US-12621103-B2 - Techniques for mapping sounding reference signal resources

US12621103B2US 12621103 B2US12621103 B2US 12621103B2US-12621103-B2

Abstract

Methods, systems, and devices for wireless communications are described. A base station may receive a capability message from a user equipment (UE) based on a number of receive antennas exceeding a number of transmit antennas at the UE. The base station may configure the UE with a mapping between sounding reference signal (SRS) resources and bit sequences, or SRS resource indices (SRIs), based on the capability message. The base station may transmit a control message including one or more SRIs indicating respective SRS resources. The UE may use the one or more SRIs included in a control message from the base station to select respective SRS resources from a resource set. Once the UE selects one or more SRS resources, the UE may transmit one or more SRSs in the SRS resources.

Inventors

Kexin XIAO
Muhammad Sayed Khairy Abdelghaffar
Yu Zhang
Bo Chen
Runxin WANG
Yeliz Tokgoz
Krishna Kiran Mukkavilli

Assignees

QUALCOMM INCORPORATED

Dates

Publication Date: 20260505
Application Date: 20201029

Claims (20)

1 . A method for wireless communication at a user equipment (UE), comprising: transmitting a capability message indicating a first number of one or more transmit antennas for antenna switching supported by the UE, a second number of receive antennas supported by the UE for antenna switching that exceeds the first number of one or more transmit antennas, and a third number of one or more ports supported for uplink transmission, wherein the capability message is transmitted based at least in part on the first number of one or more transmit antennas for antenna switching supported by the UE being less than the second number of receive antennas supported by the UE for antenna switching; receiving, based at least in part on the capability message, a sounding reference signal configuration for a plurality of sounding reference signal resources for antenna switching and codebook based sounding, wherein the sounding reference signal configuration indicates a mapping between each sounding reference signal resource for at least a subset of the plurality of sounding reference signal resources and a respective bit sequence of a plurality of bit sequences for codebook based sounding; receiving a control message comprising a first bit sequence of the plurality of bit sequences to indicate a first sounding reference signal resource of the subset of the plurality of sounding reference signal resources on which to perform codebook based sounding based at least in part on the mapping; and transmitting a first sounding reference signal in the first sounding reference signal resource based at least in part on the control message, wherein the first sounding reference signal is a codebook based sounding reference signal and the first bit sequence indicates to transmit the codebook based sounding reference signal via the first sounding reference signal resource.
2 . The method of claim 1 , wherein receiving the control message comprises: receiving an indication of a plurality of identifiers corresponding to a plurality of resource sets, wherein the subset of the plurality of sounding reference signal resources corresponds to a first resource set of the plurality of resource sets associated with a first identifier of the plurality of identifiers.
3 . The method of claim 2 , wherein the first identifier is a highest or lowest identifier of the plurality of identifiers corresponding to the plurality of resource sets.
4 . The method of claim 1 , wherein receiving the sounding reference signal configuration comprises: receiving the sounding reference signal configuration that indicates a plurality of resource sets, wherein the control message indicates a first resource set of the plurality of resource sets that is associated with the subset of the plurality of sounding reference signal resources and indicates the first sounding reference signal resource of the subset of the plurality of sounding reference signal resources.
5 . The method of claim 4 , wherein receiving the control message comprises: receiving the control message comprising a set indicator having a value of zero indicating the first resource set of the plurality of resource sets.
6 . The method of claim 4 , wherein receiving the control message comprises: receiving the control message comprising a set indicator having a non-zero value indicating the first resource set of the plurality of resource sets.
7 . The method of claim 4 , wherein receiving the control message comprises: receiving the control message comprising a resource indicator having a value of zero indicating the first sounding reference signal resource of the subset of the plurality of sounding reference signal resources.
8 . The method of claim 4 , wherein receiving the control message comprises: receiving the control message comprising a resource indicator having a non-zero value indicating the first sounding reference signal resource of the subset of the plurality of sounding reference signal resources.
9 . The method of claim 1 , wherein receiving the sounding reference signal configuration further comprises: receiving, based at least in part on the capability message, the sounding reference signal configuration that indicates a single resource set associated with the plurality of sounding reference signal resources, wherein the mapping indicates a mapping between each sounding reference signal resource of the plurality of sounding reference signal resources and a respective bit sequence of the plurality of bit sequences.
10 . The method of claim 1 , further comprising: receiving, based at least in part on the capability message, the sounding reference signal configuration that indicates a plurality of resource sets, each sounding reference signal resource of the plurality of sounding reference signal resources being associate with a respective resource set of the plurality of resource sets, wherein the mapping indicates a mapping between each sounding reference signal resource of the plurality of sounding reference signal resources and a respective bit sequence of the plurality of bit sequences.
