WO2021232419A1

WO2021232419A1 - Sounding reference signal triggering using control information

Info

Publication number: WO2021232419A1
Application number: PCT/CN2020/091857
Authority: WO
Inventors: Runxin WANG; Muhammad Sayed Khairy Abdelghaffar; Alexandros MANOLAKOS; Seyed Ali Akbar Fakoorian; Yu Zhang; Hwan Joon Kwon; Krishna Kiran Mukkavilli
Original assignee: Qualcomm Incorporated
Priority date: 2020-05-22
Filing date: 2020-05-22
Publication date: 2021-11-25

Abstract

A method of wireless communication includes receiving control information by a UE. The control information indicates a plurality of values and a plurality of SRS resource sets. The method further includes receiving, from a base station, a control message including an SRS request field. The method further includes, based on a value of the plurality of values determined at least in part based on the SRS request field, transmitting an SRS to the base station via a set of component carriers and using one or more SRS resource sets of the plurality of SRS resource sets. The control information indicates that the value is associated with the one or more SRS resource sets.

Description

SOUNDING REFERENCE SIGNAL TRIGGERING USING CONTROL INFORMATION

TECHNICAL FIELD

Aspects of the present disclosure relate generally to wireless communication systems, and more particularly, to wireless communication systems that use sounding reference signals.

INTRODUCTION

Wireless communication networks are widely deployed to provide various communication services such as voice, video, packet data, messaging, broadcast, and the like. These wireless networks may be multiple-access networks capable of supporting multiple users by sharing the available network resources. Such networks, which are usually multiple access networks, support communications for multiple users by sharing the available network resources.

A wireless communication network may include a number of base stations or node Bs that can support communication for a number of user equipments (UEs) . A UE may communicate with a base station via downlink and uplink. The downlink (or forward link) refers to the communication link from the base station to the UE, and the uplink (or reverse link) refers to the communication link from the UE to the base station.

A base station may transmit data and control information on the downlink to a UE and/or may receive data and control information on the uplink from the UE. On the downlink, a transmission from the base station may encounter interference due to transmissions from neighbor base stations or from other wireless radio frequency (RF) transmitters. On the uplink, a transmission from the UE may encounter interference from uplink transmissions of other UEs communicating with the neighbor base stations or from other wireless RF transmitters. This interference may degrade performance on both the downlink and uplink.

As the demand for mobile broadband access continues to increase, the possibilities of interference and congested networks grows with more UEs accessing the long-range wireless communication networks and more short-range wireless systems being deployed in communities. Research and development continue to advance wireless technologies not only to meet the growing demand for mobile broadband access, but to advance and enhance the user experience with mobile communications.

SUMMARY

In some aspects of the disclosure, a method of wireless communication includes receiving control information by a user equipment (UE) . The control information indicates a plurality of values and a plurality of sounding reference signal (SRS) resource sets. The method further includes receiving, from a base station, a control message including an SRS request field. The method further includes, based on a value of the plurality of values determined at least in part based on the SRS request field, transmitting an SRS to the base station via a set of component carriers and using one or more SRS resource sets of the plurality of SRS resource sets. The control information indicates that the value is associated with the one or more SRS resource sets.

In some other aspects of the disclosure, an apparatus includes a memory and one or more processors coupled to the memory. The one or more processors are configured to receive control information that indicates a plurality of values and a plurality of SRS resource sets. The one or more processors are further configured to receive, from a base station, a control message including an SRS request field. The one or more processors are further configured to transmit, based on a value of the plurality of values determined at least in part based on the SRS request field, an SRS to the base station via a set of component carriers and using one or more SRS resource sets of the plurality of SRS resource sets. The control information indicates that the value is associated with the one or more SRS resource sets.

In some other aspects of the disclosure, an apparatus includes means for receiving control information. The control information indicates a plurality of values and a plurality of SRS resource sets. The apparatus further includes means for receiving, from a base station, a control message including an SRS request field. The apparatus further includes means for transmitting, based on a value of the plurality of values determined at least in part based on the SRS request field, an SRS to the base station via a set of component carriers and using one or more SRS resource sets of the plurality of SRS resource sets. The control information indicates that the value is associated with the one or more SRS resource sets.

In some other aspects of the disclosure, a non-transitory computer-readable medium stores instructions executable by a processor to perform operations. The operations include receiving control information. The control information indicates a plurality of values and a plurality of SRS resource sets. The operations further include receiving, from a base station, a control message including an SRS request field. The operations further include, based on a value of the plurality of values determined at least in part based on the SRS request field, transmitting an SRS to the base station via a set of component carriers and using one or more SRS resource sets of the plurality of SRS resource sets. The control information indicates that the value is associated with the one or more SRS resource sets.

In some other aspects of the disclosure, a method includes transmitting, from a base station to a UE, a control message including a SRS request field. The UE stores control information indicating a plurality of values and a plurality of SRS resource sets. The method further includes, based on a value of the plurality of values determined at least in part based on the SRS request field, receiving an SRS from the UE via a set of component carriers and using one or more SRS resource sets of the plurality of SRS resource sets. The control information indicates that the value is associated with the one or more SRS resource sets.

In some other aspects of the disclosure, an apparatus includes a memory and one or more processors coupled to the memory. The one or more processors are configured to transmit, to a UE, a control message including a SRS request field. The UE stores control information indicating a plurality of values and a plurality of SRS resource sets. The one or more processors are further configured to receive, based on a value of the plurality of values determined at least in part based on the SRS request field, an SRS from the UE via a set of component carriers and using one or more SRS resource sets of the plurality of SRS resource sets. The control information indicates that the value is associated with the one or more SRS resource sets.

In some other aspects of the disclosure, an apparatus includes means for transmitting, to a UE, a control message including a SRS request field. The UE stores control information indicating a plurality of values and a plurality of SRS resource sets. The apparatus further includes means for receiving, based on a value of the plurality of values determined at least in part based on the SRS request field, an SRS from the UE via a set of component carriers and using one or more SRS resource sets of the plurality of SRS resource sets. The control information indicates that the value is associated with the one or more SRS resource sets.

In some other aspects of the disclosure, a non-transitory computer-readable medium stores instructions executable by a processor to perform operations. The operations include transmitting, to a UE, a control message including a SRS request field. The UE stores control information indicating a plurality of values and a plurality of SRS resource sets. The operations further include, based on a value of the plurality of values determined at least in part based on the SRS request field, receiving an SRS from the UE via a set of component carriers and using one or more SRS resource sets of the plurality of SRS resource sets. The control information indicates that the value is associated with the one or more SRS resource sets.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a block diagram illustrating an example of a wireless communication system according to some aspects of the disclosure.

FIG. 2 is a block diagram illustrating examples of a base station and a user equipment (UE) according to some aspects of the disclosure.

FIG. 3 is a block diagram illustrating an example of a wireless communication system according to some aspects of the disclosure.

FIG. 4 is a diagram illustrating an example of control information in accordance with some aspects of the disclosure.

FIG. 5 is a diagram illustrating examples of a bitmap and a mapping process based on the bitmap in accordance with some aspects of the disclosure.

FIG. 6 is a flow chart of an example of a method of wireless communication that may be performed by a UE in accordance with some aspects of the disclosure.

FIG. 7 is a flow chart of an example of a method of wireless communication that may be performed by a base station in accordance with some aspects of the disclosure.

FIG. 8 is a block diagram illustrating an example of a UE to according to some aspects of the disclosure.

FIG. 9 is a block diagram illustrating an example of a base station to according to some aspects of the disclosure.

The Appendix provides further details regarding various aspects of the disclosure and forms a part of the specification of this application.

DETAILED DESCRIPTION

Some wireless communication protocols use downlink control information (DCI) to provide information from a base station to a user equipment (UE) . In some examples, the DCI may trigger the UE to transmit a reference signal, such as a sounding reference signal (SRS) that may be used by one or more base stations to measure channel quality, noise, or other characteristics of wireless communication channels. For example, the DCI may include an SRS request field of a particular length (e.g., number of bits) that triggers the UE to transmit the SRS using an antenna switching technique. In some cases, the particular length may be insufficient to indicate a relatively large number of parameters, such as if the number of bits is two and the number of parameters is greater than four.

In some aspects of the disclosure, a base station transmits one or more messages (e.g., one or more higher-layer messages) to a UE to increase flexibility of DCI signaling. The use of the one or more higher-layer messages may enable use of an SRS request field of a particular length (and without increasing the length beyond a number of bits specified by a particular wireless communication protocol) while also increasing flexibility associated with the SRS request field. For example, the base station may send a radio resource control (RRC) message to the UE including control information indicating a table of SRS codepoints, component carriers (CC) sets associated with each SRS codepoint, and SRS resource sets associated with each SRS codepoint. As another example, an SRS codepoint may be associated with a plurality of CC sets, and the base station may send a medium access control (MAC) control element (MAC-CE) to the UE to select a particular CC set from among the plurality of CC sets. As a result, flexibility of the SRS request field may be enhanced without increasing DCI overhead (e.g., without increasing a number of bits of the SRS request field beyond the number specified by a particular wireless communication protocol) . In some examples, the enhanced flexibility enables the base station to trigger SRS resource sets for multiple usages, such as for a physical uplink shared channel (PUSCH) transmission (alternatively or in addition to use of SRS resource sets for antenna switching) .

