Methods and products for codebook subset restriction (CBSR) per spatial domain amplitude

Abstract

Certain aspects of the present disclosure provide techniques for channel state information (CSI) reporting with frequency domain (FD) compression. More specifically, aspects of the present disclosure provide codebook subset restriction (CBSR) per spatial domain (SD) basis amplitude.

Description

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims the benefit of and priority to International Application No. PCT / CN2019 / 092255, filed on June 21, 2019, which is hereby assigned to the assignee of this application and is expressly incorporated herein by reference in its entirety, as if fully set forth below and for all applicable purposes. Technical Field

[0003] Aspects of the present disclosure relate to wireless communications and, more particularly, to techniques for codebook subset restriction (CBSR) for CSI reporting. Background Art

[0004] Wireless communication systems are widely deployed to provide various telecommunication services such as telephony, video, data, messaging, broadcast, etc. These wireless communication systems may employ multiple-access technologies capable of supporting communication with multiple users by sharing available system resources (e.g., bandwidth, transmit power, etc.). Examples of such multiple-access systems include Third Generation Partnership Project (3GPP) Long Term Evolution (LTE) systems, LTE-Advanced (LTE-A) systems, Code Division Multiple Access (CDMA) systems, Time Division Multiple Access (TDMA) systems, Frequency Division Multiple Access (FDMA) systems, Orthogonal Frequency Division Multiple Access (OFDMA) systems, Single Carrier Frequency Division Multiple Access (SC-FDMA) systems, and Time Division Synchronous Code Division Multiple Access (TD-SCDMA) systems, to name just a few.

[0005] In some examples, a wireless multiple access communication system may include multiple base stations (BSs), each BS being capable of simultaneously supporting communications for multiple communication devices (otherwise referred to as user equipment (UE)). In an LTE or LTE-A network, a set of one or more base stations may define an eNodeB (eNB). In other examples (e.g., in a next generation, new radio (NR) or 5G network), a wireless multiple access communication system may include multiple distributed units (DUs) (e.g., edge units (EUs), edge nodes (ENs), radio heads (RHs), smart radio heads (SRHs), transmit receive points (TRPs), etc.) communicating with multiple central units (CUs) (e.g., central nodes (CNs), access node controllers (ANCs), etc.), wherein a set of one or more DUs communicating with a CU may define an access node (e.g., which may be referred to as a BS, a 5G NB, a next generation Node B (gNB or gNodeB), a transmit receive point (TRP), etc.). A BS or DU may communicate with a set of UEs on downlink channels (eg, for transmissions from the BS or DU to the UEs) and uplink channels (eg, for transmissions from the UEs to the BS or DU).

[0006] These multiple access technologies have been adopted in a variety of telecommunication standards to provide a common protocol that enables different wireless devices to communicate at a city, country, region, or even global level. NR (e.g., New Radio or 5G) is an example of an emerging telecommunication standard. NR is an enhancement set of the LTE mobile standard released by 3GPP. NR is designed to better support mobile broadband Internet access by improving spectrum efficiency, reducing costs, improving services, utilizing new spectrum, and better integrating with other open standards using OFDMA with cyclic prefix (CP) on downlink (DL) and uplink (UL). To this end, NR supports beamforming, multiple-input multiple-output (MIMO) antenna technology, and carrier aggregation.

[0007] However, as the demand for mobile broadband access continues to increase, there is a need for further improvements in NR and LTE technologies. Preferably, these improvements should be applicable to other multi-access technologies and the telecommunication standards that employ these technologies. Summary of the invention

[0008] The systems, methods, and devices of the present disclosure each have several aspects, no single one of which is solely responsible for its desirable attributes. Without limiting the scope of the present disclosure as expressed by the claims that follow, some features will now be briefly discussed. After considering this discussion, and particularly after reading the section entitled "Detailed Description," those skilled in the art will understand how the features of the present disclosure provide advantages, including improved communication between access points and stations in a wireless network.

[0009] Certain aspects of the present disclosure relate to a method for wireless communication by a user equipment (UE). The method generally includes: receiving a channel state information (CSI) request from a base station, the CSI request triggering a CSI report including at least one of a plurality of spatial domain (SD) bases, a plurality of frequency domain (FD) bases, and a plurality of linear combination coefficients; receiving a configuration, the configuration limiting the maximum average magnitude of the linear combination coefficients associated with each SD basis; and sending a CSI report, the CSI report having the linear combination coefficients generated according to the configuration.

[0010] Certain aspects of the present disclosure relate to a method for wireless communication by a user equipment (UE). The method generally includes: sending a channel state information (CSI) request to a user equipment (UE), the CSI request triggering a CSI report including at least one of a plurality of spatial domain (SD) bases, a plurality of frequency domain (FD) bases, and a plurality of linear combination coefficients; sending a configuration to the UE, the configuration limiting the maximum average magnitude of the linear combination coefficients associated with each SD basis; and receiving the CSI report; and processing the linear combination coefficients included in the CSI report according to the configuration.

[0011] To achieve the foregoing and related ends, one or more aspects include the features fully described below and particularly pointed out in the claims. The following description and the accompanying drawings set forth in detail certain illustrative features of one or more aspects. However, these features are only indicative of a small number of the various ways in which the principles of the various aspects can be employed. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] In order to be able to understand the above-mentioned features of the present disclosure in detail, a more specific description of the content briefly summarized above can be obtained by reference to various aspects, some of which are shown in the accompanying drawings. However, it should be noted that the accompanying drawings only show certain typical aspects of the present disclosure and are therefore not to be considered as limiting its scope, as the specification may admit to other equally effective aspects.

[0013] Figure 1 is a block diagram conceptually illustrating an example telecommunications system in accordance with certain aspects of the present disclosure.

[0014] Figure 2 is a block diagram illustrating an example of a communication protocol stack for implementation in an example RAN architecture in accordance with certain aspects of the present disclosure.

[0015] Figure 3 is a block diagram conceptually illustrating designs of example base stations (BSs) and user equipments (UEs) in accordance with certain aspects of the present disclosure.

[0016] Figure 4 An example of a frame format for a telecommunications system is shown in accordance with certain aspects of the present disclosure.

[0017] Figure 5 A conceptual example of a first precoder matrix for transmission layer 0 and a second precoder matrix for transmission layer 1 is shown in accordance with certain aspects of the present disclosure.

[0018] Figure 6 Three tables showing example M values ​​according to rank and layer according to certain aspects of the present disclosure are shown.

[0019] Figure 7 Various matrices are shown graphically.

[0020] Figure 8 is a flow diagram illustrating example operations for wireless communications by a UE in accordance with certain aspects of the present disclosure.

[0021] Fig. 9 is a flow diagram illustrating example operations for wireless communications by a base station in accordance with certain aspects of the present disclosure.

[0022] Fig.10 is a call flow diagram illustrating example operations for wireless communications between a UE and a BS in accordance with certain aspects of the present disclosure.

[0023] To facilitate understanding, identical reference numerals have been used, where possible, to designate identical elements that are common to the figures. It is contemplated that elements disclosed in one aspect may be beneficially utilized on other aspects without specific recitation. DETAILED DESCRIPTION

[0024] Aspects of the present disclosure provide apparatus, methods, processing systems, and computer-readable media for frequency domain (FD) compressed channel state information (CSI) reporting.

[0025] In some systems, such as some new radio systems (e.g., Release 16 5G NR systems), in order to save overhead for linear combination codebooks (also referred to as type II codebooks), a frequency-compressed codebook may be used and reported via two-stage uplink control information (UCI). In some aspects, the UE may report the selected FD basis independently for each layer, and determine the number of FD basis for each layer of each rank based on the configuration from the network. In some aspects, a two-stage FD basis report is used to indicate the FD basis selection for each layer to the network. The first stage uses an intermediate set, while the second stage includes a separate FD basis report for each layer.

[0026] In some cases, the size of the intermediate set is reported by the UE. That is, the UE freely selects the FD basis for each layer from a total of N3 FD bases; and the UE determines an intermediate set containing the union of the FD bases selected for each layer. The UE needs to report the size of the intermediate set in UCI Part 1, and report information related to the intermediate set in UCI Part 2, and report a separate FD basis for each layer in UCI Part 2. In some other aspects, the size of the intermediate set is configured by the network, or is derived by the UE based on some other configuration parameters following a rule fixed in the specification, or the size is explicitly specified in the wireless communication specification. In this case, the UE needs to find an intermediate set that is common to all layers of a certain rank based on the size of the intermediate set. Then, the UE does not need to report the size, but may or may not need to report information about the intermediate set in UCI Part 2, and also report a separate FD basis from the intermediate set for each layer in UCI Part 2.

[0027] The following description provides examples and is not intended to limit the scope, applicability or examples set forth in the claims. Without departing from the scope of the present disclosure, the functions and arrangements of the elements discussed may be changed. Various examples may omit, replace or add various processes or components as needed. For example, the described method may be performed in an order different from the order described, and various steps may be added, omitted or combined. In addition, the features described with respect to some examples may be combined in some other examples. For example, a device may be implemented or a method may be implemented using any number of aspects set forth herein. In addition, the scope of the present disclosure is intended to cover such devices or methods implemented using other structures, functions, or structures and functions other than or different from the various aspects of the disclosure set forth herein. It should be understood that any aspect of the disclosure disclosed herein may be embodied by one or more elements of the claims. The term "exemplary" is used herein to mean "used as an example, instance or illustration". Any aspect described as "exemplary" herein is not necessarily to be interpreted as being preferred or having advantages over other aspects.

