS ports if the rank of the different UE is less than the configured number of CSI-RS ports (e.g., max rank) . For example, the dummy precoder can be the precoder of the one of interference transmission layers. In yet another example, scheduling component 456 can dynamically indicate the association of CSI-RS resources / ports to the UE 104. For example, the dynamic indication can include a bit string has a size equal to number of CSI-RS resources / ports. In one example, scheduling component 456 can toggle the bit value (e.g., from 0 to 1 or vice versa) to indicate a change of the different UE napped to the CSI-RS resources. For example, a bit string “00111011” can indicate the first 2 CSI-RS are associated with a first UE, the next 3 CSI-RS are associated with a second UE, the sixth CSI-RS is associated with a third UE and the seventh and eighth CSI-RS are associated with the fourth UE.
[0102] In this example, in method 600, optionally at Block 616, a configuration indicating which of the multiple RSs correspond to which of the different UEs can be transmitted to the UE. In an aspect, RS component 452, e.g., in conjunction with processor (s) 412, memory / memories 416, transceiver 402, BS communicating component 442, etc., can transmit, to the UE (e.g., UE 104) , the configuration indicating which of the multiple RSs correspond to which of the different UEs. As described, for example, the configuration can include a bitmap indicating which CSI-RSs correspond to which UEs, where multiple CSI-RSs can be configured for a UE with a rank greater than one. In this example, in method 500, optionally at Block 514, a configuration indicating which of the multiple RSs correspond to which of the one or more different UEs can be received from the network entity. In an aspect, RS processing component 352, e.g., in conjunction with processor (s) 312, memory / memories 316, transceiver 302, UE communicating component 342, etc., can receive, from the network entity, the configuration indicating which of the multiple RSs correspond to which of the one or more difference UEs. For example, RS processing component 352 can receive the multiple RSs (e.g., at Block 502) based on the configuration, and MU reporting component 356 can accordingly generate the MU report (e.g., at Block 508) identifying the RSs of one or more of the different UEs, identifying one or more of the different UEs corresponding to multiple RSs, etc.
[0103] FIG. 7 is a diagram illustrating an example of a wireless communication network 700 including a base station 102 that communicates with a first UE 702 using a first precoder to generate beam 704 and a second UE 706 using a second precoder to generate beam 708, in accordance with aspects described herein. FIG. 8 illustrates an example of a resource allocation 800 showing resources (e.g., in time and frequency, such as over a carrier bandwidth in a slot of symbols) for a network entity to use transmitting the CSI-RSs for MU reporting, in accordance with aspects described herein. In this example, base station 102 can transmit CSI-RS for UE 104 to use in generating a MU report. Base station 102 can transmit a first CSI-RS (e.g., CSI-RS #1 in resource allocation 800) using the first precoder corresponding to beam 704 and a second CSI-RS (e.g., CSI-RS #2 in resource allocation 800) using the second precoder corresponding to beam 708. For example, as described, base station 102 may configure the UE 104 to receive the CSI-RSs for MU reporting using one or more of the various configurations described herein, to configure the CSI-RS resource allocation or resource pool (e.g., resource allocation 800) . In any case, UE 104 can receive and measure these CSI-RSs, as described above, and generate an MU report indicating one or more of the CSI-RSs or corresponding UEs as desirable for pairing with UE 104 for MU-MIMO scheduling.
[0104] FIG. 9 illustrates an example of a call flow 900 between a UE 102 and network entity 902 for performing MU reporting and MU-MIMO scheduling, in accordance with aspects described herein. For example, network entity 902 can include a base station, gNB, or other network node, as described herein. At 904, the network entity 902 can transmit an indication of a CSI-RS resource pool for MU reporting to the UE 104, as described in various examples above. At 906, the network entity 902 can also transmit, to the UE 104, a GC-DCI for indicating available CSI-RS for MU pairing measurement (e.g., where not all CSI-RSs are activated or where some CSI-RSs are associated with the same UE having a rank greater than one) . At 908, the network entity 902 can transmit, to the UE 104, CSI -RS with precoder used by interference UE (s) (e.g., UEs that may interfere with UE 104) . The UE 104 can measure the CSI-RS over the resources indicated in the CSI-RS resource pool and can generate a MU report and transmit the MU report to the network entity 902 at 910, in accordance with various examples above. The MU report can identify, or allow the network entity 902 to identify, the interfering UEs that may be desirable to pair with UE 104 in co-scheduling the UEs for MU-MIMO. At 912, the network entity 902 can accordingly update MU scheduling based on the MU report (e.g., to pair UE 104 with one or more of the interfering UEs for co-scheduling based on the MU report) . At 914, network entity 902 can perform MU-MIMO transmission to the UE 104 and / or one or more co-scheduled UEs.