To further illustrate, the disclosure relates generally to wireless communication networks, such as code division multiple access (CDMA) networks, time division multiple access (TDMA) networks, frequency division multiple access (FDMA) networks, orthogonal FDMA (OFDMA) networks, single-carrier FDMA (SC-FDMA) networks, LTE networks, GSM networks, 5th Generation (5G) or new radio (NR) networks (sometimes referred to as “5G NR” networks/systems/devices) , as well as other communications networks. As described herein, the terms “networks” and “systems” may be used interchangeably.

A CDMA network, for example, may implement a radio technology such as universal terrestrial radio access (UTRA) , cdma2000, and the like. UTRA includes wideband-CDMA (W-CDMA) and low chip rate (LCR) . CDMA2000 covers IS-2000, IS-95, and IS-856 standards.

A TDMA network may, for example implement a radio technology such as GSM. 3GPP defines standards for the GSM EDGE (enhanced data rates for GSM evolution) radio access network (RAN) , also denoted as GERAN. GERAN is the radio component of GSM/EDGE, together with the network that joins the base stations (for example, the Ater and Abis interfaces) and the base station controllers (A interfaces, etc. ) . The radio access network represents a component of a GSM network, through which phone calls and packet data are routed from and to the public switched telephone network (PSTN) and Internet to and from subscriber handsets, also known as user terminals or user equipments (UEs) . A mobile phone operator's network may comprise one or more GERANs, which may be coupled with Universal Terrestrial Radio Access Networks (UTRANs) in the case of a UMTS/GSM network. An operator network may also include one or more LTE networks, and/or one or more other networks. The various different network types may use different radio access technologies (RATs) and radio access networks (RANs) .

An OFDMA network may implement a radio technology such as evolved UTRA (E-UTRA) , IEEE 802.11, IEEE 802.16, IEEE 802.20, flash-OFDM and the like. UTRA, E-UTRA, and Global System for Mobile Communications (GSM) are part of universal mobile telecommunication system (UMTS) . In particular, long term evolution (LTE) is a release of UMTS that uses E-UTRA. UTRA, E-UTRA, GSM, UMTS and LTE are described in documents provided from an organization named “3rd Generation Partnership Project” (3GPP) , and cdma2000 is described in documents from an organization named “3rd Generation Partnership Project 2” (3GPP2) . These various radio technologies and standards are known or are being developed. For example, the 3rd Generation Partnership Project (3GPP) is a collaboration between groups of telecommunications associations that aims to define a globally applicable third generation (3G) mobile phone specification. 3GPP long term evolution (LTE) is a 3GPP project which was aimed at improving the universal mobile telecommunications system (UMTS) mobile phone standard. The 3GPP may define specifications for the next generation of mobile networks, mobile systems, and mobile devices. The present disclosure is concerned with the evolution of wireless technologies from LTE, 4G, 5G, NR, and beyond with shared access to wireless spectrum between networks using a collection of new and different radio access technologies or radio air interfaces.

5G networks contemplate diverse deployments, diverse spectrum, and diverse services and devices that may be implemented using an OFDM-based unified, air interface. To achieve these goals, further enhancements to LTE and LTE-A are considered in addition to development of the new radio technology for 5G NR networks. The 5G NR will be capable of scaling to provide coverage (1) to a massive Internet of things (IoTs) with an ultra-high density (e.g., ～1M nodes/km^2) , ultra-low complexity (e.g., ～10s of bits/sec) , ultra-low energy (e.g., ～10+ years of battery life) , and deep coverage with the capability to reach challenging locations; (2) including mission-critical control with strong security to safeguard sensitive personal, financial, or classified information, ultra-high reliability (e.g., ～99.9999% reliability) , ultra-low latency (e.g., ～ 1 ms) , and users with wide ranges of mobility or lack thereof; and (3) with enhanced mobile broadband including extreme high capacity (e.g., ～ 10 Tbps/km^2) , extreme data rates (e.g., multi-Gbps rate, 100+ Mbps user experienced rates) , and deep awareness with advanced discovery and optimizations.

5G NR devices, networks, and systems may be implemented to use optimized OFDM-based waveform features. These features may include scalable numerology and transmission time intervals (TTIs) ; a common, flexible framework to efficiently multiplex services and features with a dynamic, low-latency time division duplex (TDD) /frequency division duplex (FDD) design; and advanced wireless technologies, such as massive multiple input, multiple output (MIMO) , robust millimeter wave (mmWave) transmissions, advanced channel coding, and device-centric mobility. Scalability of the numerology in 5G NR, with scaling of subcarrier spacing, may efficiently address operating diverse services across diverse spectrum and diverse deployments. For example, in various outdoor and macro coverage deployments of less than 3GHz FDD/TDD implementations, subcarrier spacing may occur with 15 kHz, for example over 1, 5, 10, 20 MHz, and the like bandwidth. For other various outdoor and small cell coverage deployments of TDD greater than 3 GHz, subcarrier spacing may occur with 30 kHz over 80/100 MHz bandwidth. For other various indoor wideband implementations, using a TDD over the unlicensed portion of the 5 GHz band, the subcarrier spacing may occur with 60 kHz over a 160 MHz bandwidth. Finally, for various deployments transmitting with mmWave components at a TDD of 28 GHz, subcarrier spacing may occur with 120 kHz over a 500MHz bandwidth.

The scalable numerology of 5G NR facilitates scalable TTI for diverse latency and quality of service (QoS) requirements. For example, shorter TTI may be used for low latency and high reliability, while longer TTI may be used for higher spectral efficiency. The efficient multiplexing of long and short TTIs to allow transmissions to start on symbol boundaries. 5G NR also contemplates a self-contained integrated subframe design with uplink/downlink scheduling information, data, and acknowledgement in the same subframe. The self-contained integrated subframe supports communications in unlicensed or contention-based shared spectrum, adaptive uplink/downlink that may be flexibly configured on a per-cell basis to dynamically switch between uplink and downlink to meet the current traffic needs.

For clarity, certain aspects may be described below with reference to exemplary LTE implementations or in an LTE-centric way, and LTE terminology may be used as illustrative examples in portions of the description below; however, the description is not intended to be limited to LTE applications. Indeed, the present disclosure is concerned with shared access to wireless spectrum between networks using different radio access technologies or radio air interfaces, such as those of 5G NR.

Moreover, it should be understood that, in operation, wireless communication networks adapted according to the concepts herein may operate with any combination of licensed or unlicensed spectrum depending on loading and availability. Accordingly, it will be apparent to one of skill in the art that the systems, apparatus and methods described herein may be applied to other communications systems and applications than the particular examples provided.

While aspects and examples are described in this application by illustration to some examples, those skilled in the art will understand that additional implementations and use cases may come about in many different arrangements and scenarios. Innovations described herein may be implemented across many differing platform types, devices, systems, shapes, sizes, packaging arrangements. For example, implementations and/or uses may come about via integrated chip implementations and/or other non-module-component based devices (e.g., end-user devices, vehicles, communication devices, computing devices, industrial equipment, retail/purchasing devices, medical devices, AI-enabled devices, etc. ) . While some examples may or may not be specifically directed to use cases or applications, a wide assortment of applicability of described innovations may occur. Implementations may range from chip-level or modular components to non-modular, non-chip-level implementations and further to aggregated, distributed, or OEM devices or systems incorporating one or more described aspects. In some settings, devices incorporating described aspects and features may also include additional components and features. It is intended that innovations described herein may be practiced in a wide variety of implementations, including both large/small devices, chip-level components, multi-component systems (e.g. RF-chain, communication interface, processor) , distributed arrangements, end-user devices, etc. of varying sizes, shapes, and constitution.

FIG. 1 shows wireless network 100 for communication according to some aspects. Wireless network 100 may, for example, comprise a 5G wireless network. As appreciated by those skilled in the art, components appearing in FIG. 1 are likely to have related counterparts in other network arrangements including, for example, cellular-style network arrangements and non-cellular-style-network arrangements (e.g., device to device or peer to peer or ad hoc network arrangements, etc. ) .