11 . The method of claim 1 , wherein receiving the sounding reference signal configuration further comprises: receiving the sounding reference signal configuration that indicates a virtual resource set comprising the subset of the plurality of sounding reference signal resources, wherein the virtual resource set comprises the first sounding reference signal resource from a first resource set and a second sounding reference signal resource from a second resource set.
12 . The method of claim 1 , wherein receiving the sounding reference signal configuration further comprises: receiving the sounding reference signal configuration that indicates a virtual resource set comprising the subset of the plurality of sounding reference signal resources, wherein the first sounding reference signal resource is included in the subset of the plurality of sounding reference signal resources based at least in part on a slot index corresponding to the control message.
13 . The method of claim 1 , wherein receiving the control message comprises: receiving the control message that indicates a resource set identifier of a first resource set corresponding to the plurality of sounding reference signal resources.
14 . The method of claim 1 , wherein the first bit sequence comprises a single bit.
15 . The method of claim 1 , wherein the first number of one or more transmit antennas and the third number of one or more ports is the same.
16 . A method for wireless communication at a network device, comprising: receiving a capability message indicating a first number of one or more transmit antennas for antenna switching supported by a user equipment (UE), a second number of receive antennas supported by the UE for antenna switching that exceeds the first number of one or more transmit antennas, and a third number of one or more ports supported for uplink transmission, wherein the capability message is received based at least in part on the first number of one or more transmit antennas for antenna switching supported by the UE being less than the second number of receive antennas supported by the UE for antenna switching; transmitting, based at least in part on the capability message, a sounding reference signal configuration for a plurality of sounding reference signal resources for antenna switching and codebook based sounding, wherein the sounding reference signal configuration indicates a mapping between each sounding reference signal resource for at least a subset of the plurality of sounding reference signal resources and a respective bit sequence of a plurality of bit sequences for codebook based sounding; transmitting a control message comprising a first bit sequence of the plurality of bit sequences to indicate a first sounding reference signal resource of the subset of the plurality of sounding reference signal resources on which to perform codebook based sounding based at least in part on the mapping; and receiving a first sounding reference signal in the first sounding reference signal resource based at least in part on the control message, wherein the first sounding reference signal is a codebook based sounding reference signal and the first bit sequence indicates to transmit the codebook based sounding reference signal via the first sounding reference signal resource.
17 . The method of claim 16 , wherein transmitting the control message comprises: transmitting an indication of a plurality of identifiers corresponding to a plurality of resource sets, wherein the subset of the plurality of sounding reference signal resources corresponds to a first resource set of the plurality of resource sets associated with a first identifier of the plurality of identifiers.
18 . The method of claim 16 , wherein transmitting the sounding reference signal configuration comprises: transmitting the sounding reference signal configuration that indicates a plurality of resource sets, wherein the control message indicates a first resource set of the plurality of resource sets that is associated with the subset of the plurality of sounding reference signal resources and indicates the first sounding reference signal resource of the subset of the plurality of sounding reference signal resources.
19 . The method of claim 16 , wherein transmitting the sounding reference signal configuration further comprises: transmitting, based at least in part on the capability message, the sounding reference signal configuration that indicates a single resource set associated with the plurality of sounding reference signal resources, wherein the mapping indicates a mapping between each sounding reference signal resource of the plurality of sounding reference signal resources and a respective bit sequence of the plurality of bit sequences.
20 . A user equipment (UE), comprising: a processing system configured to: transmit a capability message indicating a first number of one or more transmit antennas for antenna switching supported by the UE, a second number of receive antennas supported by the UE for antenna switching that exceeds the first number of one or more transmit antennas, and a third number of one or more ports supported for uplink transmission, wherein the capability message is transmitted based at least in part on the first number of one or more transmit antennas for antenna switching supported by the UE being less than the second number of receive antennas supported by the UE for antenna switching; receive, based at least in part on the capability message, a sounding reference signal configuration for a plurality of sounding reference signal resources for antenna switching and codebook based sounding, wherein the sounding reference signal configuration indicates a mapping between each sounding reference signal resource for at least a subset of the plurality of sounding reference signal resources and a respective bit sequence of a plurality of bit sequences for codebook based sounding; receive a control message comprising a first bit sequence of the plurality of bit sequences to indicate a first sounding reference signal resource of the subset of the plurality of sounding reference signal resources on which to perform codebook based sounding based at least in part on the mapping; and transmit a first sounding reference signal in the first sounding reference signal resource based at least in part on the control message, wherein the first sounding reference signal is a codebook based sounding reference signal and the first bit sequence indicates to transmit the codebook based sounding reference signal via the first sounding reference signal resource.