[0105] FIG. 10 is a block diagram of a MIMO communication system 1000 including a base station 102 and a UE 104. The MIMO communication system 1000 may illustrate aspects of the wireless communication access network 100 described with reference to FIG. 1. The base station 102 may be an example of aspects of the base station 102 described with reference to FIG. 1. The base station 102 may be equipped with antennas 1034 and 1035, and the UE 104 may be equipped with antennas 1052 and 1053. In the MIMO communication system 1000, the base station 102 may be able to send data over multiple communication links at the same time. Each communication link may be called a “layer” and the “rank” of the communication link may indicate the number of layers used for communication. For example, in a 2x2 MIMO communication system where base station 102 transmits two “layers, ” the rank of the communication link between the base station 102 and the UE 104 is two.
[0106] At the base station 102, a transmit (Tx) processor 1020 may receive data from a data source. The transmit processor 1020 may process the data. The transmit processor 1020 may also generate control symbols or reference symbols. A transmit MIMO processor 1030 may perform spatial processing (e.g., precoding) on data symbols, control symbols, or reference symbols, if applicable, and may provide output symbol streams to the transmit modulator / demodulators 1032 and 1033. Each modulator / demodulator 1032 through 1033 may process a respective output symbol stream (e.g., for OFDM, etc. ) to obtain an output sample stream. Each modulator / demodulator 1032 through 1033 may further process (e.g., convert to analog, amplify, filter, and upconvert) the output sample stream to obtain a DL signal. In one example, DL signals from modulator / demodulators 1032 and 1033 may be transmitted via the antennas 1034 and 1035, respectively.
[0107] The UE 104 may be an example of aspects of the UEs 104 described with reference to FIGS. 1 and 3. At the UE 104, the UE antennas 1052 and 1053 may receive the DL signals from the base station 102 and may provide the received signals to the modulator / demodulators 1054 and 1055, respectively. Each modulator / demodulator 1054 through 1055 may condition (e.g., filter, amplify, downconvert, and digitize) a respective received signal to obtain input samples. Each modulator / demodulator 1054 through 1055 may further process the input samples (e.g., for OFDM, etc. ) to obtain received symbols. A MIMO detector 1056 may obtain received symbols from the modulator / demodulators 1054 and 1055, perform MIMO detection on the received symbols, if applicable, and provide detected symbols. A receive (Rx) processor 1058 may process (e.g., demodulate, deinterleave, and decode) the detected symbols, providing decoded data for the UE 104 to a data output, and provide decoded control information to a processor (s) 1080, or memory / memories 1082.
[0108] The processor (s) 1080 may in some cases execute stored instructions to instantiate a UE communicating component 342 (see e.g., FIGS. 1 and 3) .
[0109] On the uplink (UL) , at the UE 104, a transmit processor 1064 may receive and process data from a data source. The transmit processor 1064 may also generate reference symbols for a reference signal. The symbols from the transmit processor 1064 may be precoded by a transmit MIMO processor 1066 if applicable, further processed by the modulator / demodulators 1054 and 1055 (e.g., for single carrier-FDMA, etc. ) , and be transmitted to the base station 102 in accordance with the communication parameters received from the base station 102. At the base station 102, the UL signals from the UE 104 may be received by the antennas 1034 and 1035, processed by the modulator / demodulators 1032 and 1033, detected by a MIMO detector 1036 if applicable, and further processed by a receive processor 1038. The receive processor 1038 may provide decoded data to a data output and to the processor (s) 1040 or memory / memories 1042.