[0028] The technology described herein can be used for various wireless communication technologies, such as LTE, CDMA, TDMA, FDMA, OFDMA, SC-FDMA and other networks. The terms "network" and "system" are often used interchangeably. A CDMA network can implement radio technologies such as Universal Terrestrial Radio Access (UTRA), CDMA2000, etc. UTRA includes Wideband CDMA (WCDMA) and other variants of CDMA. CDMA 2000 covers IS-2000, IS-95 and IS-856 standards. A TDMA network can implement radio technologies such as Global System for Mobile Communications (GSM). An OFDMA network can implement radio technologies such as NR (e.g., 5G RA), Evolved UTRA (E-UTRA), Ultra Mobile Broadband (UMB), IEEE 802.11 (Wi-Fi), IEEE 802.16 (WiMAX), IEEE 802.20, Flash-OFDMA, etc. UTRA and E-UTRA are part of Universal Mobile Telecommunications System (UMTS).

[0029] New Radio (NR) is an emerging wireless communication technology under development in conjunction with the 5G Technology Forum (5GTF). 3GPP Long Term Evolution (LTE) and Advanced LTE (LTE-A) are versions 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 can be used for the wireless networks and radio technologies mentioned above as well as other wireless networks and radio technologies. For clarity, although various aspects are described herein using terms commonly associated with 3G and / or 4G wireless technologies, various aspects of the present disclosure can be applied to communication systems based on other generations, such as 5G and later versions, including NR technologies.

[0030] New Radio (NR) access (e.g., 5G technology) can support various wireless communication services, such as enhanced mobile broadband (eMBB) targeting wide bandwidth (e.g., 80 MHz or above), millimeter wave (mmW) targeting high carrier frequency (e.g., 25 GHz or above), massive machine type communication MTC (mMTC) targeting non-backward compatible MTC technology, and / or mission critical services targeting ultra-reliable low latency communication (URLLC). These services may include latency and reliability requirements. These services may also have different transmission time intervals (TTIs) to meet corresponding quality of service (QoS) requirements. In addition, these services can coexist in the same subframe.

[0031] Example Wireless Communication System

[0032] Figure 1 An example wireless communication network 100 is shown in which aspects of the present disclosure may be performed. For example, the wireless communication network 100 may be a new radio (NR) or 5G network. A UE 120 in the wireless communication network 100 may receive a channel state information (CSI) reporting configuration from a base station. The CSI reporting configuration configures the UE 120 to perform CSI reporting.

[0033] For example, the CSI reporting configuration configures the UE 120 to determine the precoding matrix information and the FD basis selection for each transmission layer based at least in part on an intermediate set size, wherein the intermediate set size is known between devices (e.g., a base station and a UE) and is based on a wireless network configuration or rule. The UE 120 may report the FD basis selection for a particular transmission layer in the UCI.

[0034] In some cases, the size of the intermediate set is reported by the UE. That is, the UE freely selects the FD basis for each layer from a total of N3 FD bases; and the UE determines an intermediate set containing the union of the FD bases selected for each layer. The UE needs to report the size of the intermediate set in UCI Part 1, and report information related to the intermediate set in UCI Part 2, and report a separate FD basis for each layer in UCI Part 2. In some other aspects, the size of the intermediate set is configured by the network, or is derived by the UE based on some other configuration parameters following a rule fixed in the specification, or the size is explicitly specified in the wireless communication specification. In this case, the UE needs to find an intermediate set that is common to all layers of a certain rank based on the size of the intermediate set. Then, the UE does not need to report the size, but may or may not need to report information about the intermediate set in UCI Part 2, and also report a separate FD basis from the intermediate set for each layer in UCI Part 2.

[0035] In certain aspects, the BS may determine the intermediate set and the size of the intermediate set (e.g., N3') using the same or similar methods as discussed herein for the UE. For example, the BS may utilize the same equations discussed for the UE. Information for making the determination as discussed with respect to the UE is available to the BS.

[0036] As in Figure 1As shown in , the wireless communication network 100 may include multiple base stations (BS) 110 and other network entities. A BS may be a station that communicates with a user equipment (UE). Each BS 110 may provide communication coverage for a specific geographical area. In 3GPP, the term "cell" may refer to the coverage area of ​​a node B (NB) and / or a NB subsystem serving the coverage area, depending on the context in which the term "cell" is used. In the NR system, the term "cell" and the next generation node B (gNB or gNodeB), NR BS, 5G NB, access point (AP) or transmit receive point (TRP) may be interchangeable. In some examples, the cell may not necessarily be stationary, and the geographical area of ​​the cell may move according to the location of the mobile BS. In some examples, the base station may be interconnected to each other and / or to one or more other base stations or network nodes (not shown) in the wireless communication network 100 using any appropriate transport network through various types of backhaul interfaces (such as direct physical connections, wireless connections, virtual networks, etc.).

[0037] Generally, any number of wireless networks can be deployed in a given geographic area. Each wireless network can support a specific radio access technology (RAT) and can operate on one or more frequencies. RAT can also be referred to as radio technology, air interface, etc. Frequency can also be referred to as carrier, subcarrier, frequency channel, tone, subband, etc. Each frequency can support a single RAT in a given geographic area to avoid interference between wireless networks of different RATs. In some cases, NR or 5G RAT networks can be deployed.

[0038] A BS may provide communication coverage for macro cells, pico cells, femto cells, and / or other types of cells. A macro cell may cover a relatively large geographic area (e.g., a radius of several kilometers) and may allow unrestricted access by UEs with service subscriptions. A pico cell may cover a relatively small geographic area and may allow unrestricted access by UEs with service subscriptions. A femto cell may cover a relatively small geographic area (e.g., a residence) and may allow restricted access by UEs associated with the femto cell (e.g., UEs in a closed subscriber group (CSG) , UEs for users in a home, etc.). A BS for a macro cell may be referred to as a macro BS. A BS for a pico cell may be referred to as a pico BS. A BS for a femto cell may be referred to as a femto BS or a home BS. In Figure 1In the illustrated example, BS 110a, BS 110b, and BS 110c may be macro BSs for macro cells 102a, 102b, and 102c, respectively. BS 110x may be a pico BS for pico cell 102x. BS 110y and BS 110z may be femto BSs for femto cells 102y and 102z, respectively. A BS may support one or more (e.g., three) cells.

[0039] The wireless communication network 100 may also include a relay station. A relay station is a station that receives transmissions of data and / or other information from an upstream station (e.g., a BS or a UE) and sends transmissions of data and / or other information to a downstream station (e.g., a UE or a BS). A relay station may also be a UE that relays transmissions for other UEs. Figure 1 In the example shown in FIG. 1 , a relay station 110r may communicate with a BS 110a and a UE 120r to facilitate communication between the BS 110a and the UE 120r. A relay station may also be referred to as a relay BS, a relay, or the like.

[0040] The wireless communication network 100 may be a heterogeneous network including different types of BSs (e.g., macro BSs, pico BSs, femto BSs, repeaters, etc.). These different types of BSs may have different transmit power levels, different coverage areas, and different effects on interference in the wireless communication network 100. For example, a macro BS may have a high transmit power level (e.g., 20 watts), while a pico BS, a femto BS, and a repeater may have a lower transmit power level (e.g., 1 watt).

[0041] The wireless communication network 100 may support synchronous or asynchronous operation. For synchronous operation, the BSs may have similar frame timings, and transmissions from different BSs may be approximately aligned in time. For asynchronous operation, the BSs may have different frame timings, and transmissions from different BSs may not be aligned in time. The techniques described herein may be used for both synchronous and asynchronous operation.

[0042] A network controller 130 may couple to a set of BSs and provide coordination and control for these BSs. The network controller 130 may communicate with the BSs 110 via a backhaul. The BSs 110 may also communicate with each other via a wireless backhaul or a wired backhaul (eg, directly or indirectly).

[0043] UEs 120 (e.g., UE 120x, UE 120y, etc.) may be dispersed throughout the wireless communication network 100, and each UE may be stationary or mobile. UEs may also be referred to as mobile stations, terminals, access terminals, subscriber units, stations, customer premises equipment (CPE), cellular phones, smart phones, personal digital assistants (PDAs), wireless modems, wireless communication devices, handheld devices, laptop computers, cordless phones, wireless local loop (WLL) stations, tablet computers, cameras, gaming devices, netbooks, smartbooks, ultrabooks, home appliances, medical devices or medical apparatuses, biometric sensors / devices, wearable devices (such as smart watches, smart clothes, smart glasses, smart wristbands, smart jewelry (e.g., smart rings, smart bracelets, etc.)), entertainment devices (e.g., music devices, video devices, satellite radio units, etc.), vehicle components or sensors, smart meters / sensors, industrial manufacturing equipment, global positioning system devices, or any other suitable device configured to communicate via wireless or wired media. Some UEs may be considered as machine type communication (MTC) devices or evolved MTC (eMTC) devices. MTC and eMTC UEs include, for example, robots, drones, remote devices, sensors, meters, monitors, location tags, etc. that can communicate with a BS, another device (e.g., a remote device), or some other entity. A wireless node may provide a connection to a network (e.g., a wide area network such as the Internet or a cellular network) or to a network, for example, via a wired or wireless communication link. Some UEs may be considered as Internet of Things (IoT) devices, which may be narrowband IoT (NB-IoT) devices.