Wireless network 100 illustrated in FIG. 1 includes a number of base stations 105 and other network entities. A base station may be a station that communicates with the UEs and may also be referred to as an evolved node B (eNB) , a next generation eNB (gNB) , an access point, and the like. Each base station 105 may provide communication coverage for a particular geographic area. In 3GPP, the term “cell” can refer to this particular geographic coverage area of a base station and/or a base station subsystem serving the coverage area, depending on the context in which the term is used. In implementations of wireless network 100 herein, base stations 105 may be associated with a same operator or different operators (e.g., wireless network 100 may comprise a plurality of operator wireless networks) , and may provide wireless communications using one or more of the same frequencies (e.g., one or more frequency bands in licensed spectrum, unlicensed spectrum, or a combination thereof) as a neighboring cell. In some examples, an individual base station 105 or UE 115 may be operated by more than one network operating entity. In other examples, each base station 105 and UE 115 may be operated by a single network operating entity.

A base station may provide communication coverage for a macro cell or a small cell, such as a pico cell or a femto cell, and/or other types of cell. A macro cell generally covers a relatively large geographic area (e.g., several kilometers in radius) and may allow unrestricted access by UEs with service subscriptions with the network provider. A small cell, such as a pico cell, would generally cover a relatively smaller geographic area and may allow unrestricted access by UEs with service subscriptions with the network provider. A small cell, such as a femto cell, would also generally cover a relatively small geographic area (e.g., a home) and, in addition to unrestricted access, may also provide restricted access by UEs having an association with the femto cell (e.g., UEs in a closed subscriber group (CSG) , UEs for users in the home, and the like) . A base station for a macro cell may be referred to as a macro base station. A base station for a small cell may be referred to as a small cell base station, a pico base station, a femto base station or a home base station. In the example shown in FIG. 1,

base stations

105d and 105e are regular macro base stations, while base stations 105a-105c are macro base stations enabled with one of 3 dimension (3D) , full dimension (FD) , or massive MIMO. Base stations 105a-105c take advantage of their higher dimension MIMO capabilities to exploit 3D beamforming in both elevation and azimuth beamforming to increase coverage and capacity. Base station 105f is a small cell base station which may be a home node or portable access point. A base station may support one or multiple (e.g., two, three, four, and the like) cells.

Wireless network 100 may support synchronous or asynchronous operation. For synchronous operation, the base stations may have similar frame timing, and transmissions from different base stations may be approximately aligned in time. For asynchronous operation, the base stations may have different frame timing, and transmissions from different base stations may not be aligned in time. In some scenarios, networks may be enabled or configured to handle dynamic switching between synchronous or asynchronous operations.

UEs 115 are dispersed throughout the wireless network 100, and each UE may be stationary or mobile. It should be appreciated that, although a mobile device is commonly referred to as user equipment (UE) in standards and specifications promulgated by the 3rd Generation Partnership Project (3GPP) , such device may also be referred to by those skilled in the art as a mobile station (MS) , a subscriber station, a mobile unit, a subscriber unit, a wireless unit, a remote unit, a mobile device, a wireless device, a wireless communications device, a remote device, a mobile subscriber station, an access terminal (AT) , a mobile terminal, a wireless terminal, a remote terminal, a handset, a terminal, a user agent, a mobile client, a client, a gaming device, an augmented reality device, vehicular component device/module, or some other suitable terminology. Within the present document, a “mobile” device or UE need not necessarily have a capability to move, and may be stationary. Some non-limiting examples of a UE 115 include a mobile phone, a cellular (cell) phone, a smart phone, a session initiation protocol (SIP) phone, a wireless local loop (WLL) station, a laptop, a personal computer (PC) , a notebook, a netbook, a smart book, a tablet, and a personal digital assistant (PDA) . A mobile device may additionally be an “Internet of things” (IoT) or “Internet of everything” (IoE) device such as an automotive or other transportation vehicle, a satellite radio, a global positioning system (GPS) device, a logistics controller, a drone, a multi-copter, a quad-copter, a smart energy or security device, a solar panel or solar array, municipal lighting, water, or other infrastructure; industrial automation and enterprise devices; consumer and wearable devices, such as eyewear, a wearable camera, a smart watch, a health or fitness tracker, a mammal implantable device, gesture tracking device, medical device, a digital audio player (e.g., MP3 player) , a camera, a game console, etc.; and digital home or smart home devices such as a home audio, video, and multimedia device, an appliance, a sensor, a vending machine, intelligent lighting, a home security system, a smart meter, etc. In one aspect, a UE may be a device that includes a Universal Integrated Circuit Card (UICC) . In another aspect, a UE may be a device that does not include a UICC. In some aspects, UEs that do not include UICCs may also be referred to as IoE devices. UEs 115a-115d of the example illustrated in FIG. 1 are examples of mobile smart phone-type devices accessing wireless network 100 A UE may also be a machine specifically configured for connected communication, including machine type communication (MTC) , enhanced MTC (eMTC) , narrowband IoT (NB-IoT) and the like. UEs 115e-115k illustrated in FIG. 1 are examples of various machines configured for communication that access wireless network 100.

A mobile device, such as UEs 115, may be able to communicate with any type of the base stations, whether macro base stations, pico base stations, femto base stations, relays, and the like. In FIG. 1, a lightning bolt (e.g., communication link) indicates wireless transmissions between a UE and a serving base station, which is a base station designated to serve the UE on the downlink and/or uplink, or desired transmission between base stations, and backhaul transmissions between base stations. UEs may operate as base stations or other network nodes in some scenarios. Backhaul communication between base stations of wireless network 100 may occur using wired and/or wireless communication links.

In operation at wireless network 100, base stations 105a-105c serve

UEs

115a and 115b using 3D beamforming and coordinated spatial techniques, such as coordinated multipoint (CoMP) or multi-connectivity. Macro base station 105d performs backhaul communications with base stations 105a-105c, as well as small cell, base station 105f. Macro base station 105d also transmits multicast services which are subscribed to and received by

UEs

115c and 115d. Such multicast services may include mobile television or stream video, or may include other services for providing community information, such as weather emergencies or alerts, such as Amber alerts or gray alerts.

Wireless network 100 may support mission critical communications with ultra-reliable and redundant links for mission critical devices, such UE 115e, which is a drone. Redundant communication links with UE 115e include from

macro base stations

105d and 105e, as well as small cell base station 105f. Other machine type devices, such as UE 115f (thermometer) , UE 115g (smart meter) , and UE 115h (wearable device) may communicate through wireless network 100 either directly with base stations, such as small cell base station 105f, and macro base station 105e, or in multi-hop configurations by communicating with another user device which relays its information to the network, such as UE 115f communicating temperature measurement information to the smart meter, UE 115g, which is then reported to the network through small cell base station 105f. Wireless network 100 may also provide additional network efficiency through dynamic, low-latency TDD/FDD communications, such as in a vehicle-to-vehicle (V2V) mesh network between UEs 115i-115k communicating with macro base station 105e.

FIG. 2 shows a block diagram of a design of a base station 105 and a UE 115, which may be any of the base stations and one of the UEs in FIG. 1. For a restricted association scenario (as mentioned above) , base station 105 may be small cell base station 105f in FIG. 1, and UE 115 may be

UE

115c or 115d operating in a service area of base station 105f, which in order to access small cell base station 105f, would be included in a list of accessible UEs for small cell base station 105f. Base station 105 may also be a base station of some other type. As shown in FIG. 2, base station 105 may be equipped with antennas 234a through 234t, and UE 115 may be equipped with antennas 252a through 252r for facilitating wireless communications.

At base station 105, transmit processor 220 may receive data from data source 212 and control information from controller/processor 240. The control information may be for the physical broadcast channel (PBCH) , physical control format indicator channel (PCFICH) , physical hybrid-ARQ (automatic repeat request) indicator channel (PHICH) , physical downlink control channel (PDCCH) , enhanced physical downlink control channel (EPDCCH) , MTC physical downlink control channel (MPDCCH) , etc. The data may be for the PDSCH, etc. Transmit processor 220 may process (e.g., encode and symbol map) the data and control information to obtain data symbols and control symbols, respectively. Transmit processor 220 may also generate reference symbols, e.g., for the primary synchronization signal (PSS) and secondary synchronization signal (SSS) , and cell-specific reference signal. Transmit (TX) multiple-input multiple-output (MIMO) processor 230 may perform spatial processing (e.g., precoding) on the data symbols, the control symbols, and/or the reference symbols, if applicable, and may provide output symbol streams to modulators (MODs) 232a through 232t. Each modulator 232 may process a respective output symbol stream (e.g., for OFDM, etc. ) to obtain an output sample stream. Each modulator 232 may additionally or alternatively process (e.g., convert to analog, amplify, filter, and upconvert) the output sample stream to obtain a downlink signal. Downlink signals from modulators 232a through 232t may be transmitted via antennas 234a through 234t, respectively.

At UE 115, the antennas 252a through 252r may receive the downlink signals from base station 105 and may provide received signals to demodulators (DEMODs) 254a through 254r, respectively. Each demodulator 254 may condition (e.g., filter, amplify, downconvert, and digitize) a respective received signal to obtain input samples. Each demodulator 254 may further process the input samples (e.g., for OFDM, etc. ) to obtain received symbols. MIMO detector 256 may obtain received symbols from demodulators 254a through 254r, perform MIMO detection on the received symbols if applicable, and provide detected symbols. Receive processor 258 may process (e.g., demodulate, deinterleave, and decode) the detected symbols, provide decoded data for UE 115 to data sink 260, and provide decoded control information to controller/processor 280.

