WO2021155508A1

WO2021155508A1 - Sounding reference signal usage enhancements

Info

Publication number: WO2021155508A1
Application number: PCT/CN2020/074334
Authority: WO
Inventors: Muhammad Sayed Khairy Abdelghaffar; Alexandros MANOLAKOS; Yu Zhang
Original assignee: Qualcomm Incorporated
Priority date: 2020-02-05
Filing date: 2020-02-05
Publication date: 2021-08-12

Abstract

Methods, systems, and devices for wireless communications are described. A UE may receive a configuration of a reference signal resource set (e.g., a sounding reference signal (SRS) resource set) associated with an antenna switching usage type. The UE may receive a reference signal resource indicator (e.g., an SRS resource indicator (SRI)) associated with a codebook-based uplink transmission. The UE may select a resource of the reference signal resource set for transmitting a reference signal (e.g., an SRS) based on receiving the reference signal resource indicator. The UE may transmit the reference signal over the resource of the reference signal resource set. In some cases, the UE may transmit a codebook-based uplink transmission based on transmitting the reference signal over the resource.

Description

SOUNDING REFERENCE SIGNAL USAGE ENHANCEMENTS

FIELD OF TECHNOLOGY

The following relates generally to wireless communications and more specifically to sounding reference signal usage enhancements.

BACKGROUND

Wireless communications systems are widely deployed to provide various types of communication content such as voice, video, packet data, messaging, broadcast, and so on. These systems may be capable of supporting communication with multiple users by sharing the available system resources (e.g., time, frequency, and power) . Examples of such multiple-access systems include fourth generation (4G) systems such as Long Term Evolution (LTE) systems, LTE-Advanced (LTE-A) systems, or LTE-A Pro systems, and fifth generation (5G) systems which may be referred to as New Radio (NR) systems. These systems may employ technologies such as code division multiple access (CDMA) , time division multiple access (TDMA) , frequency division multiple access (FDMA) , orthogonal frequency division multiple access (OFDMA) , or discrete Fourier transform spread orthogonal frequency division multiplexing (DFT-S-OFDM) . A wireless multiple-access communications system may include one or more base stations or one or more network access nodes, each simultaneously supporting communication for multiple communication devices, which may be otherwise known as user equipment (UE) .

In some cases, a UE may transmit a sounding reference signal (SRS) to a base station. The base station, upon receiving the SRS, may perform uplink channel estimation. The UE may receive different configurations that use different resources for transmitting SRS associated with different usage types. For instance, a firsts SRS may be configured over a first set of resources for performing antenna switching, which may be used in support of downlink beamforming by exploiting channel reciprocity. A second SRS may be configured over a second set of resources for according to a codebook usage type, which may be used for determining rank and a precoder matrix for uplink transmissions.

SUMMARY

The described techniques relate to improved methods, systems, devices, and apparatuses that support sounding reference signal (SRS) usage enhancements. Generally, the described techniques provide for a user equipment (UE) to reduce configuration overhead and resources associated with performing SRS transmissions. In one example, a UE may receive a configuration of a reference signal resource set (e.g., an SRS resource set) associated with an antenna switching usage type. The UE may receive a reference signal resource indicator (e.g., an SRS resource indicator (SRI) ) associated with a codebook-based uplink transmission. The UE may select a resource of the reference signal resource set for transmitting a reference signal (e.g., an SRS) based on receiving the reference signal resource indicator. The UE may transmit the reference signal over the resource of the reference signal resource set. In some cases, the UE may transmit a codebook-based uplink transmission based on transmitting the reference signal over the resource.

A method for wireless communication is described. The method may include receiving a configuration of a reference signal resource set, the reference signal resource set associated with an antenna switching usage type, receiving a reference signal resource indicator associated with a codebook-based uplink transmission, selecting a resource of the reference signal resource set for transmitting a reference signal based on receiving the reference signal resource indicator, and transmitting the reference signal over the resource of the reference signal resource set.

