EP4677762A1

EP4677762A1 - Codebook based uplink transmission using multiple antenna panels and shareable antenna ports

Info

Publication number: EP4677762A1
Application number: EP23725560.9A
Authority: EP
Inventors: Yushu Zhang
Original assignee: Google LLC
Current assignee: Google LLC
Priority date: 2023-04-07
Filing date: 2023-04-07
Publication date: 2026-01-14
Also published as: CN120917673A; WO2024207413A1

Abstract

Methods, systems, and techniques are disclosed for performing uplink transmissions via multiple antenna panels that may cross-share an antenna port. A user equipment (UE) has different uplink transmission behaviors under different multi-panel architectures. A method includes a UE receiving (504, 604, 1404) a message for configuring at least two SRS resource sets for codebook based uplink transmission by the UE. The UE receives (508, 608, 1408) an uplink grant indicating an SRS resource from the at least two SRS resource sets associated with a PUSCH transmission. The UE transmits (510, 610, 1410) the PUSCH transmission based on a timing condition associated with one of a first mode of operation (associated with a transmission using a same number of active ports for either single-panel or multiple-panel transmission) or a second mode of operation (associated with a transmission using different numbers of active ports for either single-panel or multiple-panel transmission).

Description

CODEBOOK BASED UPLINK TRANSMISSION USING MULTIPLE ANTENNA PANELS AND SHAREABLE ANTENNA PORTS

FIELD

This disclosure relates generally to wireless communication, and more particularly, to codebook based uplink transmission using multiple antenna panels.

BACKGROUND

The Third Generation Partnership Project (3GPP) specifies a radio interface referred to as fifth generation (5G) new radio (NR) (5G NR) . An architecture for a 5G NR wireless communication system includes a 5G core (5GC) network, a 5G radio access network (5G-RAN) , a user equipment (UE) , etc. The 5G NR architecture seeks to provide increased data rates, decreased latency, and/or increased capacity compared to prior generation cellular communication systems.
A UE may have two or more antenna panels for transmitting and receiving wireless signals in various directions. Antenna panels (or panels) include antenna arrays (of elements) to provide radio patterns (e.g., beams in particular directions) and coverage. Each of the multiple antenna panels may provide two or more antenna ports, which are logical entities used to abstract the mapping of physical antennas to specific transmission channels or signals. Antenna ports are associated with specific reference signals and physical channels, and each antenna port has a unique identifier. For example, in 5G NR, the 3GPP specifications define antenna ports in terms of the functionality.
A UE having multiple antenna panels may share or provide the same antenna port. The antenna ports and the associated configurations may be referred to as radio frequency (RF) chains. When a UE has multiple panels, the UE may employ dedicated, shared, or partially shared RF chains. The configuration of the multiple panels and how they provide one or more antenna ports is referred to as panel architecture. The UE of multiple panels may use various panel architectures, and behaves differently for each panel architecture (or when switching between the panel architectures. )
For the UE to provide uplink transmission using multiple panels, a network entity (e.g., a base station) configures two sets of sounding reference signal (SRS) for uplink channel state information (CSI) measurement. The network entity uses the received SRS for channel estimation (e.g., computing CSI that includes channel quality indicator, precoding matrix indicator, and rank indicator) and optimize communication parameters with the UE (including updating the modulation and coding scheme, adjusting the transmission power, or updating beamforming weights, etc. ) . When the network entity configures the UE to transmit the physical uplink shared channel (PUSCH) based on uplink codebook based transmission, the network entity also configures two sets of SRS resources to support the codebook based PUSCH transmission, e.g., two sets of SRS resources with the usage configured as ‘codebook’ . The SRS resources are used to provide better channel estimation and feedback to the network entity, which then uses this information to optimize the codebook-based transmission for PUSCH. The SRS resources configured for the codebook may therefore enhance the channel estimation and adaptation of the precoding matrices for the uplink transmission.
During operation, the network entity configures different transmission configuration indicator (TCI) states for the SRS resources in the two SRS resource sets. The TCI states provide information on the spatial transmission filter (beam) and uplink power control parameters for each SRS resource set. By configuring different TCI states for the two SRS resource sets, the network entity may optimize the uplink transmission by adapting the beam and power control parameters based on the channel conditions. The UE may transmit two SRS resource sets from two panels (e.g., antenna arrays) , possibly improving the spatial diversity and enhancing the channel estimation accuracy. This, in turn, may lead to better adaptation of the codebook-based precoding for the PUSCH transmission, ultimately improving the uplink performance.
For the PUSCH transmission, the network entity may configure the PUSCH to be associated with one SRS resource from one SRS resource set for single-panel transmission or two SRS resources from two SRS resource sets for multi-panel transmission. The UE transmits the PUSCH from the same antenna ports with the same spatial domain filter as the associated SRS resource (s) . The network entity may provide such indication by a field in downlink control information (DCI) , e.g., SRS resource set selection. However, when the UE employs various panel architectures that include multiple antenna panels providing multiple antenna ports, the existing codebook-based precoding operations may not apply or be able to provide reliable codebook-based uplink transmissions.
SUMMARY
The present disclosure provides methods, systems, and techniques for performing uplink transmissions via multiple antenna panels that may cross-share an antenna port. For example, two or more antenna panels may simultaneously transmit codebook based uplink signals via one or more common antenna ports. When a user equipment (UE) has two or more antenna panels (or “panels” herein) , the UE may employ dedicated, shared, or partially shared radio frequency (RF) chains (referred to as different panel architectures or modes of operations) . The UE behaves differently for each mode of operations (or when switching between the RF chains) .
When two or more panels share a common antenna port, additional transmission delay may result. The different architectures also impose different limitations on simultaneous transmission or the number of ports capable using a single panel. Therefore, this disclosure provides methods for managing the delays in different architectures, using different panels for simultaneous uplink transmission, and managing antenna ports for one or more panels in different architectures.
Conventionally, a UE uses a single antenna panel for uplink transmission. The single antenna panel may provide multiple antenna ports. Antenna ports (or “ports” herein) are logical entities that serve as an abstraction for the mapping of physical antennas to specific transmission channels or signals. In most cases, antenna ports are associated with specific reference signals and/or physical channels, and with unique respective identifiers (e.g., 3GPP TS 38.211) . For uplink transmissions, a base station (or a network entity in general) estimates uplink channel conditions (e.g., by measuring sounding reference signals (SRSs) from the UE) . Based on the estimated uplink channel conditions, the base station determines an optimal (one that results in the highest signal to noise ratio, among all available) precoding matrix (e.g., 3GPP TS 38.214 § 6.1.1.1) and indicates the precoding matrix to the UE (e.g., via a transmission precoding matrix indicator (TPMI) ) . The UE then applies the precoding matrix in the uplink transmission, such as in the physical uplink shared channel (PUSCH) . As such, the conventional precoding matrix determination has been based on a single antenna panel SRS configuration.
When there are multiple antenna panels transmitting SRS (or uplink signals) simultaneously, the channel estimation and the associated precoding matrix determination warrant additional considerations. For example, multiple antenna panels may share one or more antenna ports (e.g., by performing cross-panel antenna switching) and result in delays (e.g., when signals are processed and transmitted by different panels) that affect SRS transmission. The delays may, in some cases, cause existing precoding matrices to be outdated (e.g., not accurate, applicable, or useful in view of the cross-panel antenna port switching) . The present disclosure provides methods and techniques for providing robust codebook based uplink transmissions using multiple antenna panels by handling various delays associated different panel architectures (e.g., multiple antenna panels used for dedicated or shared antenna ports) .
Benefits of this disclosure includes enabling the use of multiple UE antenna panels (e.g., facing various directions) to create a better channel condition than using a single antenna panel, such as when the multiple antenna panels are used for a common antenna port. The UE with multiple antenna panels enjoys options to configure various RF chains by having multiple antenna panels share some or all antenna ports, as well as having a panel use dedicated antenna ports in proper situations (e.g., when a dedicated antenna port via a single panel provides the best channel condition among available options) . This disclosure also provides example precoding matrices for such multi-panel transmissions, as previous precoding matrices have been for single-panel situations.
An example method includes a UE receiving, from a network entity, a message for configuring at least two SRS resource sets for codebook based uplink transmission by the UE. The UE receives, from the network entity, an uplink grant indicating an SRS resource from the at least two SRS resource sets associated with a PUSCH transmission. The UE transmits, according to the uplink grant, the PUSCH transmission based on a timing condition associated with one of a first mode of operation or a second mode of operation.
The first mode of operation is associated with a transmission using a same number of active ports for either single-panel or multiple-panel transmission and the second mode of operation is associated with a transmission using different numbers of active ports for either single-panel or multiple-panel transmission. For example, active ports include non-zero-power ports or may correspond to a non-zero value in the precoder matrix as shown in Tables 3 and 4. With port sharing, the number of ports may be the same for both single-panel and multi-panel operation, the same as the number of RF chains, e.g., four. Without cross-panel port sharing, the number of ports for single-panel operation would be smaller than multi-panel operation.
This disclosure provides for multi-panel transmissions with cross-panel port sharing to allow for a same number of ports to be active in either single-panel or multi-panel operations. For example, the UE configures, based on the message, two or more antenna panels configurable to perform in the first mode of operation or the second mode of operation. In the first mode of operation, at least one antenna port is shared among the two or more antenna panels (e.g., an antenna port may be shared by or switch between two panels) . In the second mode of operation, no antenna port is shared among the two or more antenna panels (e.g., each port has its dedicated panel) .
In aspects, in response to SRSs from the UE and for the PUSCH transmission, the network entity transmits to the UE, a precoder indicated for each of the two or more antenna panels based on a transmission rank indicator (TRI) and a transmission precoder matrix indicator (TPMI) corresponding to the codebook with a number of ports being equal to the number of PUSCH ports per panel. The UE identifies the precoder corresponding to the indicated TRI and TPMI having associated layers correspond to one or more common antenna ports. In some cases, the network entity transmits a precoder with number of non-zero-power PUSCH ports per panel smaller than or equal to a maximum number of PUSCH ports per panel reported by the UE regarding cross-panel port sharing capabilities. Other implementations are further discussed in various embodiments of the detailed description.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 illustrates a diagram of a wireless communications system that includes a plurality of user equipments (UEs) and network entities in communication over one or more cells.
FIG. 2 illustrates an example port configuration for multiple antenna panels such that each antenna port has a dedicated panel, according to aspects of the present disclosure.
FIG. 3 illustrates an example port configuration for multiple antenna panels such that each antenna port is shared by the multiple antenna panels, according to aspects of the present disclosure.
FIG. 4 illustrates an example port configuration for multiple antenna panels such that some antenna ports are shared by some of the multiple antenna panels, according to aspects of the present disclosure.
FIG. 5 is a signaling diagram illustrating communications between a user equipment (UE) and a network entity for robust codebook based uplink multi-panel transmission, according to aspects of the present disclosure.
FIG. 6 is a flowchart of a method of robust codebook based uplink multi-panel transmission at a UE, according to aspects of the present disclosure.
FIG. 7 is a flowchart of a method of robust codebook based uplink multi-panel transmission at a network entity, according to aspects of the present disclosure.
FIG. 8 illustrates an example scheduling offset, according to aspects of the present disclosure.
FIG. 9 illustrates an example of switching antenna ports mapping on different sounding reference signal (SRS) resource sets, according to aspects of the present disclosure.
FIG. 10 illustrates an example of switching antenna ports mapping on different uplink signals, according to aspects of the present disclosure.
FIG. 11 illustrates an example of switching some of the antenna ports mapping on different uplink signals, according to aspects of the present disclosure.
FIG. 12 illustrates an example of antenna ports mapping to multiple antenna panels with multiple associated SRS ports per panel, according to aspects of the present disclosure.
FIG. 13 illustrates an example of precoder indication based on multi-port codebook for multiple antenna ports mapping to multiple panels, according to aspects of the present disclosure.
FIG. 14 is a flowchart of a method of wireless communication at a UE, according to aspects of the present disclosure.
FIG. 15 is a flowchart of a method of wireless communication at a network entity, according to aspects of the present disclosure.
FIG. 16 is a diagram illustrating a hardware implementation for an example UE apparatus.
FIG. 17 is a diagram illustrating a hardware implementation for one or more example network entities.
Like reference numerals indicate like elements.

