WO2021168803A1 - Balayage de faisceau srs dans de multiples scénarios de point de réception de transmission - Google Patents

Balayage de faisceau srs dans de multiples scénarios de point de réception de transmission Download PDF

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Publication number
WO2021168803A1
WO2021168803A1 PCT/CN2020/077216 CN2020077216W WO2021168803A1 WO 2021168803 A1 WO2021168803 A1 WO 2021168803A1 CN 2020077216 W CN2020077216 W CN 2020077216W WO 2021168803 A1 WO2021168803 A1 WO 2021168803A1
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WO
WIPO (PCT)
Prior art keywords
srs
beams
reference signals
uplink
uplink beams
Prior art date
Application number
PCT/CN2020/077216
Other languages
English (en)
Inventor
Min Huang
Jing Dai
Qiaoyu Li
Original Assignee
Qualcomm Incorporated
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Publication date
Application filed by Qualcomm Incorporated filed Critical Qualcomm Incorporated
Priority to PCT/CN2020/077216 priority Critical patent/WO2021168803A1/fr
Priority to PCT/CN2021/076845 priority patent/WO2021169848A1/fr
Publication of WO2021168803A1 publication Critical patent/WO2021168803A1/fr

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    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04B—TRANSMISSION
    • H04B7/00—Radio transmission systems, i.e. using radiation field
    • H04B7/02—Diversity systems; Multi-antenna system, i.e. transmission or reception using multiple antennas
    • H04B7/04—Diversity systems; Multi-antenna system, i.e. transmission or reception using multiple antennas using two or more spaced independent antennas
    • H04B7/06—Diversity systems; Multi-antenna system, i.e. transmission or reception using multiple antennas using two or more spaced independent antennas at the transmitting station
    • H04B7/0686—Hybrid systems, i.e. switching and simultaneous transmission
    • H04B7/0695—Hybrid systems, i.e. switching and simultaneous transmission using beam selection
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
    • H04L5/00—Arrangements affording multiple use of the transmission path
    • H04L5/0001—Arrangements for dividing the transmission path
    • H04L5/0014—Three-dimensional division
    • H04L5/0023—Time-frequency-space
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
    • H04L5/00—Arrangements affording multiple use of the transmission path
    • H04L5/003—Arrangements for allocating sub-channels of the transmission path
    • H04L5/0032—Distributed allocation, i.e. involving a plurality of allocating devices, each making partial allocation
    • H04L5/0035—Resource allocation in a cooperative multipoint environment
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
    • H04L5/00—Arrangements affording multiple use of the transmission path
    • H04L5/003—Arrangements for allocating sub-channels of the transmission path
    • H04L5/0048—Allocation of pilot signals, i.e. of signals known to the receiver