On the uplink, at UE 115, transmit processor 264 may receive and process data (e.g., for the physical uplink shared channel (PUSCH) ) from data source 262 and control information (e.g., for the physical uplink control channel (PUCCH) ) from controller/processor 280. Transmit processor 264 may also generate reference symbols for a reference signal. The symbols from transmit processor 264 may be precoded by TX MIMO processor 266 if applicable, further processed by modulators 254a through 254r (e.g., for SC-FDM, etc. ) , and transmitted to base station 105. At base station 105, the uplink signals from UE 115 may be received by antennas 234, processed by demodulators 232, detected by MIMO detector 236 if applicable, and further processed by receive processor 238 to obtain decoded data and control information sent by UE 115. Processor 238 may provide the decoded data to data sink 239 and the decoded control information to controller/processor 240.

Controllers/

processors

240 and 280 may direct the operation at base station 105 and UE 115, respectively. Controller/processor 240 and/or other processors and modules at base station 105 and/or controller/processor 280 and/or other processors and modules at UE 115 may perform or direct the execution of various processes for the techniques described herein, such as to perform or direct the operations illustrated in FIG. 6, the operations illustrated in FIG. 7, one or more other operations, or a combination thereof.

Memories

242 and 282 may store data and program codes for base station 105 and UE 115, respectively. Scheduler 244 may schedule UEs for data transmission on the downlink and/or uplink.

Wireless communications systems operated by different network operating entities (e.g., network operators) may share spectrum. In some instances, a network operating entity may be configured to use an entirety of a designated shared spectrum for at least a period of time before another network operating entity uses the entirety of the designated shared spectrum for a different period of time. Thus, in order to allow network operating entities use of the full designated shared spectrum, and in order to mitigate interfering communications between the different network operating entities, certain resources (e.g., time) may be partitioned and allocated to the different network operating entities for certain types of communication.

For example, a network operating entity may be allocated certain time resources reserved for exclusive communication by the network operating entity using the entirety of the shared spectrum. The network operating entity may also be allocated other time resources where the entity is given priority over other network operating entities to communicate using the shared spectrum. These time resources, prioritized for use by the network operating entity, may be utilized by other network operating entities on an opportunistic basis if the prioritized network operating entity does not utilize the resources. Additional time resources may be allocated for any network operator to use on an opportunistic basis.

Access to the shared spectrum and the arbitration of time resources among different network operating entities may be centrally controlled by a separate entity, autonomously determined by a predefined arbitration scheme, or dynamically determined based on interactions between wireless nodes of the network operators.

In some cases, UE 115 and base station 105 may operate in a shared radio frequency spectrum band, which may include licensed or unlicensed (e.g., contention-based) frequency spectrum. In an unlicensed frequency portion of the shared radio frequency spectrum band, UEs 115 or base stations 105 may traditionally perform a medium-sensing procedure to contend for access to the frequency spectrum. For example, UE 115 or base station 105 may perform a listen before talk (LBT) procedure such as a clear channel assessment (CCA) prior to communicating in order to determine whether the shared channel is available. A CCA may include an energy detection procedure to determine whether there are any other active transmissions. For example, a device may infer that a change in a received signal strength indicator (RSSI) of a power meter indicates that a channel is occupied. Specifically, signal power that is concentrated in a certain bandwidth and exceeds a predetermined noise floor may indicate another wireless transmitter. A CCA also may include detection of specific sequences that indicate use of the channel. For example, another device may transmit a specific preamble prior to transmitting a data sequence. In some cases, an LBT procedure may include a wireless node adjusting its own backoff window based on the amount of energy detected on a channel and/or the acknowledge/negative-acknowledge (ACK/NACK) feedback for its own transmitted packets as a proxy for collisions.

FIG. 3 illustrates an example of a wireless communications system 300 in accordance with some aspects of the disclosure. The wireless communications system 300 includes one or more base stations, such as the base station 105, and further includes one or more UEs, such as the UE 115.

During operation, the UE 115 may receive control information 322 (e.g., from the base station 105 or from another device) . In some examples, the UE 115 receives the control information 322 via a radio resource control (RRC) message 320.

The control information 322 may indicate a plurality of values 324 and a plurality of sounding reference signal (SRS) resource sets 328. To illustrate, the plurality of values 324 may include a value 326, and the plurality of SRS resource sets 328 may include one or more SRS resource sets 330. In some examples, the control information 322 further indicates a set of component carriers (CCs) 334. In some implementations, the control information 322 indicates a single set of CCs 334. In some other implementations, the control information 322 indicates a plurality of sets of CCs 332 including the set of CCs 334.

The UE 115 may receive a control message 340 including an SRS request field 344. For example, the base station 105 may send the control message 340 to the UE 115 to indicate parameters of a physical downlink shared channel (PDSCH) transmission from the base station 105 to the UE 115. The control message 340 may be sent to the UE 115 via a physical downlink control channel (PDCCH) . The SRS request field 344 may indicate a request for the UE 115 to generate an SRS 350.

In some examples, the control message 340 includes or corresponds to downlink control information (DCI) 342 that includes the SRS request field 344. In some implementations, the DCI 342 is associated with a particular format (e.g., format 2_3) specified by a wireless communication protocol (e.g., a 5G NR wireless communication protocol) and includes a block of a type A specified by the wireless communication protocol. The block may include the SRS request field 344.

The UE 115 may determine a value of the plurality of values 324 (e.g., the value 326) based at least in part on the SRS request field 344. To illustrate, in some implementations, a value of the SRS request field 344 may be selected from the plurality of values 324. In this case, a value of the SRS request field 344 may map directly to a value of the plurality of values 324. For example, the UE 115 may use the value 326 as a lookup index to the control information 322 to determine one or more SRS resource sets associated with the value 326, to determine one or more sets of CCs associated with the value 326, or both. In some other examples, values of the SRS request field 344 may be different than the plurality of values 326, as described further with reference to the example of FIG. 5.

To further illustrate, FIG. 4 depicts an illustrative example of the control information 322. In the example of FIG. 4, the plurality of values 324 represent a plurality of SRS codepoints. The plurality of values 324 may include a first value representing a first SRS codepoint (e.g., “00” ) , a second value representing a second SRS codepoint (e.g., “01” ) , a third value representing a third SRS codepoint (e.g., “10” ) , and a fourth value representing a fourth SRS codepoint (e.g., “11) . Each SRS codepoint may include N bits, where N is a positive integer greater than one. In the example of FIG. 2, N = 2. In other examples, N may correspond to another value. The value 326 of FIG. 3 may represent a particular SRS codepoint of the plurality of SRS codepoints (e.g., the value 326 may correspond to “00, ” “01, ” “10, ” or “11” ) . As used herein, a “value” of the plurality of values 324 may include multiple bits (e.g., a value of zero may be represented using the bits “00, ” and a value of two may be represented using the bits “10” ) .

In FIG. 4, each value of the plurality of values 324 is associated with a CC set of the plurality of sets of CCs 332. To illustrate, the first value of the plurality of values 324 may be associated with a first CC set ( “CC set1” ) , the second value of the plurality of values 324 may be associated with a second CC set ( “CC set2” ) , the third value of the plurality of values 324 may be associated with a third CC set ( “CC set3” ) , and the fourth value of the plurality of values 324 may be associated with a fourth CC set ( “CC set4” ) . The first CC set may include CC1, CC2, and CC3, and the second CC set may include CC4 and CC5. The third CC set may include CC1 and CC4, and the fourth CC set may include CC6, CC7, and CC8. In some examples, the set of CCs 334 of FIG. 3 corresponds to the first CC set, the second CC set, the third CC set, or the fourth CC set.

In FIG. 4, each CC of a CC set is associated with an SRS resource set. To illustrate, referring to the first CC set, CC1 may be associated with SRS resource set0 and SRS resource set1, CC2 may be associated with SRS resource set1 and SRS resource set2, and CC3 may be associated with SRS resource set3. In this example, the first value of the plurality of values 324 may be associated with an SRS resource set including { (SRS resource set0 and SRS resource set1) , (SRS resource set1 and SRS resource set2) , and SRS resource set3} .

Referring again to FIG. 3, the UE 115 may transmit the SRS 350 based on the value 326. For example, based on the control information 322 indicating that the value 326 is associated with the one or more SRS resource sets 330 and the set of CCs 334, the UE 115 may transmit the SRS 350 via the set of CCs 334 and using the one or more SRS resource sets 330. The UE 115 may transmit the SRS 350 to one or more base stations 105.