DETAILED DESCRIPTION

The present disclosure provides methods, systems, and techniques for performing uplink transmissions via multiple antenna panels that may cross-share an antenna port. A user equipment (UE) has different uplink transmission behaviors under different multi-panel architectures. FIGS. 1-4 illustrate the context for the UE operation and how the UE may use multiple antenna panels for codebook based uplink transmissions.
A network entity estimates channel conditions using sounding reference signals (SRS) from the UE. Based on the SRS, the network entity then calculates (or otherwise receives) parameters, such as channel quality indicator (CQI) , precoding matrix indictor (PMI) , and rank indicator (RI) . The network entity determines a modulation and coding scheme (MCS) based on the CQI and have the UE transmit uplink signals using the MCS. When the UE has multiple antenna panels, the network entity may accordingly configure the SRS from the UE in view of multiple antenna ports and related properties (e.g., transmission comb, power scaling, configuration index, etc. ) . The present disclosure provides methods and techniques for managing multi-panel uplink transmission, simultaneous uplink signal transmission using multiple panels, and port and precoder indication for one or more antenna panels.
In codebook based transmission schemes, the UE may select a precoding matrix from a codebook to transmit data on the uplink. The codebook-based transmission scheme may optimize the use of multiple antennas to improve system performance. When a UE uses multiple antenna panels to provide for multiple antenna ports (some dedicated, some shared, in different panel architectures) , internal delays (e.g., due to antenna ports switching between different panels when shared) and codebook/precoder selection pose challenges not addressed by conventional practices. The present disclosure provides support for codebook-based uplink transmission from multiple panels with regard to different UE panel architectures, improving (over single-panel cases) the performance for the uplink transmissions for each multi-panel architecture.
FIG. 1 illustrates a diagram 100 of a wireless communications system associated with a plurality of cells 190. The wireless communications system includes user equipments (UEs) 102 and base stations/network entities 104. Some base stations may include an aggregated base station architecture and other base stations may include a disaggregated base station architecture. The aggregated base station architecture includes a radio unit (RU) 106, a distributed unit (DU) 108, and a centralized unit (CU) 110 that are configured to utilize a radio protocol stack that is physically or logically integrated within a single radio access network (RAN) node. A disaggregated base station architecture utilizes a protocol stack that is physically or logically distributed among two or more units (e.g., RUs 106, DUs 108, CUs 110) . For example, a CU 110 is implemented within a RAN node, and one or more DUs 108 may be co-located with the CU 110, or alternatively, may be geographically or virtually distributed throughout one or multiple other RAN nodes. The DUs 108 may be implemented to communicate with one or more RUs 106. Each of the RU 106, the DU 108 and the CU 110 may be implemented as virtual units, such as a virtual radio unit (VRU) , a virtual distributed unit (VDU) , or a virtual central unit (VCU) . The base station/network entity 104 (e.g., an aggregated base station or disaggregated units of the base station, such as the RU 106, the DU 108, or the CU 110) , may be referred to as a transmission reception point (TRP) .
Operations of the base station 104 and/or network designs may be based on aggregation characteristics of base station functionality. For example, disaggregated base station architectures are utilized in an integrated access backhaul (IAB) network, an open-radio access network (O-RAN) network, or a virtualized radio access network (vRAN) , which may also be referred to a cloud radio access network (C-RAN) . Disaggregation may include distributing functionality across the two or more units at various physical locations, as well as distributing functionality for at least one unit virtually, which may enable flexibility in network designs. The various units of the disaggregated base station architecture, or the disaggregated RAN architecture, may be configured for wired or wireless communication with at least one other unit. For example, the base stations 104a/104e and/or the RUs 106a-106d may communicate with the UEs 102a-102d and 102s via one or more radio frequency (RF) access links based on a Uu interface. In examples, multiple RUs 106 and/or base stations 104 may simultaneously serve the UEs 102, such as by intra-cell and/or inter-cell access links between the UEs 102 and the RUs 106/base stations 104.
The RU 106, the DU 108, and the CU 110 may include (or may be coupled to) one or more interfaces configured to transmit or receive information/signals via a wired or wireless transmission medium. A base station 104 or any of the one or more disaggregated base station units may be configured to communicate with one or more other base stations 104 or one or more other disaggregated base station units via the wired or wireless transmission medium. In examples, a processor, a memory, and/or a controller associated with executable instructions for the interfaces may be configured to provide communication between the base stations 104 and/or the one or more disaggregated base station units via the wired or wireless transmission medium. For example, a wired interface may be configured to transmit or receive the information/signals over a wired transmission medium, such as via the fronthaul link 160 between the RU 106d and the baseband unit (BBU) 112 of the base station 104d associated with the cell 190d. The BBU 112 includes a DU 108 and a CU 110, which may also have a wired interface (e.g., midhaul link) configured between the DU 108 and the CU 110 to transmit or receive the information/signals between the DU 108d and the CU 110d. In further examples, a wireless interface, which may include a receiver, a transmitter, or a transceiver, such as an RF transceiver, configured to transmit and/or receive the information/signals via the wireless transmission medium, such as for information communicated between the RU 106a of the cell 190a and the base station 104e of the cell 190e via cross-cell communication beams 136-138 of the RU 106a and the base station 104e.
The RUs 106 may be configured to implement lower layer functionality. For example, the RU 106 is controlled by the DU 108 and may correspond to a logical node that hosts RF processing functions, or lower layer PHY functionality, such as execution of fast Fourier transform (FFT) , inverse FFT (iFFT) , digital beamforming, physical random access channel (PRACH) extraction and filtering, etc. The functionality of the RU 106 may be based on the functional split, such as a functional split of lower layers.
The RUs 106 may transmit or receive over-the-air (OTA) communication with one or more UEs 102. For example, the RU 106b of the cell 190b communicates with the UE 102b of the cell 190b via a first set of communication beams 132 of the RU 106b and a second set of communication beams 134b of the UE 102b, which may correspond to inter-cell communication beams or, in some examples, cross-cell communication beams. For instance, the UE 102b of the cell 190b may communicate with the RU 106a of the cell 190a via a third set of communication beams 134a of the UE 102b and a fourth set of communication beams 136 of the RU 106a. Both real-time and non-real-time features of control plane and user plane communications of the RUs 106 may be controlled by associated DUs 108.
Any combination of the RU 106, the DU 108, and the CU 110, or reference thereto individually, may correspond to a base station 104. Thus, the base station 104 may include at least one of the RU 106, the DU 108, or the CU 110. The base stations 104 provide the UEs 102 with access to a core network. The base stations 104 might relay communications between the UEs 102 and the core network. The base stations 104 may be associated with macrocells for high-power cellular base stations and/or small cells for low-power cellular base stations. For example, the cell 190e may correspond to a macrocell, whereas the cells 190a-190d may correspond to small cells. Small cells include femtocells, picocells, microcells, etc. A cell structure that includes at least one macrocell and at least one small cell may be referred to as a “heterogeneous network. ”
Transmissions from a UE 102 to a base station 104/RU 106 are referred to as uplink (UL) transmissions, whereas transmissions from the base station 104/RU 106 to the UE 102 are referred to as downlink (DL) transmissions. Uplink transmissions may also be referred to as reverse link transmissions and downlink transmissions may also be referred to as forward link transmissions. For example, the RU 106d utilizes antennas 114 of the base station 104d of cell 190d to transmit a downlink/forward link communication to the UE 102d or receive an uplink/reverse link communication from the UE 102d based on the Uu interface associated with the access link between the UE 102d and the base station 104d/RU 106d.
Communication links between the UEs 102 and the base stations 104/RUs 106 may be based on multiple-input and multiple-output (MIMO) antenna technology, including spatial multiplexing, beamforming, and/or transmit diversity. The communication links may be associated with one or more carriers. The UEs 102 and the base stations 104/RUs 106 may utilize a spectrum bandwidth of Y MHz (e.g., 5, 10, 15, 20, 100, 400, 800, 1600, 2000, etc. MHz) per carrier allocated in a carrier aggregation of up to a total of Yx MHz, where x component carriers (CCs) are used for communication in each of the uplink and downlink directions. The carriers may or may not be adjacent to each other along a frequency spectrum. In examples, uplink and downlink carriers may be allocated in an asymmetric manner, more or fewer carriers may be allocated to either the uplink or the downlink. A primary component carrier and one or more secondary component carriers may be included in the component carriers. The primary component carrier may be associated with a primary cell (PCell) and a secondary component carrier may be associated with as a secondary cell (SCell) .
Some UEs 102, such as the UEs 102a and 102s, may perform device-to-device (D2D) communications over sidelink. For example, a sidelink communication/D2D link utilizes a spectrum for a wireless wide area network (WWAN) associated with uplink and downlink communications. The sidelink communication/D2D link may also use one or more sidelink channels, such as a physical sidelink broadcast channel (PSBCH) , a physical sidelink discovery channel (PSDCH) , a physical sidelink shared channel (PSSCH) , and/or a physical sidelink control channel (PSCCH) , to communicate information between UEs 102a and 102s. Such sidelink/D2D communication may be performed through various wireless communications systems, such as wireless fidelity (Wi-Fi) systems, Bluetooth systems, Long Term Evolution (LTE) systems, New Radio (NR) systems, etc.
The electromagnetic spectrum is often subdivided into different classes, bands, channels, etc., based on different frequencies/wavelengths associated with the electromagnetic spectrum. Fifth-generation (5G) NR is generally associated with two operating frequency ranges (FRs) referred to as frequency range 1 (FR1) and frequency range 2 (FR2) . FR1 ranges from 410 MHz -7.125 GHz and FR2 ranges from 24.25 GHz -71.0 GHz, which includes FR2-1 (24.25 GHz -52.6 GHz) and FR2-2 (52.6 GHz -71.0 GHz) . Although a portion of FR1 is actually greater than 6 GHz, FR1 is often referred to as the “sub-6 GHz” band. In contrast, FR2 is often referred to as the “millimeter wave” (mmW) band. FR2 is different from, but a near subset of, the “extremely high frequency” (EHF) band, which ranges from 30 GHz -300 GHz and is sometimes also referred to as a “millimeter wave” band. Frequencies between FR1 and FR2 are often referred to as “mid-band” frequencies. The operating band for the mid-band frequencies may be referred to as frequency range 3 (FR3) , which ranges 7.125 GHz -24.25 GHz. Frequency bands within FR3 may include characteristics of FR1 and/or FR2. Hence, features of FR1 and/or FR2 may be extended into the mid-band frequencies. Higher operating frequency bands have been identified to extend 5G NR communications above 52.6 GHz associated with the upper limit of FR2. Three of these higher operating frequency bands include FR2-2, which ranges from 52.6 GHz -71.0 GHz, FR4, which ranges from 71.0 GHz -114.25 GHz, and FR5, which ranges from 114.25 GHz -300 GHz. The upper limit of FR5 corresponds to the upper limit of the EHF band. Thus, unless otherwise specifically stated herein, the term “sub-6 GHz” may refer to frequencies that are less than 6 GHz, within FR1, or may include the mid-band frequencies. Further, unless otherwise specifically stated herein, the term “millimeter wave” , or mmW, refers to frequencies that may include the mid-band frequencies, may be within FR2-1, FR4, FR2-2, and/or FR5, or may be within the EHF band.
The UEs 102 and the base stations 104/RUs 106 may each include a plurality of antennas. The plurality of antennas may correspond to antenna elements, antenna panels, and/or antenna arrays that may facilitate beamforming operations. For example, the RU 106b transmits a downlink beamformed signal based on a first set of communication beams 132 to the UE 102b in one or more transmit directions of the RU 106b. The UE 102b may receive the downlink beamformed signal based on a second set of communication beams 134b from the RU 106b in one or more receive directions of the UE 102b. In a further example, the UE 102b may also transmit an uplink beamformed signal to the RU 106b based on the second set of communication beams 134b in one or more transmit directions of the UE 102b. The RU 106b may receive the uplink beamformed signal from the UE 102b in one or more receive directions of the RU 106b.
The UE 102b may perform beam training to determine the best receive and transmit directions for the beamformed signals. The transmit and receive directions for the UEs 102 and the base stations 104/RUs 106 might or might not be the same. In further examples, beamformed signals may be communicated between a first base station/RU 106a and a second base station 104e. For instance, the base station 104e of the cell 190e may transmit a beamformed signal to the RU 106a based on the communication beams 138 in one or more transmit directions of the base station 104e. The RU 106a may receive the beamformed signal from the base station 104e of the cell 190e based on the RU communication beams 136 in one or more receive directions of the RU 106a. In further examples, the base station 104e transmits a downlink beamformed signal to the UE 102e based on the communication beams 138 in one or more transmit directions of the base station 104e. The UE 102e receives the downlink beamformed signal from the base station 104e based on UE communication beams 130 in one or more receive directions of the UE 102e. The UE 102e may also transmit an uplink beamformed signal to the base station 104e based on the UE communication beams 130 in one or more transmit directions of the UE 102e, such that the base station 104e may receive the uplink beamformed signal from the UE 102e in one or more receive directions of the base station 104e.
The base station 104 may include and/or be referred to as a network entity. That is, “network entity” may refer to the base station 104 or at least one unit of the base station 104, such as the RU 106, the DU 108, and/or the CU 110. The base station 104 may also include and/or be referred to as a next generation evolved Node B (ng-eNB) , a generation NB (gNB) , an evolved NB (eNB) , an access point, a base transceiver station, a radio base station, a radio transceiver, a transceiver function, a basic service set (BSS) , an extended service set (ESS) , a TRP, a network node, network equipment, or other related terminology. The base station 104 or an entity at the base station 104 may be implemented as an IAB node, a relay node, a sidelink node, an aggregated (monolithic) base station with an RU 106 and a BBU 112 that includes a DU 108 and a CU 110, or as a disaggregated base station including one or more RUs 106, DUs 108, and/or CUs 110. A set of aggregated or disaggregated base stations may be referred to as a next generation-radio access network (NG-RAN) . In some examples, the UE 102a operates in dual connectivity (DC) with the base station 104e and the base station/RU 106a. In such cases, the base station 104e may be a master node and the base station/RU 160a may be a secondary node.