Definitions

  • aspects of the present disclosure relate to wireless communications, and more particularly, to techniques for beam management in scenarios involving multiple transmission reception points (TRPs) .
  • TRPs transmission reception points
  • Wireless communication systems are widely deployed to provide various telecommunication services such as telephony, video, data, messaging, broadcasts, 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. ) .
  • available system resources e.g., bandwidth, transmit power, etc.
  • multiple-access systems examples include 3rd 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 a few.
  • 3GPP 3rd Generation Partnership Project
  • LTE Long Term Evolution
  • LTE-A LTE Advanced
  • CDMA code division multiple access
  • TDMA time division multiple access
  • FDMA frequency division multiple access
  • OFDMA orthogonal frequency division multiple access
  • SC-FDMA single-carrier frequency division multiple access
  • TD-SCDMA time division synchronous code division multiple access
  • a wireless multiple-access communication system may include a number of base stations (BSs) , which are each capable of simultaneously supporting communication for multiple communication devices, otherwise known as user equipments (UEs) .
  • BSs base stations
  • UEs user equipments
  • a set of one or more base stations may define an eNodeB (eNB) .
  • eNB eNodeB
  • a wireless multiple access communication system may include a number of distributed units (DUs) (e.g., edge units (EUs) , edge nodes (ENs) , radio heads (RHs) , smart radio heads (SRHs) , transmission reception points (TRPs) , etc.
  • DUs distributed units
  • EUs edge units
  • ENs edge nodes
  • RHs radio heads
  • SSRHs smart radio heads
  • TRPs transmission reception points
  • CUs central units
  • CNs central nodes
  • ANCs access node controllers
  • a base station or distributed unit may communicate with a set of UEs on downlink channels (e.g., for transmissions from a base station or to a UE) and uplink channels (e.g., for transmissions from a UE to a base station or distributed unit) .
  • New Radio (e.g., 5G) is an example of an emerging telecommunication standard.
  • NR is a set of enhancements to the LTE mobile standard promulgated by 3GPP. It is designed to better support mobile broadband Internet access by improving spectral efficiency, lowering costs, improving services, making use of new spectrum, and better integrating with other open standards using OFDMA with a cyclic prefix (CP) on the downlink (DL) and on the uplink (UL) .
  • CP cyclic prefix
  • NR supports beamforming, multiple-input multiple-output (MIMO) antenna technology, and carrier aggregation.
  • MIMO multiple-input multiple-output
  • Certain aspects provide a method for wireless communication performed by a user equipment (UE) .
  • the method generally includes receiving a sounding reference signals (SRS) configuration indicating an SRS resource set and one or more reference signals, determining a first plurality of uplink beams based on the one or more reference signals, determining a second plurality of uplink beams for transmitting SRS in different directions, based on correlation between the second plurality of beams and the first plurality of beams, and performing a beam sweep of SRS using the second plurality of uplink beams.
  • SRS sounding reference signals
  • Certain aspects provide a method for wireless communication performed by a network entity.
  • the method generally includes sending, to a UE, an SRS configuration indicating an SRS resource set and one or more reference signals and at least one threshold, monitoring for SRS transmitted from the UE in different directions using a plurality of uplink beams determined based on the one or more reference signals and the threshold value, and signaling the UE an indication of an uplink beam selected based on the monitored SRS transmissions.
  • aspects of the present disclosure provide means for, apparatus, processors, and computer-readable mediums for performing the methods described herein.
  • the one or more aspects comprise the features hereinafter fully described and particularly pointed out in the claims.
  • the following description and the appended drawings set forth in detail certain illustrative features of the one or more aspects. These features are indicative, however, of but a few of the various ways in which the principles of various aspects may be employed.
  • FIG. 1 is a block diagram conceptually illustrating an example telecommunications system, in accordance with certain aspects of the present disclosure.
  • FIG. 2 is a block diagram illustrating an example logical architecture of a distributed radio access network (RAN) , in accordance with certain aspects of the present disclosure.
  • RAN radio access network
  • FIG. 3 is a diagram illustrating an example physical architecture of a distributed RAN, in accordance with certain aspects of the present disclosure.
  • FIG. 4 is a block diagram conceptually illustrating a design of an example base station (BS) and user equipment (UE) , in accordance with certain aspects of the present disclosure.
  • BS base station
  • UE user equipment
  • FIG. 5 is a diagram showing examples for implementing a communication protocol stack, in accordance with certain aspects of the present disclosure.
  • FIG. 6 illustrates an example of a frame format for a new radio (NR) system.
  • NR new radio
  • FIG. 7 illustrates how different synchronization signal blocks (SSBs) may be sent using different beams, in accordance with certain aspects of the present disclosure.
  • SSBs synchronization signal blocks
  • FIG. 8 shows an exemplary transmission resource mapping, according to aspects of the present disclosure.
  • FIG. 9 illustrates example quasi co-location (QCL) relationships.
  • FIGs. 10A and 10B illustrate examples of multiple transmission reception point (TRP) scenarios, in which aspects of the present disclosure may be practiced.
  • TRP transmission reception point
  • FIG. 11 illustrates example operations for wireless communication by a user equipment (UE) , in accordance with some aspects of the present disclosure.
  • UE user equipment
  • FIG. 12 illustrates example operations for wireless communication by a network entity, in accordance with some aspects of the present disclosure.
  • FIGs. 13 and 14 illustrate example correlation coefficients that may be used to select uplink beams, in accordance with some aspects of the present disclosure.
  • aspects of the present disclosure relate to wireless communications, and more particularly, to techniques for beam management in scenarios involving multiple transmission reception points (TRPs) .
  • TRPs transmission reception points
  • a CDMA network may implement a radio technology such as Universal Terrestrial Radio Access (UTRA) , cdma2000, etc.
  • UTRA includes Wideband CDMA (WCDMA) and other variants of CDMA.
  • cdma2000 covers IS-2000, IS-95 and IS-856 standards.
  • a TDMA network may implement a radio technology such as Global System for Mobile Communications (GSM) .
  • An OFDMA network may implement a radio technology such as NR (e.g.
  • E-UTRA Evolved UTRA
  • UMB Ultra Mobile Broadband
  • IEEE 802.11 Wi-Fi
  • IEEE 802.16 WiMAX
  • IEEE 802.20 Flash-OFDMA
  • UTRA and E-UTRA are part of Universal Mobile Telecommunication System (UMTS) .
  • New Radio is an emerging wireless communications technology under development in conjunction with the 5G Technology Forum (5GTF) .
  • 3GPP Long Term Evolution (LTE) and LTE-Advanced (LTE-A) are releases of UMTS that use E-UTRA.
  • UTRA, E-UTRA, UMTS, LTE, LTE-A and GSM are described in documents from an organization named “3rd Generation Partnership Project” (3GPP) .
  • cdma2000 and UMB are described in documents from an organization named “3rd Generation Partnership Project 2” (3GPP2) .
  • the techniques described herein may be used for the wireless networks and radio technologies mentioned above as well as other wireless networks and radio technologies. For clarity, while aspects may be described herein using terminology commonly associated with 3G and/or 4G wireless technologies, aspects of the present disclosure can be applied in other generation-based communication systems, such as 5G and later, including NR technologies.
  • New radio (NR) access may support various wireless communication services, such as enhanced mobile broadband (eMBB) targeting wide bandwidth (e.g., 80 MHz or beyond) , millimeter wave (mmW) targeting high carrier frequency (e.g., 25 GHz or beyond) , massive machine type communications MTC (mMTC) targeting non-backward compatible MTC techniques, and/or mission critical targeting ultra-reliable low-latency communications (URLLC) .
  • eMBB enhanced mobile broadband
  • mmW millimeter wave
  • mMTC massive machine type communications MTC
  • URLLC ultra-reliable low-latency communications
  • These services may include latency and reliability requirements.
  • These services may also have different transmission time intervals (TTI) to meet respective quality of service (QoS) requirements.
  • TTI transmission time intervals
  • QoS quality of service
  • these services may co-exist in the same subframe.
  • FIG. 1 illustrates an example wireless communication network 100 (e.g., an NR/5G network) , in which aspects of the present disclosure may be performed.
  • the wireless network 100 may include a UE 120 configured to perform operations 1100 of FIG. 11 to perform an SRS beam sweep, while a BS 110 may be configured to perform operations 1200 of FIG. 12 to select an uplink beam, based on the SRS beam sweep.
  • the wireless network 100 may include a number of base stations (BSs) 110 and other network entities.
  • a BS may be a station that communicates with user equipments (UEs) .
  • Each BS 110 may provide communication coverage for a particular geographic area.
  • the term “cell” can refer to a coverage area of a NodeB (NB) and/or a NodeB subsystem serving this coverage area, depending on the context in which the term is used.
  • gNB next generation NodeB
  • NR BS new radio base station
  • 5G NB access point
  • AP access point
  • TRP transmission reception point
  • a cell may not necessarily be stationary, and the geographic area of the cell may move according to the location of a mobile BS.
  • the base stations may be interconnected to one another and/or to one or more other base stations or network nodes (not shown) in wireless communication network 100 through various types of backhaul interfaces, such as a direct physical connection, a wireless connection, a virtual network, or the like using any suitable transport network.
  • any number of wireless networks may be deployed in a given geographic area.
  • Each wireless network may support a particular radio access technology (RAT) and may operate on one or more frequencies.
  • a RAT may also be referred to as a radio technology, an air interface, etc.
  • a frequency may also be referred to as a carrier, a subcarrier, a frequency channel, a tone, a subband, etc.
  • Each frequency may support a single RAT in a given geographic area to avoid interference between wireless networks of different RATs.
  • NR or 5G RAT networks may be deployed.
  • a base station may provide communication coverage for a macro cell, a pico cell, a femto cell, and/or other types of cells.