[0044] Some wireless networks (e.g., LTE) utilize orthogonal frequency division multiplexing (OFDM) on the downlink and single carrier frequency division multiplexing (SC-FDM) on the uplink. OFDM and SC-FDM divide the system bandwidth into multiple (K) orthogonal subcarriers, which are also commonly referred to as tones, frequencies, etc. Each subcarrier can be modulated with data. Typically, modulation symbols are sent in the frequency domain using OFDM and in the time domain using SC-FDM. The spacing between adjacent subcarriers can be fixed, and the total number of subcarriers (K) can depend on the system bandwidth. For example, the spacing of the subcarriers can be 15kHz and the minimum resource allocation (referred to as a "resource block" (RB)) can be 12 subcarriers (or 180kHz). Therefore, for system bandwidths of 1.25, 2.5, 5, 10, or 20 megahertz (MHz), the nominal fast Fourier transform (FFT) size can be equal to 128, 256, 512, 1024, or 2048, respectively. The system bandwidth may also be partitioned into subbands. For example, a subband may cover 1.08 MHz (ie, 6 resource blocks), and there may be 1, 2, 4, 8, or 16 subbands for system bandwidths of 1.25, 2.5, 5, 10, or 20 MHz, respectively.

[0045] Communication systems such as NR can utilize OFDM with cyclic prefix (CP) on the uplink and downlink, and include support for half-duplex operation using time division duplex (TDD). Beamforming can be supported, and the beam direction can be dynamically configured. MIMO transmission with precoding can also be supported. The MIMO configuration in the DL can support up to 8 transmit antennas, with multi-layer DL transmission of up to 8 streams and up to 4 streams per UE. Multi-layer transmission of up to 4 streams per UE can be supported. Aggregation of multiple cells of up to 8 serving cells can be supported.

[0046] In some examples, access to the air interface can be scheduled. A scheduling entity (e.g., BS) allocates resources for communications between some or all devices and equipment within its service area or cell. A scheduling entity may be responsible for scheduling, allocating, reconfiguring, and releasing resources for one or more subordinate entities. That is, for scheduled communications, subordinate entities utilize resources allocated by the scheduling entity. The base station is not the only entity that can act as a scheduling entity. In some examples, a UE may act as a scheduling entity, and resources may be scheduled for one or more subordinate entities (e.g., one or more other UEs), and other UEs may utilize resources scheduled by the UE for wireless communications. In some examples, a UE may act as a scheduling entity in a peer-to-peer (P2P) network and / or a mesh network. In a mesh network example, UEs may communicate directly with each other in addition to communicating with a scheduling entity.

[0047] exist Figure 1 In FIG. 1 , a solid line with double arrows indicates desired transmissions between a UE and a serving BS, which is a BS designated to serve the UE on the downlink and / or uplink. A thin dashed line with double arrows indicates interfering transmissions between the UE and the BS.

[0048] Figure 2 A schematic diagram illustrating an example of implementing a communication protocol stack in a RAN (e.g., such as RAN 100) according to various aspects of the present disclosure is shown. The communication protocol stack 200 shown can be implemented by a device operating in a wireless communication system (e.g., a 5G NR system (e.g., wireless communication network 100)). In various examples, the layers in the protocol stack 200 can be implemented as separate software modules, parts of a processor or ASIC, parts of non-co-located devices connected by a communication link, or various combinations thereof. For example, co-located and non-co-located implementations can be used in a protocol stack for a network access device or UE. As shown in Figure 2 As shown in , the system can support various services through one or more protocols. One or more protocol layers of the protocol stack 200 can be implemented by AN and / or UE.

[0049] As in Figure 2 As shown in FIG. , the protocol stack 200 is implemented in an AN (eg, Figure 1 The AN may be implemented by the AN. For example, the CU-CP may implement the RRC layer 205 and the PDCP layer 210. The DU may implement the RLC layer 215 and the MAC layer 220. The AU / RRU may implement the PHY layer 225 and the RF layer (230). The PHY layer 225 may include a high PHY layer and a low PHY layer.

[0050] The UE may implement the entire protocol stack 200 (eg, the RRC layer 205, the PDCP layer 210, the RLC layer 215, the MAC layer 220, the PHY layer 225, and the RF layer 230).

[0051] Figure 3 BS 110 and UE 120 are shown (as in Figure 1 ), the example components may be used to implement aspects of the present disclosure. For example, antenna 352, processors 366, 358, 364, and / or controller / processor 380 of UE 120 and / or antenna 334, processors 320, 330, 338, and / or controller / processor 340 of BS 110 may be used to perform the various techniques and methods described herein. For example, as shown in Figure 3As shown in , the processor 340 has an intermediate set size calculation module 390, which can be configured to determine precoding matrix information for each layer based on the intermediate set size, the precoding matrix information including a common indication of the intermediate set size of the frequency domain (FD) basis and the FD basis selection. According to various aspects described herein, the intermediate set size calculation module 390 can also configure the UE 120 to report an indication of the size of the intermediate set of FD bases across all layers in a first part of uplink control information (UCI) and report the FD basis selection for a specific transmission layer in a second part of the UCI. For example, as shown in Figure 3 As shown in FIG. 3 , according to various aspects described herein, processor 380 has a CSI report configuration module 392, which can be configured to generate one or more CSI report parameters and send the parameters to the UE.

[0052] At BS 110, a transmit processor 320 may receive data from a data source 312 and control information from a controller / processor 340. The control information may be for a physical broadcast channel (PBCH), a physical control format indicator channel (PCFICH), a physical hybrid ARQ indicator channel (PHICH), a physical downlink control channel (PDCCH), a group common PDCCH (GC PDCCH), etc. The data may be for a physical downlink shared channel (PDSCH), etc. The processor 320 may process (e.g., encode and symbol map) the data and the control information, respectively, to obtain data symbols and control symbols. The processor 320 may also generate reference symbols, e.g., for a primary synchronization signal (PSS), a secondary synchronization signal (SSS), and a cell-specific reference signal (CRS). The transmit (TX) multiple-input multiple-output (MIMO) processor 330 may perform spatial processing (e.g., precoding) on ​​the data symbols, control symbols, and / or reference symbols, if applicable, and provide output symbol streams to modulators (MODs) 332a to 332t. Each modulator 332 can process a corresponding output symbol stream (e.g., for OFDM, etc.) to obtain an output sample stream. Each modulator can also process (e.g., convert to analog, amplify, filter, and upconvert) the output sample stream to obtain a downlink signal. The downlink signals from modulators 332a to 332t can be transmitted via antennas 334a to 334t, respectively.

[0053] At the UE 120, antennas 352a to 352r can receive downlink signals from the base station 110 and provide received signals to demodulators (DEMODs) 354a to 354r in the transceiver, respectively. Each demodulator 354 can condition (e.g., filter, amplify, downconvert, and digitize) a corresponding received signal to obtain input samples. Each demodulator can further process the input samples (e.g., for OFDM, etc.) to obtain received symbols. A MIMO detector 356 can obtain received symbols from all demodulators 354a to 354r, perform MIMO detection on the received symbols (if applicable), and provide detected symbols. A receive processor 358 can process (e.g., demodulate, deinterleave, and decode) the detected symbols, provide decoded data for the UE 120 to a data sink 360, and provide decoded control information to a controller / processor 380.

[0054] In a MIMO system, a transmitter (e.g., BS 120) includes multiple transmit antennas 354a to 354r, and a receiver (e.g., UE 110) includes multiple receive antennas 352a to 352r. Therefore, there are multiple signal paths 394 from the transmit antennas 354a to 354r to the receive antennas 352a to 352r. For example, each of the transmitter and the receiver can be implemented within UE 110, BS 120, or any other suitable wireless communication device.

[0055] The use of such multi-antenna technology enables wireless communication systems to exploit the spatial domain to support spatial multiplexing, beamforming, and transmit diversity. Spatial multiplexing can be used to transmit different data streams (also referred to as layers) simultaneously on the same time-frequency resources. Data streams can be sent to a single UE to increase the data rate, or to multiple UEs to increase the overall system capacity, the latter of which is called multi-user MIMO (MU-MIMO). This is achieved by spatially precoding each data stream (i.e., multiplying the data stream with different weights and phase shifts), and then sending each spatially precoded stream through multiple transmit antennas on the downlink. The spatially precoded data streams arrive at the UE with different spatial characteristics, which enables each UE to recover one or more data streams intended for the UE. On the uplink, each UE sends a spatially precoded data stream, which enables the base station to identify the source of each spatially precoded data stream.