Uplink/downlink signaling may also be communicated via a satellite positioning system (SPS) 114. In an example, the SPS 114 of the cell 190c may be in communication with one or more UEs 102, such as the UE 102c, and one or more base stations 104/RUs 106, such as the RU 106c. The SPS 114 may correspond to one or more of a Global Navigation Satellite System (GNSS) , a global position system (GPS) , a non-terrestrial network (NTN) , or other satellite position/location system. The SPS 114 may be associated with LTE signals, NR signals (e.g., based on round trip time (RTT) and/or multi-RTT) , wireless local area network (WLAN) signals, a terrestrial beacon system (TBS) , sensor-based information, NR enhanced cell ID (NR E-CID) techniques, downlink angle-of-departure (DL-AoD) , downlink time difference of arrival (DL-TDOA) , uplink time difference of arrival (UL-TDOA) , uplink angle-of-arrival (UL-AoA) , and/or other systems, signals, or sensors.
Still referring to FIG. 1, in certain aspects, any of the UEs 102 may include a multi-panel configuration component 140 configured to receive, from the base station 104, a message for configuring at least two SRS resource sets for codebook based uplink transmission. The multi-panel configuration component 140 receives, from the base station 104, an uplink grant indicating an SRS resource from the at least two SRS resource sets associated with a PUSCH transmission. The UE 102 transmits, according to the uplink grant, the PUSCH transmission based on a timing condition associated with one of a first mode of operation or a second mode of operation. The first mode of operation is associated with a multiple panel transmission and the second mode of operation is associated with a single panel transmission. For example, in the first mode of operation, at least one antenna port is shared among the two or more antenna panels; and in the second mode of operation, no antenna port is shared among the two or more antenna panels.
In certain aspects, any of the base stations 104 or a network entity of the base stations 104 may include an uplink transmission configuration component 150 configured to transmit, to the UE 102, a message for configuring at least two SRS resource sets for codebook based uplink transmission by the UE 102. The uplink transmission configuration component 150 transmits to the UE 102 an uplink grant indicating an SRS resource from the at least two SRS resource sets associated with a PUSCH transmission. The uplink transmission configuration component 150 receives, from the UE according to the uplink grant, the PUSCH transmission based on a timing condition associated with one of a first mode of operation or a second mode of operation. The first mode of operation is associated with a multiple panel transmission and the second mode of operation is associated with a single panel transmission.
In some implementations, the network entity (e.g., the base station 104) configures the UE 102 to transmit PUSCH based on uplink codebook based transmission. The network entity also configures two sets of SRS resources, which are associated with the codebook used in the uplink codebook based transmission. The SRS configured by the network entity is to support the codebook-based transmission. For example, the network entity may configure different transmission configuration indicator (TCI) states for the SRS resources in the two SRS resource sets. The TCI states provide information on the spatial transmission filter (beam) and uplink power control parameters for each SRS resource set.
By configuring different TCI states for the two SRS resource sets, the network entity may optimize the uplink transmission by adapting the beam and power control parameters based on the channel conditions. The UE may transmit two SRS resource sets from two panels, improving the spatial diversity and enhancing the channel estimation accuracy. The parameters update may lead to better adaptation of the codebook-based precoding for the PUSCH transmission. The network entity may configure different TCI states for the SRS resources in the two sets, optimizing the spatial transmission filter (beam) and uplink power control parameters.
Accordingly, FIG. 1 describes a wireless communication system that may be implemented in connection with aspects of one or more other figures described herein, such as aspects illustrated in FIGS. 2-15. Further, although the following description may be focused on 5G NR, the concepts described herein may be applicable to other similar areas, such as 5G-Advanced and future versions, LTE, LTE-advanced (LTE-A) , and other wireless technologies, such as 6G.
FIG. 2 illustrates an example port configuration 200 for multiple antenna panels 202, 204, and 206, such that each antenna port has a dedicated panel, according to aspects of the present disclosure. As shown, the three panels 202, 204, and 206 may be configured, with the port connections 220, to respectively support dedicated antenna ports 210 (e.g., two ports on each panel) .
FIG. 3 illustrates an example port configuration 300 for multiple antenna panels 302, 304, and 306, such that each antenna port 310 is shared by the multiple antenna panels 302, 304, and 306, according to aspects of the present disclosure. As shown, the three panels 302, 304, and 306 may be configured, with switchable connections 320, to share or support common antenna ports 310 (e.g., each port on all panels) .
FIG. 4 illustrates an example port configuration 400 for multiple antenna panels 402, 404, and 406, such that some antenna ports 410 are shared by some of the multiple antenna panels 402, 404, and 406, according to aspects of the present disclosure. As shown, the three panels 402, 404, and 406, may be configured, with switchable connections 420, to share or support some of the multiple antenna ports 410. For example, while all three panels 402, 404, and 406 may support ports 0 and 1, port 2 and port 3 may use panels 404 and 406, but not panel 402.
In FIGS. 3 and 4, additional processing delay may result for a UE to transmit an uplink signal, e.g., SRS or PUSCH, with cross-panel antenna switching (e.g., port connections 320 linking the port 0 and port 1 from panel 302 to panel 306, or port connections 420 linking the port 0 and port 1 from panel 402 to panel 406) . Thus, when a UE needs to transmit port 0 from panel 306, which is switched from panel 302, additional processing delay may result (similarly, when a UE needs to transmit port 0 from panel 406, which is switched from panel 402, additional processing delay may result) .
FIGS. 2-4 illustrates different UE panel architectures. When a UE having three antenna panels (or more) , the UE may use any of the architectures shown in FIGS. 2-4 (with actual port-panel to be differently configured) . That is, the UE may be configured to have antenna ports dedicated (e.g., not sharing over) to the multiple antenna panels (e.g., port configuration 200) , antenna ports shared by all of the multiple antenna panels (e.g., port configuration 300) , or antenna ports shared by some of the multiple antenna panels (e.g., port configuration 400) . For these different architectures, the uplink transmission behaviors of the UE are different.
Even when different UEs have multiple antenna panels with cross-panel port sharing capabilities, the respective performance on uplink simultaneous multi-panel transmissions could be different. For the configuration 200 in FIG. 2, the UE is able to transmit the uplink signals from different panels simultaneously (on respective dedicated antenna ports) . However, for the UE panel architectures shown in FIG. 3 and FIG. 4, the UE’s simultaneous multi-panel transmissions are limited: simultaneously from multiple panels only when the total number of antenna ports for the uplink signal does not exceed the maximum number of antenna ports.
The UE capability for maximum number of ports for single-panel transmission may also be different for different UE panel architectures. For the UE architecture shown in FIG. 2, the UE is able to transmit the uplink signal with up to only two ports from one panel (each of the panels 202, 204, and 206) . For the UE architecture in FIG. 3, the UE is able to transmit the uplink signal with up to four ports from one panel (each of the panels 302, 304, and 306) . For the UE architecture in FIG. 4, the UE is able to transmit the uplink signal with up to two ports (e.g., port 0 and port 1) from the first panel 402 and the UE is able to transmit the uplink signal with up to 4 ports from the second and third panels 404 and 406.
The methods and techniques herein support uplink transmission from multiple panels of different UE panel architectures. Aspects of this disclosure may improve the performance for uplink multi-panel transmission for each particular UE panel architecture. Without the proposed methods, the uplink transmission from multi-panel transmission may be limited to requiring additional delay for the cross-panel antenna switching. Otherwise, like in conventional practices, the UE might be limited to supporting two ports for each panel without taking advantage of multiple antenna panels.
FIG. 5 is a signaling diagram 500 illustrating communications between a user equipment (UE) 102 and a network entity 104 for robust codebook based uplink multi-panel transmission, according to aspects of the present disclosure. The network entity 104 may correspond to a base station or a unit of a base station, such as the RU 106, the DU 108, the CU 110, etc. As shown, the UE 102 transmits 502 a UE capability or report indicating supported configuration (s) for single-panel and multi-panel based uplink transmission. The UE capability may optionally indicate the cross-panel port sharing capability, such as using a same antenna port via two or more antenna panels (e.g., configurations 300 and 400) . For example, the UE reports a UE capability or UE report on UE panel related information including one or more parameters on the maximum number of ports per SRS resource for single-panel transmission and multi-panel transmission, additional processing delay for PUSCH and SRS preparation, and simultaneous transmission operation for signals from different panels.
Based on the received UE capability and related report/indication from the UE, the network entity 104 transmits 504 radio resource control (RRC) signaling that configures two SRS resource sets for codebook based uplink transmission, and correspondingly provides the UE a report configuration for a cross-panel port sharing status report. For example, the network entity may configure two SRS resource sets for codebook based transmission by Radio Resource Control (RRC) signaling, e.g., RRCReconfiguration. For Type-1 configured-grant PUSCH, the network entity may configure an uplink grant for PUSCH by the RRC signaling, where it may configure the selected SRS resource set index (es) , one or more than one SRS resource indicator (SRI) , and one or more than one precoder information indicators, e.g., transmission rank indicator (TRI) and transmission precoder matrix indicator (TPMI) . For dynamic-grant PUSCH or Type-2 configured-grant PUSCH, the network entity may transmit a DCI indicating an uplink grant for the PUSCH. For aperiodic SRS, the network entity may transmit a DCI scheduling the SRS.
In response, the UE 102 reports 506 the cross-panel port sharing status for a group of synchronization signal blocks (SSBs) or channel state information (CSI) reference signals (CSI-RSs) . The network entity 104 transmits 508 downlink control information (DCI) (1) to schedule a physical uplink shared channel (PUSCH) transmission by indicating one or more SRIs and precoders associated with the indicated SRIs, and/or (2) to schedule a configured set of SRS resources.
Correspondingly, the UE 102 transmits 510 the scheduled PUSCH and SRS resources in the SRS resource set based on the indicated precoders when one or more timing conditions are met, such as when/if the scheduling offset for the PUSCH or SRS is greater than the minimum preparation time for the PUSCH or SRS with multi-panel or single-panel transmission. For example, based on the received RRC signaling and DCI, the UE transmits the scheduled PUSCH or SRS from one or more than one panels if the scheduling offset for the PUSCH or SRS is larger than or equal to the minimum preparation time for the PUSCH or SRS with the reported additional processing delay; otherwise, the UE refrains from transmitting the scheduled PUSCH or SRS.
FIG. 6 is a flowchart 600 of a method of robust codebook based uplink multi-panel transmission at a UE (e.g., the UE 102 of FIG. 5) , according to aspects of the present disclosure. As shown, the UE transmits 602 a UE capability indicating supported configurations for single-panel and multi-panel based uplink transmission, and optionally indicates the cross-panel port sharing capability. The UE receives 604 an RRC signaling configuring two SRS resource sets for codebook based uplink transmission based on the received UE capability and UE report. The RRC signaling optionally configures a report configuration with cross-panel port sharing status report. In response, the UE transmits 606 a report of the cross-panel port sharing status for a group of SSBs or CSI-RSs.
The UE receives 608 a DCI scheduling a PUSCH by indicating one or more than one SRIs and precoders associated with the indicated SRIs or scheduling a configured set of SRS resource. The UE transmits 610 the scheduled PUSCH and SRS resources in the SRS resource set based on the indicated precoders if the scheduling offset for the PUSCH or SRS is greater than the minimum preparation time for the PUSCH or SRS with multi-panel or single-panel transmission.
FIG. 7 is a flowchart 700 of a method of robust codebook based uplink multi-panel transmission at a network entity (e.g., the network entity 104 of FIG. 5) , according to aspects of the present disclosure. The method of the flowchart 700 at the network entity complements the method at the UE of the flowchart 600. As shown, the network entity receives 702 a UE capability indicating supported configurations for single-panel and multi-panel based uplink transmission, and optionally indicates the cross-panel port sharing capability. The network entity transmits 704 an RRC signaling configuring two SRS resource sets for codebook based uplink transmission based on the received UE capability and UE report. The RRC signaling optionally configures a report configuration with cross-panel port sharing status report. The network entity then receives 706 a report of the cross-panel port sharing status for a group of SSBs or CSI-RSs.
The network entity transmits 708 a DCI scheduling a PUSCH by indicating one or more than one SRIs and precoders associated with the indicated SRIs or scheduling a configured set of SRS resource. The network entity then receives 710 the scheduled PUSCH and SRS resources in the SRS resource set based on the indicated precoders when the scheduling offset for the PUSCH or SRS is greater than the minimum preparation time for the PUSCH or SRS with multi-panel or single-panel transmission.
In this disclosure, a RRC signaling may indicate a RRC reconfiguration message from the network entity to UE, or a system information block (SIB) , where the SIB may be an existing SIB (e.g., SIB1) or a new SIB (e.g., SIB J, where J is an integer above 21) transmitted by the network entity. In some implementations, the network entity receives the UE capability from a core network (e.g., Access and Mobility Management Function (AMF) ) . In some other implementations, the network entity receives the UE capability from another base station (e.g., gNB or eNB) .