An apparatus for wireless communication is described. The apparatus may include a processor, memory in electronic communication with the processor, and instructions stored in the memory. The instructions may be executable by the processor to cause the apparatus to receive a configuration of a reference signal resource set, the reference signal resource set associated with an antenna switching usage type, receive a reference signal resource indicator associated with a codebook-based uplink transmission, select a resource of the reference signal resource set for transmitting a reference signal based on receiving the reference signal resource indicator, and transmit the reference signal over the resource of the reference signal resource set.

Another apparatus for wireless communication is described. The apparatus may include means for receiving a configuration of a reference signal resource set, the reference signal resource set associated with an antenna switching usage type, means for receiving a reference signal resource indicator associated with a codebook-based uplink transmission, means for selecting a resource of the reference signal resource set for transmitting a reference signal based on receiving the reference signal resource indicator, and means for transmitting the reference signal over the resource of the reference signal resource set.

A non-transitory computer-readable medium storing code for wireless communication is described. The code may include instructions executable by a processor to receive a configuration of a reference signal resource set, the reference signal resource set associated with an antenna switching usage type, receive a reference signal resource indicator associated with a codebook-based uplink transmission, select a resource of the reference signal resource set for transmitting a reference signal based on receiving the reference signal resource indicator, and transmit the reference signal over the resource of the reference signal resource set.

Some examples of the method, apparatuses, and non-transitory computer-readable medium described herein may further include operations, features, means, or instructions for transmitting the codebook-based uplink transmission based on transmitting the reference signal over the resource.

In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, the reference signal resource set includes at least a second resource for transmitting the reference signal, and where selecting the resource of the reference signal resource set includes selecting between the resource and the at least the second resource.

In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, the configuration includes a second reference signal resource set associated with the antenna switching usage type, where the second reference signal resource set includes a second resource for transmitting the reference signal, and where selecting the resource of the reference signal resource set includes selecting between the resource of the reference signal resource set and the second resource of the second reference signal resource set.

In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, the resource over which the reference signal may be transmitted may include operations, features, means, or instructions for transmitting a second reference signal over a second instance of the resource of the reference signal resource set, and receiving a downlink transmission based on transmitting the second reference signal over the second instance of the resource of the reference signal resource set.

In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, one or more ports associated with the second instance of the resource includes one or more ports associated with the second instance of the resource.

In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, selecting the resource may include operations, features, means, or instructions for selecting the resource among a subset of resources of the reference signal resource set, where the subset includes two or more lowest indexed resources of the reference signal resource set, and where the reference signal resource set includes a second resource excluded from the subset.

In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, receiving the reference signal resource indicator may include operations, features, means, or instructions for receiving control signaling indicating the reference signal resource indicator.

In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, the control signaling includes downlink control information.

In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, the reference signal may be a sounding reference signal.

A method for wireless communications is described. The method may include transmitting a configuration of a reference signal resource set, the reference signal resource set associated with an antenna switching usage type, identifying a resource of the reference signal resource set for receiving a reference signal associated with a codebook-based uplink transmission, transmitting a reference signal resource indicator based on identifying the resource, and receiving the reference signal over the resource of the reference signal resource set.

An apparatus for wireless communications is described. The apparatus may include a processor, memory in electronic communication with the processor, and instructions stored in the memory. The instructions may be executable by the processor to cause the apparatus to transmit a configuration of a reference signal resource set, the reference signal resource set associated with an antenna switching usage type, identify a resource of the reference signal resource set for receiving a reference signal associated with a codebook-based uplink transmission, transmit a reference signal resource indicator based on identifying the resource, and receive the reference signal over the resource of the reference signal resource set.

Another apparatus for wireless communications is described. The apparatus may include means for transmitting a configuration of a reference signal resource set, the reference signal resource set associated with an antenna switching usage type, means for identifying a resource of the reference signal resource set for receiving a reference signal associated with a codebook-based uplink transmission, means for transmitting a reference signal resource indicator based on identifying the resource, and means for receiving the reference signal over the resource of the reference signal resource set.