  • a macro cell may cover a relatively large geographic area (e.g., several kilometers in radius) and may allow unrestricted access by UEs with service subscription.
  • a pico cell may cover a relatively small geographic area and may allow unrestricted access by UEs with service subscription.
  • a femto cell may cover a relatively small geographic area (e.g., a home) and may allow restricted access by UEs having an association with the femto cell (e.g., UEs in a Closed Subscriber Group (CSG) , UEs for users in the home, etc. ) .
  • CSG Closed Subscriber Group
  • 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.
  • the BSs 110a, 110b and 110c may be macro BSs for the macro cells 102a, 102b and 102c, respectively.
  • the BS 110x may be a pico BS for a pico cell 102x.
  • the BSs 110y and 110z may be femto BSs for the femto cells 102y and 102z, respectively.
  • a BS may support one or multiple (e.g., three) cells.
  • Wireless communication network 100 may also include relay stations.
  • a relay station is a station that receives a transmission of data and/or other information from an upstream station (e.g., a BS or a UE) and sends a transmission of the 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.
  • a relay station 110r may communicate with the 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, etc.
  • Wireless network 100 may be a heterogeneous network that includes BSs of different types, e.g., macro BS, pico BS, femto BS, relays, etc. These different types of BSs may have different transmit power levels, different coverage areas, and different impact on interference in the wireless network 100.
  • macro BS may have a high transmit power level (e.g., 20 Watts) whereas pico BS, femto BS, and relays may have a lower transmit power level (e.g., 1 Watt) .
  • Wireless communication network 100 may support synchronous or asynchronous operation.
  • the BSs may have similar frame timing, and transmissions from different BSs may be approximately aligned in time.
  • the BSs may have different frame timing, and transmissions from different BSs may not be aligned in time.
  • the techniques described herein may be used for both synchronous and asynchronous operation.
  • 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 one another (e.g., directly or indirectly) via wireless or wireline backhaul.
  • the UEs 120 may be dispersed throughout the wireless network 100, and each UE may be stationary or mobile.
  • a UE may also be referred to as a mobile station, a terminal, an access terminal, a subscriber unit, a station, a Customer Premises Equipment (CPE) , a cellular phone, a smart phone, a personal digital assistant (PDA) , a wireless modem, a wireless communication device, a handheld device, a laptop computer, a cordless phone, a wireless local loop (WLL) station, a tablet computer, a camera, a gaming device, a netbook, a smartbook, an ultrabook, an appliance, a medical device or medical equipment, a biometric sensor/device, a wearable device such as a smart watch, smart clothing, smart glasses, a smart wrist band, smart jewelry (e.g., a smart ring, a smart bracelet, etc.
  • CPE Customer Premises Equipment
  • PDA personal digital assistant
  • WLL wireless local loop
  • an entertainment device e.g., a music device, a video device, a satellite radio, etc.
  • a vehicular component or sensor e.g., a smart meter/sensor, industrial manufacturing equipment, a global positioning system device, gaming device, reality augmentation device (augmented reality (AR) , extended reality (XR) , or virtual reality (VR) ) , or any other suitable device that is configured to communicate via a wireless or wired medium.
  • AR augmented reality
  • XR extended reality
  • VR virtual reality
  • Some UEs may be considered 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 may communicate with a BS, another device (e.g., remote device) , or some other entity.
  • a wireless node may provide, for example, connectivity for or to a network (e.g., a wide area network such as Internet or a cellular network) via a wired or wireless communication link.
  • Some UEs may be considered Internet-of-Things (IoT) devices, which may be narrowband IoT (NB-IoT) devices.
  • IoT Internet-of-Things
  • NB-IoT narrowband IoT
  • Certain wireless networks utilize orthogonal frequency division multiplexing (OFDM) on the downlink and single-carrier frequency division multiplexing (SC-FDM) on the uplink.
  • OFDM and SC-FDM partition the system bandwidth into multiple (K) orthogonal subcarriers, which are also commonly referred to as tones, bins, etc.
  • K orthogonal subcarriers
  • Each subcarrier may be modulated with data.
  • modulation symbols are sent in the frequency domain with OFDM and in the time domain with SC-FDM.
  • the spacing between adjacent subcarriers may be fixed, and the total number of subcarriers (K) may be dependent on the system bandwidth.
  • the spacing of the subcarriers may be 15 kHz and the minimum resource allocation (called a “resource block” (RB) ) may be 12 subcarriers (or 180 kHz) . Consequently, the nominal Fast Fourier Transfer (FFT) size may be equal to 128, 256, 512, 1024 or 2048 for system bandwidth of 1.25, 2.5, 5, 10, or 20 megahertz (MHz) , respectively.
  • the system bandwidth may also be partitioned into subbands. For example, a subband may cover 1.08 MHz (i.e., 6 resource blocks) , and there may be 1, 2, 4, 8, or 16 subbands for system bandwidth of 1.25, 2.5, 5, 10 or 20 MHz, respectively.
  • NR may utilize OFDM with a CP on the uplink and downlink and include support for half-duplex operation using TDD. Beamforming may be supported and beam direction may be dynamically configured. MIMO transmissions with precoding may also be supported. MIMO configurations in the DL may support up to 8 transmit antennas with multi-layer DL transmissions up to 8 streams and up to 2 streams per UE. Multi-layer transmissions with up to 2 streams per UE may be supported. Aggregation of multiple cells may be supported with up to 8 serving cells.
  • a scheduling entity e.g., a base station (BS) , Node B, eNB, gNB, or the like
  • the scheduling entity may be responsible for scheduling, assigning, reconfiguring, and releasing resources for one or more subordinate entities. That is, for scheduled communication, subordinate entities can utilize resources allocated by one or more scheduling entities.
  • Base stations are not the only entities that may function as a scheduling entity.
  • a UE may function as a scheduling entity and may schedule resources for one or more subordinate entities (e.g., one or more other UEs) , and the other UEs may utilize the resources scheduled by the UE for wireless communication.
  • a UE may function as a scheduling entity in a peer-to-peer (P2P) network, and/or in a mesh network.
  • P2P peer-to-peer
  • UEs may communicate directly with one another in addition to communicating with a scheduling entity.
  • FIG. 1 this figure illustrates a variety of potential deployments for various deployment scenarios.
  • 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 finely dashed line with double arrows indicates interfering transmissions between a UE and a BS.
  • Other lines show component to component (e.g., UE to UE) communication options.
  • FIG. 2 illustrates an example logical architecture of a distributed Radio Access Network (RAN) 200, which may be implemented in the wireless communication network 100 illustrated in FIG. 1.
  • a 5G access node 206 may include an access node controller (ANC) 202.
  • ANC 202 may be a central unit (CU) of the distributed RAN 200.
  • the backhaul interface to the Next Generation Core Network (NG-CN) 204 may terminate at ANC 202.
  • the backhaul interface to neighboring next generation access Nodes (NG-ANs) 210 may terminate at ANC 202.
  • ANC 202 may include one or more transmission reception points (TRPs) 208 (e.g., cells, BSs, gNBs, etc. ) .
  • TRPs transmission reception points
  • the TRPs 208 may be a distributed unit (DU) .
  • TRPs 208 may be connected to a single ANC (e.g., ANC 202) or more than one ANC (not illustrated) .
  • a single ANC e.g., ANC 202
  • ANC e.g., ANC 202
  • RaaS radio as a service
  • TRPs 208 may be connected to more than one ANC.
  • TRPs 208 may each include one or more antenna ports.
  • TRPs 208 may be configured to individually (e.g., dynamic selection) or jointly (e.g., joint transmission) serve traffic to a UE.
  • the logical architecture of distributed RAN 200 may support various backhauling and fronthauling solutions. This support may occur via and across different deployment types.
  • the logical architecture may be based on transmit network capabilities (e.g., bandwidth, latency, and/or jitter) .
  • next generation access node (NG-AN) 210 may support dual connectivity with NR and may share a common fronthaul for LTE and NR.
  • NG-AN next generation access node
  • the logical architecture of distributed RAN 200 may enable cooperation between and among TRPs 208, for example, within a TRP and/or across TRPs via ANC 202.
  • An inter-TRP interface may not be used.
  • Logical functions may be dynamically distributed in the logical architecture of distributed RAN 200.
  • the Radio Resource Control (RRC) layer, Packet Data Convergence Protocol (PDCP) layer, Radio Link Control (RLC) layer, Medium Access Control (MAC) layer, and a Physical (PHY) layers may be adaptably placed at the DU (e.g., TRP 208) or CU (e.g., ANC 202) .
  • RRC Radio Resource Control
  • PDCP Packet Data Convergence Protocol
  • RLC Radio Link Control
  • MAC Medium Access Control
  • PHY Physical
  • FIG. 3 illustrates an example physical architecture of a distributed Radio Access Network (RAN) 300, according to aspects of the present disclosure.
  • a centralized core network unit (C-CU) 302 may host core network functions.
  • C-CU 302 may be centrally deployed.
  • C-CU 302 functionality may be offloaded (e.g., to advanced wireless services (AWS) ) , in an effort to handle peak capacity.
  • AWS advanced wireless services
  • a centralized RAN unit (C-RU) 304 may host one or more ANC functions.
  • the C-RU 304 may host core network functions locally.
  • the C-RU 304 may have distributed deployment.
  • the C-RU 304 may be close to the network edge.
  • a DU 306 may host one or more TRPs (Edge Node (EN) , an Edge Unit (EU) , a Radio Head (RH) , a Smart Radio Head (SRH) , or the like) .
  • the DU may be located at edges of the network with radio frequency (RF) functionality.
  • RF radio frequency
  • FIG. 4 illustrates example components of BS 110 and UE 120 (as depicted in FIG. 1) , which may be used to implement aspects of the present disclosure.
  • antennas 452, processors 466, 458, 464, and/or controller/processor 480 of the UE 120 may be used to perform operations 1100 of FIG. 11, while antennas 434, processors 420, 460, 438, and/or controller/processor 440 of the BS 110 may be used to perform operations 1200 of FIG. 12.
  • a transmit processor 420 may receive data from a data source 412 and control information from a controller/processor 440.
  • the control information may be for the physical broadcast channel (PBCH) , physical control format indicator channel (PCFICH) , physical hybrid ARQ indicator channel (PHICH) , physical downlink control channel (PDCCH) , group common PDCCH (GC PDCCH) , etc.
  • the data may be for the physical downlink shared channel (PDSCH) , etc.