[0056] The number of data streams or layers corresponds to the rank of the transmission. Typically, the rank of a MIMO system is limited to the number of transmit antennas or receive antennas (whichever is lower). In addition, the channel conditions at the UE and other considerations (such as available resources at the base station) may also affect the transmission rank. For example, the rank (and therefore the number of transmission layers) assigned to a specific UE on the downlink can be determined based on a rank indicator (RI) sent from the UE to the base station. The RI can be determined based on the antenna configuration (e.g., the number of transmit antennas and receive antennas) and the signal to interference plus noise ratio (SINR) measured on each receive antenna. For example, the RI can indicate the number of layers that can be supported under the current channel conditions. The base station can use the RI together with resource information (e.g., available resources and the amount of data to be scheduled for the UE) to allocate a transmission rank to the UE.

[0057] On the uplink, at the UE 120, a transmit processor 364 may receive and process data from a data source 362 (e.g., for a physical uplink shared channel (PUSCH)) and control information from a controller / processor 380 (e.g., for a physical uplink control channel (PUCCH)). The transmit processor 364 may also generate reference symbols for reference signals (e.g., for a sounding reference signal (SRS)). The symbols from the transmit processor 364 may be precoded by a TX MIMO processor 366 (if applicable), further processed by demodulators 354a through 354r in the transceiver (e.g., for SC-FDM, etc.), and transmitted back to the base station 110. At the BS 110, the uplink signals from the UE 120 may be received by the antenna 334, processed by the modulator 332, detected by the MIMO detector 336 (if applicable), and further processed by the receive processor 338 to obtain decoded data and control information sent by the UE 120. The receive processor 338 may provide decoded data to a data sink 339 and decoded control information to a controller / processor 340 .

[0058] Controllers / processors 340 and 380 may direct the operation at BS 110 and UE 120, respectively. Processor 340 and / or other processors and modules at BS 110 may perform or direct the execution of processes for the techniques described herein. Memories 342 and 382 may store data and program codes for BS 110 and UE 120, respectively. Scheduler 344 may schedule UEs for data transmission on the downlink and / or uplink.

[0059] Figure 44 is a schematic diagram showing an example of a frame format 400 for NR. The transmission timeline for each of the downlink and uplink can be divided into units of radio frames. Each radio frame can have a predetermined duration (e.g., 10ms) and can be divided into 10 subframes indexed from 0 to 9, each subframe being 1ms. Each subframe can include a variable number of slots, depending on the subcarrier spacing. Each slot can include a variable number of symbol periods (e.g., 7 or 14 symbols), depending on the subcarrier spacing. An index can be assigned to the symbol period in each slot. A microslot, which can be referred to as a subslot structure, refers to a transmission time interval (e.g., 2, 3, or 4 symbols) having a duration less than a slot. Each symbol in a slot can indicate a link direction (e.g., DL, UL, or flexible) for data transmission, and the link direction for each subframe can be switched dynamically. The link direction can be based on the slot format. Each slot can include DL / UL data and DL / UL control information.

[0060] In NR, a synchronization signal (SS) block is sent. The SS block includes PSS, SSS, and two-symbol PBCH. It can be sent at a fixed time slot position (e.g., Figure 4 SS blocks are sent on the physical downlink shared channel (PDSCH) in certain subframes (symbols 0-3 shown in ). PSS and SSS can be used by UE for cell search and acquisition. PSS can provide half-frame timing, and SS can provide CP length and frame timing. PSS and SSS can provide cell identification. PBCH carries some basic system information, such as downlink system bandwidth, timing information within a radio frame, SS burst set period, system frame number, etc. SS blocks can be organized into SS bursts to support beam scanning. Additional system information, such as remaining minimum system information (RMSI), system information block (SIB), and other system information (OSI), can be sent on the physical downlink shared channel (PDSCH) in certain subframes. SS blocks can be sent up to 64 times, for example, for mmW, in up to 64 different beam directions. Up to 64 transmissions of SS blocks are called SS burst sets. SS blocks in an SS burst set are sent in the same frequency domain, while SS blocks in different SS burst sets can be sent at different frequency positions.

[0061] The UE may operate under various radio resource configurations, including a configuration associated with sending a pilot using a dedicated resource set (e.g., a radio resource control (RRC) dedicated state, etc.), or a configuration associated with sending a pilot using a common resource set (e.g., an RRC common state, etc.). When operating in the RRC dedicated state, the UE may select a dedicated resource set to send a pilot signal to the network. When operating in the RRC common state, the UE may select a common resource set to send a pilot signal to the network. In either case, the pilot signal sent by the UE may be received by one or more network access devices (such as an AN or DU or a portion thereof). Each receiving network access device may be configured to receive and measure a pilot signal sent on a common resource set, and also receive and measure a pilot signal sent on a dedicated resource set allocated to a UE, the network access device being a member of a monitoring set of network access devices for the UE. The receiving network access device or one or more of the CUs to which the receiving network access device sends the measured pilot signal may use the measurement to identify a serving cell for the UE, or to initiate a change of a serving cell for one or more of the UEs.

[0062] Example CSI Report Configuration

[0063] Channel state information (CSI) may refer to channel properties of a communication link. CSI may represent, for example, the combined effects of scattering, fading, and power attenuation with distance between the transmitter and the receiver. Channel estimation using a pilot such as a CSI reference signal (CSI-RS) may be performed to determine these effects on the channel. CSI may be used to adapt transmissions based on current channel conditions, which is useful for achieving reliable communications, particularly in multi-antenna systems with high data rates. CSI is typically estimated, quantized, and fed back to the transmitter at the receiver.

[0064] The time and frequency resources that can be used by the UE to report CSI are controlled by the base station (e.g., gNB). The CSI may include a channel quality indicator (CQI), a precoding matrix indicator (PMI), a CSI-RS resource indicator (CRI), a SS / PBCH block resource indicator (SSBRI), a layer indicator (LI), a rank indicator (RI), and / or L1-RSRP. However, as described below, additional or other information may be included in the report.

[0065] The base station may configure the UE for CSI reporting. For example, the BS configures the UE with a CSI reporting configuration or multiple CSI reporting configurations. The CSI reporting configuration may be provided to the UE via higher layer signaling, such as radio resource control (RRC) signaling (e.g., CSI-ReportConfig). The CSI reporting configuration may be associated with CSI-RS resources for channel measurement (CM), interference measurement (IM), or both. The CSI reporting configuration configures the CSI-RS resources for measurement (e.g., CSI-ResourceConfig). The CSI-RS resources are provided to the UE to map a CSI-RS port or a CSI-RS port group to time and frequency resources (e.g., resource elements (REs)). The CSI-RS resources may be zero power (ZP) or non-zero power (NZP) resources. At least one NZP CSI-RS resource may be configured for CM.

[0066] For Type II single-panel codebooks, the PMI is a linear combination of beams; it has a subset of orthogonal beams for the linear combination, and has amplitude and phase per layer, per polarization, for each beam. For any type of PMI, there can be a wideband (WB) PMI and / or a subband (SB) PMI as configured.

[0067] The CSI reporting configuration can configure the UE for aperiodic, periodic or semi-persistent CSI reporting. For periodic CSI, the UE can be configured with periodic CSI-RS resources. Periodic CSI and semi-persistent CSI reporting on the physical uplink control channel (PUCCH) can be triggered via RRC or media access control (MAC) control elements (CE). For aperiodic and semi-persistent CSI on the physical uplink shared channel (PUSCH), the BS can signal the UE with a CSI report trigger, which indicates that the UE sends a CSI report for one or more CSI-RS resources, or configures the CSI-RS report trigger state (e.g., CSI-AperiodicTriggerStateList and CSI-SemiPersistentOnPUSCH-TriggerStateList). CSI report triggers for aperiodic CSI and semi-persistent CSI on PUSCH can be provided via downlink control information (DCI). CSI-RS triggering can be signaling to the UE indicating that CSI-RS will be sent for CSI-RS resources.

[0068] The UE may report CSI feedback based on the CSI reporting configuration and the CSI reporting trigger. For example, the UE may measure the channel associated with the CSI for the triggered CSI-RS resource. Based on the measurement, the UE may select a preferred CSI-RS resource. The UE reports CSI feedback for the selected CSI-RS resource. The LI may be calculated conditional on the reported CQI, PMI, RI, and CRI; the CQI may be calculated conditional on the reported PMI, RI, and CRI; the PMI may be calculated conditional on the reported RI and CRI; and the RI may be calculated conditional on the reported CRI.

[0069] Each CSI reporting configuration may be associated with a single downlink bandwidth part (BWP). A CSI reporting setting configuration may define a CSI reporting band as a subset of a subband of a BWP. The associated DL BWP may be indicated by a higher layer parameter (e.g., bwp-Id) for channel measurement in the CSI reporting configuration and contains parameters for one CSI reporting band, such as codebook configuration, time domain behavior, frequency granularity for CSI, measurement restriction configuration, and CSI-related quantities to be reported by the UE. Each CSI resource setting may be located in a DL BWP identified by a higher layer parameter, and all CSI resource settings may be linked to a CSI reporting setting with the same DL BWP.