[0110] The processor (s) 1040 may in some cases execute stored instructions to instantiate a BS communicating component 442 (see e.g., FIGS. 1 and 4) .
[0111] The components of the UE 104 may, individually or collectively, be implemented with one or more ASICs adapted to perform some or all of the applicable functions in hardware. Each of the noted modules may be a means for performing one or more functions related to operation of the MIMO communication system 1000. Similarly, the components of the base station 102 may, individually or collectively, be implemented with one or more application specific integrated circuits (ASICs) adapted to perform some or all of the applicable functions in hardware. Each of the noted components may be a means for performing one or more functions related to operation of the MIMO communication system 1000.
[0112] The following aspects are illustrative only and aspects thereof may be combined with aspects of other embodiments or teaching described herein, without limitation.
[0113] Aspect 1 is a method for wireless communications at a UE including receiving, from a network entity, multiple reference signals that each have a precoder of a different UE applied, and transmitting, to the network entity and based on a measurement of each of the multiple reference signals, a MU report indicating at least a portion of the multiple reference signals for MU pairing the UE with one or more of the different UEs.
[0114] In Aspect 2, the method of Aspect 1 includes generating the MU report to include at least the portion of the multiple reference signals having the measurement less than a threshold, where the measurement relates to an energy or interference level.
[0115] In Aspect 3, the method of any of Aspects 1 or 2 includes generating the MU report to include at least the portion of the multiple reference signals based on sorting by a level of energy or interference.
[0116] In Aspect 4, the method of any of Aspects 1 to 3 includes where the multiple reference signals are zero power CSI-IM signals, and where each resource of the multiple reference signals corresponds to all interference layers of the one or more of the different UEs.
[0117] In Aspect 5, the method of Aspect 4 includes where the measurement is L1-SINR computed based at least in part on comparing the measurement to a measured channel power from a non-zero power CSI-RS resource or a DMRS in a downlink data channel.
[0118] In Aspect 6, the method of any of Aspects 4 or 5 includes where generating the MU report is based on comparing the measurement of the multiple reference signals to a reference measurement of a CSI-IM resource configured as a reference resource.
[0119] In Aspect 7, the method of Aspect 6 includes where the MU report indicates, for each of at least the portion of the multiple reference signals, a power difference relative to the reference measurement.
[0120] In Aspect 8, the method of any of Aspects 1 to 7 includes where the multiple reference signals are non-zero power CSI-RSs, and where each port of the multiple reference signals corresponds to an interference layer from the one or more of different UEs.
[0121] In Aspect 9, the method of Aspect 8 includes where the measurement is L1-RSRP, and generating the MU report to include at least the portion of the multiple reference signals based on comparing the L1-RSRP to a threshold.
[0122] In Aspect 10, the method of Aspect 9 includes where the threshold is based on one or more of a measured power of a separate non-zero power CSI-RS resource, or a DMRS in a downlink data channel.
[0123] In Aspect 11, the method of any of Aspects 9 or 10 includes where the MU report indicates, for each of at least the portion of the multiple reference signals, a power difference between the L1-RSRP and the threshold.
[0124] In Aspect 12, the method of any of Aspects 8 to 11 includes where the measurement is L1-SINR computed as a signal power of an associated reference signal divided by an averaged inter-cell interference and noise power from the multiple reference signals.
[0125] In Aspect 13, the method of any of Aspects 1 to 12 includes receiving, from the network entity, a configuration indicating a reference signal resource pool over which the multiple reference signals are transmitted by the network entity, where the reference signal resource pool is different from a resource pool configured by the network entity for CSI reference signals for CSI reporting.
[0126] In Aspect 14, the method of any of Aspects 1 to 13 includes where performing the measurement of each of the multiple reference signals is based on using a reported PMI to measure a signal power of a serving channel, and comparing the signal power to the measurement of each of the multiple reference signals.
[0127] In Aspect 15, the method of any of Aspects 1 to 14 includes where transmitting the MU report includes transmitting the MU report periodically, semi-persistently, or aperiodically.
[0128] In Aspect 16, the method of any of Aspects 1 to 15 includes receiving, from the network entity, a configuration indicating which of the multiple reference signals are activated for measurement, and where resources corresponding to at least a portion of remaining reference signals are used for data transmission.