  • the processor 420 may process (e.g., encode and symbol map) the data and control information to obtain data symbols and control symbols, respectively.
  • the processor 420 may also generate reference symbols, e.g., for the primary synchronization signal (PSS) , secondary synchronization signal (SSS) , and cell-specific reference signal (CRS) .
  • a transmit (TX) multiple-input multiple-output (MIMO) processor 430 may perform spatial processing (e.g., precoding) on the data symbols, the control symbols, and/or the reference symbols, if applicable, and may provide output symbol streams to the modulators (MODs) 432a through 432t. Each modulator 432 may process a respective output symbol stream (e.g., for OFDM, etc. ) to obtain an output sample stream.
  • Each modulator may further process (e.g., convert to analog, amplify, filter, and upconvert) the output sample stream to obtain a downlink signal.
  • Downlink signals from modulators 432a through 432t may be transmitted via the antennas 434a through 434t, respectively.
  • antennas 452a through 452r may receive downlink signals from the base station 110 and may provide received signals to demodulators (DEMODs) in transceivers 454a through 454r, respectively.
  • Each demodulator 454 may condition (e.g., filter, amplify, down convert, and digitize) a respective received signal to obtain input samples.
  • Each demodulator may further process input samples (e.g., for OFDM, etc. ) to obtain received symbols.
  • a MIMO detector 456 may obtain received symbols from all demodulators 454a through 454r, perform MIMO detection on the received symbols if applicable, and provide detected symbols.
  • a receive processor 458 may process (e.g., demodulate, deinterleave, and decode) the detected symbols, provide decoded data for the UE 120 to a data sink 460, and provide decoded control information to a controller/processor 480.
  • a transmit processor 464 may receive and process data (e.g., for the physical uplink shared channel (PUSCH) ) from a data source 462 and control information (e.g., for the physical uplink control channel (PUCCH) from the controller/processor 480.
  • the transmit processor 464 may also generate reference symbols for a reference signal (e.g., for the sounding reference signal (SRS) ) .
  • the symbols from the transmit processor 464 may be precoded by a TX MIMO processor 466 if applicable, further processed by the demodulators in transceivers 454a through 454r (e.g., for SC-FDM, etc. ) , and transmitted to the base station 110.
  • data e.g., for the physical uplink shared channel (PUSCH)
  • control information e.g., for the physical uplink control channel (PUCCH) from the controller/processor 480.
  • the transmit processor 464 may also generate reference symbols for a reference signal (e.g., for the
  • uplink signals from the UE 120 may be received by the antennas 434, processed by the modulators 432, detected by a MIMO detector 436 if applicable, and further processed by a receive processor 438 to obtain decoded data and control information sent by the UE 120.
  • the receive processor 438 may provide the decoded data to a data sink 439 and the decoded control information to the controller/processor 440.
  • the controllers/processors 440 and 480 may direct operations at the base station 110 and the UE 120, respectively.
  • the processor 440 and/or other processors and modules at the BS 110 may perform or direct execution of processes for techniques described herein.
  • the memories 442 and 482 may store data and program codes for BS 110 and UE 120, respectively.
  • a scheduler 444 may schedule UEs for data transmission on the downlink and/or uplink.
  • FIG. 5 illustrates a diagram 500 showing examples for implementing a communications protocol stack, according to aspects of the present disclosure.
  • the illustrated communications protocol stacks may be implemented by devices operating in a wireless communication system, such as a 5G system (e.g., a system that supports uplink-based mobility) .
  • Diagram 500 illustrates a communications protocol stack including a Radio Resource Control (RRC) layer 510, a Packet Data Convergence Protocol (PDCP) layer 515, a Radio Link Control (RLC) layer 520, a Medium Access Control (MAC) layer 525, and a Physical (PHY) layer 530.
  • RRC Radio Resource Control
  • PDCP Packet Data Convergence Protocol
  • RLC Radio Link Control
  • MAC Medium Access Control
  • PHY Physical
  • the layers of a protocol stack may be implemented as separate modules of software, portions of a processor or ASIC, portions of non-collocated devices connected by a communications link, or various combinations thereof. Collocated and non-collocated implementations may be used, for example, in a protocol stack for a network access device (e.g., ANs, CUs, and/or DUs) or a UE.
  • a network access device e.g., ANs, CUs, and/or DUs
  • a first option 505-a shows a split implementation of a protocol stack, in which implementation of the protocol stack is split between a centralized network access device (e.g., an ANC 202 in FIG. 2) and distributed network access device (e.g., DU 208 in FIG. 2) .
  • a centralized network access device e.g., an ANC 202 in FIG. 2
  • distributed network access device e.g., DU 208 in FIG. 2
  • an RRC layer 510 and a PDCP layer 515 may be implemented by the central unit
  • an RLC layer 520, a MAC layer 525, and a PHY layer 530 may be implemented by the DU.
  • the CU and the DU may be collocated or non-collocated.
  • the first option 505-a may be useful in a macro cell, micro cell, or pico cell deployment.
  • a second option 505-b shows a unified implementation of a protocol stack, in which the protocol stack is implemented in a single network access device.
  • RRC layer 510, PDCP layer 515, RLC layer 520, MAC layer 525, and PHY layer 530 may each be implemented by the AN.
  • the second option 505-b may be useful in, for example, a femto cell deployment.
  • a UE may implement an entire protocol stack as shown in 505-c (e.g., the RRC layer 510, the PDCP layer 515, the RLC layer 520, the MAC layer 525, and the PHY layer 530) .
  • Embodiments discussed herein may include a variety of spacing and timing deployments.
  • the basic transmission time interval (TTI) or packet duration is the 1 ms subframe.
  • a subframe is still 1 ms, but the basic TTI is referred to as a slot.
  • a subframe contains a variable number of slots (e.g., 1, 2, 4, 8, 16, slots) depending on the subcarrier spacing.
  • the NR RB is 12 consecutive frequency subcarriers.
  • NR may support a base subcarrier spacing of 15 KHz and other subcarrier spacing may be defined with respect to the base subcarrier spacing, for example, 30 kHz, 60 kHz, 120 kHz, 240 kHz, etc.
  • the symbol and slot lengths scale with the subcarrier spacing.
  • the CP length also depends on the subcarrier spacing.
  • FIG. 6 is a diagram showing an example of a frame format 600 for NR.
  • the transmission timeline for each of the downlink and uplink may be partitioned into units of radio frames.
  • Each radio frame may have a predetermined duration (e.g., 10 ms) and may be partitioned into 10 subframes, each of 1 ms, with indices of 0 through 9.
  • Each subframe may include a variable number of slots depending on the subcarrier spacing.
  • Each slot may include a variable number of symbol periods (e.g., 7 or 14 symbols) depending on the subcarrier spacing.
  • the symbol periods in each slot may be assigned indices.
  • a mini-slot is a subslot structure (e.g., 2, 3, or 4 symbols) .
  • Each symbol in a slot may indicate a link direction (e.g., DL, UL, or flexible) for data transmission and the link direction for each subframe may be dynamically switched.
  • the link directions may be based on the slot format.
  • Each slot may include DL/UL data as well as DL/UL control information.
  • a synchronization signal (SS) block (SSB) is transmitted.
  • the SS block includes a PSS, a SSS, and a two symbol PBCH.
  • the SS block can be transmitted in a fixed slot location, such as the symbols 0-3 as shown in FIG. 6.
  • the PSS and SSS may be used by UEs for cell search and acquisition.
  • the PSS may provide half-frame timing, and the SS may provide the CP length and frame timing.
  • the PSS and SSS may provide the cell identity.
  • the PBCH carries some basic system information, such as downlink system bandwidth, timing information within radio frame, SS burst set periodicity, system frame number, etc.
  • RMSI remaining minimum system information
  • SIBs system information blocks
  • OSI system information
  • PDSCH physical downlink shared channel
  • the SS blocks may be organized into SS burst sets to support beam sweeping.
  • each SSB within a burst set may be transmitted using a different beam, which may help a UE quickly acquire both transmit (Tx) and receive (Rx) beams (particular for mmW applications) .
  • a physical cell identity (PCI) may still decoded from the PSS and SSS of the SSB.
  • Certain deployment scenarios may include one or both NR deployment options. Some may be configured for non-standalone (NSA) and/or standalone (SA) option.
  • a standalone cell may need to broadcast both SSB and remaining minimum system information (RMSI) , for example, with SIB1 and SIB2.
  • RMSI remaining minimum system information
  • a non-standalone cell may only need to broadcast SSB, without broadcasting RMSI.
  • multiple SSBs may be sent in different frequencies, and may include the different types of SSB.
  • Control Resource Sets (CORESETs)
  • a control resource set (CORESET) for an OFDMA system may comprise one or more control resource (e.g., time and frequency resources) sets, configured for conveying PDCCH, within the system bandwidth.
  • control resource e.g., time and frequency resources
  • search spaces e.g., common search space (CSS) , UE-specific search space (USS) , etc.
  • search spaces are generally areas or portions where a communication device (e.g., a UE) may look for control information.
  • a CORESET is a set of time and frequency domain resources, defined in units of resource element groups (REGs) .
  • Each REG may comprise a fixed number (e.g., twelve) tones in one symbol period (e.g., a symbol period of a slot) , where one tone in one symbol period is referred to as a resource element (RE) .
  • a fixed number of REGs may be included in a control channel element (CCE) .
  • CCE control channel element
  • Sets of CCEs may be used to transmit new radio PDCCHs (NR-PDCCHs) , with different numbers of CCEs in the sets used to transmit NR-PDCCHs using differing aggregation levels.
  • Multiple sets of CCEs may be defined as search spaces for UEs, and thus a NodeB or other base station may transmit an NR-PDCCH to a UE by transmitting the NR-PDCCH in a set of CCEs that is defined as a decoding candidate within a search space for the UE, and the UE may receive the NR-PDCCH by searching in search spaces for the UE and decoding the NR-PDCCH transmitted by the NodeB.
  • Operating characteristics of a NodeB or other base station in an NR communications system may be dependent on a frequency range (FR) in which the system operates.
  • a frequency range may comprise one or more operating bands (e.g., “n1” band, “n2” band, “n7” band, and “n41” band) , and a communications system (e.g., one or more NodeBs and UEs) may operate in one or more operating bands.
  • Frequency ranges and operating bands are described in more detail in “Base Station (BS) radio transmission and reception” TS38.104 (Release 15) , which is available from the 3GPP website.