[0070] In some systems, the UE may be configured with one of two possible subband sizes indicating the frequency granularity of the CSI report (e.g., reportFreqConfiguration included in CSI-ReportConfig) through higher layer signaling (e.g., in the CSI reporting configuration), where the subband may be defined as The UE may also receive an indication of the subbands for which CSI feedback is requested. In some examples, a subband mask is configured for the requested subbands for CSI reporting. The UE calculates a precoder for each requested subband and finds a PMI that matches the precoder calculated on each subband.

[0071] Compressed CSI feedback coefficient report

[0072] As discussed above, a user equipment (UE) may be configured to perform channel state information (CSI) reporting, for example, by receiving a CSI configuration message from a base station. In some systems (e.g., Release 15 5GNR), the UE may be configured to report at least the type II precoder across the configured frequency domain (FD) units. For example, the precoder matrix W for layer r is rIncludes the W1 matrix (reports a subset of the beams that use spatial compression) and the W 2,r matrix (reports the linear combination coefficients of the beams (2L in number) for the FD cells used for the selected cross-polarization across configurations):

[0073] Where

[0074] Where, b i is the selected beam, c i is the set of linear combination coefficients (i.e., the entries of the W 2,r matrix), L is the number of selected spatial beams, and N3 corresponds to the number of frequency cells (e.g., subbands, resource blocks (RBs), etc.). In some configurations, L is RRC-configured. The precoder is based on a linear combination of DFT beams. Type II codebooks can improve MU-MIMO performance. In some configurations considering the presence of two polarizations, the size of the W 2,r matrix is 2L X N3.

[0075] In some systems (e.g., Release 16 5G NR), the UE can be configured to report FD-compressed precoder feedback to reduce the overhead of CSI reporting. As shown in Figure 5 , the precoder matrix (W 2,i ) for layer i (where i = 0, 1) can use the FD compression matrix to compress the precoder matrix into a matrix of size 2L X M (where M is network-configured and is transmitted via RRC or DCI in the CSI configuration message, and M < N3), as given below:

[0076]

[0077] Where the precoder matrix W i (not shown) has P = 2N1N2 rows (spatial domain, number of ports) and N3 columns (frequency domain compression units containing RBs or reported subbands), and where M bases are independently selected for each of layers 0 and 1. Matrix 520 includes linear combination coefficients (amplitude and in-phase), where each element represents the coefficient for the tap of the beam. As shown in matrix 520 is defined by size 2L X M, where one row corresponds to one spatial beam in W1 (not shown) of size P X 2L (where L is network-configured (via RRC)), and one entry therein represents the coefficient for one tap of that spatial beam. The UE can be configured to report (e.g., CSI report) A subset K0 of the linear combination coefficients of matrix 520 < 2LM. For example, the UE may report K shown as shaded squares NZ,i <K0 coefficients (where K NZ,i corresponds to the maximum number of non-zero coefficients for layer i (where i = 0 or 1), and K0 is configured by the network (via RRC) (unreported coefficients are set to zero). In some configurations, in the entries in matrix 520 correspond to the rows of matrix 530. In the example shown, at layer 0 matrix 520 and at layer 1 matrix 550 are both 2L×M.

[0078] Matrix 530 includes basis vectors for performing compression in the frequency domain (each row is a basis vector). In the example shown, at layer 0 matrix 530 and at layer 1 matrix 560 both include M = 4 FD bases (shown as shaded rows) from N3 candidate DFT bases. In some configurations, the UE may report a subset of the selected bases of the matrix via CSI reporting. M bases are specifically selected at layer 0 and layer 1. That is, the M bases selected at layer 0 may be the same / partially overlapping / non-overlapping with the M bases selected at layer 1.

[0079] Example codebook without frequency domain compression

[0080] The codebook operation without FD compression (e.g., version 15 codebook operation) can be as follows. For layer l, the precoder that spans N3 FD units (also referred to as PMI subbands) can be given by a matrix W t of size N l ×N3, as follows:

[0081] W l = W1×W 2,l ,

[0082] where W1 and W 2,l are as described in the following table:

[0083]

[0084]

[0085] These two matrices can be written as:

[0086]

[0087] where the SD basis is DFT-based and has an index and The SD base is written as:

[0088]

[0089]

[0090] The coefficient matrix can be written as:

[0091]

[0092] In some cases, a common (P1) value may be applied to all In this case, given 2L rows in the matrix, the P1 values ​​are row-specific, and there may be 2L different values ​​for these coefficients.

[0093] coefficient and Described as follows:

[0094]

[0095]

[0096] More precisely, the linear combination representation can be written as:

[0097]

[0098] Frequency domain compression for high rank indication

[0099] Figure 6 Three alternative examples for determining the FD basis for a particular RI are shown. Each example is shown as a table with a left column indicating the RI (e.g., RI={1,2,3,4}) and a bottom row indicating the transmission layer (e.g., layer 0, layer 1, layer 2, layer 3). That is, the number of layers indicates the transmission rank, where RI=1 is limited to a single spatial layer, RI=2 corresponds to two spatial layers, RI=3 corresponds to three spatial layers, and RI=4 corresponds to four spatial layers. Therefore, Type IICSI may involve UEs with up to four spatial layers.

[0100] In some configurations using FD compression, each layer reports up to K0 non-zero coefficients (NZCs), regardless of rank, and the total number of NZCs across all layers is limited to 2K0. That is, for ranks 1 and 2, only the per-layer constraint needs to be considered, since the total NZC constraint across layers becomes redundant (since the total NZC of two layers, both constrained to K0, cannot exceed 2K0). On the other hand, for ranks 3 and 4, both the per-layer constraint and the total constraint are considered.

[0101] Similarly, for FD groups with RI = {3,4} (M i ) is equivalent to RI=2. In one example, each layer (layer 0 and layer 1) of RI=2 uses M FD bases, so that the FD bases across all four layers of RI=4 are equivalent to 2M. That is, for a given RI, M i can be described as:

[0102]

[0103] exist Figure 5 In the example shown, Matrix 530 includes an FD basis M=4 (M0=4), and Matrix 560 includes M = 4 FD bases (M1 = 4), resulting in a total of 8 FD bases for RI = 2. Therefore, for RI = {3, 4}, the total number of FD bases across all four layers should be comparable to M0 + M1 or 2M (e.g., between 6 and 10 FD bases for RI = {3, 4}).

[0104] As in Figure 6 As shown in , Table 610 shows an example for making the total number of FD bases for RI={3,4} comparable to RI=2. In this example, for RI={3,4}, the FD base for each of layers 0-3 is M2. In some cases, in the standard specification, M2 may be set equal to M / 2 or 2 / 3*M. The M value may be determined, for example, by the following equation:

[0105] M=ceil(p*N3),

[0106] M2 can be determined by the following equation:

[0107] M2=ceil(v0*N3),

[0108] Among them, p and v0 are jointly configured, for example from:

[0109] (p,v0)=(1 / 2,1 / 4),(1 / 4,1 / 4) and (1 / 4,1 / 8).

[0110] In various aspects of the techniques described herein, a UE may be configured to perform CSI reporting, for example, by receiving a CSI configuration message from a base station. In some systems, a UE may be configured to report at least a type II precoder across configured frequency domain (FD) units. For example, a precoder for a layer l on N3 subbands may be represented as a matrix W of size P×N3. l :

[0111]

[0112] In this equation, L is the number of spatial domain (SD) basis (or bases) (e.g., spatial beams) configured through RRC signaling of CSI report configuration, (where i = 0, 1, ..., L-1) is The SD basis is based on DFT and has the index and The SD base can be written as:

[0113]

[0114]

[0115] In this equation, N1 and N2 represent the first and second dimensions of the configured codebook, respectively. In some cases, these parameters may refer to the number of antenna elements in the vertical and horizontal dimensions at the base station, respectively. The oversampling factor is represented by O1 and O2.

[0116] also, (where m = 0, 1, ... M l ) is a N3×1FD basis (i.e., is a 1×N3 row vector), which is also called the transfer domain basis. l is the number of FD bases selected for layer 1 and is derived based on the RRC configuration. In some cases, for each layer of rank 1 and rank 2, there are M bases, and The value of is determined by the ratio p configured by RRC, and R is the number of precoding matrix indicator (PMI) subbands in one CQI subband. The FD basis can be a DFT basis and has an index The FD basis is expressed as:

[0117]

[0118] As noted above, the linear combination coefficients may include three parts: parameter represents the amplitude reference for the first polarization, and represents the amplitude reference for the second polarization. These values ​​are common to all coefficients associated with the corresponding polarization (e.g., and parameter Represents and has index and The SD basis is associated with and in the first polarization with the index The (differential) magnitudes of the coefficients associated with the FD basis, while Represents and has index and The SD base is associated with the second polarization with index The (differential) magnitudes of the coefficients associated with the FD basis of . Similarly, the parameters Represents and has index and The SD basis is associated with the first polarization with index The (differential) magnitudes of the coefficients associated with the FD basis, while Represents and has index and The SD basis is associated with and in the second polarization with the index The (differential) magnitudes of the coefficients associated with the FD basis.