Although certain examples have been described with reference to one base station 105 for illustration, in some aspects of the disclosure, the UE 115 may communicate with multiple base stations 105. To illustrate, each set of component carriers described herein may correspond to a plurality of base stations 105 (e.g., a set of serving cells) . In some examples, the base station 105 depicted in FIG. 3 corresponds to a primary cell of the plurality of base stations 105, and other base stations of the plurality of base stations 105 correspond to secondary base stations of the plurality of base stations 105. The UE 115 may communicate with the plurality of base stations 105 using a set of CCs. For example, depending on the particular example, the UE 115 may use the CCs of a set of CCs to simultaneously communicate with the plurality of base stations 105 using the set of CCs or to sequentially communicate with the plurality of base stations 105 using the set of CCs. In some examples, the UE 115 performs carrier aggregation (CA) using a set of CCs.

Although the example of FIG. 3 illustrates one set of CCs 334, in some implementations, multiple sets of CCs may be associated with a value of the SRS request field 344, such as the value 326. In some examples, the base station 105 may provide an indication 304 to the UE 115 selecting the set of CCs 334 from among the multiple sets of CCs associated with the value 326. In some implementations, the indication 304 is included in a medium access control (MAC) control element (MAC-CE) 302. To further illustrate, in some examples, a row of the control information 322 of FIG. 4 (and each SRS codepoint) includes multiple sets of CCs, such as if the SRS codepoint “11” in FIG. 4 is associated with a CC set5 (in addition to CC set4) .

In some other implementations, one set of CCs 334 may be associated with a value of the SRS request field 344, such as the value 326. In this example, the base station 105 may avoid sending the indication 304 to the UE 115 (because no selection among multiple sets of CCs may be needed in the case of a single set of CCs 334) . In some examples, the indication 304 is not used if a number of rows of the control information 322 is greater than or equal to the number of sets of CCs. To illustrate, in the example of FIG. 4, the control information 322 includes four rows corresponding to four SRS codepoints and indicates four sets of CCs. In this case, each row (and each SRS codepoint) may be associated with one set of CCs, and thus the indication 304 may be unnecessary. In some other cases, a row of the control information 322 (and an SRS codepoint) may be associated with multiple sets of CCs, and the indication 304 may be used to select among the multiple sets of CCs.

In some examples, SRS request field 344 is represented using (or includes) a particular number of bits, and each value the plurality of values 324 is represented using (or includes) the particular number of bits. To illustrate, in some examples, the SRS request field 344 is represented using two bits, and each value of the plurality of values 324 includes N=2 bits, such as illustrated in the example of FIG. 4.

In some other examples, the SRS request field 344 is represented using a first number bits, and at least one value of the plurality of values 324 is represented using a second number of bits that is greater than the first number. To illustrate, in some wireless communication protocols, the SRS request field 344 may be limited to two bits (and may indicate one of the four

values

00, 01, 10, and 11) . In this case, if the control information 322 indicates more than four SRS codepoints, then the SRS request field 344 may not directly indicate an SRS codepoint of the control information 322. For example, if the first number of bits of the SRS request field 344 corresponds to two, and the second number of bits of each value of the plurality of values 324 corresponds to three, then the SRS request field 344 may indicate one of the

values

00, 01, 10, or 11, and the plurality of values 324 may include the values 000, 001, 010, 011, 100, 101, 110, and 111.

In implementations where the second number is greater than the first number, the base station 105 may transmit a command 312 indicating a subset 316 of the plurality of values 324. The UE 115 may select a particular value from among the plurality of values 324 (such as the value 326) based on the command 312. To illustrate, if the SRS request field 344 includes two bits and if each value of the plurality of values 324 includes three bits, the subset 316 may identify four values of the plurality of values 324 that are eligible to be selected using the two bits of the SRS request field 344. In this example, the command 312 may specify that the remaining four values of the plurality of values 324 are ineligible to be selected using the two bits of the SRS request field 344. In some examples, the command 312 includes or corresponds to a MAC-CE, such as the MAC-CE 302 or another MAC-CE that is distinct from the MAC-CE 302. In some examples, the command 312 includes a bitmap 314 indicating the subset 316.

To further illustrate, FIG. 5 depicts examples of the bitmap 314 and a mapping process 500 based on the bitmap 314. In FIG. 5, each rectangular region of the bitmap 314 may represent a corresponding value of the plurality of values 324. In this case, the plurality of values 324 may include sixteen values (and the second number of bits used to represent each value may correspond to four) . If the first number of bits of the SRS request field 344 corresponds to two, then the SRS request field 344 may not directly indicate a value of the plurality of values 324.

To enable the UE 115 to determine a value of the plurality values 324 based on the SRS request field 344, the bitmap 314 may identify the subset 316. In FIG. 5, the subset 316 includes

values

316a, 316b, 316c, and 316d (e.g., using one values instead of zero values associated with other regions of the bitmap 314) . In some examples, UE 115 determines the value 326 based on the subset 316 by mapping the subset 316 to values of the SRS request field. In the mapping process 500, the UE 115 may convert values 0010, 0100, 1001, and 1111 to 00, 01, 10, and 11 (e.g., by deleting the two least-significant bits from the values 0010, 0100, 1001, and 1111) . As a result, the command 312 may enable the UE 115 to select, based on a first number of bits of the SRS request field 344, from among values of the plurality of values 324 each having a second number of bits greater than the first number.

In some examples, messages, signals, or information described herein can be received using one or more layers associated with a protocol stack of a wireless communication protocol, such as a 5G NR wireless communication protocol. To illustrate, the UE 115 may receive the control message 340 via a first layer of the protocol stack and may receive one or both of the indication 304 or the command 312 via a second layer of the protocol stack. The first layer may have a first layer order that is less than a second layer order of the second layer. In some examples, the first layer order corresponds to one, and the second layer order corresponds to two. In some examples, the first layer is a physical layer of the protocol stack, and the second layer is a MAC layer of the protocol stack. To further illustrate, the UE 115 may receive the control information 322 via a third layer of the protocol stack. The third layer may have a third layer order that is greater than the second layer order. In some examples, the third layer order corresponds to three. In some examples, the third layer is a RRC layer of the protocol stack.

In some aspects of the disclosure, a set of CCs, such as the set of CCs 334, is selected independently of the SRS request field 344. For example, one or more of the control information 322, the indication 304, or the command 312 may enable the base station 105 and the UE 115 to determine the set of CCs 334 independently of the SRS request field 344. As a result, flexibility may be increased as compared to some conventional systems that determine sets of CCs and SRS resource sets based on an SRS request field (such as compared to conventional systems that “repurpose” the SRS request field to select sets of CCs) .

In some examples, transmission of the SRS 350 is associated with a plurality of applications including antenna switching and at least one other application different than the antenna switching. For example, each set of SRS resources of the plurality of SRS resource sets 328 may be associated with a respective application of multiple applications. An example of an application is antenna switching. In some examples, one or more CC sets of the plurality of sets of CCs 332 are associated with a physical uplink shared channel (PUSCH) , and an application includes PUSCH transmission. To illustrate, one or more SRS resource sets of the plurality of SRS resource sets 328 and one or more CC sets of the plurality of sets of CCs 334 may be used to transmit the SRS 350 for PUSCH communication.

One or more aspects of FIGS. 3-5 may enhance performance in a wireless communication system. To illustrate, the use of one or more higher-layer messages may enable use of an SRS request field 344 of a particular length, such as two bits (and without increasing the length beyond a number of bits specified by a particular wireless communication protocol) , while also increasing flexibility associated with the SRS request field 344. For example, the base station 105 may send the RRC message 320 to the UE 115 including the control information 322. As another example, the base station may send the MAC-CE 302 or the command 312 to the UE 115 to select a particular CC set from among a plurality of CC sets. As a result, flexibility of the SRS request field 344 may be enhanced without increasing DCI overhead (e.g., without increasing a number of bits of the SRS request field 344 beyond the number specified by a particular wireless communication protocol) . In some examples, the enhanced flexibility enables the base station 105 to trigger SRS resource sets for multiple usages, such as for PUSCH transmission (alternatively or in addition to use of SRS resource sets for antenna switching) .

FIG. 6 illustrates an example of a method 600 that may be performed by a UE, such as the UE 115. The method 600 includes receiving control information by a UE, at 602. The control information indicates a plurality of values and a plurality of SRS resource sets. The method 600 further includes receiving, from a base station, a control message including an SRS request field, at 604. The method 600 further includes, based on a value of the plurality of values determined at least in part based on the SRS request field, transmitting an SRS to the base station via a set of component carriers and using one or more SRS resource sets of the plurality of SRS resource sets, at 606. The control information indicates that the value is associated with the one or more SRS resource sets.

FIG. 7 illustrates an example of a method 700 that may be performed by a base station, such as the base station 105. The method 700 includes transmitting, from a base station to a UE, a control message including a SRS request field, at 702. The UE stores control information indicating a plurality of values and a plurality of SRS resource sets. The method 700 further includes, based on a value of the plurality of values determined at least in part based on the SRS request field, receiving an SRS from the UE via a set of component carriers and using one or more SRS resource sets of the plurality of SRS resource sets, at 704. The control information indicates that the value is associated with the one or more SRS resource sets.