[0129] In Aspect 17, the method of any of Aspects 1 to 16 includes receiving, from the network entity, a configuration indicating which of the multiple reference signals correspond to which of the one or more different UEs.
[0130] Aspect 18 is a method for wireless communications at a network entity including transmitting multiple reference signals that each have a precoder of a different UE applied, receiving, from a UE, a MU report indicating at least a portion of the multiple reference signals for MU pairing the UE with one or more of the different UEs, and scheduling, based on the MU report, the UE and the one or more different UEs for MU-MIMO communications.
[0131] In Aspect 19, the method of Aspect 18 includes where the MU report indicates a measurement of at least the portion of the multiple reference signals and a level of interference of each of at least the portion of the multiple reference signals.
[0132] In Aspect 20, the method of any of Aspects 18 or 19 includes where scheduling the UE and the one or more different UEs for MU-MIMO communications is based on at least one of the MU report indicating a measurement of a reference signal corresponding to the one or more different UEs as being less than a threshold or a different MU report from the one or more different UEs indicating a measurement of a reference signal corresponding to the UE as being less than the threshold.
[0133] In Aspect 21, the method of any of Aspects 18 to 20 includes where the multiple reference signals are zero-power CSI-IM signals, and where each resource of the multiple reference signals corresponds to all interference layers of the one or more of the different UEs.
[0134] In Aspect 22, the method of Aspect 21 includes configuring, for the UE, a resource for measuring a non-zero power channel state information (CSI) reference signal from the network entity.
[0135] In Aspect 23, the method of any of Aspects 21 or 22 includes configuring, for the UE, a reference resource for measuring a reference CSI-IM signal, where the MU report includes at least the portion of the reference signals based on a reference measurement of the reference CSI-IM signal.
[0136] In Aspect 24, the method of Aspect 23 includes where the MU report indicates, for each of at least the portion of the multiple reference signals, a power difference relative to the reference measurement.
[0137] In Aspect 25, the method of any of Aspects 18 to 24 includes where the multiple reference signals are non-zero power CSI-RSs, and where each port of the multiple reference signals corresponds to an interference layer from the one or more of different UEs.
[0138] In Aspect 26, the method of Aspect 25 includes configuring, for the UE, a resource for measuring a reference non-zero power CSI reference signal from the network entity.
[0139] In Aspect 27, the method of any of Aspects 18 to 26 includes transmitting, to the UE, a configuration indicating a reference signal resource pool over which the multiple reference signals are transmitted by the network entity, where the reference signal resource pool is different from a resource pool configured by the network entity for CSI reference signals for CSI reporting.
[0140] In Aspect 28, the method of any of Aspects 18 to 27 includes where receiving the MU report includes receiving the MU report periodically, semi-persistently, or aperiodically.
[0141] In Aspect 29, the method of any of Aspects 18 to 28 includes where the multiple reference signals include at least one reference signal transmitted based on a generic precoder that is not specific to any of the different UEs.
[0142] In Aspect 30, the method of any of Aspects 18 to 29 includes transmitting, to the UE, a configuration indicating which of the multiple reference signals are activated for measurement, and where resources corresponding to at least a portion of remaining reference signals are used for data transmission.
[0143] In Aspect 31, the method of any of Aspects 18 to 30 includes where transmitting the multiple reference signals includes multiplexing multiple layers from one of different UEs having a rank greater than one on a single CSI-IM resource.
[0144] In Aspect 32, the method of any of Aspects 18 to 31 includes where transmitting the multiple reference signals includes transmitting, for at least one of the different UEs, at least one reference signal using a generic precoder where a rank of the at least one of the different UEs is less than a number of reference signal ports configured for the at least one of the different UEs.
[0145] In Aspect 33, the method of any of Aspects 18 to 32 includes transmitting, to the UE, a configuration indicating which of the multiple reference signals correspond to which of the different UEs.
[0146] Aspect 34 is an apparatus for wireless communication including one or more processors, one or more memories coupled with the one or more processors, and instructions stored in the one or more memories and operable, when executed by the one or more processors, to cause the apparatus to perform any of the methods of Aspects 1 to 33.