Description

CROSS REFERENCE The present application is a 371 national stage filing of International PCT Application No. PCT/CN2020/124698 by Xiao et al. entitled “TECHNIQUES FOR MAPPING SOUNDING REFERENCE SIGNAL RESOURCES,” filed Oct. 29, 2020, which is assigned to the assignee hereof, and which is expressly incorporated by reference in its entirety herein. FIELD OF TECHNOLOGY The following relates to wireless communications, including techniques for mapping sounding reference signal (SRS) resources. BACKGROUND Wireless communications systems are widely deployed to provide various types of communication content such as voice, video, packet data, messaging, broadcast, and so on. These systems may be capable of supporting communication with multiple users by sharing the available system resources (e.g., time, frequency, and power). Examples of such multiple-access systems include fourth generation (4G) systems such as Long Term Evolution (LTE) systems, LTE-Advanced (LTE-A) systems, or LTE-A Pro systems, and fifth generation (5G) systems which may be referred to as New Radio (NR) systems. These systems may employ technologies such as code division multiple access (CDMA), time division multiple access (TDMA), frequency division multiple access (FDMA), orthogonal FDMA (OFDMA), or discrete Fourier transform spread orthogonal frequency division multiplexing (DFT-S-OFDM). A wireless multiple-access communications system may include one or more base stations or one or more network access nodes, each simultaneously supporting communication for multiple communication devices, which may be otherwise known as user equipment (UE). SUMMARY The described techniques relate to improved methods, systems, devices, and apparatuses that support techniques for mapping sounding reference signal (SRS) resources. Generally, the described techniques provide for a base station to configure a user equipment (UE) with a mapping between SRS resources and bit sequences, or SRS resource indices (SRIs), based on a capability message from the UE. In some cases, the UE may use one or more SRIs included in a control message from the base station to select respective SRS resources from a default resource set (e.g., the resource set with a smallest identifier). In some other cases, the base station may include an SRS set indicator in the control message in addition to the one or more SRIs. In some examples, the base station may build a lookup table, and configure the UE with the mapping table, to map the one or more SRIs in the control message to each SRS resource (e.g., based on a bit sequence) in one resource set or multiple resource sets. In some other examples, the UE may use the one or more SRIs in the control message to select SRS resources from a static virtual resource set, which may be indicated in control signaling, or a dynamic virtual set, which may be based on a slot index. Once the UE selects one or more SRS resources, the UE may transmit one or more SRSs in the SRS resources. A method for wireless communication at a user equipment (UE) is described. The method may include transmitting a capability message indicating a first number of one or more transmit antennas for antenna switching supported by the UE, a second number of receive antennas supported by the UE for antenna switching that exceeds the first number of one or more transmit antennas, and a third number of one or more ports supported for uplink transmission, receiving, based on the capability message, an SRS configuration for a set of multiple SRS resources that indicates a mapping between each SRS resource for at least a subset of the set of multiple SRS resources and a respective bit sequence of a set of multiple bit sequences, receiving a control message including a first bit sequence of the set of multiple bit sequences to indicate a first SRS resource of the subset of the set of multiple SRS resources based on the mapping, and transmitting a first SRS in the first SRS resource based on the control message. An apparatus for wireless communication at a UE is described. The apparatus may include a processor, memory in electronic communication with the processor, and instructions stored in the memory. The instructions may be executable by the processor to cause the apparatus to transmit a capability message indicating a first number of one or more transmit antennas for antenna switching supported by the UE, a second number of receive antennas supported by the UE for antenna switching that exceeds the first number of one or more transmit antennas, and a third number of one or more ports supported for uplink transmission, receive, based on the capability message, an SRS configuration for a set of multiple SRS resources that indicates a mapping between each SRS resource for at least a subset of the set of multiple SRS resources and a respective bit sequence of a set of multiple bit sequences, receive a control message including a first bit sequence of the set of multiple bit sequences