FIG. 8 is a block diagram illustrating an example of a UE 115 to perform two-dimensional operations for a non-coherent transmission according to some aspects of the disclosure. The UE 115 may include the processor 280 and the memory 282. The processor 280 may execute instructions 802 stored in the memory 282 to initiate, perform, or control one or more operations described herein. The processor 280 may execute the instructions 802 to transmit and receive signals via wireless radios 801a-r and the antennas 252a-r. The wireless radios 801a-r may include hardware or other components corresponding to one or more features described with reference to FIG. 2, such as the modulator/demodulators 254a-r, the MIMO detector 256, the receive processor 258, the transmit processor 264, the TX MIMO processor 266, one or more other components, or a combination thereof. In some examples, the processor 280 executes SRS resource set and CC mapping instructions 802 to perform one or more operations described herein, such as one or more operations of the method 600.

FIG. 9 is a block diagram illustrating an example of a base station 105 to perform two-dimensional operations for a non-coherent transmission according to some aspects of the disclosure. The base station 105 may include the processor 240 and the memory 242. The processor 240 may execute instructions 902 stored in the memory 242 to initiate, perform, or control one or more operations described herein. The processor 240 may execute the instructions 902 to transmit and receive signals via wireless radios 901a-t and the antennas 234a-t. The wireless radios 901a-t may include hardware or other components corresponding to one or more features described with reference to FIG. 2, such as the modulator/demodulators 232a-t, the MIMO detector 236, the receive processor 238, the transmit processor 220, the TX MIMO processor 230, one or more other components, or a combination thereof. In some examples, the processor 240 executes SRS resource set and CC mapping instructions 902 to perform one or more operations described herein, such as one or more operations of the method 700.

In a first aspect, a method of wireless communication includes receiving control information by a UE. The control information indicates a plurality of values and a plurality of SRS resource sets. The method further includes receiving, from a base station, a control message including an SRS request field. The method further includes, based on a value of the plurality of values determined at least in part based on the SRS request field, transmitting an SRS to the base station via a set of component carriers and using one or more SRS resource sets of the plurality of SRS resource sets. The control information indicates that the value is associated with the one or more SRS resource sets.

In a second aspect alone or in combination with the first aspect, the control information indicates multiple sets of component carriers associated with the value.

In a third aspect alone or in combination with one or more of the first through second aspects, the method further includes receiving an indication selecting the set of component carriers from among the multiple sets of component carriers associated with the value.

In a fourth aspect alone or in combination with one or more of the first through third aspects, the indication is included in a MAC-CE.

In a fifth aspect alone or in combination with one or more of the first through fourth aspects, the UE receives the control message via a first layer of a protocol stack of a wireless communication protocol, and the UE receives the indication via a second layer of the protocol stack, the first layer having a first layer order that is less than a second layer order of the second layer.

In a sixth aspect alone or in combination with one or more of the first through fifth aspects, the first layer is a physical layer of the protocol stack, and the second layer is a MAC layer of the protocol stack.

In a seventh aspect alone or in combination with one or more of the first through sixth aspects, the UE receives the control information via a third layer of the protocol stack, the third layer having a third layer order that is greater than the second layer order.

In an eight aspect alone or in combination with one or more of the first through seventh aspects, the third layer is an RRC layer of the protocol stack.

In a ninth aspect alone or in combination with one or more of the first through eighth aspects, one set of component carriers is associated with the value.

In a tenth aspect alone or in combination with one or more of the first through ninth aspects, the control information is received via an RRC message.

In an eleventh aspect alone or in combination with one or more of the first through tenth aspects, the control message includes DCI that includes the SRS request field.

In a twelfth aspect alone or in combination with one or more of the first through eleventh aspects, the DCI is associated with a format 2_3 specified by a wireless communication protocol and includes a block of a type A specified by the wireless communication protocol, and the block includes the SRS request field.

In a thirteenth aspect alone or in combination with one or more of the first through twelfth aspects, the plurality of values represent a plurality of SRS codepoints, and the value represents a particular SRS codepoint of the plurality of SRS codepoints.

In a fourteenth aspect alone or in combination with one or more of the first through thirteenth aspects, transmission of the SRS is associated with a plurality of applications including antenna switching and at least one other application different than the antenna switching.

In a fifteenth aspect alone or in combination with one or more of the first through fourteenth aspects, the set of component carriers are associated with a PUSCH.

In a sixteenth aspect alone or in combination with one or more of the first through fifteenth aspects, the set of component carriers is selected independently of the SRS request field.

In a seventeenth aspect alone or in combination with one or more of the first through sixteenth aspects, the SRS request field is represented using a particular number of bits, and each value the plurality of values is represented using the particular number of bits.

In an eighteenth aspect alone or in combination with one or more of the first through seventeenth aspects, the SRS request field is represented using a first number bits, and at least one value of the plurality of values is represented using a second number of bits that is greater than the first number.

In a nineteenth aspect alone or in combination with one or more of the first through eighteenth aspects, the method further includes receiving a command indicating a subset of the plurality of values and determining the value based on the subset indicated by the command.

In a twentieth aspect alone or in combination with one or more of the first through nineteenth aspects, determining the value based on the subset includes mapping the subset to values of the SRS request field.

In a twenty-first aspect alone or in combination with one or more of the first through twentieth aspects, the command corresponds to a MAC-CE.

In a twenty-second aspect alone or in combination with one or more of the first through twenty-first aspects, the command includes a bitmap indicating the subset.

In a twenty-third aspect, an apparatus includes a memory and one or more processors coupled to the memory. The one or more processors are configured to receive control information that indicates a plurality of values and a plurality of SRS resource sets. The one or more processors are further configured to receive, from a base station, a control message including an SRS request field. The one or more processors are further configured to transmit, based on a value of the plurality of values determined at least in part based on the SRS request field, an SRS to the base station via a set of component carriers and using one or more SRS resource sets of the plurality of SRS resource sets. The control information indicates that the value is associated with the one or more SRS resource sets.

In a twenty-fourth aspect, an apparatus includes means for receiving control information. The control information indicates a plurality of values and a plurality of SRS resource sets. The apparatus further includes means for receiving, from a base station, a control message including an SRS request field. The apparatus further includes means for transmitting, based on a value of the plurality of values determined at least in part based on the SRS request field, an SRS to the base station via a set of component carriers and using one or more SRS resource sets of the plurality of SRS resource sets. The control information indicates that the value is associated with the one or more SRS resource sets.

In a twenty-fifth aspect, a non-transitory computer-readable medium stores instructions executable by a processor to perform operations. The operations include receiving control information. The control information indicates a plurality of values and a plurality of SRS resource sets. The operations further include receiving, from a base station, a control message including an SRS request field. The operations further include, based on a value of the plurality of values determined at least in part based on the SRS request field, transmitting an SRS to the base station via a set of component carriers and using one or more SRS resource sets of the plurality of SRS resource sets. The control information indicates that the value is associated with the one or more SRS resource sets.

In a twenty-sixth aspect, a method includes transmitting, from a base station to a UE, a control message including a SRS request field. The UE stores control information indicating a plurality of values and a plurality of SRS resource sets. The method further includes, based on a value of the plurality of values determined at least in part based on the SRS request field, receiving an SRS from the UE via a set of component carriers and using one or more SRS resource sets of the plurality of SRS resource sets. The control information indicates that the value is associated with the one or more SRS resource sets.

In a twenty-seventh aspect alone or in combination with one or more of the first through twenty-sixth aspects, the control information indicates multiple sets of component carriers associated with the value.

In a twenty-eighth aspect alone or in combination with one or more of the first through twenty-seventh aspects, the method further includes transmitting an indication selecting the set of component carriers from among the multiple sets of component carriers associated with the value.

In a twenty-ninth aspect alone or in combination with one or more of the first through twenty-eighth aspects, the indication is included in a MAC-CE.

In a thirtieth aspect alone or in combination with one or more of the first through twenty-ninth aspects, the control message is transmitted via a first layer of a protocol stack of a wireless communication protocol, and the indication is transmitted via a second layer of the protocol stack, the first layer having a first layer order that is less than a second layer order of the second layer.

In a thirty-first aspect alone or in combination with one or more of the first through thirtieth aspects, the first layer is a physical layer of the protocol stack, and the second layer is a MAC layer of the protocol stack.

In a thirty-second aspect alone or in combination with one or more of the first through thirty-first aspects, the control information is transmitted via a third layer of the protocol stack, the third layer having a third layer order that is greater than the second layer order.

In a thirty-third aspect alone or in combination with one or more of the first through thirty-second aspects, the third layer is an RRC layer of the protocol stack.

In a thirty-fourth aspect alone or in combination with one or more of the first through thirty-third aspects, one set of component carriers is associated with the value.