Referring to FIGS. 5-7 collectively, the UE 102 may report or indicate its cross-panel port sharing capability and/or status by specifying one or more properties below. In some cases, the UE may indicate the cross-panel port sharing status in the capability indication. For example, the UE may report the UE capability indicating the maximum number of SRS ports per SRS resource for single-panel transmission and/or the maximum number of SRS ports per SRS resource for multi-panel transmission. The UE may further report at least one of the UE capabilities, including the supported codebook subset coherency type (e.g., full-coherent, partial-coherent and non-coherent) , uplink full power transmission mode (e.g., as provided in 3GPP TS 38.213 section 7.1.1) , the maximum number of PUSCH layers, the maximum number of non-zero-power PUSCH ports (e.g., active ports) for each panel for single-panel and multi-panel transmission separately, e.g., PUSCH associated with one selected SRS resource set or associated with more one selected SRS resource set.
In an embodiment, the UE may report the UE capability indicating whether it supports cross-panel port sharing (e.g., example architectures in FIGS. 3 and 4) . In some implementations, the UE reports whether the cross-panel port sharing is preferred or supported explicitly. The UE may report the UE capability for any number of configured SRS ports or for each number of configured ports. In one example, the UE reports whether cross-panel port sharing is preferred or supported when the number of SRS ports is configured as 1, 2, and 4 separately. For example, in the UE panel configuration 200 of FIG. 2, the UE reports cross-panel port sharing is not supported or preferred for any number of configured ports. For the UE configurations 300 and 400 of FIGS. 3 and 4, the UE reports cross-panel port sharing is not supported or preferred when the number of SRS ports is configured as 1 or 2, but the cross-panel port sharing is supported or preferred when the number of SRS ports is configured as 4.
In some implementations, the UE reports whether the cross-panel port sharing is preferred or supported implicitly based on some other UE capability report, e.g., simultaneous transmission of SRS resources from two SRS resource sets for codebook based transmission, additional processing delay for PUSCH or SRS preparation, whether the UE needs a guard period (GP) between the SRS resources from different SRS resource sets and so on. In some implementations, the UE reports the UE capabilities for any number of configured SRS ports. In some other implementations, the UE reports the UE capabilities for each number of configured ports.
In one example, the UE may report the UE capability indicating whether it supports simultaneous transmission for SRS resources from different SRS resource sets for codebook, and/or the additional processing delay for PUSCH or SRS, and/or whether a GP is preferred between the SRS resources from different SRS resource sets when each SRS resource is configured with 1 port, 2 port or 4 ports separately. Then the network entity may determine the cross-panel port sharing is preferred for the SRS resource sets if the simultaneous transmission for the two SRS resources is not supported or if the additional processing delay is above 0 or if the GP is above 0; the network entity may determine the cross-panel port sharing is not preferred for the SRS resource sets, otherwise.
In some other implementations, the UE reports the maximum number of PUSCH ports or maximum number of non-zero-power PUSCH ports (e.g., active ports) , maximum number of SRS ports per resourcemaximum number of SRS resource sets for codebook via UE capability. If the cross-panel port sharing is supported; otherwise, the cross-panel port sharing is not supported. In some implementations, the UE may report the UE capability indicating the maximum number of PUSCH ports per panel for multi-panel transmission. In some cases, the maximum number of non-zero-power PUSCH ports (e.g., active ports) may be defined as NZP ports. For PUSCH transmission, the network may indicate a precoder like [1, 0 , 0 , 0] . In such situations, one RF chain is needed.
In some cases, the UE may report the cross-panel port sharing status via the UE assistance information report. For example, the UE may report the UE assistance information to the network entity indicating whether it supports cross-panel port sharing. An RRC message may carry the UE assistance information. The UE may report at least one of the parameters in the UE assistance information, including the preferred number of SRS ports per SRS resource for codebook based transmission; whether the UE is capable of transmitting the SRS resources from both SRS resource sets simultaneously or not; whether the UE needs additional processing delay for SRS and PUSCH preparation; whether the UE needs a guard period (GP) between the SRS resources from different SRS resource sets; maximum number of PUSCH ports across panels and/or per panel, among other information.
In some cases, the UE may report the cross-panel port sharing status via the layer one (L1) or layer two (L2) report. The UE may report whether the UE supports cross-panel port sharing for a group of network beams, e.g., a group of downlink reference signals, such as: synchronization signal blocks (SSBs) and CSI reference signals (CSI-RSs) , by uplink control information (UCI) report on PUCCH or PUSCH or MAC CE.
In some implementations, the network entity may enable the report by RRC signaling. In one example, the network entity may configure the report quantity in a CSI report configuration as cross-panel port sharing status report for group-based beam report. In another example, the network entity may configure the UE to report beam quality, e.g., layer 1 reference signal received power (L1-RSRP) or layer 1 signal-to-interference plus noise ratio (L1-SINR) for the group of beams.
In some implementations, the UE reports the cross-panel port sharing status only for the network beams corresponding to the indicated TCI states for PUSCH or SRS. For example, Table 1 below illustrates one example for the UE report on cross-panel port sharing status from two sets of configured network beams. In the CSI field, information related to CSI-RS resource indictor (CRI) , SSB resource indicator (SSBRI) , and reference signal received power (RSRP) are included. In some other implementations, the UE reports the cross-panel port sharing status for the network beams corresponding to each activated TCI states pair for PUSCH or SRS. In some other implementations, the UE reports the cross-panel port sharing status for a sub-set of or all groups of network beams configured by the network entity, where the number of network beam groups to be reported may be configured by the network entity or reported by the UE.
Table 1: An example for the UE report on cross-panel port sharing status from two sets of configured network beams
In one example, for UE panel configuration 200 of FIG. 2, the UE reports the cross-panel port sharing is not supported for any group of network beams; for UE panel structure 2, the UE reports the cross-panel port sharing is supported for any group of network beams; for UE panel structure 3, the UE reports the cross-panel port sharing is supported for the group of network beams corresponding to UE panel 2 and 3, and cross-panel port sharing is supported for the first 2 ports for the group of network beams corresponding to UE panel 1 and 2.
In some implementations, the UE may report a common indicator indicating whether every port may be shared between the PUSCH and SRS corresponding to different SRS resources. In some other implementations, the UE may report a separate indicator for each port indicating whether the port may be shared between the PUSCH and SRS corresponding to different SRS resources. In one example, when a UE is configured with 4-port SRS transmission or when the UE reports that it supports up to 4-ports for a SRS resource, it may report a 4-bit bitmap indicating whether each port may be shared for the SRS resources from different sets.
In some cases, the network entity may enable or disable, at the UE, the cross-panel port sharing for an uplink bandwidth part or for a serving cell or serving cell group in a band or band combination by RRC signaling or media access control (MAC) control element (CE) .
In some implementations, the network entity may configure the maximum total number of PUSCH ports or non-zero-power PUSCH ports for multi-panel transmission or the maximum number of PUSCH ports or non-zero-power PUSCH ports per panel for multi-panel transmission by RRC signaling or MAC CE. If the total number of PUSCH ports or non-zero-power PUSCH ports for the multi-panel transmission is smaller than or equal to the total maximum number of ports for the SRS resources across the SRS resource sets, the network entity and the UE determine that the cross-panel port sharing is enabled; otherwise, the network entity and the UE determine that the cross-panel port sharing is disabled.
In some other implementations, the network entity and the UE may determine status of enabling or disabling the cross-panel port sharing based on the configured maximum number of ports for SRS resources in a resource set and number of configured SRS resource sets for codebook based transmission and the UE capability of maximum number of PUSCH ports If the cross-panel port sharing is enabled; otherwise, the cross-panel port sharing is disabled.
In some other implementations, the network entity configures the number of PUSCH ports per panel or the number of associated SRS ports for PUSCH associated with one SRI by RRC signaling or MAC CE If is smaller than the configured number of SRS ports across the SRS resource sets, the network entity and the UE determine the cross-panel port sharing is enabled; otherwise, the network entity and the UE determine the cross-panel port sharing is disabled.
FIG. 8 illustrates an example scheduling offset 800, according to aspects of the present disclosure. As shown, the network entity may schedule a PUSCH or SRS following the physical downlink control channel (PDCCH) signaling, such as a DCI. If the scheduling offset between the last symbol of the DCI and the first symbol of the scheduled PUSCH or SRS from one or more than one panels is equal to or more than a sum of: (1) the PUSCH or SRS preparation time and (2) an additional processing delay, then the UE proceeds to transmit the PUSCH or SRS.
For example, the minimum preparation time for the PUSCH and SRS may be predefined or reported by the UE via UE capability. In one example, the minimum preparation time for the PUSCH is T_proc, 2 as provided in 3GPP TS 38.214 section 6.4, and the minimum preparation time for the SRS is k₂ or k₂+14 as provided in 3GPP TS 38.214 section 6.4. If the scheduling offset between the last symbol of the DCI and the first symbol of the scheduled PUSCH or SRS is smaller than the PUSCH or SRS preparation time plus an additional processing delay, the UE refrains from transmitting the PUSCH or SRS. FIG. 8 illustrates one example for the processing delay management for PUSCH or SRS from one or more than one panels.
FIG. 9 illustrates an example 900 of switching antenna ports mapping on different sounding reference signal (SRS) resource sets, according to aspects of the present disclosure. The network entity and the UE have a configured a guard period (GP) between the uplink signals transmitted from different panels with cross-panel antenna switching (cross-panel port sharing) . As shown, the UE proceeds with transmission when the offset between the first and the second SRS resource sets is greater than the GP, so that the antenna ports may update the panel mapping for the respective SRS resource sets.
In some implementations, the GP may the same as the additional processing delay. In some other implementations, the GP may be predefined or configured by the network entity by RRC signaling or MAC CE or reported by the UE via UE capability report.
The network entity configures the two uplink signals that require the cross-panel antenna switching (cross-panel port sharing) with an offset above the GP. During the GP, the UE refrains from transmitting any uplink signal from the serving cell or serving cell lists within a band or band combination that share the same antenna. The UE may report the band combination that share the same antenna via UE capability. If the offset between the two uplink signals is smaller than the GP, the UE may refrain from transmitting the first and/or second uplink signal or determines this is an error configuration and trigger RRC reconfiguration request.
As shown in the example 900 of FIG. 9, the network entity configures two sets of SRS resources. Each SRS resource is from four antenna ports (Ports 0 to 3) based on the UE antenna architecture (e.g., configuration 300 of FIG. 3) . Then the network entity may preferably reserve a GP between the two sets of SRS resources so that the UE may have enough time to perform cross-panel antenna switching.
In an embodiment, the network entity and/or UE determine additional processing delay for the PUSCH or SRS based on the UE report and/or network entity configuration of whether the cross-panel port sharing is enabled or not.
In some implementations, the UE may report the value for the additional processing delay. In some other implementations, the value for the additional processing delay may be predefined. In one example, the additional processing delay is provided in the unit of symbol or slots, which is based on the subcarrier spacing for the PUSCH or SRS, or based on the minimum or maximum subcarrier spacing between the DCI scheduling the PUSCH or SRS and the PUSCH or SRS. Table 2 illustrates one example for the predefined additional processing delay.
Table 2: An example for the additional processing delay for the PUSCH or SRS preparation time
FIG. 10 illustrates an example 1000 of switching antenna ports mapping on different uplink signals, according to aspects of the present disclosure. As shown, cross-panel antenna switching results in an additional processing delay that is greater than zero (e.g., the additional processing delay is above zero for the second uplink signal) . In some cases, the network entity and/or UE determine that additional processing delay may be above 0 only for the PUSCH or SRS that requires cross-panel antenna switching. The network entity and/or UE determine whether the additional processing delay based on the transmission antenna ports for the first uplink signal in the most recent transmission and the second uplink signal scheduled by the network entity. The UE may transmit the first and the second uplink signal may be from the same serving cell or different serving cells in a band or band combination that share common antennas.
FIG. 11 illustrates an example 1100 of switching some of the antenna ports mapping on different uplink signals, according to aspects of the present disclosure. FIG. 11 illustrates an example for zero additional processing delay when cross-panel antenna switching is needed. As shown, port 0 and port 1 are mapped to panel 1 for the first SRS resource set, and port 2 and port 3 are mapped to panel 2 for the second SRS resource set. As the scheduled uplink signal does not require cross-panel antenna switching, the additional processing delay is 0. Otherwise, the additional processing delay may be above 0 as shown in the example 900 of FIG. 9.
In some implementations, if the UE supports simultaneous transmission for the first uplink signal and the second uplink signal, the additional processing delay is 0; otherwise, the additional processing delay may be more than 0. In some other implementations, if the first and second uplink signals are from the same antenna ports, e.g., the first uplink signal is an SRS and the second uplink signal is a PUSCH associated with the SRS, the additional processing delay may be 0; otherwise, the additional processing delay may be above 0.
FIG. 12 illustrates an example 1200 of antenna ports mapping to multiple antenna panels with multiple associated SRS ports per panel, according to aspects of the present disclosure. As shown, panels 1 and 2 provide multi-panel transmission with two associated SRS ports per panel indicated when the number of SRS ports is four. The network entity configures or indicates the number of PUSCH ports or associated SRS ports per panel as two. The first two PUSCH ports are associated with the first two ports for the first indicated SRS resource; and the next two PUSCH ports are associated with the first two ports for the second indicated SRS resource.