A non-transitory computer-readable medium storing code for wireless communications is described. The code may include instructions executable by a processor to transmit a configuration of a reference signal resource set, the reference signal resource set associated with an antenna switching usage type, identify a resource of the reference signal resource set for receiving a reference signal associated with a codebook-based uplink transmission, transmit a reference signal resource indicator based on identifying the resource, and receive the reference signal over the resource of the reference signal resource set.

Some examples of the method, apparatuses, and non-transitory computer-readable medium described herein may further include operations, features, means, or instructions for receiving the codebook-based uplink transmission based on receiving the reference signal over the resource.

In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, the reference signal resource set includes at least a second resource for transmitting the reference signal, and where the resource of the reference signal resource set may be identified among the resource and the at least the second resource.

In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, the configuration includes a second reference signal resource set associated with the antenna switching usage type, where the second reference signal resource set includes a second resource for transmitting the reference signal, and where the resource of the reference signal resource set may be identified among the resource of the reference signal resource set and the second resource of the second reference signal resource set.

In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, the resource over which the reference signal may be received may include operations, features, means, or instructions for receiving a second reference signal over a second instance of the resource of the reference signal resource set, and transmitting a downlink transmission based on transmitting the second reference signal over the second instance of the resource of the reference signal resource set.

In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, identifying the resource may include operations, features, means, or instructions for identifying the resource among a subset of the reference signal resource set, where the subset includes two or more lowest indexed resources of the reference signal resource set, and where the reference signal resource set includes a second resource excluded from the subset.

In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, transmitting the reference signal resource indicator may include operations, features, means, or instructions for transmitting control signaling indicating the reference signal resource indicator.

In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, the reference signal may be a sounding reference signal. )

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 illustrates an example of a wireless communications system that supports sounding reference signal usage enhancements in accordance with aspects of the present disclosure.

FIG. 2 illustrates an example of a wireless communications system that supports sounding reference signal usage enhancements in accordance with aspects of the present disclosure.

FIGs. 3A and 3B illustrate examples of switching configurations that support sounding reference signal usage enhancements in accordance with aspects of the present disclosure.

FIGs. 4A and 4B illustrate examples of switching configurations that support sounding reference signal usage enhancements in accordance with aspects of the present disclosure.

FIG. 5 illustrates an example of a process flow that supports sounding reference signal usage enhancements in accordance with aspects of the present disclosure.

FIGs. 6 and 7 show block diagrams of devices that support sounding reference signal usage enhancements in accordance with aspects of the present disclosure.

FIG. 8 shows a block diagram of a communication manager that supports sounding reference signal usage enhancements in accordance with aspects of the present disclosure.

FIG. 9 shows a diagram of a system including a device that supports sounding reference signal usage enhancements in accordance with aspects of the present disclosure.

FIGs. 10 and 11 show block diagrams of devices that support sounding reference signal usage enhancements in accordance with aspects of the present disclosure.

FIG. 12 shows a block diagram of a communication manager that supports sounding reference signal usage enhancements in accordance with aspects of the present disclosure.

FIG. 13 shows a diagram of a system including a device that supports sounding reference signal usage enhancements in accordance with aspects of the present disclosure.

FIGs. 14 through 17 show flowcharts illustrating methods that support sounding reference signal usage enhancements in accordance with aspects of the present disclosure.

DETAILED DESCRIPTION

In some cases, a user equipment (UE) may be configured with one or more sounding reference signal (SRS) resource sets, where each SRS resource set may contain one or more resources. Each SRS resource set may be associated with a different usage type. For instance, a first SRS resource set may be configured with a codebook usage type, and the UE may use one or more resources of the first SRS resource set to transmit an SRS involved in setting up codebook-based uplink communications. A second SRS resource set may be configured with an antenna switching usage type, and the UE may use one or more resources of the second SRS resource set to transmit an SRS involved in enabling a receiving base station to perform downlink channel estimation using the SRS, which may enable downlink beamforming. Typically, each of these SRS resource sets may map to mutually exclusive resources.