  • a CORESET is a set of time and frequency domain resources.
  • the CORESET can be configured for conveying PDCCH within system bandwidth.
  • a UE may determine a CORESET and monitors the CORESET for control channels.
  • a UE may identify an initial CORESET (CORESET #0) configuration from a field (e.g., pdcchConfigSIB1) in a maser information block (MIB) .
  • This initial CORESET may then be used to configure the UE (e.g., with other CORESETs and/or bandwidth parts via dedicated (UE-specific) signaling.
  • the UE When the UE detects a control channel in the CORESET, the UE attempts to decode the control channel and communicates with the transmitting BS (e.g., the transmitting cell) according to the control data provided in the control channel (e.g., transmitted via the CORESET) .
  • the transmitting BS e.g., the transmitting cell
  • the UE may receive a master information block (MIB) .
  • the MIB can be in a synchronization signal and physical broadcast channel (SS/PBCH) block (e.g., in the PBCH of the SS/PBCH block) on a synchronization raster (sync raster) .
  • SS/PBCH synchronization signal and physical broadcast channel
  • the sync raster may correspond to an SSB.
  • the UE may determine an operating band of the cell. Based on a cell’s operation band, the UE may determine a minimum channel bandwidth and a subcarrier spacing (SCS) of the channel.
  • SCS subcarrier spacing
  • the UE may then determine an index from the MIB (e.g., four bits in the MIB, conveying an index in a range 0-15) .
  • the UE may look up or locate a CORESET configuration (this initial CORESET configured via the MIB is generally referred to as CORESET #0) . This may be accomplished from one or more tables of CORESET configurations. These configurations (including single table scenarios) may include various subsets of indices indicating valid CORESET configurations for various combinations of minimum channel bandwidth and SCS. In some arrangements, each combination of minimum channel bandwidth and SCS may be mapped to a subset of indices in the table.
  • the UE may select a search space CORESET configuration table from several tables of CORESET configurations. These configurations can be based on a minimum channel bandwidth and SCS.
  • the UE may then look up a CORESET configuration (e.g., a Type0-PDCCH search space CORESET configuration) from the selected table, based on the index.
  • the UE may then determine the CORESET to be monitored (as mentioned above) based on the location (in time and frequency) of the SS/PBCH block and the CORESET configuration.
  • FIG. 8 shows an exemplary transmission resource mapping 800, according to aspects of the present disclosure.
  • a BS e.g., BS 110a, shown in FIG. 1 transmits an SS/PBCH block 802.
  • the SS/PBCH block includes a MIB conveying an index to a table that relates the time and frequency resources of the CORESET 804 to the time and frequency resources of the SS/PBCH block.
  • the BS may also transmit control signaling.
  • the BS may also transmit a PDCCH to a UE (e.g., UE 120, shown in FIG. 1) in the (time/frequency resources of the) CORESET.
  • the PDCCH may schedule a PDSCH 806.
  • the BS then transmits the PDSCH to the UE.
  • the UE may receive the MIB in the SS/PBCH block, determine the index, look up a CORESET configuration based on the index, and determine the CORESET from the CORESET configuration and the SS/PBCH block.
  • the UE may then monitor the CORESET, decode the PDCCH in the CORESET, and receive the PDSCH that was allocated by the PDCCH.
  • each configuration may indicate a number of resource blocks (e.g., 24, 48, or 96) , a number of symbols (e.g., 1-3) , as well as an offset (e.g., 0-38 RBs) that indicates a location in frequency.
  • resource blocks e.g., 24, 48, or 96
  • symbols e.g., 1-3
  • offset e.g., 0-38 RBs
  • a UE it is important for a UE to know which assumptions it can make on a channel corresponding to different transmissions. For example, the UE may need to know which reference signals it can use to estimate the channel in order to decode a transmitted signal (e.g., PDCCH or PDSCH) . It may also be important for the UE to be able to report relevant channel state information (CSI) to the BS (gNB) for scheduling, link adaptation, and/or beam management purposes.
  • CSI channel state information
  • gNB BS
  • the concept of quasi co-location (QCL) and transmission configuration indicator (TCI) states is used to convey information about these assumptions.
  • TCI states generally include configurations such as QCL-relationships, for example, between the DL RSs in one CSI-RS set and the PDSCH DMRS ports.
  • a UE may be configured with up to M TCI-States. Configuration of the M TCI-States can come about via higher layer signalling, while a UE may be signalled to decode PDSCH according to a detected PDCCH with DCI indicating one of the TCI states.
  • Each configured TCI state may include one RS set TCI-RS-SetConfig that indicates different QCL assumptions between certain source and target signals.
  • FIG. 9 illustrate examples of the association of DL reference signals with corresponding QCL types that may be indicated by a TCI-RS-SetConfig.
  • a source reference signal is indicated in the top block and is associated with a target signal indicated in the bottom block.
  • a target signal generally refers to a signal for which channel properties may be inferred by measuring those channel properties for an associated source signal.
  • a UE may use the source RS to determine various channel parameters, depending on the associated QCL type, and use those various channel properties (determined based on the source RS) to process the target signal.
  • a target RS does not necessarily need to be PDSCH’s DMRS, rather it can be any other RS: PUSCH DMRS, CSIRS, TRS, and SRS.
  • each TCI-RS-SetConfig contains parameters. These parameters can, for example, configure quasi co-location relationship (s) between reference signals in the RS set and the DM-RS port group of the PDSCH.
  • the RS set contains a reference to either one or two DL RSs and an associated quasi co-location type (QCL-Type) for each one configured by the higher layer parameter QCL-Type.
  • QCL-Type quasi co-location type
  • the QCL types can take on a variety of arrangements. For example, QCL types may not be the same, regardless of whether the references are to the same DL RS or different DL RSs.
  • SSB is associated with Type C QCL for P-TRS
  • CSI-RS for beam management (CSIRS–BM) is associated with Type D QCL.
  • QCL information and/or types may in some scenarios depend on or be a function of other information.
  • the quasi co-location (QCL) types indicated to the UE can be based on higher layer parameter QCL-Type and may take one or a combination of the following types:
  • QCL-TypeA ⁇ Doppler shift, Doppler spread, average delay, delay spread ⁇ ,
  • Spatial QCL assumptions may be used to help a UE to select an analog Rx beam (e.g., during beam management procedures) .
  • an SSB resource indicator may indicate a same beam for a previous reference signal should be used for a subsequent transmission.
  • An initial CORESET (e.g., CORESET ID 0 or simply CORESET#0) in NR may be identified during initial access by a UE (e.g., via a field in the MIB) .
  • a ControlResourceSet information element (CORESET IE) sent via radio resource control (RRC) signaling may convey information regarding a CORESET configured for a UE.
  • the CORESET IE generally includes a CORESET ID, an indication of frequency domain resources (e.g., number of RBs) assigned to the CORESET, contiguous time duration of the CORESET in a number of symbols, and Transmission Configuration Indicator (TCI) states.
  • TCI Transmission Configuration Indicator
  • a subset of the TCI states provide quasi co-location (QCL) relationships between DL RS (s) in one RS set (e.g., TCI-Set) and PDCCH demodulation RS (DMRS) ports.
  • a particular TCI state for a given UE may be conveyed to the UE by the Medium Access Control (MAC) Control Element (MAC-CE) .
  • the particular TCI state is generally selected from the set of TCI states conveyed by the CORESET IE, with the initial CORESET (CORESET#0) generally configured via MIB.
  • Search space information may also be provided via RRC signaling.
  • the Search Space IE is another RRC IE that defines how and where to search for PDCCH candidates for a given CORESET. Each search space is associated with one CORESET.
  • the Search Space IE identifies a search space configured for a CORESET by a search space ID.
  • the search space ID associated with CORESET #0 is Search Space ID #0.
  • the search space is generally configured via PBCH (MIB) .
  • NR networks are expected to utilize multiple transmission and reception points (TRPs) to improve reliability and capacity performance through flexible deployment scenarios. For example, allowing UEs to access wireless networks via multi-TRPs may help support increased mobile data traffic and enhance the coverage.
  • Multi-TRPs may be used to implement one or more macro-cells, small cells, pico-cells, or femto-cells, and may include remote radio heads, relay nodes, and the like.
  • FIG. 10A illustrates an example multi-TRP scenario, in which two TRPs (TRP 1 and TRP 2) serve three UEs (UE1, UE2, and UE3) .
  • multiple PDCCHs may be used for scheduling.
  • Each PDCCH may include corresponding downlink control information (DCI) .
  • DCI downlink control information
  • PDCCH1 (transmitted from TRP 1) may carry a first DCI that schedules a first codeword (CW1) to be transmitted from TRP1 in PDSCH1.
  • PDCCH2 (transmitted from TRP2) may carry a second DCI that schedules a second codeword (CW2) to be transmitted from TRP2 in PDSCH2.
  • CORESETs For monitoring the DCIs transmitted from different TRPs, a number of different control resource sets (CORESETs) may be used.
  • CORESET generally refers to a set of physical resources (e.g., a specific area on the NR Downlink Resource Grid) and a set of parameters that is used to carry PDCCH/DCI.
  • a CORESET may by similar in area to an LTE PDCCH area (e.g., the first 1, 2, 3, 4 OFDM symbols in a subframe) .
  • TRP differentiation at the UE side may be based on CORESET groups.
  • a UE may monitor for transmissions in different CORESET groups and infer that transmissions sent in different CORESET groups come from different TRPs. There may be other ways in which the notion of different TRPs may be transparent to the UE.
  • aspects of the present disclosure relate to wireless communications, and more particularly, to techniques for beam management in scenarios involving multiple transmission reception points (TRPs) .
  • TRPs transmission reception points
  • the UE is normally required to transmit one or more SRS.
  • the gNB determines one or more UL beams based on the channel gains of the one or more SRSs (e.g., selecting the beams of the SRSs with the highest channel gains) .
  • the gNB indicates these beams in a UL data channel scheduling grant (e.g., DCI format 0-1) , where the UE is required to transmit the UL data channel (e.g., PUSCH) along these beams.
  • a UL data channel scheduling grant e.g., DCI format 0-1
  • a gNB typically configures SRS resources for a UE using radio resource control (RRC) signaling, such that each SRS resource has an attribute.