[0147] Aspect 35 is an apparatus for wireless communication including means for performing any of the methods of Aspects 1 to 33.
[0148] Aspect 36 is one or more computer-readable media including code executable by one or more processors for wireless communications, the code including code for performing any of the methods of Aspects 1 to 33.
[0149] The above detailed description set forth above in connection with the appended drawings describes examples and does not represent the only examples that may be implemented or that are within the scope of the claims. The term “example, ” when used in this description, means “serving as an example, instance, or illustration, ” and not “preferred” or “advantageous over other examples. ” The detailed description includes specific details for the purpose of providing an understanding of the described techniques. These techniques, however, may be practiced without these specific details. In some instances, well-known structures and apparatuses are shown in block diagram form in order to avoid obscuring the concepts of the described examples.
[0150] Information and signals may be represented using any of a variety of different technologies and techniques. For example, data, instructions, commands, information, signals, bits, symbols, and chips that may be referenced throughout the above description may be represented by voltages, currents, electromagnetic waves, magnetic fields or particles, optical fields or particles, computer-executable code or instructions stored on a computer-readable medium, or any combination thereof.
[0151] The various illustrative blocks and components described in connection with the disclosure herein may be implemented or performed with a specially programmed device, such as but not limited to a processor, a digital signal processor (DSP) , an ASIC, a field programmable gate array (FPGA) or other programmable logic device, a discrete gate or transistor logic, a discrete hardware component, or any combination thereof designed to perform the functions described herein. A specially programmed processor may be a microprocessor, but in the alternative, the processor may be any conventional processor, controller, microcontroller, or state machine. A specially programmed processor may also be implemented as a combination of computing devices, e.g., a combination of a DSP and a microprocessor, multiple microprocessors, one or more microprocessors in conjunction with a DSP core, or any other such configuration.
[0152] The functions described herein may be implemented in hardware, software executed by a processor, firmware, or any combination thereof. If implemented in software executed by a processor, the functions may be stored on or transmitted over as one or more instructions or code on a non-transitory computer-readable medium. Other examples and implementations are within the scope and spirit of the disclosure and appended claims. For example, due to the nature of software, functions described above can be implemented using software executed by a specially programmed processor, hardware, firmware, hardwiring, or combinations of any of these. Features implementing functions may also be physically located at various positions, including being distributed such that portions of functions are implemented at different physical locations. Also, as used herein, including in the claims, “or” as used in a list of items prefaced by “at least one of” indicates a disjunctive list such that, for example, a list of “at least one of A, B, or C” means A or B or C or AB or AC or BC or ABC (i.e., A and B and C) .
[0153] Computer-readable media includes both computer storage media and communication media including any medium that facilitates transfer of a computer program from one place to another. A storage medium may be any available medium that can be accessed by a general purpose or special purpose computer. By way of example, and not limitation, computer-readable media can comprise RAM, ROM, EEPROM, CD-ROM or other optical disk storage, magnetic disk storage or other magnetic storage devices, or any other medium that can be used to carry or store desired program code means in the form of instructions or data structures and that can be accessed by a general-purpose or special-purpose computer, or a general-purpose or special-purpose processor. Also, any connection is properly termed a computer-readable medium. For example, if the software is transmitted from a website, server, or other remote source using a coaxial cable, fiber optic cable, twisted pair, digital subscriber line (DSL) , or wireless technologies such as infrared, radio, and microwave, then the coaxial cable, fiber optic cable, twisted pair, DSL, or wireless technologies such as infrared, radio, and microwave are included in the definition of medium. Disk and disc, as used herein, include compact disc (CD) , laser disc, optical disc, digital versatile disc (DVD) , floppy disk and Blu-ray disc where disks usually reproduce data magnetically, while discs reproduce data optically with lasers. Combinations of the above are also included within the scope of computer-readable media.