The network entity may configure or indicate the number of PUSCH ports or associated SRS ports per panel K by RRC signaling, MAC CE or DCI. Then the network entity indicates the precoder for each panel based on the TRI and TPMI corresponding to the codebook with number of ports equal to the number of PUSCH ports per panel K. The associated SRS ports for PUSCH ports corresponding to each panel may be predefined, e.g., the first K SRS ports, or indicated by the network entity by RRC signaling, MAC CE or DCI.
FIG. 13 illustrates an example 1300 of precoder indication based on multi-port codebook for multiple antenna ports mapping to multiple panels, according to aspects of the present disclosure. As shown, the example 1300 illustrates the multi-panel transmission with orthogonal non-zero-power PUSCH ports when the number of SRS ports is four. The network entity indicates to the UE the precoder based on the four-port codebook with antenna selection. The first indicated precoder may be and the second indicated precoder may be
The network entity may configure or indicate the precoder for each panel based on the TRI and TPMI corresponding to the codebook with number of ports equal to the number of SRS ports per panel. In some implementations, for each panel, the network entity indicates a precoder with number of non-zero-power PUSCH ports (e.g., active ports) per panel smaller than or equal to the maximum number of PUSCH ports per panel reported by the UE capability. Alternatively, for each precoder, each panel, the network entity indicates a precoder with number of non-zero-power PUSCH ports per panel smaller than or equal to the maximum number of PUSCH ports reported by the divided by number of selected SRS resource sets.
In some cases, the network entity may refrain from indicating a greater number of non-zero-power PUSCH ports per panel than the maximum number of PUSCH ports per panel that the UE reported. The UE may refrain from transmitting the PUSCH if the number of non-zero-power PUSCH ports per panel is greater than the maximum number of PUSCH ports per panel the UE reported.
In some implementations, for rank ＞ 1 partial-coherent precoders, the indicated TRI and TPMI may correspond to a precoder where all the layers are corresponding to the same antenna ports, e.g., the non-zero coefficients are in the same rows. In one example, as shown in Table 3, at least one of the following 4-ports partial coherent precoders from TPMI 22 to TPMI 37 may be introduced for rank 2 operation. In another example, a dedicated codebook may be defined for the cross-panel port sharing case. The rank 1 codebook could comprise the non-coherent and partial-coherent precoders. The rank 2 codebook could comprise the non-coherent precoders (TPMI 0-5) and partial-coherent precoders with the same antenna ports for each layers (TPMI 22 to 37) . Although Table 3 provides specific examples of TPMI indices, the cross-panel port sharing codebook may use precoders in other TPMI indices, as shown in Table 4 (x and n being natural numbers) .
Table 3: An example for rank 2 4-port codebook
In some other implementations, when the number of ports for an SRS resource is above the maximum number of PUSCH ports per panel, the network entity may only indicate the non-coherent based precoder.
In some other implementations, the network entity may configure a codebook subset by RRC signaling including the partial coherent precoders with the same antenna ports for each layer, e.g., TPMI 22 to 37.
Table 4: An example for rank 2 4-port codebook
FIG. 14 illustrates a flowchart 1400 of a method of wireless communication at a UE.With reference to FIGS. 1 and 16, the method may be performed by the UE 102, the UE apparatus 1602, etc., which may include the memory 1626′, 1606′, 1616, and which may correspond to the entire UE 102 or the entire UE apparatus 1602, or a component of the UE 102 or the UE apparatus 1602, such as the wireless baseband processor 1626 and/or the application processor 1606.
The UE reports 1402 to a network entity, a capability of configuring the first and the second mode of operation based on a capability of the UE of antenna port sharing across the two or more antenna panels for uplink transmissions, and a status related to the first and the second mode of operation for a group of synchronization signal blocks (SSBs) or channel state information reference signals (CSI-RSs) (e.g., operation 502 of FIG. 5) .
The UE receives 1404, from the network entity, a message for configuring at least two SRS resource sets for codebook based uplink transmission by the UE (e.g., operation 504 of FIG. 5) . The UE may, in response, report the cross-panel port sharing status for a group of SSBs or CSI-RSs.
The UE receives 1408, from the network entity, an uplink grant indicating an SRS resource from the at least two SRS resource sets associated with a PUSCH transmission (e.g., operation 508 of FIG. 5) .
The UE transmits 1410, according to the uplink grant, the PUSCH transmission based on a timing condition associated with one of a first mode of operation or a second mode of operation. The first mode of operation is associated with a transmission using a same number of active ports for either single-panel or multiple-panel transmission. The second mode of operation is associated with a transmission using different numbers of active ports for either single-panel or multiple-panel transmission.
FIG. 14 describes a method from a UE-side of a wireless communication link, whereas FIG. 15 describes a method from a network-side of the wireless communication link.
FIG. 15 is a flowchart 1500 of a method of wireless communication at a network entity. With reference to FIGS. 1 and 17, the method may be performed by one or more network entities 104, which may correspond to a base station or a unit of the base station, such as the RU 106, the DU 108, the CU 110, an RU processor 1706, a DU processor 1726, a CU processor 1746, etc. The one or more network entities 104 may include memory 1706’ /1726’ /1746’ , which may correspond to an entirety of the one or more network entities 104, or a component of the one or more network entities 104, such as the RU processor 1706, the DU processor 1726, or the CU processor 1746.
The network entity receives 1502, from a user equipment (UE) , a capability of configuring the first and the second mode of operation based on a capability of the UE of antenna port sharing across the two or more antenna panels for uplink transmissions, and a status related to the first and the second mode of operation for a group of synchronization signal blocks (SSBs) or channel state information reference signals (CSI-RSs) .
The network entity transmits 1504, to the UE, a message for configuring at least two sounding reference signal (SRS) resource sets for codebook based uplink transmission by the UE. The network entity receives the report of the cross-panel port sharing status for a group of SSBs or CSI-RSs.
The network entity transmits 1508, to the UE, an uplink grant indicating an SRS resource from the at least two SRS resource sets associated with a PUSCH transmission.
The network entity receives 1510, from the UE, the PUSCH transmission based on a timing condition associated with one of a first mode of operation or a second mode of operation. The first mode of operation is associated with a transmission using a same number of active ports for either single-panel or multiple-panel transmission. The second mode of operation is associated with a transmission using different numbers of active ports for either single-panel or multiple-panel transmission.
Regarding both FIGS. 14 and 15, one or more detail aspects may be implemented. For example, the UE may configure, based on the message that configures the at least two SRS resource sets, two or more antenna panels configurable to perform in the first mode of operation or the second mode of operation. In the first mode of operation, at least one antenna port is shared among the two or more antenna panels. In the second mode of operation, no antenna port is shared among the two or more antenna panels. In some cases, under the first mode of operation, the UE shares two or more common antenna ports among the two or more antenna panels (e.g., the configurations 300 and 400 of FIGS. 3 and 4, respectively) . Under the second mode of operation, the UE dedicates a fixed number of antenna ports to each of the two or more antenna panels (e.g., the configuration 200 of FIG. 2) .
In aspects, the UE configures the two or more antenna panels by cross-sharing available antenna ports in the two or more antenna panels under the first mode of operation. For example, cross-sharing includes switching a common antenna port between two or more antenna panels.
In aspects, the UE receives a downlink control information (DCI) as the uplink grant scheduling the PUSCH transmission (e.g., under the second mode of operation) . The DCI schedules a configured set of SRS resource. The UE transmits respective SRSs based on the configured set of SRS resource via at least one of the two or more antenna panels having dedicated antenna ports.
In aspects, the UE receives a downlink control information (DCI) indicating one or more SRS resource indicators (SRIs) and associated precoders (e.g., under the first mode of operation) . The UE uses the SRS resources indicated by the one or more SRIs and the associated precoders to transmit the PUSCH transmission.
In aspects, the UE reports, to the network entity, a capability of configuring the first and the second mode of operation based on a capability of the UE of antenna port sharing across the two or more antenna panels for uplink transmissions.
In aspects, the UE reports, to the network entity, a status related to the first and the second mode of operation for a group of synchronization signal blocks (SSBs) or channel state information reference signals (CSI-RSs) .
In aspects, the UE receives, from the network entity, an enabling indication of whether the first mode of operation is to be enabled at the UE.
In aspects, the UE determines a scheduling offset between a last symbol of the uplink grant or an associated downlink control information (DCI) , and a first symbol of the PUSCH transmission or an SRS. The UE identifies a processing delay associated with sharing at least one antenna port under the first mode of operation. The UE identifies a preparation time associated with the UE.
In aspects, the timing condition is satisfied when the scheduling offset is greater than or equal to a total of the preparation time and the processing delay. The UE may identify the processing delay by determining the processing delay as a characteristic of the UE regardless which of the first or the second mode of operation has been configured. In some cases, the UE reports the processing delay to the network entity prior to receiving the message.
In aspects, the UE identifies the processing delay by: determining that the processing delay is zero based on a previous uplink transmission when: scheduled uplink signals do not require cross-panel port switching; simultaneous transmission for multiple uplink signals is supported across the two or more antenna panels; or a same antenna port is used.
In aspects, the UE receives, from the network entity, a precoder indicated for each of the two or more antenna panels based on a transmission rank indicator (TRI) and a transmission precoder matrix indicator (TPMI) corresponding to the codebook with a number of ports being equal to the number of PUSCH ports per panel. In some cases, the UE identifies, for partial-coherent precoders having a rank greater than one, the precoder corresponding to the indicated TRI and TPMI having associated layers correspond to one or more common antenna ports.
A UE apparatus 1602, as described in FIG. 16 below, may perform the method of flowchart 1400. The one or more network entities 104, as described in FIG. 17 below, may perform the method of flowchart 1500.
FIG. 16 is a diagram 1600 illustrating an example of a hardware implementation for a UE apparatus 1602. The UE apparatus 1602 may be the UE 102, a component of the UE 102, or may implement UE functionality. The UE apparatus 1602 may include an application processor 1606, which may have on-chip memory 1606’. In examples, the application processor 1606 may be coupled to a secure digital (SD) card 1608 and/or a display 1610. The application processor 1606 may also be coupled to a sensor (s) module 1612, a power supply 1614, an additional module of memory 1616, a camera 1618, and/or other related components. For example, the sensor (s) module 1612 may control a barometric pressure sensor/altimeter, a motion sensor such as an inertial management unit (IMU) , a gyroscope, accelerometer (s) , a light detection and ranging (LIDAR) device, a radio-assisted detection and ranging (RADAR) device, a sound navigation and ranging (SONAR) device, a magnetometer, an audio device, and/or other technologies used for positioning.
The UE apparatus 1602 may further include a wireless baseband processor 1626, which may be referred to as a modem. The wireless baseband processor 1626 may have on-chip memory 1626′. Along with, and similar to, the application processor 1606, the wireless baseband processor 1626 may also be coupled to the sensor (s) module 1612, the power supply 1614, the additional module of memory 1616, the camera 1618, and/or other related components. The wireless baseband processor 1626 may be additionally coupled to one or more subscriber identity module (SIM) card (s) 1620 and/or one or more transceivers 1630 (e.g., wireless RF transceivers) .
Within the one or more transceivers 1630, the UE apparatus 1602 may include a Bluetooth module 1632, a WLAN module 1634, an SPS module 1636 (e.g., GNSS module) , and/or a cellular module 1638. The Bluetooth module 1632, the WLAN module 1634, the SPS module 1636, and the cellular module 1638 may each include an on-chip transceiver (TRX) , or in some cases, just a transmitter (TX) or just a receiver (RX) . The Bluetooth module 1632, the WLAN module 1634, the SPS module 1636, and the cellular module 1638 may each include dedicated antennas and/or utilize antennas 1640 for communication with one or more other nodes. For example, the UE apparatus 1602 may communicate through the transceiver (s) 1630 via the antennas 1640 with another UE 102 (e.g., sidelink communication) and/or with a network entity 104 (e.g., uplink/downlink communication) , where the network entity 104 may correspond to a base station or a unit of the base station, such as the RU 106, the DU 108, or the CU 110.
The wireless baseband processor 1626 and the application processor 1606 may each include a computer-readable medium /memory 1626′, 1606′, respectively. The additional module of memory 1616 may also be considered a computer-readable medium /memory. Each computer-readable medium /memory 1626′, 1606′, 1616 may be non-transitory. The wireless baseband processor 1626 and the application processor 1606 may each be responsible for general processing, including execution of software stored on the computer-readable medium /memory 1626′, 1606′, 1616. The software, when executed by the wireless baseband processor 1626 /application processor 1606, causes the wireless baseband processor 1626 /application processor 1606 to perform the various functions described herein. The computer-readable medium /memory may also be used for storing data that is manipulated by the wireless baseband processor 1626 /application processor 1606 when executing the software. The wireless baseband processor 1626 /application processor 1606 may be a component of the UE 102. The UE apparatus 1602 may be a processor chip (e.g., modem and/or application) and include just the wireless baseband processor 1626 and/or the application processor 1606. In other examples, the UE apparatus 1602 may be the entire UE 102 and include the additional modules of the apparatus 1602.