According to various aspects, SRS resource sets associated with different usage types may be merged. For instance, a first SRS resource set associated with a first usage type may have resources that are a subset of resources of a second SRS resource set associated with a second usage type. As such, one or more SRS resource sets may be configured according to a first usage type (e.g., antenna switching) , and SRS may be transmitted over resources of the one or more SRS resource sets for the first usage or for the second usage.

To differentiate between whether an SRS is to be transmitted for a first usage or for a second usage, the UE may receive one or more indicators. For example, the UE may receive an SRS resource indicator (SRI) associated with a codebook-based uplink transmission (e.g., in downlink control information (DCI) signaling or configuration signaling) . If a base station transmits an SRI to the UE and receives a corresponding SRS, the base station may determine that the SRS is associated with a codebook-based uplink transmission (i.e., a codebook SRS) . To activate an SRS transmission used for antenna switching (i.e., an antenna switching SRS) , the base station may send an aperiodic SRS request for an antenna switching SRS, or may configure a periodic SRS for the antenna switching usage type.

Additionally, the base station may use the SRI to indicate which SRS resource set or which resource of an SRS resource set over which to transmit a codebook SRS. For instance, if an SRS resource set for merged usage types has multiple resources, a subset of resources with the lowest resource indexes may be used for codebook SRS transmissions, and SRI may be used to select between the resources of the subset. Alternatively, if an SRS resource set for merged usage types has a single resource, one or more additional SRS resource sets may be configured for the codebook SRS.

Aspects of the disclosure are initially described in the context of wireless communications systems. Additional aspects of the disclosure are described in the context of an additional wireless communications system, switching configurations, and a process flow. Aspects of the disclosure are further illustrated by and described with reference to apparatus diagrams, system diagrams, and flowcharts that relate to sounding reference signal usage enhancements.

FIG. 1 illustrates an example of a wireless communications system 100 that supports sounding reference signal usage enhancements in accordance with aspects of the present disclosure. The wireless communications system 100 may include one or more base stations 105, one or more UEs 115, and a core network 130. In some examples, the wireless communications system 100 may be a Long Term Evolution (LTE) network, an LTE-Advanced (LTE-A) network, an LTE-A Pro network, or a New Radio (NR) network. In some examples, the wireless communications system 100 may support enhanced broadband communications, ultra-reliable (e.g., mission critical) communications, low latency communications, communications with low-cost and low-complexity devices, or any combination thereof.

The base stations 105 may be dispersed throughout a geographic area to form the wireless communications system 100 and may be devices in different forms or having different capabilities. The base stations 105 and the UEs 115 may wirelessly communicate via one or more communication links 125. Each base station 105 may provide a coverage area 110 over which the UEs 115 and the base station 105 may establish one or more communication links 125. The coverage area 110 may be an example of a geographic area over which a base station 105 and a UE 115 may support the communication of signals according to one or more radio access technologies.

The UEs 115 may be dispersed throughout a coverage area 110 of the wireless communications system 100, and each UE 115 may be stationary, or mobile, or both at different times. The UEs 115 may be devices in different forms or having different capabilities. Some example UEs 115 are illustrated in FIG. 1. The UEs 115 described herein may be able to communicate with various types of devices, such as other UEs 115, the base stations 105, or network equipment (e.g., core network nodes, relay devices, integrated access and backhaul (IAB) nodes, or other network equipment) , as shown in FIG. 1.

The base stations 105 may communicate with the core network 130, or with one another, or both. For example, the base stations 105 may interface with the core network 130 through one or more backhaul links 120 (e.g., via an S1, N2, N3, or other interface) . The base stations 105 may communicate with one another over the backhaul links 120 (e.g., via an X2, Xn, or other interface) either directly (e.g., directly between base stations 105) , or indirectly (e.g., via core network 130) , or both. In some examples, the backhaul links 120 may be or include one or more wireless links.