[0154] The previous description of the disclosure is provided to enable a person skilled in the art to make or use the disclosure. Various modifications to the disclosure will be readily apparent to those skilled in the art, and the common principles defined herein may be applied to other variations without departing from the spirit or scope of the disclosure. Furthermore, although elements of the described aspects and / or embodiments may be described or claimed in the singular, the plural is contemplated unless limitation to the singular is explicitly stated. Additionally, all or a portion of any aspect and / or embodiment may be utilized with all or a portion of any other aspect and / or embodiment, unless stated otherwise. Thus, the disclosure is not to be limited to the examples and designs described herein but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.
Claims
1.An apparatus for wireless communication, comprising:a transceiver;one or more memories configured to, individually or in combination, store instructions; andone or more processors communicatively coupled with the one or more memories, wherein the one or more processors are, individually or in combination, configured to execute the instructions to cause the apparatus to:receive, from a network entity, multiple reference signals that each have a precoder of a different user equipment (UE) applied; andtransmit, to the network entity and based on a measurement of each of the multiple reference signals, a multi-user (MU) report indicating at least a portion of the multiple reference signals for MU pairing the UE with one or more of the different UEs.2.The apparatus of claim 1, wherein the one or more processors are, individually or in combination, configured to execute the instructions to cause the apparatus to generate the MU report to include at least the portion of the multiple reference signals having the measurement less than a threshold, wherein the measurement relates to an energy or interference level.3.The apparatus of claim 1, wherein the one or more processors are, individually or in combination, configured to execute the instructions to cause the apparatus to generate the MU report to include at least the portion of the multiple reference signals based on sorting by a level of energy or interference.4.The apparatus of claim 1, wherein the multiple reference signals are zero power channel station information (CSI) -interference measurement (IM) signals, and wherein each resource of the multiple reference signals corresponds to all interference layers of the one or more of the different UEs.5.The apparatus of claim 4, wherein the measurement is layer 1 (L1) -signal-to-interference-and-noise-ratio (SINR) computed based at least in part on comparing the measurement to a measured channel power from a non-zero power CSI-reference signal (RS) resource or a demodulation reference signal (DMRS) in a downlink data channel.6.The apparatus of claim 4, wherein the one or more processors are, individually or in combination, configured to execute the instructions to cause the apparatus to generate the MU report based on comparing the measurement of the multiple reference signals to a reference measurement of a CSI-IM resource configured as a reference resource.7.The apparatus of claim 6, wherein the MU report indicates, for each of at least the portion of the multiple reference signals, a power difference relative to the reference measurement.8.The apparatus of claim 1, wherein the multiple reference signals are non-zero power channel station information (CSI) -reference signals (RSs) , and wherein each port of the multiple reference signals corresponds to an interference layer from the one or more of different UEs.9.The apparatus of claim 8, wherein the measurement is layer 1 (L1) reference signal received power (RSRP) , and wherein the one or more processors are, individually or in combination, configured to execute the instructions to cause the apparatus to generate the MU report to include at least the portion of the multiple reference signals based on comparing the L1-RSRP to a threshold.10.The apparatus of claim 9, wherein the threshold is based on one or more of a measured power of a separate non-zero power CSI-RS resource, or a demodulation reference signal (DMRS) in a downlink data channel.11.The apparatus of claim 9, wherein the MU report indicates, for each of at least the portion of the multiple reference signals, a power difference between the L1-RSRP and the threshold.12.The apparatus of claim 8, wherein the measurement is layer 1 (L1) -signal-to-interference-and-noise-ratio (SINR) computed as a signal power of an associated reference signal divided by an averaged inter-cell interference and noise power from the multiple reference signals.13.The apparatus of claim 1, wherein the one or more processors are, individually or in combination, configured to execute the instructions to cause the apparatus to receive, from the network entity, a configuration indicating a reference signal resource pool over which the multiple reference signals are transmitted by the network entity, wherein the reference signal resource pool is different from a resource pool configured by the network entity for channel state information (CSI) reference signals for CSI reporting.14.The apparatus of claim 1, wherein the one or more processors are, individually or in combination, configured to execute the instructions to cause the apparatus to perform the measurement of each of the multiple reference signals based on using a reported precoding matrix indicator (PMI) to measure a signal power of a serving channel, and comparing the signal power to the measurement of each of the multiple reference signals.15.The apparatus of claim 