US-12627440-B2 - System and method for mapping sounding reference signals to resources

US12627440B2US 12627440 B2US12627440 B2US 12627440B2US-12627440-B2

Abstract

A user equipment (UE) may receive, from a base station, a sounding reference signal (SRS) configuration indicating at least two resource allocations for each SRS resource of an SRS resource set, and each of the at least two resource allocations may include a time resource allocation and a frequency resource allocation. The UE may further transmit, to the base station, an SRS on a respective SRS resource of the SRS resource set based on one of the at least two resource allocations for the respective SRS resource. The base station may transmit, to the UE, the SRS configuration indicating at least two resource allocations for each SRS resource of an SRS resource set, and receive, from the UE, the SRS on a respective SRS resource of the SRS resource set based on the one of the at least two resource allocations for the respective SRS resource.

Inventors

Muhammad Sayed Khairy Abdelghaffar
Chenxi HAO
Yu Zhang
Wanshi Chen

Assignees

QUALCOMM INCORPORATED

Dates

Publication Date: 20260512
Application Date: 20201023

Claims (20)

1 . A method of wireless communication by a user equipment (UE), comprising: receiving, from a base station, a sounding reference signal (SRS) configuration indicating at least two resource allocations for each SRS resource of an SRS resource set, each of the at least two resource allocations comprising a time resource allocation and a frequency resource allocation; based on a determination that an information configuring selection is not received, selecting the one of the at least two resource allocations for the respective SRS resource based on a default selection that is preconfigured; and transmitting, to the base station, an SRS on a respective SRS resource of the SRS resource set based on one of the at least two resource allocations for the respective SRS resource, wherein the frequency resource allocation of the one of the at least two resource allocations for the respective SRS resource is configured with a first transmission comb value, and the frequency resource allocation of another of the at least two resource allocations for the respective SRS resource is configured with a second transmission comb value.
2 . The method of claim 1 , wherein the time resource allocation of each of the at least two resource allocations is configured with one or more of a start position, a number of symbols, or a repetition factor associated with resource mapping of the respective SRS resource.
3 . The method of claim 1 , wherein the frequency resource allocation of the one of the at least two resource allocations for the respective SRS resource is configured without frequency hopping, and the frequency resource allocation of another of the at least two resource allocations for the respective SRS resource is configured with frequency hopping.
4 . The method of claim 3 , wherein the frequency resource allocation of each of the at least two resource allocations is further configured with one or more of a frequency domain position or a frequency domain shift associated with resource mapping of the respective SRS resource.
5 . The method of claim 1 , further comprising: receiving, from the base station, information configuring selection of the one of the at least two resource allocations, wherein the one of the at least two resource allocations is selected based on the information configuring selection.
6 . The method of claim 5 , wherein the information configuring selection of the one of the at least two resource allocations comprises a trigger value associated with aperiodic SRS transmission.
7 . The method of claim 6 , wherein the trigger value has a one-to-one association with the one of the at least two resource allocations for each SRS resource of the SRS resource set.
8 . The method of claim 5 , wherein the information configuring selection comprises downlink control information (DCI).
9 . The method of claim 8 , wherein the DCI comprises at least one code point, and the at least one code point indicates the information configuring selection of the one of the at least two resource allocations.
10 . The method of claim 9 , wherein the at least one code point further triggers the transmitting of the SRS on the respective SRS resource of the SRS resource set.
11 . The method of claim 8 , wherein the DCI comprises one of DCI scheduling information for the UE, DCI from which the scheduling information is absent, or DCI that is groupcast.
12 . The method of claim 11 , wherein the DCI from which the scheduling information is absent comprises a set of bit fields associated with scheduling data, and at least one code point indicating the information configuring selection of the one of the at least two resource allocations is included in the set of bit fields associated with scheduling data.
13 . The method of claim 11 , wherein the DCI scheduling information for the UE comprises at least one code point associated with at least one of a time-domain resource allocation or a frequency-domain resource allocation, and at least one code point indicating the information configuring selection of the one of the at least two resource allocations is indicated by the at least one code point associated with the at least one of the time-domain resource allocation or the frequency-domain resource allocation.
14 . The method of claim 11 , wherein the DCI that is groupcast comprises a block of bits assigned to the UE, and at least one code point indicating the information configuring selection of the one of the at least two resource allocations is included in the block of bits assigned to the UE.
15 . The method of claim 8 , wherein the information configuring selection of the one of the at least two resource allocations for the respective SRS resource indicates the one of the at least two resource allocations is a wideband resource allocation when the SRS on the respective SRS resource of the SRS resource set is jointly triggered based on an aperiodic CSI request included in the DCI.
16 . The method of claim 10 , wherein the information configuring selection of the one of the at least two resource allocations for the respective SRS resource indicates the one of the at least two resource allocations is a default resource allocation when the SRS on the respective SRS resource of the SRS resource set is triggered based on an independent SRS trigger included in the DCI.
17 . A method of wireless communication by a base station, comprising: transmitting, to a user equipment (UE), a sounding reference signal (SRS) configuration indicating at least two resource allocations for each SRS resource of an SRS resource set, each of the at least two resource allocations comprising a time resource allocation and a frequency resource allocation; and receiving, from the UE, an SRS on a respective SRS resource of the SRS resource set based on one of the at least two resource allocations for the respective SRS resource, wherein the one of the two at least two resource allocations for the respective SRS resource is selected based on a default selection that is preconfigured, wherein the frequency resource allocation of the one of the at least two resource allocations for the respective SRS resource is configured with a first transmission comb value, and the frequency resource allocation of another of the at least two resource allocations for the respective SRS resource is configured with a second transmission comb value.
18 . The method of claim 17 , wherein the time resource allocation of each of the at least two resource allocations comprises one or more of a start position, a number of symbols, or a repetition factor associated with resource mapping of the respective SRS resource.
19 . The method of claim 17 , wherein the frequency resource allocation of the one of the at least two resource allocations for the respective SRS resource is configured without frequency hopping, and another of the at least two resource allocations for the respective SRS resource is configured with frequency hopping.
20 . The method of claim 19 , wherein the frequency resource allocation of each of the at least two resource allocations is further configured with one or more of a frequency domain position or a frequency domain shift associated with resource mapping of the respective SRS resource.