  • the attribute may be Spatial Relation Information (spatialRelationInfo) , which contains the index of only one reference signal. If the UE is signaled to transmit SRS in a certain SRS resource, it should use the beam that corresponds with the reference signal contained in the spatialRelationInfo.
  • RRC radio resource control
  • the UE is expected to transmit an SRS along the beam that is used to receive SSBs or CSI-RSs in the corresponding SSB resource or CSI-RS resource. If an SRS resource is contained, the UE is expected transmit SRS along the beam that is used to transmit an SRS in the corresponding SRS resource.
  • SSB synchronization signal block
  • CSI-RS channel state information reference signal
  • a gNB may configure to a UE with a list of SRS resource sets in an SRS configuration message.
  • Each SRS resource set includes a list of SRS resources.
  • Each SRS resource set has a property of usage, such as beamManagement, codebook, nonCodebook, and antennaSwitching.
  • a gNB connects to multiple geographically-distributed TRPs. These TRPs can separately or jointly transmit signals to one or more UEs or receive signals from one or more UEs.
  • Current standards mainly consider the downlink data channel (PDSCH) based on multi-TRP.
  • gNB may transmit signals from different TRPs to a UE on multiple PDSCH links, by which the diversity gain, DL system capacity and/or DL cell coverage can be enhanced.
  • FIG. 10B illustrates how UEs may cause mutual interference for uplink transmissions in a multli-TRP scenario.
  • a UE may be restricted by a maximum transmission power.
  • a UE may be scheduled to transmit an UL data channel (e.g., PUSCH) signal to the target a TRP, which has the highest channel gain, with full transmission power.
  • the link from a UE to its target TRP may be called the UE’s target link, as shown in FIG. 10B.
  • a gNB may schedule another UE to transmit in UL data channel (e.g., PUSCH) to another TRP, so as to improve the spectrum efficiency and the cell throughput.
  • UL data channel e.g., PUSCH
  • the link from a UE to the non-target TRP may be called as the UE’s interference link.
  • a gNB may configure a UE to sweep uplink beams by transmitting SRS in various beam directions, by which gNB can determine a suitable uplink beam direction for UE to transmit uplink data and signaling messages.
  • the network may expect the UE not to cause strong interference to one or more TRPs, (e.g., when those TRPs are receiving higher-priority uplink access transmissions from other UEs or backhaul transmissions from another network node (e.g., an integrated access and backhaul (IAB) node) ) .
  • IAB integrated access and backhaul
  • gNB may want the UE to sweep uplink beams in the beam directions that do not cause strong interference to those TRPs.
  • a parameter of an SRS spatial relation may be associated with an SRS resource, so that UE can transmit SRS along the beam corresponding to the SRS spatial relation in the SRS resource.
  • this SRS configuration may not be able satisfy the above-mentioned requirement in multi-TRP scenarios for one or more reasons.
  • the UE may use the SRS spatial relation parameter to determine the target link’s beam to a target TRP instead of the interference link’s beam to a non-target TRPs.
  • the UE may use this parameter to determine a beam for uplink data and signaling transmission (i.e., PUSCH, PUCCH) , rather than to determine a beam for uplink interference avoidance.
  • PUSCH uplink data and signaling transmission
  • PUCCH Physical channels dedicated to Physical channels
  • this SRS spatial relation parameter is associated with a single SRS resource in current standard. Therefore, a UE cannot use this parameter to perform SRS beam sweeping, which may include transmitting SRS using multiple SRS resources.
  • a UE may be configured with associated reference signals related to non-target TRPs. The UE may use these reference signals to select beams to transmit SRS that generate low received power at the beam direction related to these reference signals (and, hence the non-target TRPs) .
  • FIG. 11 is a flow diagram illustrating example operations 1100 for wireless communication by a UE, in accordance with certain aspects of the present disclosure.
  • the operations 1200 may be performed, for example, by a UE 120.
  • Operations 1100 begin, at 1102, by the UE receiving an SRS configuration indicating an SRS resource set and one or more reference signals.
  • the SRS resource set contains a plurality of SRS resources at different time instances.
  • Each of the SRS resources is associated with one or parameters including at least one of: a time-domain position, a frequency-domain position, a cyclic shift, a comb offset, frequency hopping mode, or a sequence hopping mode.
  • the SRS resource configuration is received via at least one of: a RRC message, a medium access control (MAC) control element (CE) , or a downlink control information (DCI) .
  • a RRC message a RRC message
  • MAC medium access control
  • CE control element
  • DCI downlink control information
  • the UE determines a first plurality of uplink beams based on the one or more reference signals.
  • the one or more reference signals indicated in the SRS configuration comprise at least one of: SSBs, CSI-RS, or SRS.
  • determining the first plurality of uplink beams comprises: determining receive beams used to receive the one or more reference signals and determining the first plurality of uplink beams based on the determined receive beams.
  • determining the first plurality of uplink beams comprises: determining the first plurality of uplink beams based on uplink beams used by SRS indicated as reference signals by the SRS configuration.
  • the UE determines a second plurality of uplink beams for transmitting SRS in different directions, based on correlation between the second plurality of beams and the first plurality of beams.
  • the SRS configuration also indicates at least one threshold. Correlation coefficients between the second plurality of uplink beams and first plurality of uplink beams is less than the at least one threshold.
  • the second plurality of SRS beams are selected, based on a range of correlation coefficient values that are less than the at least one threshold, such their corresponding directions are distributed in a direction scope.
  • the second plurality of SRS beams are selected based on quantized values of offsets between the first plurality of uplink beams and the second plurality of uplink beams.
  • the UE performs a beam sweep of SRS using the second plurality of uplink beams.
  • receiving an indication of an identifier of an SRS resource selected based on the beam sweep of SRS using the second plurality of uplink beams and using an uplink beam corresponding to the SRS resource or one or more subsequent uplink transmissions is a technique that uses the beam sweep of SRS to generate a downlink beam.
  • FIG. 12 is a flow diagram illustrating example operations 1200 for wireless communication by a network entity, and may be considered complementary to operations 1100 of FIG. 11.
  • operations 1200 may be performed, for example, by a BS 110 (e.g., a gNB) in conjunction with a UE 120 performing operations 1100 of FIG. 11.
  • a BS 110 e.g., a gNB
  • UE 120 performing operations 1100 of FIG. 11.
  • Operations 1200 begin, at 1202, by sending, to a UE, an SRS configuration indicating an SRS resource set and one or more reference signals and at least one threshold.
  • the network entity monitors for SRS transmitted from the UE in different directions using a plurality of uplink beams determined based on the one or more reference signals and the threshold value.
  • the network entity signals the UE an indication of an uplink beam selected based on the monitored SRS transmissions.
  • the indication of the uplink beam selected by the network entity is signaled as an indication of an index of an SRS resource selected based on the monitored SRS transmissions.
  • a gNB may transmit an SRS resource configuration message to a UE, indicating an SRS resource set containing a plurality of SRS resources, one or more downlink reference signals associated with the SRS resource set, and a threshold.
  • the reference signals may include a downlink CSI-RS, a downlink SSB, and an uplink SRS.
  • a gNB may indicate in this message that the usage of the SRS resource set is beam management or beam sweeping.
  • the UE determines a plurality of SRS beams.
  • the correlation coefficients which are between the UE’s determined SRS beams and the SRS beams used by the indicated SRS or else corresponding to the reception of the indicated downlink reference signals, are smaller than the indicated threshold.
  • the UE may transmit a plurality of SRS signals with the determined SRS beams at the indicated SRS resource set.
  • a gNB may determine uplink beam based on the received SRS.
  • a gNB may indicate to a UE the index of the SRS resource associated with the determined uplink beam.
  • the UE may transmit a signal in a UL data channel along the SRS beam associated with the indicated SRS resource.
  • a gNB may transmit a signaling message about SRS resource configuration to UE.
  • This signaling message can be transmitted in a RRC signaling message, a MAC CE or a DCI, or their combinations.
  • the signaling message may indicate an SRS resource set, which contains multiple SRS resources. These SRS resources are at different time instances.
  • An SRS resource may be associated with the parameters like a time-domain position, a frequency-domain position, a cyclic shift, a comb offset, frequency hopping mode, sequence hopping mode, etc.
  • the signaling (SRS resource configuration) message may indicate identifiers of one or more downlink reference signals, (e.g., SSB index, CSI-RS index, SRS) .
  • each TRP may transmit a downlink reference signal, and then a gNB may indicate to UE the identifiers for each of these reference signals. Because the TRPs lie in the same cell or are controlled by the same gNB as the target TRP, the gNB may easily know the identifiers of these reference signals.
  • the signaling message may indicate a threshold whose value is between 0 and 1.
  • the UE may determine the receive beams that are used to receive the indicated downlink reference signals (e.g., if the indicated reference signal is CSI-RS or SSB) . By using these receive beams, UE may obtain higher reception performance (e.g., the highest SINR) of the indicated downlink reference signals. If there are multiple downlink reference signals, the UE may determine multiple receive beams, each of which is used to receive a respective downlink reference signal.
  • the UE may determine one or more first SRS beams based on a determined receive beams and DL-UL reciprocity. These first SRS beams may be equal to the determined receive beams based on DL-UL reciprocity. If the indicated reference signal is SRS, first SRS beams are the beams used by the indicated SRS.
  • the UE may determine a plurality of second SRS beams that have low correlation with the first SRS beams. For example, the UE may select second SRS beams if the correlation coefficients between these second SRS beams and those first SRS beams are smaller than the indicated threshold.
  • second SRS beams may be determined in a manner designed to provide a sufficient number of candidate beam directions for a gNB to choose.