As discussed in FIG. 1 and implemented with respect to FIGS. 6 and 14, the multi-panel configuration component 140 is configured to receive, from the base station 104, a message for configuring at least two SRS resource sets for codebook based uplink transmission. The multi-panel configuration component 140 receives, from the base station 104, an uplink grant indicating an SRS resource from the at least two SRS resource sets associated with a PUSCH transmission. The UE 102 transmits, according to the uplink grant, the PUSCH transmission based on a timing condition associated with one of a first mode of operation or a second mode of operation. The multi-panel configuration component 140 may be within the application processor 1606 (e.g., at 140a) , the wireless baseband processor 1626 (e.g., at 140b) , or both the application processor 1606 and the wireless baseband processor 1626. The multi-panel configuration component 140a-140b may be one or more hardware components specifically configured to carry out the stated processes/algorithm, implemented by one or more processors configured to perform the stated processes/algorithm, stored within a computer-readable medium for implementation by the one or more processors, or a combination thereof.
FIG. 17 is a diagram 1700 illustrating an example of a hardware implementation for one or more network entities 104. The one or more network entities 104 may be a base station, a component of a base station, or may implement base station functionality. The one or more network entities 104 may include, or may correspond to, at least one of the RU 106, the DU, 108, or the CU 110. The CU 110 may include a CU processor 1746, which may have on-chip memory 1746′. In some aspects, the CU 110 may further include an additional module of memory 1756 and/or a communications interface 1748, both of which may be coupled to the CU processor 1746. The CU 110 may communicate with the DU 108 through a midhaul link 162, such as an F1 interface between the communications interface 1748 of the CU 110 and a communications interface 1728 of the DU 108.
The DU 108 may include a DU processor 1726, which may have on-chip memory 1726′. In some aspects, the DU 108 may further include an additional module of memory 1736 and/or the communications interface 1728, both of which may be coupled to the DU processor 1726. The DU 108 may communicate with the RU 106 through a fronthaul link 160 between the communications interface 1728 of the DU 108 and a communications interface 1708 of the RU 106.
The RU 106 may include an RU processor 1706, which may have on-chip memory 1706′. In some aspects, the RU 106 may further include an additional module of memory 1716, the communications interface 1708, and one or more transceivers 1730, all of which may be coupled to the RU processor 1706. The RU 106 may further include antennas 1740, which may be coupled to the one or more transceivers 1730, such that the RU 106 may communicate through the one or more transceivers 1730 via the antennas 1740 with the UE 102.
The on-chip memory 1706′, 1726′, 1746′and the additional modules of memory 1716, 1736, 1756 may each be considered a computer-readable medium /memory. Each computer-readable medium /memory may be non-transitory. Each of the processors 1706, 1726, 1746 is responsible for general processing, including execution of software stored on the computer-readable medium /memory. The software, when executed by the corresponding processor (s) 1706, 1726, 1746 causes the processor (s) 1706, 1726, 1746 to perform the various functions described herein. The computer-readable medium /memory may also be used for storing data that is manipulated by the processor (s) 1706, 1726, 1746 when executing the software. In examples, the uplink transmission configuration component 150 may sit at any of the one or more network entities 104, such as at the CU 110; both the CU 110 and the DU 108; each of the CU 110, the DU 108, and the RU 106; the DU 108; both the DU 108 and the RU 106; or the RU 106.
As discussed in FIG. 1 and implemented with respect to FIGS. 7 and 15, the uplink transmission configuration component 150 is configured to transmit, to the UE 102, a message for configuring at least two SRS resource sets for codebook based uplink transmission by the UE 102. The uplink transmission configuration component 150 transmits to the UE 102 an uplink grant indicating an SRS resource from the at least two SRS resource sets associated with a PUSCH transmission. The uplink transmission configuration component 150 receives, from the UE according to the uplink grant, the PUSCH transmission based on a timing condition associated with one of a first mode of operation or a second mode of operation. The uplink transmission configuration component 150 may be within one or more processors of the one or more network entities 104, such as the RU processor 1706 (e.g., at 150a) , the DU processor 1726 (e.g., at 150b) , and/or the CU processor 1746 (e.g., at 150c) . The uplink transmission configuration component 150a-150c may be one or more hardware components specifically configured to carry out the stated processes/algorithm, implemented by one or more processors 1706, 1726, 1746 configured to perform the stated processes/algorithm, stored within a computer-readable medium for implementation by the one or more processors 1706, 1726, 1746, or a combination thereof.
The specific order or hierarchy of blocks in the processes and flowcharts disclosed herein is an illustration of example approaches. Hence, the specific order or hierarchy of blocks in the processes and flowcharts may be rearranged. Some blocks may also be combined or deleted. Dashed lines may indicate optional elements of the diagrams. The accompanying method claims present elements of the various blocks in an example order, and are not limited to the specific order or hierarchy presented in the claims, processes, and flowcharts.
The detailed description set forth herein describes various configurations in connection with the drawings and does not represent the only configurations in which the concepts described herein may be practiced. The detailed description includes specific details for the purpose of providing a thorough explanation of various concepts. However, these concepts may be practiced without these specific details. In some instances, well known structures and components are shown in block diagram form in order to avoid obscuring such concepts.
Aspects of wireless communication systems, such as telecommunication systems, are presented with reference to various apparatuses and methods. These apparatuses and methods are described in the following detailed description and are illustrated in the accompanying drawings by various blocks, components, circuits, processes, call flows, systems, algorithms, etc. (collectively referred to as “elements” ) . These elements may be implemented using electronic hardware, computer software, or combinations thereof. Whether such elements are implemented as hardware or software depends upon the particular application and design constraints imposed on the overall system.
An element, or any portion of an element, or any combination of elements may be implemented as a “processing system” that includes one or more processors. Examples of processors include microprocessors, microcontrollers, graphics processing units (GPUs) , central processing units (CPUs) , application processors, digital signal processors (DSPs) , reduced instruction set computing (RISC) processors, systems-on-chip (SoC) , baseband processors, field programmable gate arrays (FPGAs) , programmable logic devices (PLDs) , state machines, gated logic, discrete hardware circuits, and other similar hardware configured to perform the various functionality described throughout this disclosure. One or more processors in the processing system may execute software, which may be referred to as software, firmware, middleware, microcode, hardware description language, or otherwise. Software shall be construed broadly to mean instructions, instruction sets, code, code segments, program code, programs, subprograms, software components, applications, software applications, software packages, routines, subroutines, objects, executables, threads of execution, procedures, functions, or any combination thereof.
If the functionality described herein is implemented in software, the functions may be stored on, or encoded as, one or more instructions or code on a computer-readable medium, such as a non-transitory computer-readable storage medium. Computer-readable media includes computer storage media and may include a random-access memory (RAM) , a read-only memory (ROM) , an electrically erasable programmable ROM (EEPROM) , optical disk storage, magnetic disk storage, other magnetic storage devices, combinations of these types of computer-readable media, or any other medium that may be used to store computer executable code in the form of instructions or data structures that may be accessed by a computer. Storage media may be any available media that may be accessed by a computer.
Aspects, implementations, and/or use cases described herein may be implemented across many differing platform types, devices, systems, shapes, sizes, and packaging arrangements. For example, the aspects, implementations, and/or use cases may come about via integrated chip implementations and other non-module-component based devices, such as end-user devices, vehicles, communication devices, computing devices, industrial equipment, retail/purchasing devices, medical devices, artificial intelligence (AI) -enabled devices, machine learning (ML) -enabled devices, etc. The aspects, implementations, and/or use cases may range from chip-level or modular components to non-modular or non-chip-level implementations, and further to aggregate, distributed, or original equipment manufacturer (OEM) devices or systems incorporating one or more techniques described herein.
Devices incorporating the aspects and features described herein may also include additional components and features for the implementation and practice of the claimed and described aspects and features. For example, transmission and reception of wireless signals necessarily includes a number of components for analog and digital purposes, such as hardware components, antennas, RF-chains, power amplifiers, modulators, buffers, processor (s) , interleavers, adders/summers, etc. Techniques described herein may be practiced in a wide variety of devices, chip-level components, systems, distributed arrangements, aggregated or disaggregated components, end-user devices, etc., of varying configurations.
The description herein is provided to enable a person skilled in the art to practice the various aspects described herein. Various modifications to these aspects will be readily apparent to those skilled in the art, and the generic principles defined herein may be applied to other aspects. Thus, the claims are not limited to the aspects described herein, but are to be interpreted in view of the full scope of the present disclosure consistent with the language of the claims.
Reference to an element in the singular does not mean “one and only one” unless specifically stated, but rather “one or more. ” Terms such as “if, ” “when, ” and “while” do not imply an immediate temporal relationship or reaction. That is, these phrases, e.g., “when, ” do not imply an immediate action in response to or during the occurrence of an action, but simply imply that if a condition is met then an action will occur, but without requiring a specific or immediate time constraint for the action to occur. The terms “may” , “might” , and “may” , as used in this disclosure, often carry certain connotations. For example, “may” refers to a permissible feature that may or may not occur, “might” refers to a feature that probably occurs, and “may” refers to a capability (e.g., capable of) . The phrase “For example” often carries a similar connotation to “may” and, therefore, “may” is sometimes excluded from sentences that include “for example” or other similar phrases.
Unless specifically stated otherwise, the term “some” refers to one or more. Combinations such as “at least one of A, B, or C” or “one or more of A, B, or C” include any combination of A, B, and/or C, such as A and B, A and C, B and C, or A and B and C, and may include multiples of A, multiples of B, and/or multiples of C, or may include A only, B only, or C only. Sets should be interpreted as a set of elements where the elements number one or more.
Unless otherwise specifically indicated, ordinal terms such as “first” and “second” do not necessarily imply an order in time, sequence, numerical value, etc., but are used to distinguish between different instances of a term or phrase that follows each ordinal term. Reference numbers, as used in the specification and figures, are sometimes cross-referenced among drawings to denote same or similar features. A feature that is exactly the same in multiple drawings may be labeled with the same reference number in the multiple drawings. A feature that is similar among the multiple drawings, but not exactly the same, may be labeled with reference numbers that have different leading numbers, but have one or more of the same trailing numbers (e.g., 206, 306, 406, etc., may refer to similar features in the drawings) . Sometimes an “X” is used to universally denote multiple variations of a feature. For instance, “X06” may universally refer to all reference numbers that end in “06” (e.g., 206, 306, 406, etc. ) .
Structural and functional equivalents to elements of the various aspects described throughout this disclosure that are known or later come to be known to those of ordinary skill in the art are expressly incorporated herein by reference and are encompassed by the claims. The words “module, ” “mechanism, ” “element, ” “device, ” and the like may not be a substitute for the word “means. ” As such, no claim element is to be construed as a means plus function unless the element is expressly recited using the phrase “means for. ” As used herein, the phrase “based on” shall not be construed as a reference to a closed set of information, one or more conditions, one or more factors, or the like. In other words, the phrase “based on A” , where “A” may be information, a condition, a factor, or the like, shall be construed as “based at least on A” unless specifically recited differently.
The following examples are illustrative only and may be combined with other examples or teachings described herein, without limitation.
Example 1. A method for wireless communications by a user equipment (UE) , the method comprising:
receiving, from a network entity, a message for configuring at least two sounding reference signal (SRS) resource sets for codebook based uplink transmission by the UE;
receiving, from the network entity, an uplink grant indicating an SRS resource from the at least two SRS resource sets associated with a physical uplink shared channel (PUSCH) transmission; and
transmitting, according to the uplink grant, the PUSCH transmission based on a timing condition associated with one of a first mode of operation or a second mode of operation, the first mode of operation being associated with a transmission using a same number of active ports for either single-panel or multiple-panel transmission and the second mode of operation being associated with a transmission using different numbers of active ports for either single-panel or multiple-panel transmission.
Example 2. The method of Example 1, further comprising:
configuring, by the UE based on the message, two or more antenna panels configurable to perform in the first mode of operation or the second mode of operation, wherein:
in the first mode of operation, at least one antenna port is shared among the two or more antenna panels; and
in the second mode of operation, no antenna port is shared among the two or more antenna panels.
Example 3. The method of Example 2, wherein configuring the two or more antenna panels comprises:
under the first mode of operation, sharing two or more common antenna ports among the two or more antenna panels; or
under the second mode of operation, dedicating a fixed number of antenna ports to each of the two or more antenna panels.
Example 4. The method of Example 2 or 3, wherein configuring the two or more antenna panels comprises:
under the first mode of operation, cross-sharing available antenna ports in the two or more antenna panels.
Example 5. The method of Example 2 or 3, wherein receiving the uplink grant comprises:
under the second mode of operation, receiving a downlink control information (DCI) as the uplink grant scheduling the PUSCH transmission, the DCI scheduling a configured set of SRS resource; and the method further comprising:
transmitting respective SRSs based on the configured set of SRS resource via at least one of the two or more antenna panels having dedicated antenna ports.
Example 6. The method of any one of Examples 1 to 4, wherein receiving the uplink grant comprises:
under the first mode of operation, receiving a downlink control information (DCI) indicating one or more SRS resource indicators (SRIs) and associated precoders; and
wherein transmitting the PUSCH transmission comprises:
using SRS resources indicated by the one or more SRIs and the associated precoders to transmit the PUSCH transmission.
Example 7. The method of any one of Examples 1 to 6, further comprising:
reporting, to the network entity, a capability of configuring the first and the second mode of operation based on a capability of the UE of antenna port sharing across the two or more antenna panels for uplink transmissions.
Example 8. The method of any one of Examples 1 to 7, further comprising:
reporting, to the network entity, a status related to the first and the second mode of operation for a group of synchronization signal blocks (SSBs) or channel state information reference signals (CSI-RSs) .
Example 9. The method of Example 8, wherein the status comprises at least one of:
a maximum number of SRS ports for every SRS resource for uplink transmissions;
a supported codebook subset coherency type;
a mode of uplink full power transmission; or
an indication of whether the reporting is explicit or implicit.
Example 10. The method of Example 8, wherein reporting the status related to the first and the second modes of operations comprises:
transmitting a UE assistance information by a radio resource control (RRC) message to indicate:
a preferred number of SRS ports per SRS resource for codebook based transmission;
whether the UE transmits the SRS resources simultaneously from the at least two SRS resource sets;
a request by the UE for a processing preparation;
a guard period between the SRS resources from the at least two SRS resource sets; or
a maximum number of PUSCH ports for (1) each of the two or more antenna panels or (2) sharing among the two or more antenna panels.
Example 11. The method of Example 8, wherein reporting the status related to the first and the second modes of operations comprises:
indicating, to the network entity, whether the UE supports port sharing among the two or more antenna panels for a group of network beams via a layer 1 or layer 2 report.
Example 12. The method of any one of Examples 1 to 11, further comprising:
receiving, from the network entity, an enabling indication of whether the first mode of operation is to be enabled at the UE.
Example 13. The method of Example 12, wherein receiving the enabling indication comprises:
identifying, in the message for configuring the UE, at least one of: for multi-panel transmission, a maximum number of PUSCH ports, a maximum number of non-zero-power (NZP) PUSCH ports, a maximum number of PUSCH ports per antenna panel, or a maximum number of NZP PUSCH ports per antenna panel; and
determining the enabling indication based on, in view of the identified maximum number, a maximum number of antenna ports for SRS resources across the SRS resource sets.
Example 14. The method of Example 12, wherein receiving the enabling indication comprises:
identifying, in the message for configuring the UE, a maximum number of ports for SRS resources in a resource set and a number of configured SRS resource sets for codebook based transmission; and
determining the enabling indication based on, in view of the identified maximum number, a number of PUSCH ports supported by the UE.
Example 15. The method of Example 12, wherein receiving the enabling indication comprises:
identifying, in the message for configuring the UE, a number of PUSCH ports per panel and a number of associated SRS ports for a PUSCH transmission associated with one SRI; and
determining the enabling indication based on a comparison between the number of PUSCH ports per panel and the number of the associated SRS ports for the PUSCH transmission associated with one SRI.
Example 16. The method of any one of Examples 1 to 15, further comprising:
determining a scheduling offset between a last symbol of the uplink grant or an associated downlink control information (DCI) , and a first symbol of the PUSCH transmission or an SRS;
identifying a processing delay associated with sharing at least one antenna port under the first mode of operation; and
identifying a preparation time associated with the UE.
Example 17. The method of Example 16, wherein the timing condition is satisfied when the scheduling offset is greater than or equal to a total of the preparation time and the processing delay.
Example 18. The method of Example 16, further comprising:
determining a guard period between uplink signals transmitted from different ones of the two or more antenna panels.
Example 19. The method of Example 18, wherein the guard period equals to the processing delay.
Example 20. The method of Example 18, wherein the guard period is configured by the network entity or is associated with the UE.
Example 21. The method of Example 18, wherein the timing condition is satisfied when the scheduling offset is greater than the guard period.
Example 22. The method of any one of Examples 16 to 21, wherein identifying the processing delay comprises:
determining the processing delay as a characteristic of the UE regardless which of the first or the second mode of operation has been configured.
Example 23. The method of any one of Examples 1 to 22, further comprising:
reporting the processing delay to the network entity prior to receiving the message.
Example 24. The method of any one of Examples 16 to 21, wherein identifying the processing delay comprises:
determining that the processing delay is zero based on a previous uplink transmission when:
scheduled uplink signals do not require cross-panel port switching;
simultaneous transmission for multiple uplink signals is supported across the two or more antenna panels; or
a same antenna port is used.
Example 25. The method of any one of Examples 1 to 24, further comprising:
receiving, from the network entity, a precoder indicated for each of the two or more antenna panels based on a transmission rank indicator (TRI) and a transmission precoder matrix indicator (TPMI) corresponding to the codebook with a number of ports being equal to the number of PUSCH ports per panel.
Example 26. The method of Example 25, wherein receiving the precoder indicated for each of the two or more antenna panels comprises:
identifying, for partial-coherent precoders having a rank greater than one, the precoder corresponding to the indicated TRI and TPMI having associated layers correspond to one or more common antenna ports.
Example 27. The method of Example 25, wherein receiving the precoder indicated for each of the two or more antenna panels comprises:
receiving, from the network entity, a precoder with number of non-zero-power PUSCH ports per panel smaller than or equal to a maximum number of PUSCH ports per panel reported by the UE regarding cross-panel port sharing capabilities.
Example 28. The method of Example 25, wherein receiving the precoder indicated for each of the two or more antenna panels comprises:
receiving, from the network entity, a non-coherent based precoder when a number of ports for an SRS resource is greater than a maximum number of PUSCH ports per panel
Example 29. The method of Example 25, wherein receiving the precoder indicated for each of the two or more antenna panels comprises:
receiving, from the network entity, a codebook subset to include partial coherent precoders having one or more common antenna ports for each layer.
Example 30. A method for wireless communications by a network entity, the method comprising:
transmitting, to a user equipment (UE) , a message for configuring at least two sounding reference signal (SRS) resource sets for codebook based uplink transmission by the UE;
transmitting, to the UE, an uplink grant indicating an SRS resource from the at least two SRS resource sets associated with a physical uplink shared channel (PUSCH) transmission; and
receiving, from the UE according to the uplink grant, the PUSCH transmission based on a timing condition associated with one of a first mode of operation or a second mode of operation, the first mode of operation being associated with a transmission using a same number of active ports for either single-panel or multiple-panel transmission and the second mode of operation being associated with a transmission using different numbers of active ports for either single-panel or multiple-panel transmission.
Example 31. The method of Example 30, wherein the message configures, in the UE, two or more antenna panels to perform in the first mode of operation or the second mode of operation, wherein:
in the first mode of operation, at least one antenna port is shared among the two or more antenna panels; and
in the second mode of operation, no antenna port is shared among the two or more antenna panels.
Example 32. The method of Example 31, wherein the message configures, in the UE, two or more antenna panels to perform:
under the first mode of operation, sharing two or more common antenna ports among the two or more antenna panels; or
under the second mode of operation, dedicating a fixed number of antenna ports to each of the two or more antenna panels.
Example 33. The method of Example 31 or 32, wherein the message configures, in the UE, two or more antenna panels to perform:
under the first mode of operation, cross-sharing available antenna ports in the two or more antenna panels.
Example 34. The method of Example 31 or 32, wherein transmitting the uplink grant comprises:
when the UE is under the second mode of operation, transmitting a downlink control information (DCI) as the uplink grant scheduling the PUSCH transmission, the DCI scheduling a configured set of SRS resource; and the method further comprising:
receiving respective SRSs based on the configured set of SRS resource via at least one of the two or more antenna panels having dedicated antenna ports.
Example 35. The method of any one of Examples 30 to 33, wherein transmitting the uplink grant comprises:
when the UE is under the first mode of operation, transmitting a downlink control information (DCI) indicating one or more SRS resource indicators (SRIs) and associated precoders; and
wherein receiving the PUSCH transmission comprises:
monitoring the PUSCH transmission in SRS resources indicated by the one or more SRIs and the associated precoders.
Example 36. The method of any one of Examples 30 to 35, further comprising:
receiving, from the UE, a capability report of configuring the first and the second mode of operation based on a capability of the UE of antenna port sharing across the two or more antenna panels for uplink transmissions.
Example 37. The method of any one of Examples 30 to 36, further comprising:
receiving, from the UE, a status report related to the first and the second mode of operation for a group of synchronization signal blocks (SSBs) or channel state information reference signals (CSI-RSs) .
Example 38. The method of Example 37, wherein the status report comprises at least one of:
a maximum number of SRS ports for every SRS resource for uplink transmissions;
a supported codebook subset coherency type;
a mode of uplink full power transmission; or
an indication of whether the reporting is explicit or implicit.
Example 39. The method of Example 37, wherein receiving the status report related to the first and the second modes of operations comprises:
receiving a UE assistance information by a radio resource control (RRC) message to indicate:
a preferred number of SRS ports per SRS resource for codebook based transmission;
whether the UE transmits the SRS resources simultaneously from the at least two SRS resource sets;
a request by the UE for a processing preparation;
a guard period between the SRS resources from the at least two SRS resource sets; or
a maximum number of PUSCH ports for (1) each of the two or more antenna panels or (2) sharing among the two or more antenna panels.
Example 40. The method of Example 37, wherein receiving the status report related to the first and the second modes of operations comprises:
receiving, from the UE, an indication of whether the UE supports port sharing among the two or more antenna panels for a group of network beams via a layer 1 or layer 2 report.
Example 41. The method of any one of Examples 30 to 40, further comprising:
transmitting, to the UE, an enabling indication of whether the first mode of operation is to be enabled at the UE.
Example 42. The method of any one of Examples 30 to 41, further comprising:
receiving, from the UE, a report of a processing delay associated with sharing at least one antenna port under the first mode of operation prior to transmitting the message.
Example 43. The method of any one of Examples 30 to 42, further comprising:
transmitting, to the UE, a precoder indicated for each of the two or more antenna panels based on a transmission rank indicator (TRI) and a transmission precoder matrix indicator (TPMI) corresponding to the codebook with a number of ports being equal to the number of PUSCH ports per panel.
Example 44. The method of Example 43, wherein transmitting the precoder indicated for each of the two or more antenna panels comprises:
identifying, for partial-coherent precoders having a rank greater than one, the precoder corresponding to the indicated TRI and TPMI having associated layers correspond to one or more common antenna ports.
Example 45. The method of Example 43, wherein transmitting the precoder indicated for each of the two or more antenna panels comprises:
transmitting, to the UE, a precoder with number of non-zero-power PUSCH ports per panel smaller than or equal to a maximum number of PUSCH ports per panel reported by the UE regarding cross-panel port sharing capabilities.
Example 46. The method of Example 43, wherein transmitting the precoder indicated for each of the two or more antenna panels comprises:
transmitting, to the UE, a non-coherent based precoder when a number of ports for an SRS resource is greater than a maximum number of PUSCH ports per panel
Example 47. The method of Example 43, wherein transmitting the precoder indicated for each of the two or more antenna panels comprises:
transmitting, to the UE, a codebook subset to include partial coherent precoders having one or more common antenna ports for each layer.
Example 48. An apparatus for wireless communication comprising a transceiver, a memory, and a processor coupled to the memory and the transceiver, the apparatus being configured to implement a method as in any of Examples 1-47.
Example 49. An apparatus, comprising a processer configured to cause a User Equipment, UE, to:
receive a control signaling configuring:
two sounding reference signal, SRS, resource sets for codebook based transmission; and
physical uplink shared channel, PUSCH, transmission scheme as codebook based transmission; and
whether the SRS resources from different sets are from the same antenna ports or not
receive an uplink grant indicating:
one or two SRS resource from the configured SRS resource sets associated with the PUSCH transmission; and
precoders for the PUSCH ports associated with each SRS resource based on a predefined codebook
transmit the PUSCH based on the indicated precoders if the offset between the last symbol of the uplink grant and the first symbol of the PUSCH is above or equal to the minimum preparation time plus an additional processing delay.
Example 50. An apparatus, comprising a processer configured to cause a Base Station, BS, to:
transmit a control signaling configuring:
two sounding reference signal, SRS, resource sets for codebook based transmission; and
physical uplink shared channel, PUSCH, transmission scheme as codebook based transmission; and
whether the SRS resources from different sets are from the same antenna ports or not
transmit an uplink grant indicating:
one or two SRS resource from the configured SRS resource sets associated with the PUSCH transmission; and
precoders for the PUSCH ports associated with each SRS resource based on a predefined codebook
receive the PUSCH based on the indicated precoders if the offset between the last symbol of the uplink grant and the first symbol of the PUSCH is above or equal to the minimum preparation time plus an additional processing delay.