In a thirty-fifth aspect alone or in combination with one or more of the first through thirty-fourth aspects, the control information is received via an RRC message.

In a thirty-sixth aspect alone or in combination with one or more of the first through thirty-fifth aspects, the control message includes DCI that includes the SRS request field.

In a thirty-seventh aspect alone or in combination with one or more of the first through thirty-sixth aspects, the DCI is associated with a format 2_3 specified by a wireless communication protocol and includes a block of a type A specified by the wireless communication protocol, and wherein the block includes the SRS request field.

In a thirty-eighth aspect alone or in combination with one or more of the first through thirty-seventh aspects, the plurality of values represent a plurality of SRS codepoints, and wherein the value represents a particular SRS codepoint of the plurality of SRS codepoints.

In a thirty-ninth aspect alone or in combination with one or more of the first through thirty-eighth aspects, transmission of the SRS is associated with a plurality of applications including antenna switching and at least one other application different than the antenna switching.

In a fortieth aspect alone or in combination with one or more of the first through thirty-ninth aspects, the set of component carriers are associated with a PUSCH.

In a forty-first aspect alone or in combination with one or more of the first through fortieth aspects, the set of component carriers is selected independently of the SRS request field.

In a forty-second aspect alone or in combination with one or more of the first through forty-first aspects, the SRS request field is represented using a particular number of bits, and each value the plurality of values is represented using the particular number of bits.

In a forty-third aspect alone or in combination with one or more of the first through forty-second aspects, the SRS request field is represented using a first number bits, and at least one value of the plurality of values is represented using a second number of bits that is greater than the first number.

In a forty-fourth aspect alone or in combination with one or more of the first through forty-third aspects, the method further includes transmitting a command indicating a subset of the plurality of values.

In a forty-fifth aspect alone or in combination with one or more of the first through forty-fourth aspects, determining the value based on the subset includes mapping the subset to values of the SRS request field.

In a forty-sixth aspect alone or in combination with one or more of the first through forty-fifth aspects, the command corresponds to a MAC-CE.

In a forty-seventh aspect alone or in combination with one or more of the first through forty-sixth aspects, the command includes a bitmap indicating the subset.

In a forty-eighth aspect, an apparatus includes a memory and one or more processors coupled to the memory. The one or more processors are configured to transmit, to a UE, a control message including a SRS request field. The UE stores control information indicating a plurality of values and a plurality of SRS resource sets. The one or more processors are further configured to receive, based on a value of the plurality of values determined at least in part based on the SRS request field, an SRS from the UE via a set of component carriers and using one or more SRS resource sets of the plurality of SRS resource sets. The control information indicates that the value is associated with the one or more SRS resource sets.

In a forty-ninth aspect, an apparatus includes means for transmitting, to a UE, a control message including a SRS request field. The UE stores control information indicating a plurality of values and a plurality of SRS resource sets. The apparatus further includes means for receiving, based on a value of the plurality of values determined at least in part based on the SRS request field, an SRS from the UE via a set of component carriers and using one or more SRS resource sets of the plurality of SRS resource sets. The control information indicates that the value is associated with the one or more SRS resource sets.

In a fiftieth aspect, a non-transitory computer-readable medium stores instructions executable by a processor to perform operations. The operations include transmitting, to a UE, a control message including a SRS request field. The UE stores control information indicating a plurality of values and a plurality of SRS resource sets. The operations further include, based on a value of the plurality of values determined at least in part based on the SRS request field, receiving an SRS from the UE via a set of component carriers and using one or more SRS resource sets of the plurality of SRS resource sets. The control information indicates that the value is associated with the one or more SRS resource sets.

Those of skill in the art would understand that information and signals may be represented using any of a variety of different technologies and techniques. For example, data, instructions, commands, information, signals, bits, symbols, and chips that may be referenced throughout the above description may be represented by voltages, currents, electromagnetic waves, magnetic fields or particles, optical fields or particles, or any combination thereof.

The functional blocks and modules described herein (e.g., the functional blocks and modules in FIG. 2) may comprise processors, electronics devices, hardware devices, electronics components, logical circuits, memories, software codes, firmware codes, etc., or any combination thereof. In addition, one or more features described herein may be implemented via specialized processor circuitry, via executable instructions, and/or combinations thereof.

Those of skill would further appreciate that the various illustrative logical blocks, modules, circuits, and operations (e.g., the operations illustrated in FIGS. 6 and 7) described in connection with the disclosure herein may be implemented as electronic hardware, computer software, or combinations of both. To illustrate, various components, blocks, modules, circuits, and operations have been described above generally in terms of their functionality. Whether such functionality is implemented as hardware or software depends upon the particular application and design constraints imposed on the overall system. Skilled artisans may implement the described functionality in varying ways for each particular application, but such implementation decisions should not be interpreted as causing a departure from the scope of the disclosure. Skilled artisans will also readily recognize that the order or combination of components, methods, or interactions that are described herein are merely examples and that the components, methods, or interactions of the various aspects of the present disclosure may be combined or performed in ways other than those illustrated and described herein.

The various illustrative logical blocks, modules, and circuits described in connection with the disclosure herein may be implemented or performed with a general-purpose processor, a digital signal processor (DSP) , an application specific integrated circuit (ASIC) , a field programmable gate array (FPGA) or other programmable logic device, discrete gate or transistor logic, discrete hardware components, or any combination thereof designed to perform the functions described herein. A general-purpose processor may be a microprocessor, but in the alternative, the processor may be any conventional processor, controller, microcontroller, or state machine. A processor may also be implemented as a combination of computing devices, e.g., a combination of a DSP and a microprocessor, a plurality of microprocessors, one or more microprocessors in conjunction with a DSP core, or any other such configuration.

The operations of a method or process described herein may be embodied directly in hardware, in a software module executed by a processor, or in a combination of the two. A software module may reside in RAM memory, flash memory, ROM memory, EPROM memory, EEPROM memory, registers, hard disk, a removable disk, a CD-ROM, or any other form of storage medium known in the art. An exemplary storage medium is coupled to the processor such that the processor can read information from, and write information to, the storage medium. In the alternative, the storage medium may be integral to the processor. The processor and the storage medium may reside in an ASIC. The ASIC may reside in a user terminal. In the alternative, the processor and the storage medium may reside as discrete components in a user terminal.

In one or more exemplary designs, the functions described may be implemented in hardware, software, firmware, or any combination thereof. If implemented in software, the functions may be stored on or transmitted over as one or more instructions or code on a computer-readable medium. Computer-readable media includes both computer storage media and communication media including any medium that facilitates transfer of a computer program from one place to another. Computer-readable storage media may be any available media that can be accessed by a general purpose or special purpose computer. By way of example, and not limitation, such computer-readable media can comprise RAM, ROM, EEPROM, CD-ROM or other optical disk storage, magnetic disk storage or other magnetic storage devices, or any other medium that can be used to carry or store desired program code means in the form of instructions or data structures and that can be accessed by a general-purpose or special-purpose computer, or a general-purpose or special-purpose processor. Also, a connection may be properly termed a computer-readable medium. For example, if the software is transmitted from a website, server, or other remote source using a coaxial cable, fiber optic cable, twisted pair, or digital subscriber line (DSL) , then the coaxial cable, fiber optic cable, twisted pair, or DSL, are included in the definition of medium. Disk and disc, as used herein, includes compact disc (CD) , laser disc, optical disc, digital versatile disc (DVD) , hard disk, solid state disk, and blu-ray disc where disks usually reproduce data magnetically, while discs reproduce data optically with lasers. Combinations of the above should also be included within the scope of computer-readable media.

As used herein, including in the claims, the term “and/or, ” when used in a list of two or more items, means that any one of the listed items can be employed by itself, or any combination of two or more of the listed items can be employed. For example, if a composition is described as containing components A, B, and/or C, the composition can contain A alone; B alone; C alone; A and B in combination; A and C in combination; B and C in combination; or A, B, and C in combination. Also, as used herein, including in the claims, “or” as used in a list of items prefaced by “at least one of” indicates a disjunctive list such that, for example, a list of “at least one of A, B, or C” means A or B or C or AB or AC or BC or ABC (i.e., A and B and C) or any of these in any combination thereof.