  • the UE may make the directions of these second SRS beams spread a broad direction scope which has low correlation coefficients with the first SRS beams.
  • the directions of these second SRS beams are uniformly distributed in the direction scope.
  • the weight vector of a first SRS beam is:
  • UE may determine the direction scope
  • ⁇ is the configured correlation coefficient threshold. It may be noted that the less than operator above could also be less than or equal to or some other similar expression.
  • the direction scope S is the set of ⁇ values that makes the value of
  • the determined scope of beam directions (from 0.62 to 3.38) is smaller than the set of all possible beam directions (from 0 to 4) . This improves SRS sweeping efficiency.
  • the UE can adopt the discrete quantized value where n ⁇ ⁇ 0, 1, 2, ..., N-1 ⁇ , O ⁇ 1 denotes the oversampling factor, q ⁇ ⁇ 0, 1, 2, ..., O-1 ⁇ denotes the deviation factor, and satisfying
  • the UE can transmit a plurality of SRS signals with a respective beam weight vector equal to f ( ⁇ n, q ) , where n is one of ⁇ 0, 1, 2, ..., N-1 ⁇ , q is one of ⁇ 0, 1, 2, ..., O-1 ⁇ .
  • the direction scope S is the set of ⁇ n, q values that makes the value of
  • ⁇ 0.75, 1, 1.25, 1.5, 1.75, 2, 2.25, 2.5, 2.75, 3, 3.25 ⁇ .
  • the UE may transmit SRS signals along with different SRS beams at respective SRS resources, where the SRS resources are included in the indicated SRS resource set.
  • One SRS resource is one-to-one associated with one SRS beam. If the SRS resource set is configured with a periodicity (e.g., the period length is L slots) , UE may transmit the SRS signal with the same SRS beam at the associated SRS resource of each period.
  • the gNB may determine an optimal uplink beam. For example, a gNB may select the SRS beam associated with the received SRS having the highest receiving SINR. Then, the gNB may indicate to the UE the index of the SRS resource where a gNB receives the SRS with the selected SRS beam.
  • aspects of the present disclosure may enable a UE to determine the beams for SRS beam sweeping, which can avoid strong interference to the configured non-target TRPs. In this way, the efficiency of SRS sweeping is improved because the radio resource consumption and the SRS sweeping latency is reduced. This helps the gNB to improve spectrum efficiency and helps the UE to accelerate beam management.
  • the SRS resource configuration message containing an SRS resource set and its associated downlink reference signals and the threshold may be defined by a standard.
  • This approach may be considered different from current standards in that, according to aspects of the present disclosure, the spatial relation may be associated with an SRS resource set and the associated downlink reference signal may be considered as related to the non-target TRP (e.g., the UE is expected to transmit SRS to generate low received power at the beam direction related to this RS) .
  • the methods disclosed herein comprise one or more steps or actions for achieving the methods.
  • the method steps and/or actions may be interchanged with one another without departing from the scope of the claims.
  • the order and/or use of specific steps and/or actions may be modified without departing from the scope of the claims.
  • a phrase referring to “at least one of” a list of items refers to any combination of those items, including single members.
  • “at least one of: a, b, or c” is intended to cover a, b, c, a-b, a-c, b-c, and a-b-c, as well as any combination with multiples of the same element (e.g., a-a, a-a-a, a-a-b, a-a-c, a-b-b, a-c-c, b-b, b-b-b, b-b-c, c-c, and c-c-c or any other ordering of a, b, and c) .
  • determining encompasses a wide variety of actions. For example, “determining” may include calculating, computing, processing, deriving, investigating, looking up (e.g., looking up in a table, a database or another data structure) , ascertaining and the like. Also, “determining” may include receiving (e.g., receiving information) , accessing (e.g., accessing data in a memory) and the like. Also, “determining” may include resolving, selecting, choosing, establishing and the like.
  • the various operations of methods described above may be performed by any suitable means capable of performing the corresponding functions.
  • the means may include various hardware and/or software component (s) and/or module (s) , including, but not limited to a circuit, an application specific integrated circuit (ASIC) , or processor.
  • ASIC application specific integrated circuit
  • DSP digital signal processor
  • ASIC application specific integrated circuit
  • FPGA field programmable gate array
  • PLD programmable logic device
  • a general- purpose processor may be a microprocessor, but in the alternative, the processor may be any commercially available processor, controller, microcontroller, or state machine.
  • a processor may also be implemented as a combination of computing devices, e.g., a combination of a DSP and a microprocessor, a plurality of microprocessors, one or more microprocessors in conjunction with a DSP core, or any other such configuration.
  • an example hardware configuration may comprise a processing system in a wireless node.
  • the processing system may be implemented with a bus architecture.
  • the bus may include any number of interconnecting buses and bridges depending on the specific application of the processing system and the overall design constraints.
  • the bus may link together various circuits including a processor, machine-readable media, and a bus interface.
  • the bus interface may be used to connect a network adapter, among other things, to the processing system via the bus.
  • the network adapter may be used to implement the signal processing functions of the PHY layer.
  • a user interface e.g., keypad, display, mouse, joystick, etc.
  • a user interface e.g., keypad, display, mouse, joystick, etc.
  • the bus may also link various other circuits such as timing sources, peripherals, voltage regulators, power management circuits, and the like, which are well known in the art, and therefore, will not be described any further.
  • the processor may be implemented with one or more general-purpose and/or special-purpose processors. Examples include microprocessors, microcontrollers, DSP processors, and other circuitry that can execute software. Those skilled in the art will recognize how best to implement the described functionality for the processing system depending on the particular application and the overall design constraints imposed on the overall system.
  • the functions may be stored or transmitted over as one or more instructions or code on a computer readable medium.
  • Software shall be construed broadly to mean instructions, data, or any combination thereof, whether referred to as software, firmware, middleware, microcode, hardware description language, or otherwise.
  • Computer-readable media include both computer storage media and communication media including any medium that facilitates transfer of a computer program from one place to another.
  • the processor may be responsible for managing the bus and general processing, including the execution of software modules stored on the machine-readable storage media.
  • a computer-readable storage medium may be coupled to a processor such that the processor can read information from, and write information to, the storage medium. In the alternative, the storage medium may be integral to the processor.
  • the machine-readable media may include a transmission line, a carrier wave modulated by data, and/or a computer readable storage medium with instructions stored thereon separate from the wireless node, all of which may be accessed by the processor through the bus interface.
  • the machine-readable media, or any portion thereof may be integrated into the processor, such as the case may be with cache and/or general register files.
  • machine-readable storage media may include, by way of example, 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 drives, or any other suitable storage medium, or any combination thereof.
  • RAM Random Access Memory
  • ROM Read Only Memory
  • PROM Programmable Read-Only Memory
  • EPROM Erasable Programmable Read-Only Memory
  • EEPROM Electrical Erasable Programmable Read-Only Memory
  • registers magnetic disks, optical disks, hard drives, or any other suitable storage medium, or any combination thereof.
  • the machine-readable media may be embodied in a computer-program product.
  • a software module may comprise a single instruction, or many instructions, and may be distributed over several different code segments, among different programs, and across multiple storage media.
  • the computer-readable media may comprise a number of software modules.
  • the software modules include instructions that, when executed by an apparatus such as a processor, cause the processing system to perform various functions.
  • the software modules may include a transmission module and a receiving module. Each software module may reside in a single storage device or be distributed across multiple storage devices.
  • a software module may be loaded into RAM from a hard drive when a triggering event occurs.
  • the processor may load some of the instructions into cache to increase access speed.
  • One or more cache lines may then be loaded into a general register file for execution by the processor.
  • any connection is properly termed a computer-readable medium.
  • 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
  • the coaxial cable, fiber optic cable, twisted pair, DSL, or wireless technologies such as infrared, radio, and microwave are included in the definition of medium.
  • Disk and disc include compact disc (CD) , laser disc, optical disc, digital versatile disc (DVD) , floppy disk, and disc where disks usually reproduce data magnetically, while discs reproduce data optically with lasers.
  • computer-readable media may comprise non-transitory computer-readable media (e.g., tangible media) .
  • computer-readable media may comprise transitory computer-readable media (e.g., a signal) . Combinations of the above should also be included within the scope of computer-readable media.
  • certain aspects may comprise a computer program product for performing the operations presented herein.
  • a computer program product may comprise 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. For example, instructions for performing the operations described herein and illustrated in FIGs. 11-12.
  • modules and/or other appropriate means for performing the methods and techniques described herein can be downloaded and/or otherwise obtained by a user terminal and/or base station as applicable.
  • a user terminal and/or base station can be coupled to a server to facilitate the transfer of means for performing the methods described herein.
  • various methods described herein can be provided via storage means (e.g., RAM, ROM, a physical storage medium such as a compact disc (CD) or floppy disk, etc. ) , such that a user terminal and/or base station can obtain the various methods upon coupling or providing the storage means to the device.
  • storage means e.g., RAM, ROM, a physical storage medium such as a compact disc (CD) or floppy disk, etc.
  • CD compact disc
  • floppy disk etc.
  • any other suitable technique for providing the methods and techniques described herein to a device can be utilized.