[0119] For RI = {1,2}, for each layer, the number of FD bases M = M 1,2 ,in The value of is determined by the ratio p configured by RRC, and R is the number of precoding matrix indicator (PMI) subbands in one CQI subband. For RI = {3, 4}, the number of FD bases M = M 3,4 ,in The value of is determined by the ratio v0 configured by RRC. Possible combinations of p and v0 include In addition, for each layer with RI={1,2,3,4}, the UE is configured to report a total of 2LM 1,2 or a total of 2LM 3,4 The maximum number of coefficients to be reported per layer is K0, and the maximum total number of coefficients to be reported across all layers is 2K0, where and It is configured by RRC. It can be noted that regardless of the rank, K0 uses M 1,2 Calculated.

[0120] For codebook operation with FD compression, for layer 1, the precoder across N3 FD units (also called PMI subbands) is t ×N3 matrix W l Given, as follows:

[0121]

[0122] Among them, W1, and W f As shown below:

[0123]

[0124]

[0125] exist Figure 7 The three matrices shown graphically in Figure 7 Only two layers are shown, but in reality it can be 3 or 4 layers with the same structure, where the only difference is the number of FD bases and the number of non-zero coefficients or NZCs), which can be written as:

[0126]

[0127]

[0128]

[0129] The SD basis is based on the DFT and has index and The SD base is written as:

[0130]

[0131]

[0132] The FD basis can be a DFT basis and has index The FD basis is expressed as:

[0133]

[0134] coefficient It can be described as follows:

[0135]

[0136]

[0137] Given these definitions, more precisely, the linear combination representation can be expressed as:

[0138]

[0139] Example CBSR for each SD base amplitude for Type II codebook with FD compression

[0140] In some cases, to deal with inter-cell interference, the gNB may restrict the UE on SD basis selection. For example, some SD basis may cause interference to other cells, or may be subject to strong interference from other cells. In this case, the gNB can request the UE to avoid selecting those SD basis, or only select SD basis with limited power. This mechanism is usually called codebook subset restriction (CBSR).

[0141] In Release 15, CBSR is implemented through the following process. In the first step, the gNB can configure the UE to apply CBSR to up to 4 groups of SD bases. A total of N1O1×N2O2 SD bases can be divided into O1O2 groups, where each group contains N1N2 SD bases. SD bases within the same group are orthogonal, while SD bases in different groups are non-orthogonal. The gNB can A maximum of 4 groups are selected and configured for the UE from a total of o1O2 groups.

[0142] In the second step, for each SD base of each group, the gNB may configure the The following table shows the 2-bit indication of the maximum amplitude / power limit for each SD base.

[0143]

[0144]

[0145] In the (version 16) linear combination codebook with FD compression, if the version 15 method is reused (e.g., for up to 4 sets of SD basis This will actually limit the maximum power of the polarization because The value is common to all SD bases for each polarization.

[0146] It is not the correct intention to limit the maximum power of a polarization in this way. Therefore, a new CBSR is needed in Release-16 Type-II codebook with FD compression.

[0147] Figure 8 8 is a flow diagram illustrating example operations 800 for wireless communications by a UE utilizing CBSR in accordance with certain aspects of the present disclosure. The example operations 800 may be performed by a UE. For example, the operations 800 may be performed by a UE 120 (eg, UE 120a) in a wireless communications network 100.

[0148] Operations 800 begin at 802 by receiving a channel state information (CSI) request from a base station, the CSI request triggering a CSI report including at least one of a plurality of spatial domain (SD) bases, a plurality of frequency domain (FD) bases, and a plurality of linear combination coefficients.

[0149] At 804, the UE receives a configuration that limits, for each SD basis, a maximum average magnitude of linear combination coefficients associated with the SD basis. At 806, the UE sends a CSI report with the linear combination coefficients generated according to the configuration.

[0150] Fig. 9 900 is a flow diagram illustrating example operations 900 for wireless communications by a network entity (e.g., a base station, such as an eNB or gNB) in accordance with certain aspects of the present disclosure. The example operations 900 may be performed by a base station. For example, the operations 900 may be performed by BS 110 in wireless communication network 100.

[0151] Operations 900 begin at 902 by sending a channel state information (CSI) request to a user equipment (UE), the CSI request triggering a CSI report including at least one of a plurality of spatial domain (SD) bases, a plurality of frequency domain (FD) bases, and a plurality of linear combination coefficients.

[0152] At 904, the network entity sends a configuration to the UE, the configuration limiting the maximum average magnitude of the linear combination coefficients associated with each SD basis. At 906, the network entity receives the CSI report, and at 908, the network entity processes the linear combination coefficients included in the CSI report according to the configuration.

[0153] exist Fig.10 The call flow diagram 1000 shows the CBSR technology proposed in this article. Fig.10 An example scenario for CSI reporting between UE 1002 and base station 1004 is shown in accordance with certain aspects of the present disclosure.

[0154] First, UE 1002 receives a CSI report configuration message 1006 from BS 1004. As shown at 1008, the CSI report configuration message may include information for performing codebook subset restriction (CBSR) on each SD basis amplitude. At 1009, BS 1004 sends a CSI request that triggers a CSI report. At 1010, the UE generates a CSI report using the linear combination coefficients generated according to the CBSR.

[0155] According to one method for CBSR, for each beam, the configuration limits the power relative to the strongest beam / coefficient across both polarizations. In some cases, the strongest beam / coefficient across both polarizations may be normalized to 1.

[0156] In one example case, the relative power may be the power / power of each coefficient of the strongest beam / coefficient across both polarizations. Limiting the relative power may be based on a threshold value (p thr,l ), such as:

[0157] or

[0158]

[0159] In one example case, the relative power may be the average power of all coefficients of the corresponding beam, / the power of the strongest beam / coefficient across both polarizations. In some cases, based on a threshold value p thr,l The amplitude / power limitation can be as follows:

[0160]

[0161] In other cases, based on γ i+pL The amplitude / power limits can be:

[0162]

[0163] in, indicates the reference amplitude for layer l (l=0,1,…,ν-1) at polarization p=0,1, Indicates the SD basis i (i = 0, 1, ..., L-1) and the FD basis f (f = 0, 1, ..., M-1) for the layer l (l = 0, 1, ..., ν-1) at polarization p = 0. ν -1) the magnitude of the difference in the associated coefficients; Indicates the SD basis i (i = 0, 1, ..., L-1) and the FD basis f (f = 0, 1, ..., M-1) of the layer l (l = 0, 1, ..., v-1) at polarization p = 0. ν -1) whether the associated coefficient is a non-zero coefficient. Therefore, The total power associated with SD basis i is generated on polarization p of layer l, The total number of non-zero coefficients associated with SD basis i is generated on polarization p of layer l. The left side of the equation provides the average amplitude.

[0164] According to one method for CBSR, for each beam, the power is limited relative to a reference power for each polarization. In this case, the reference power may be the power of the strongest beam / coefficient for the corresponding polarization. In this case, the relative power may be the power of each coefficient relative to the reference power, and the limits on the amplitude / power coefficients may be:

[0165] or

[0166]

[0167] In other cases, the relative power may be the average power of all coefficients relative to a reference power. In some cases, the limits on relative power may be:

[0168]

[0169] The threshold value may be signaled by the base station to the UE so that the UE is synchronized in terms of how it will perform CBSR and how the base station will interpret the coefficients received from the UE. For example, the threshold value may be provided as part of the CSI reporting configuration.

[0170] By providing the CBSR for each SD basis maximum average magnitude, aspects of the present disclosure may avoid limiting the maximum power of a polarization for Release-16 Type-II codebook with FD compression.

[0171] Example Embodiments

[0172] Embodiment 1: A method for wireless communication performed by a user equipment (UE), comprising: receiving a channel state information (CSI) request from a base station, the CSI request triggering a CSI report including at least one of a plurality of spatial domain (SD) bases, a plurality of frequency domain (FD) bases, and a plurality of linear combination coefficients; receiving a configuration, the configuration limiting, for each SD basis, a maximum average amplitude of a linear combination coefficient associated with the SD basis; and sending a CSI report, the CSI report having the linear combination coefficients generated according to the configuration.

[0173] Embodiment 2: A method according to embodiment 1, wherein: each linear combination coefficient is associated with a specific SD basis and a specific FD basis; the report of each linear combination coefficient includes at least one of a reference amplitude, a differential amplitude and a phase; and the amplitude of the coefficient depends jointly on the reference amplitude and the differential amplitude.

[0174] Embodiment 3: A method according to embodiment 2, wherein: the reference amplitude is common to all coefficients associated with the same beam; or the reference amplitude is common to all coefficients associated with the same polarization.

[0175] Embodiment 4: A method according to any of embodiments 1 to 3, wherein the configuration of the maximum average amplitude further comprises: limiting the maximum amplitude relative to the strongest SD basis or the strongest coefficient across two polarizations.

[0176] Embodiment 5: A method according to embodiment 4, wherein, for each SD basis, the limitation on the maximum average amplitude limits the maximum amplitude of each coefficient, wherein the amplitude of each coefficient is based on the product of a reference amplitude and a differential amplitude.

[0177] Embodiment 6: A method according to embodiment 4 or 5, further wherein, for each SD basis, the limitation on the maximum average amplitude limits the maximum average amplitude of the amplitudes across all coefficients associated with the SD basis, wherein the amplitude of each coefficient is based on the product of a reference amplitude and a differential amplitude.