Description

CROSS REFERENCE TO RELATED APPLICATION(S) This application is a National Phase entry of PCT Application No. PCT/CN2020/123217, entitled “SYSTEM AND METHOD FOR MAPPING SOUNDING REFERENCE SIGNALS TO RESOURCES” and filed on Oct. 23, 2020, which is expressly incorporated by reference herein in its entirety. BACKGROUND Technical Field The present disclosure generally relates to communication systems, and more particularly, to a user equipment configured to transmit sounding reference signals to a base station. INTRODUCTION Wireless communication systems are widely deployed to provide various telecommunication services such as telephony, video, data, messaging, and broadcasts. Typical wireless communication systems may employ multiple-access technologies capable of supporting communication with multiple users by sharing available system resources. Examples of such multiple-access technologies include code division multiple access (CDMA) systems, time division multiple access (TDMA) systems, frequency division multiple access (FDMA) systems, orthogonal frequency division multiple access (OFDMA) systems, single-carrier frequency division multiple access (SC-FDMA) systems, and time division synchronous code division multiple access (TD-SCDMA) systems. These multiple access technologies have been adopted in various telecommunication standards to provide a common protocol that enables different wireless devices to communicate on a municipal, national, regional, and even global level. An example telecommunication standard is 5G New Radio (NR). 5G NR is part of a continuous mobile broadband evolution promulgated by Third Generation Partnership Project (3GPP) to meet new requirements associated with latency, reliability, security, scalability (e.g., with Internet of Things (IoT)), and other requirements. 5G NR includes services associated with enhanced mobile broadband (eMBB), massive machine type communications (mMTC), and ultra-reliable low latency communications (URLLC). Some aspects of 5G NR may be based on the 4G Long Term Evolution (LTE) standard. There exists a need for further improvements in 5G NR technology. These improvements may also be applicable to other multi-access technologies and the telecommunication standards that employ these technologies. SUMMARY The following presents a simplified summary of one or more aspects in order to provide a basic understanding of such aspects. This summary is not an extensive overview of all contemplated aspects, and is intended to neither identify key or critical elements of all aspects nor delineate the scope of any or all aspects. Its sole purpose is to present some concepts of one or more aspects in a simplified form as a prelude to the more detailed description that is presented later. In access networks of some example radio access technologies (RATs), such as a 5G New Radio (NR) access network, a base station may estimate at least one channel on which transmissions are received from a user equipment (UE) (e.g., an uplink channel) using at least one sounding reference signal (SRS). Additionally or alternatively, SRS can be used for uplink frequency selective scheduling and/or uplink timing estimation. Accordingly, the UE transmits the at least one SRS to the base station. In so doing, the UE may sound all ports of an SRS resource in each symbol of the SRS resource. In some aspects, the UE may aperiodically transmit SRSs to the base station, with such aperiodic SRS transmission being triggered by the base station, for example, via downlink or uplink downlink control information (DCI) (e.g., SRS request field). For frequency-division duplexing (FDD) (e.g., paired spectrum), the base station may utilize SRS to derive frequency domain-spatial domain (FD-SD) bases for precoding of channel state information (CSI) reference signals (RSs). However, if SRS is sounded per band, such as with SRS frequency hopping, the base station may be unable to combine FD bases determined via SRS measurement. Similarly, in time-division duplexing (TDD), the base station may be unable to perform joint processing (e.g., noise filtering) using the channel impulse response (CIR) of two or more subbands. Thus, a need exists for facilitating derivation of FD bases determined via SRS measurement by a base station. The present disclosure provides various techniques and solutions to the derivation of FD bases determined via SRS measurement by a base station. In particular, the present disclosure describes configuring a UE with two SRS resource allocations for each SRS resource of an SRS resource set, with each resource allocation including a resource allocation for both time and frequency. A first resource allocation of the at least two resource allocations may be based on subband sounding, and therefore, may include frequency hopping in the frequency resource allocation. Further, a second resource allocation of the at least two resource allocations may be based on wideband sounding, and therefore, m