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  • Engineering & Computer Science (AREA)
  • Signal Processing (AREA)
  • Computer Networks & Wireless Communication (AREA)
  • Mobile Radio Communication Systems (AREA)

Abstract

Des aspects de la présente divulgation concernent des communications sans fil et, plus particulièrement, des techniques de gestion de faisceau dans des scénarios impliquant de multiples points de réception de transmission (TRP).
PCT/CN2020/077216 2020-02-28 2020-02-28 Balayage de faisceau srs dans de multiples scénarios de point de réception de transmission WO2021168803A1 (fr)

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PCT/CN2020/077216 WO2021168803A1 (fr) 2020-02-28 2020-02-28 Balayage de faisceau srs dans de multiples scénarios de point de réception de transmission
PCT/CN2021/076845 WO2021169848A1 (fr) 2020-02-28 2021-02-19 Balayage de faisceau de signaux de référence de sondage (srs) dans des scénarios à multiples points de réception de transmission (trp)

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PCT/CN2021/076845 WO2021169848A1 (fr) 2020-02-28 2021-02-19 Balayage de faisceau de signaux de référence de sondage (srs) dans des scénarios à multiples points de réception de transmission (trp)

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Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2024113861A1 (fr) * 2023-06-30 2024-06-06 Zte Corporation Saut de décalage de peigne et saut de changement cyclique de signaux de référence de sondage

Families Citing this family (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN115882904A (zh) * 2021-09-29 2023-03-31 维沃移动通信有限公司 参考信号处理方法、装置、终端及介质
CN115426015B (zh) * 2022-07-14 2023-12-08 中信科移动通信技术股份有限公司 一种波束管理方法及系统
CN115550948B (zh) * 2022-11-25 2023-08-18 北京九天微星科技发展有限公司 一种上行探测参考信号传输方法及设备

Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN110235496A (zh) * 2017-02-03 2019-09-13 华为技术有限公司 Ue辅助srs资源分配
CN110430584A (zh) * 2019-08-06 2019-11-08 北京邮电大学 一种毫米波网络中非活跃用户的上行多波束初始接入方法
WO2020028394A1 (fr) * 2018-08-02 2020-02-06 Qualcomm Incorporated Transmissions de signaux de référence de sondage appariées dans une opération de point de réception/multi-transmission
CN110769502A (zh) * 2018-07-25 2020-02-07 维沃移动通信有限公司 用于多波束发送上行信道的方法、终端设备和网络侧设备
WO2020037207A1 (fr) * 2018-08-17 2020-02-20 Idac Holdings, Inc. Gestion de faisceau pour multi-trp

Family Cites Families (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN108736944B (zh) * 2017-04-19 2021-07-27 上海朗帛通信技术有限公司 一种基站、用户设备中的用于多天线传输的方法和装置

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN110235496A (zh) * 2017-02-03 2019-09-13 华为技术有限公司 Ue辅助srs资源分配
CN110769502A (zh) * 2018-07-25 2020-02-07 维沃移动通信有限公司 用于多波束发送上行信道的方法、终端设备和网络侧设备
WO2020028394A1 (fr) * 2018-08-02 2020-02-06 Qualcomm Incorporated Transmissions de signaux de référence de sondage appariées dans une opération de point de réception/multi-transmission
WO2020037207A1 (fr) * 2018-08-17 2020-02-20 Idac Holdings, Inc. Gestion de faisceau pour multi-trp
CN110430584A (zh) * 2019-08-06 2019-11-08 北京邮电大学 一种毫米波网络中非活跃用户的上行多波束初始接入方法

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2024113861A1 (fr) * 2023-06-30 2024-06-06 Zte Corporation Saut de décalage de peigne et saut de changement cyclique de signaux de référence de sondage

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