[0178] Embodiment 7: A method according to any of embodiments 1 to 6, wherein the configuration of the maximum average amplitude includes: limiting the maximum amplitude relative to the strongest SD basis or the strongest coefficient for each polarization.

[0179] Embodiment 8: A method according to embodiment 7, wherein, for each SD basis, the limitation on the maximum average amplitude limits the maximum amplitude of each coefficient, wherein the amplitude of each coefficient includes the differential amplitude.

[0180] Embodiment 9: A method according to embodiment 7 or 8, wherein, for each SD basis, the limit on the maximum average amplitude limits the maximum average amplitude of the amplitudes across all coefficients associated with the SD basis, wherein the amplitude of each coefficient includes a differential amplitude.

[0181] Embodiment 10: A method for wireless communication performed by a base station, comprising: sending a channel state information (CSI) request to a user equipment (UE), the CSI request triggering a CSI report including at least one of a plurality of spatial domain (SD) bases, a plurality of frequency domain (FD) bases, and a plurality of linear combination coefficients; sending a configuration to the UE, the configuration limiting, for each SD basis, a maximum average amplitude of the linear combination coefficients associated with the SD basis; receiving the CSI report; and according to the configuration, processing the linear combination coefficients included in the CSI report.

[0182] Embodiment 11: A method according to embodiment 10, wherein: each linear combination coefficient is associated with a specific SD basis and a specific FD basis; the report of each linear combination coefficient includes at least one of a reference amplitude, a differential amplitude and a phase; and the amplitude of the coefficient depends jointly on the reference amplitude and the differential amplitude.

[0183] Embodiment 12: A method according to embodiment 11, wherein: the reference amplitude is common to all coefficients associated with the same beam; or the reference amplitude is common to all coefficients associated with the same polarization.

[0184] Embodiment 13: A method according to any of embodiments 10 to 12, wherein the configuration of the maximum average amplitude further comprises: limiting the maximum amplitude relative to the strongest SD basis or the strongest coefficient across two polarizations.

[0185] Embodiment 14: A method according to embodiment 13, wherein, for each SD basis, the limitation on the maximum average amplitude limits the maximum amplitude of each coefficient, wherein the amplitude of each coefficient is based on the product of a reference amplitude and a differential amplitude.

[0186] Embodiment 15: A method according to embodiment 13 or 14, further wherein, for each SD basis, the limit on the maximum average amplitude limits the maximum average amplitude of the amplitudes across all coefficients associated with the SD basis, wherein the amplitude of each coefficient is based on the product of a reference amplitude and a differential amplitude.

[0187] Embodiment 16: A method according to any of embodiments 10 to 15, wherein the configuration of the maximum average amplitude includes: limiting the maximum amplitude relative to the strongest SD basis or the strongest coefficient for each polarization.

[0188] Embodiment 17: A method according to embodiment 16, wherein, for each SD basis, the limit on the maximum average amplitude limits the maximum amplitude of each coefficient, wherein the amplitude of each coefficient includes the differential amplitude.

[0189] Embodiment 18: A method according to embodiment 16 or 17, wherein, for each SD basis, the limit on the maximum average amplitude limits the maximum average amplitude of the amplitudes across all coefficients associated with the SD basis, wherein the amplitude of each coefficient includes a differential amplitude.

[0190] Embodiment 19: An apparatus for wireless communication performed by a user equipment (UE), comprising: a unit for receiving a channel state information (CSI) request from a base station, the CSI request triggering a CSI report including at least one of a plurality of spatial domain (SD) bases, a plurality of frequency domain (FD) bases, and a plurality of linear combination coefficients; a unit for receiving a configuration, the configuration limiting, for each SD basis, a maximum average amplitude of a linear combination coefficient associated with the SD basis; and a unit for sending a CSI report having linear combination coefficients generated according to the configuration.

[0191] Embodiment 20: An apparatus for wireless communication performed by a base station, comprising: a unit for sending a channel state information (CSI) request to a user equipment (UE), the CSI request triggering a CSI report including at least one of a plurality of spatial domain (SD) bases, a plurality of frequency domain (FD) bases, and a plurality of linear combination coefficients; a unit for sending a configuration to the UE, the configuration limiting, for each SD basis, a maximum average amplitude of the linear combination coefficients associated with the SD basis; a unit for receiving a CSI report; and a unit for processing the linear combination coefficients included in the CSI report according to the configuration.

[0192] The method disclosed herein includes one or more steps or actions for implementing the method. The method steps and / or actions may be interchangeable without departing from the scope of the claims. In other words, unless a specific order of steps or actions is specified, the order and / or use of specific steps and / or actions may be modified without departing from the scope of the claims.

[0193] As used herein, a phrase referring to "at least one of" a list of items refers to any combination of those items, including single members. As an example, "at least one of a, b, or c" is intended to cover a, b, c, ab, ac, bc, and abc, as well as any combination with multiples of the same element (e.g., aa, aaa, aab, aac, abb, acc, bb, bbb, bbc, cc, and ccc or any other ordering of a, b, and c).

[0194] As used herein, the term "determining" includes many actions. For example, "determining" may include calculating, computing, processing, deriving, investigating, searching (e.g., searching in a table, a database, or another data structure), ascertaining, etc. In addition, "determining" may include receiving (e.g., receiving information), accessing (e.g., accessing data in a memory), etc. In addition, "determining" may include resolving, selecting, choosing, establishing, etc.

[0195] The previous description is provided to enable those skilled in the art to implement the various aspects described herein. Various modifications to these aspects will be apparent to those skilled in the art, and the overall principles defined herein may be applicable to other aspects. Therefore, the claims are not intended to be limited to the various aspects shown herein, but to be given a full range consistent with the claim language, wherein, unless specifically so stated, references to singular elements are not intended to mean "one and only one", but "one or more". Unless otherwise specifically stated, the term "some" refers to one or more. All structural and functional equivalents of the elements of the various aspects described throughout the present disclosure are expressly incorporated herein by reference and are intended to be covered by the claims, and the structural and functional equivalents are known or will be known to those skilled in the art. In addition, there is no disclosure herein that is intended to be dedicated to the public, regardless of whether such disclosure is explicitly recorded in the claims. In addition, no claim element is to be interpreted in accordance with 35 U.S.C. § 112 (f), unless the element is explicitly recorded using the phrase "unit for...", or in the case of a method claim, the element is recorded using the phrase "step for...".

[0196] The various operations of the methods described above may be performed by any appropriate unit capable of performing the corresponding functions. The unit may include various hardware and / or software components and / or modules, including but not limited to circuits, application specific integrated circuits (ASICs) or processors. For example, in Figure 3 The various processors shown in FIG. 1 may be configured to perform Figure 8 and Fig. 9Operations 800 and 900.

[0197] The various illustrative logic blocks, modules and circuits described in conjunction with the disclosed content herein may be implemented or executed using a general purpose processor, a digital signal processor (DSP), an application specific integrated circuit (ASIC), a field programmable gate array (FPGA) or other programmable logic device (PLD), discrete gate or transistor logic, discrete hardware components, or any combination thereof designed to perform the functions described herein. A general purpose processor may be a microprocessor, but in an alternative, the processor may also be any commercially available processor, controller, microcontroller or state machine. The processor may also be implemented as a combination of computing devices, for example, a combination of a DSP and a microprocessor, a plurality of microprocessors, a combination of one or more microprocessors and a DSP core, or any other such configuration.

[0198] When implemented in hardware, an example hardware configuration may include a processing system in a wireless node. The processing system may be implemented using a bus architecture. Depending on the specific application and overall design constraints of the processing system, the bus may include any number of interconnecting buses and bridges. The bus may link together various circuits including a processor, a machine-readable medium, and a bus interface. The bus interface may be used to connect a network adapter, etc., to the processing system via the bus. The network adapter may be used to implement the signal processing functions of the PHY layer. In the user terminal 120 (see Figure 1 ), a user interface (e.g., a keypad, display, mouse, joystick, etc.) may also be connected to the bus. The bus also links various other circuits, such as timing sources, peripherals, voltage regulators, power management circuits, etc., which are well known in the art and therefore will not be described further. The processor may be implemented using one or more general purpose processors and / or special purpose processors. Examples include microprocessors, microcontrollers, DSP processors, and other circuits capable of executing software. Those skilled in the art will recognize how to best implement the described functionality for the processing system depending on the specific application and the overall design constraints imposed on the entire system.

[0199] When implemented in software, the functions may be stored on a computer-readable medium or transmitted via a computer-readable medium as one or more instructions or codes. Whether referred to as software, firmware, middleware, microcode, hardware description language or other terms, software should be broadly interpreted as meaning instructions, data or any combination thereof. Computer-readable media include both computer storage media and communication media, and communication media include any media that facilitates the transmission of computer programs from one place to another. The processor may be responsible for managing the bus and general processing, including executing software stored on a machine-readable storage medium. The computer-readable storage medium may be coupled to the processor so that the processor can read information from the storage medium and write information to the storage medium. In an alternative, the storage medium may be a component of the processor. By way of example, the machine-readable medium may include a transmission line, a carrier modulated by data and / or a computer-readable storage medium having instructions stored thereon separated from a wireless node, all of which may be accessed by the processor via a bus interface. Alternatively or additionally, the machine-readable medium or any part thereof may be integrated into the processor, such as, for example, with a cache and / or a general register file. By way of example, examples of machine-readable storage media may include RAM (random access memory), flash memory, ROM (read only memory), PROM (programmable read only memory), EPROM (erasable programmable read only memory), EEPROM (electrically erasable programmable read only memory), registers, magnetic disks, optical disks, hard disk drives, or any other suitable storage media, or any combination thereof. The machine-readable medium may be embodied in a computer program product.