The previous description of the disclosure is provided to enable any person skilled in the art to make or use the disclosure. Various modifications to the disclosure will be readily apparent to those skilled in the art, and the generic principles defined herein may be applied to other variations without departing from the spirit or scope of the disclosure. Thus, the disclosure is not intended to be limited to the examples and designs described herein but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

A method of wireless communication, comprising:

receiving control information by a user equipment (UE) , wherein the control information indicates a plurality of values and a plurality of sounding reference signal (SRS) resource sets;

receiving, from a base station, a control message including an SRS request field; and

based on a value of the plurality of values determined at least in part based on the SRS request field, transmitting an SRS to the base station via a set of component carriers and using one or more SRS resource sets of the plurality of SRS resource sets, wherein the control information indicates that the value is associated with the one or more SRS resource sets.
The method of claim 1, wherein the control information indicates multiple sets of component carriers associated with the value.
The method of any of claims 1-2, further comprising receiving an indication selecting the set of component carriers from among the multiple sets of component carriers associated with the value.
The method of any of claims 1-3, wherein the indication is included in a medium access control (MAC) control element (MAC-CE) .
The method of any of claims 1-4, wherein the UE receives the control message via a first layer of a protocol stack of a wireless communication protocol, and wherein the UE receives the indication via a second layer of the protocol stack, the first layer having a first layer order that is less than a second layer order of the second layer.
The method of any of claims 1-5, wherein the first layer is a physical layer of the protocol stack, and wherein the second layer is a MAC layer of the protocol stack.
The method of any of claims 1-6, wherein the UE receives the control information via a third layer of the protocol stack, the third layer having a third layer order that is greater than the second layer order.
The method of any of claims 1-7, wherein the third layer is a radio resource control (RRC) layer of the protocol stack.
The method of any of claims 1-8, wherein one set of component carriers is associated with the value.
The method of any of claims 1-9, wherein the control information is received via a radio resource control (RRC) message.
The method of any of claims 1-10, wherein the control message includes downlink control information (DCI) that includes the SRS request field.
The method of any of claims 1-11, wherein the DCI is associated with a format 2_3 specified by a wireless communication protocol and includes a block of a type A specified by the wireless communication protocol, and wherein the block includes the SRS request field.
The method of any of claims 1-12, wherein the plurality of values represent a plurality of SRS codepoints, and wherein the value represents a particular SRS codepoint of the plurality of SRS codepoints.
The method of any of claims 1-13, wherein transmission of the SRS is associated with a plurality of applications including antenna switching and at least one other application different than the antenna switching.
The method of any of claims 1-14, wherein the set of component carriers are associated with a physical uplink shared channel (PUSCH) .
The method of any of claims 1-15, wherein the set of component carriers is selected independently of the SRS request field.
The method of any of claims 1-16, wherein the SRS request field is represented using a particular number of bits, and wherein each value the plurality of values is represented using the particular number of bits.
The method of any of claims 1-17, wherein the SRS request field is represented using a first number bits, and wherein at least one value of the plurality of values is represented using a second number of bits that is greater than the first number.
The method of any of claims 1-18, further comprising:

receiving a command indicating a subset of the plurality of values; and

determining the value based on the subset indicated by the command.
The method of any of claims 1-19, wherein determining the value based on the subset includes mapping the subset to values of the SRS request field.
The method of any of claims 1-20, wherein the command corresponds to a medium access control (MAC) control element (MAC-CE) .
The method of any of claims 1-21, wherein the command includes a bitmap indicating the subset.
An apparatus comprising:

a memory; and

one or more processors coupled to the memory and configured to:

receive control information, wherein the control information indicates a plurality of values and a plurality of sounding reference signal (SRS) resource sets;

receive, from a base station, a control message including an SRS request field; and

based on a value of the plurality of values determined at least in part based on the SRS request field, transmit an SRS to the base station via a set of component carriers and using one or more SRS resource sets of the plurality of SRS resource sets, wherein the control information indicates that the value is associated with the one or more SRS resource sets.
An apparatus comprising:

means for receiving control information, wherein the control information indicates a plurality of values and a plurality of sounding reference signal (SRS) resource sets;

means for receiving, from a base station, a control message including an SRS request field; and

means for transmitting, based on a value of the plurality of values determined at least in part based on the SRS request field, an SRS to the base station via a set of component carriers and using one or more SRS resource sets of the plurality of SRS resource sets, wherein the control information indicates that the value is associated with the one or more SRS resource sets.
A non-transitory computer-readable medium storing instructions executable by a processor to perform operations, the operations comprising:

receiving control information, wherein the control information indicates a plurality of values and a plurality of sounding reference signal (SRS) resource sets;

receiving, from a base station, a control message including an SRS request field; and

based on a value of the plurality of values determined at least in part based on the SRS request field, transmitting an SRS to the base station via a set of component carriers and using one or more SRS resource sets of the plurality of SRS resource sets, wherein the control information indicates that the value is associated with the one or more SRS resource sets.
A method of wireless communication, comprising:

transmitting, from a base station to a user equipment (UE) , a control message including a sounding reference signal (SRS) request field, wherein the UE stores control information indicating a plurality of values and a plurality of sounding reference signal (SRS) resource sets; and

based on a value of the plurality of values determined at least in part based on the SRS request field, receiving an SRS from the UE via a set of component carriers and using one or more SRS resource sets of the plurality of SRS resource sets, wherein the control information indicates that the value is associated with the one or more SRS resource sets.
The method of claim 26, wherein the control information indicates multiple sets of component carriers associated with the value.
The method of any of claims 26-27, further comprising transmitting an indication selecting the set of component carriers from among the multiple sets of component carriers associated with the value.
The method of any of claims 26-28, wherein the indication is included in a medium access control (MAC) control element (MAC-CE) .
The method of any of claims 26-28, wherein the control message is transmitted via a first layer of a protocol stack of a wireless communication protocol, and wherein the indication is transmitted via a second layer of the protocol stack, the first layer having a first layer order that is less than a second layer order of the second layer.
The method of any of claims 26-30, wherein the first layer is a physical layer of the protocol stack, and wherein the second layer is a MAC layer of the protocol stack.
The method of any of claims 26-31, wherein the control information is transmitted via a third layer of the protocol stack, the third layer having a third layer order that is greater than the second layer order.
The method of any of claims 26-32, wherein the third layer is a radio resource control (RRC) layer of the protocol stack.
The method of any of claims 26-33, wherein one set of component carriers is associated with the value.
The method of any of claims 26-34, wherein the control information is received via a radio resource control (RRC) message.
The method of any of claims 26-35, wherein the control message includes downlink control information (DCI) that includes the SRS request field.
The method of any of claims 26-36, wherein the DCI is associated with a format 2_3 specified by a wireless communication protocol and includes a block of a type A specified by the wireless communication protocol, and wherein the block includes the SRS request field.
The method of any of claims 26-37, wherein the plurality of values represent a plurality of SRS codepoints, and wherein the value represents a particular SRS codepoint of the plurality of SRS codepoints.
The method of any of claims 26-38, wherein transmission of the SRS is associated with a plurality of applications including antenna switching and at least one other application different than the antenna switching.
The method of any of claims 26-39, wherein the set of component carriers are associated with a physical uplink shared channel (PUSCH) .
The method of any of claims 26-40, wherein the set of component carriers is selected independently of the SRS request field.
The method of any of claims 26-41, wherein the SRS request field is represented using a particular number of bits, and wherein each value the plurality of values is represented using the particular number of bits.
The method of any of claims 26-42, wherein the SRS request field is represented using a first number bits, and wherein at least one value of the plurality of values is represented using a second number of bits that is greater than the first number.
The method of any of claims 26-43, further comprising transmitting a command indicating a subset of the plurality of values.
The method of any of claims 26-44, wherein determining the value based on the subset includes mapping the subset to values of the SRS request field.
The method of any of claims 26-45, wherein the command corresponds to a medium access control (MAC) control element (MAC-CE) .
The method of any of claims 26-46, wherein the command includes a bitmap indicating the subset.
An apparatus comprising:

a memory; and

one or more processors coupled to the memory and configured to:

transmit, to a user equipment (UE) , a control message including a sounding reference signal (SRS) request field, wherein the UE stores control information indicating a plurality of values and a plurality of sounding reference signal (SRS) resource sets; and

based on a value of the plurality of values determined at least in part based on the SRS request field, receive an SRS from the UE via a set of component carriers and using one or more SRS resource sets of the plurality of SRS resource sets, wherein the control information indicates that the value is associated with the one or more SRS resource sets.
An apparatus comprising:

means for transmitting, to a user equipment (UE) , a control message including a sounding reference signal (SRS) request field, wherein the UE stores control information indicating a plurality of values and a plurality of sounding reference signal (SRS) resource sets; and

means for receiving, based on a value of the plurality of values determined at least in part based on the SRS request field, an SRS from the UE via a set of component carriers and using one or more SRS resource sets of the plurality of SRS resource sets, wherein the control information indicates that the value is associated with the one or more SRS resource sets.
A non-transitory computer-readable medium storing instructions executable by a processor to perform operations, the operations comprising:

transmitting, to a user equipment (UE) , a control message including a sounding reference signal (SRS) request field, wherein the UE stores control information indicating a plurality of values and a plurality of sounding reference signal (SRS) resource sets; and

based on a value of the plurality of values determined at least in part based on the SRS request field, receiving an SRS from the UE via a set of component carriers and using one or more SRS resource sets of the plurality of SRS resource sets, wherein the control information indicates that the value is associated with the one or more SRS resource sets.