Claims

A method for wireless communications by a user equipment (UE) , the method comprising:

receiving (504, 604, 1404) , from a network entity, a message for configuring at least two sounding reference signal (SRS) resource sets for codebook based uplink transmission by the UE;

receiving (508, 608, 1408) , from the network entity, an uplink grant indicating an SRS resource from the at least two SRS resource sets associated with a physical uplink shared channel (PUSCH) transmission; and

transmitting (510, 610, 1410) , according to the uplink grant, the PUSCH transmission based on a timing condition associated with one of a first mode of operation or a second mode of operation, the first mode of operation being associated with a transmission using a same number of active ports for either single-panel or multiple-panel transmission and the second mode of operation being associated with a transmission using different numbers of active ports for either single-panel or multiple-panel transmission.
The method of claim 1, further comprising:

configuring, by the UE based on the message, two or more antenna panels configurable to perform in the first mode of operation or the second mode of operation, wherein:

in the first mode of operation, at least one antenna port is shared among the two or more antenna panels; and

in the second mode of operation, no antenna port is shared among the two or more antenna panels.
The method of claim 2, wherein configuring the two or more antenna panels comprises:

under the first mode of operation, sharing two or more common antenna ports among the two or more antenna panels; or

under the second mode of operation, dedicating a fixed number of antenna ports to each of the two or more antenna panels.
The method of claim 2 or 3, wherein configuring the two or more antenna panels comprises:

under the first mode of operation, cross-sharing available antenna ports in the two or more antenna panels.
The method of claim 2 or 3, wherein receiving the uplink grant comprises:

under the second mode of operation, receiving a downlink control information (DCI) as the uplink grant scheduling the PUSCH transmission, the DCI scheduling a configured set of SRS resource; and the method further comprising:

transmitting respective SRSs based on the configured set of SRS resource via at least one of the two or more antenna panels having dedicated antenna ports.
The method of any one of claims 1 to 4, wherein receiving the uplink grant comprises:

under the first mode of operation, receiving a downlink control information (DCI) indicating one or more SRS resource indicators (SRIs) and associated precoders; and

wherein transmitting the PUSCH transmission comprises:

using SRS resources indicated by the one or more SRIs and the associated precoders to transmit the PUSCH transmission.
The method of any one of claims 1 to 6, further comprising:

reporting, to the network entity, a capability of configuring the first and the second mode of operation based on a capability of the UE of antenna port sharing across the two or more antenna panels for uplink transmissions.
The method of any one of claims 1 to 7, further comprising:

reporting, to the network entity, a status related to the first and the second mode of operation for a group of synchronization signal blocks (SSBs) or channel state information reference signals (CSI-RSs) .
The method of any one of claims 1 to 8, further comprising:

receiving, from the network entity, an enabling indication of whether the first mode of operation is to be enabled at the UE.
The method of any one of claims 1 to 9, further comprising:

determining a scheduling offset between a last symbol of the uplink grant or an associated downlink control information (DCI) , and a first symbol of the PUSCH transmission or an SRS;

identifying a processing delay associated with sharing at least one antenna port under the first mode of operation; and

identifying a preparation time associated with the UE.
The method of claim 10, wherein the timing condition is satisfied when the scheduling offset is greater than or equal to a total of the preparation time and the processing delay.
The method of any one of claim 10 or 11, wherein identifying the processing delay comprises:

determining the processing delay as a characteristic of the UE regardless which of the first or the second mode of operation has been configured.
The method of any one of claims 1 to 12, further comprising:

reporting the processing delay to the network entity prior to receiving the message.
The method of any one of claim 10 or 11, wherein identifying the processing delay comprises:

determining that the processing delay is zero based on a previous uplink transmission when:

scheduled uplink signals do not require cross-panel port switching;

simultaneous transmission for multiple uplink signals is supported across the two or more antenna panels; or

a same antenna port is used.
The method of any one of claims 1 to 14, further comprising:

receiving, from the network entity, a precoder indicated for each of the two or more antenna panels based on a transmission rank indicator (TRI) and a transmission precoder matrix indicator (TPMI) corresponding to the codebook with a number of ports being equal to the number of PUSCH ports per panel.
The method of claim 15, wherein receiving the precoder indicated for each of the two or more antenna panels comprises:

identifying, for partial-coherent precoders having a rank greater than one, the precoder corresponding to the indicated TRI and TPMI having associated layers correspond to one or more common antenna ports.
A method for wireless communications by a network entity, the method comprising:

transmitting (504, 604, 1404) , to a user equipment (UE) , a message for configuring at least two sounding reference signal (SRS) resource sets for codebook based uplink transmission by the UE;

transmitting (508, 608, 1408) , to the UE, an uplink grant indicating an SRS resource from the at least two SRS resource sets associated with a physical uplink shared channel (PUSCH) transmission; and

receiving (510, 610, 1410) , from the UE according to the uplink grant, the PUSCH transmission based on a timing condition associated with one of a first mode of operation or a second mode of operation, the first mode of operation being associated with a transmission using a same number of active ports for either single-panel or multiple-panel transmission and the second mode of operation being associated with a transmission using different numbers of active ports for either single-panel or multiple-panel transmission.
The method of claim 17, wherein the message configures, in the UE, two or more antenna panels to perform in the first mode of operation or the second mode of operation, wherein:

in the first mode of operation, at least one antenna port is shared among the two or more antenna panels; and

in the second mode of operation, no antenna port is shared among the two or more antenna panels.
An apparatus for wireless communication comprising a transceiver, a memory, and a processor coupled to the memory and the transceiver, the apparatus being configured to implement a method as in any of claims 1-18.