[0200] A software module may include a single instruction or many instructions, and may be distributed over several different code segments, distributed among different programs, and distributed across multiple storage media. A computer-readable medium may include multiple software modules. A software module includes instructions, which, when executed by a device (such as a processor), cause a processing system to perform various functions. A software module may include a transmission module and a receiving module. Each software module may be located in a single storage device, or distributed across multiple storage devices. By way of example, when a triggering event occurs, a software module may be loaded from a hard disk drive into a RAM. During the execution of a software module, a processor may load some of the instructions into a cache to increase access speed. Subsequently, one or more cache lines may be loaded into a general register file for execution by the processor. When referring to the functions of the software modules below, it will be understood that such functions are implemented by the processor when executing instructions from the software module.

[0201] Additionally, 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 (IR), 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. As used herein, disk and disc include compact disc (CD), laser disc, optical disc, digital versatile disc (DVD), floppy disk and Blu-ray Optical disks, where magnetic disks typically reproduce data magnetically, and optical disks use lasers to reproduce data optically. Thus, in some aspects, computer-readable media may include non-transitory computer-readable media (e.g., tangible media). Additionally, for other aspects, computer-readable media may include temporary computer-readable media (e.g., signals). Combinations of the above should also be included within the scope of computer-readable media.

[0202] Thus, certain aspects may include a computer program product for performing the operations presented herein. For example, such a computer program product may include a computer-readable medium having instructions stored (and / or encoded) thereon, the instructions being executable by one or more processors to perform the operations described herein (e.g., for performing the operations described herein and in Figure 8 and Fig. 9 ).

[0203] In addition, it should be understood that the modules and / or other appropriate units for performing the methods and techniques described herein can be downloaded and / or obtained on demand by a user terminal and / or a base station. For example, such a device can be coupled to a server to facilitate the transmission of units for performing the methods described herein. Alternatively, the various methods described herein can be provided via a storage unit (e.g., RAM, ROM, physical storage media, such as a compact disc (CD) or a floppy disk, etc.), so that the user terminal and / or the base station can obtain the various methods when the storage unit is coupled to or provided to the device. In addition, any other appropriate technology for providing the methods and techniques described herein to a device can be utilized.

[0204] It is to be understood that the claims are not limited to the precise configuration and components shown above. Various modifications, changes and variations may be made in the arrangement, operation and details of the methods and apparatus described above without departing from the scope of the claims.

Claims

1. A method for wireless communication performed by a user equipment UE, comprising: receiving a channel state information (CSI) request from a base station, wherein the CSI request triggers a CSI report based on a plurality of linear combination coefficients; receiving a configuration that, for each spatial domain SD basis, constrains a maximum average magnitude of the plurality of linear combination coefficients for an associated SD basis; as well as The CSI report based on the plurality of linear combination coefficients generated according to the configuration of the maximum average amplitude is transmitted, wherein the amplitude of each linear combination coefficient in the plurality of linear combination coefficients is based on a reference amplitude and a differential amplitude.

2. The method according to claim 1, wherein: Each linear combination coefficient of the plurality of linear combination coefficients is associated with a specific SD basis and a specific frequency domain FD basis; Each linear combination coefficient of the plurality of linear combination coefficients includes at least one of a reference amplitude, a differential amplitude, or a phase; as well as The magnitude of each linear combination coefficient of the plurality of linear combination coefficients is jointly dependent on a corresponding reference magnitude and a corresponding differential magnitude.

3. The method according to claim 2, wherein: The reference amplitude is common to all linear combination coefficients associated with the same beam; or The reference amplitude is common to all linear combination coefficients associated with the same polarization.

4. The method according to claim 1, wherein: The configuration of the maximum average amplitude also includes a limitation on the maximum amplitude relative to the strongest SD basis or the strongest linear combination coefficient across both polarizations.

5. The method according to claim 4, wherein: For each SD basis, the limit on the maximum average amplitude limits the maximum amplitude of each linear combination coefficient, wherein the amplitude of each linear combination coefficient is based on the product of a reference amplitude and a differential amplitude.

6. The method according to claim 4, further wherein: For each SD basis, the limit on the maximum average amplitude limits the maximum average amplitude across the amplitudes of all linear combination coefficients associated with the SD basis, wherein the amplitude of each linear combination coefficient is based on the product of a reference amplitude and a differential amplitude.

7. The method according to claim 1, wherein: The configuration of the maximum average amplitude comprises a limitation on the maximum amplitude with respect to the strongest SD basis or the strongest linear combination coefficient for each polarization.

8. The method according to claim 7, wherein: For each SD basis, the limit on the maximum average amplitude limits the maximum amplitude of each linear combination coefficient, wherein the amplitude of each linear combination coefficient includes the differential amplitude.

9. The method according to claim 7, wherein: For each SD basis, the limit on the maximum average amplitude limits the maximum average amplitude across the amplitudes of all linear combination coefficients associated with the SD basis, wherein the amplitude of each linear combination coefficient includes a differential amplitude.

10. A method for wireless communication by a base station, comprising: Sending a channel state information CSI request to a user equipment UE, where the CSI request triggers a CSI report based on multiple linear combination coefficients; sending a configuration to the UE, the configuration limiting, for each spatial domain SD basis, a maximum average magnitude of the plurality of linear combination coefficients for an associated SD basis; receiving the CSI report; as well as The CSI report is processed according to the configuration of the maximum average amplitude, wherein the amplitude of each linear combination coefficient of the plurality of linear combination coefficients is based on a reference amplitude and a differential amplitude.

11. The method according to claim 10, wherein: Each linear combination coefficient of the plurality of linear combination coefficients is associated with a specific SD basis and a specific frequency domain FD basis; Each linear combination coefficient includes at least one of a reference amplitude, a differential amplitude, or a phase; as well as The magnitude of each linear combination coefficient of the plurality of linear combination coefficients is jointly dependent on a corresponding reference magnitude and a corresponding differential magnitude.

12. The method according to claim 11, wherein: The reference amplitude is common to all linear combination coefficients associated with the same beam; or The reference amplitude is common to all linear combination coefficients associated with the same polarization.

13. The method according to claim 10, wherein: The configuration of the maximum average amplitude also includes a limitation on the maximum amplitude relative to the strongest SD basis or the strongest linear combination coefficient across both polarizations.

14. The method according to claim 13, wherein: For each SD basis, the limit on the maximum average amplitude limits the maximum amplitude of each linear combination coefficient, wherein the amplitude of each linear combination coefficient is based on the product of a reference amplitude and a differential amplitude.

15. The method according to claim 13, further wherein: For each SD basis, the limit on the maximum average amplitude limits the maximum average amplitude across the amplitudes of all linear combination coefficients associated with the SD basis, wherein the amplitude of each linear combination coefficient is based on the product of a reference amplitude and a differential amplitude.

16. The method according to claim 10, wherein: The configuration of the maximum average amplitude comprises a limitation on the maximum amplitude with respect to the strongest SD basis or the strongest linear combination coefficient for each polarization.

17. The method according to claim 16, wherein: For each SD basis, the limit on the maximum average amplitude limits the maximum amplitude of each linear combination coefficient, wherein the amplitude of each linear combination coefficient includes the differential amplitude.

18. The method according to claim 16, wherein: For each SD basis, the limit on the maximum average amplitude limits the maximum average amplitude across the amplitudes of all linear combination coefficients associated with the SD basis, wherein the amplitude of each linear combination coefficient includes a differential amplitude.

19. A user equipment UE configured for wireless communication, comprising: a memory including computer executable instructions; as well as one or more processors configured to execute the computer executable instructions and cause the UE to: receiving a channel state information (CSI) request from a base station, wherein the CSI request triggers a CSI report based on a plurality of linear combination coefficients; receiving a configuration that, for each spatial domain SD basis, constrains a maximum average magnitude of the plurality of linear combination coefficients for an associated SD basis; as well as The CSI report based on the plurality of linear combination coefficients generated according to the configuration of the maximum average amplitude is transmitted, wherein the amplitude of each linear combination coefficient in the plurality of linear combination coefficients is based on a reference amplitude and a differential amplitude.

20. A base station configured for wireless communication, comprising: a memory including computer executable instructions; as well as one or more processors configured to execute the computer executable instructions and cause the base station to: Sending a channel state information CSI request to a user equipment UE, where the CSI request triggers a CSI report based on multiple linear combination coefficients; sending a configuration to the UE, the configuration limiting, for each spatial domain SD basis, a maximum average magnitude of the plurality of linear combination coefficients for an associated SD basis; receiving the CSI report; as well as The CSI report is processed according to the configuration of the maximum average amplitude, wherein the amplitude of each linear combination coefficient of the plurality of linear combination coefficients is based on a reference amplitude and a differential amplitude.

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