1, wherein the one or more processors are, individually or in combination, configured to execute the instructions to cause the apparatus to transmit the MU report periodically, semi-persistently, or aperiodically.16.The apparatus of claim 1, wherein the one or more processors are, individually or in combination, configured to execute the instructions to cause the apparatus to receive, from the network entity, a configuration indicating which of the multiple reference signals are activated for measurement, and wherein resources corresponding to at least a portion of remaining reference signals are used for data transmission.17.The apparatus of claim 1, wherein the one or more processors are, individually or in combination, configured to execute the instructions to cause the apparatus to receive, from the network entity, a configuration indicating which of the multiple reference signals correspond to which of the one or more different UEs.18.An apparatus for wireless communication, comprising:a transceiver;one or more memories configured to, individually or in combination, store instructions; andone or more processors communicatively coupled with the one or more memories, wherein the one or more processors are, individually or in combination, configured to execute the instructions to cause the apparatus to:transmit multiple reference signals that each have a precoder of a different user equipment (UE) applied;receive, from a UE, a multi-user (MU) report indicating at least a portion of the multiple reference signals for MU pairing the UE with one or more of the different UEs; andschedule, based on the MU report, the UE and the one or more different UEs for MU-multiple-input multiple-output (MIMO) communications.19.The apparatus of claim 18, wherein the MU report indicates a measurement of at least the portion of the multiple reference signals and a level of interference of each of at least the portion of the multiple reference signals.20.The apparatus of claim 18, wherein the one or more processors are, individually or in combination, configured to execute the instructions to cause the apparatus to schedule the UE and the one or more different UEs for MU-MIMO communications based on at least one of the MU report indicating a measurement of a reference signal corresponding to the one or more different UEs as being less than a threshold or a different MU report from the one or more different UEs indicating a measurement of a reference signal corresponding to the UE as being less than the threshold.21.The apparatus of claim 18, wherein the multiple reference signals are zero-power channel station information (CSI) -interference measurement (IM) signals, and wherein each resource of the multiple reference signals corresponds to all interference layers of the one or more of the different UEs.22.The apparatus of claim 21, wherein the one or more processors are, individually or in combination, configured to execute the instructions to cause the apparatus to configure, for the UE, a resource for measuring a non-zero power channel state information (CSI) reference signal from the network entity.23.The apparatus of claim 21, wherein the one or more processors are, individually or in combination, configured to execute the instructions to cause the apparatus to configure, for the UE, a reference resource for measuring a reference CSI-IM signal, wherein the MU report includes at least the portion of the reference signals based on a reference measurement of the reference CSI-IM signal.24.The apparatus of claim 23, wherein the MU report indicates, for each of at least the portion of the multiple reference signals, a power difference relative to the reference measurement.25.The apparatus of claim 18, wherein the multiple reference signals are non-zero power channel station information (CSI) -reference signals (RSs) , and wherein each port of the multiple reference signals corresponds to an interference layer from the one or more of different UEs.26.The apparatus of claim 25, wherein the one or more processors are, individually or in combination, configured to execute the instructions to cause the apparatus to configure, for the UE, a resource for measuring a reference non-zero power channel state information (CSI) reference signal from the network entity.27.A method for wireless communications at a user equipment (UE) , comprising:receiving, from a network entity, multiple reference signals that each have a precoder of a different UE applied; andtransmitting, to the network entity and based on a measurement of each of the multiple reference signals, a multi-user (MU) report indicating at least a portion of the multiple reference signals for MU pairing the UE with one or more of the different UEs.28.The method of claim 27, further comprising generating the MU report to include at least the portion of the multiple reference signals having the measurement less than a threshold, wherein the measurement relates to an energy or interference level.29.A method for wireless communications at a network entity, comprising:transmitting multiple reference signals that each have a precoder of a different user equipment (UE) applied;receiving, from a UE, a multi-user (MU) report indicating at least a portion of the multiple reference signals for MU pairing the UE with one or more of the different UEs; andscheduling, based on the MU report, the UE and the one or more different UEs for MU-multiple-input multiple-output (MIMO) communications.30.The method of claim 29, wherein the MU report indicates a measurement of at least the portion of the multiple reference signals and a level of interference of each of at least the portion of the multiple reference signals.
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