One or more of the base stations 105 described herein may include or may be referred to by a person having ordinary skill in the art as a base transceiver station, a radio base station, an access point, a radio transceiver, a NodeB, an eNodeB (eNB) , a next-generation NodeB or a giga-NodeB (either of which may be referred to as a gNB) , a Home NodeB, a Home eNodeB, or other suitable terminology.

A UE 115 may include or may be referred to as a mobile device, a wireless device, a remote device, a handheld device, or a subscriber device, or some other suitable terminology, where the “device” may also be referred to as a unit, a station, a terminal, or a client, among other examples. A UE 115 may also include or may be referred to as a personal electronic device such as a cellular phone, a personal digital assistant (PDA) , a tablet computer, a laptop computer, or a personal computer. In some examples, a UE 115 may include or be referred to as a wireless local loop (WLL) station, an Internet of Things (IoT) device, an Internet of Everything (IoE) device, or a machine type communications (MTC) device, among other examples, which may be implemented in various objects such as appliances, or vehicles, meters, among other examples.

The UEs 115 described herein may be able to communicate with various types of devices, such as other UEs 115 that may sometimes act as relays as well as the base stations 105 and the network equipment including macro eNBs or gNBs, small cell eNBs or gNBs, or relay base stations, among other examples, as shown in FIG. 1.

The UEs 115 and the base stations 105 may wirelessly communicate with one another via one or more communication links 125 over one or more carriers. The term “carrier” may refer to a set of radio frequency spectrum resources having a defined physical layer structure for supporting the communication links 125. For example, a carrier used for a communication link 125 may include a portion of a radio frequency spectrum band (e.g., a bandwidth part (BWP) ) that is operated according to one or more physical layer channels for a given radio access technology (e.g., LTE, LTE-A, LTE-A Pro, NR) . Each physical layer channel may carry acquisition signaling (e.g., synchronization signals, system information) , control signaling that coordinates operation for the carrier, user data, or other signaling. The wireless communications system 100 may support communication with a UE 115 using carrier aggregation or multi-carrier operation. A UE 115 may be configured with multiple downlink component carriers and one or more uplink component carriers according to a carrier aggregation configuration. Carrier aggregation may be used with both frequency division duplexing (FDD) and time division duplexing (TDD) component carriers.

Signal waveforms transmitted over a carrier may be made up of multiple subcarriers (e.g., using multi-carrier modulation (MCM) techniques such as orthogonal frequency division multiplexing (OFDM) or discrete Fourier transform spread OFDM (DFT-S-OFDM) ) . In a system employing MCM techniques, a resource element may include one symbol period (e.g., a duration of one modulation symbol) and one subcarrier, where the symbol period and subcarrier spacing are inversely related. The number of bits carried by each resource element may depend on the modulation scheme (e.g., the order of the modulation scheme, the coding rate of the modulation scheme, or both) . Thus, the more resource elements that a UE 115 receives and the higher the order of the modulation scheme, the higher the data rate may be for the UE 115. A wireless communications resource may refer to a combination of a radio frequency spectrum resource, a time resource, and a spatial resource (e.g., spatial layers or beams) , and the use of multiple spatial layers may further increase the data rate or data integrity for communications with a UE 115.

The time intervals for the base stations 105 or the UEs 115 may be expressed in multiples of a basic time unit which may, for example, refer to a sampling period of T _s=1/ (Δf _max·N _f) seconds, where Δf _max may represent the maximum supported subcarrier spacing, and N _f may represent the maximum supported discrete Fourier transform (DFT) size. Time intervals of a communications resource may be organized according to radio frames each having a specified duration (e.g., 10 milliseconds (ms) ) . Each radio frame may be identified by a system frame number (SFN) (e.g., ranging from 0 to 1023) .

Each frame may include multiple consecutively numbered subframes or slots, and each subframe or slot may have the same duration. In some examples, a frame may be divided (e.g., in the time domain) into subframes, and each subframe may be further divided into a number of slots. Alternatively, each frame may include a variable number of slots, and the number of slots may depend on subcarrier spacing. Each slot may include a number of symbol periods (e.g., depending on the length of the cyclic prefix prepended to each symbol period) . In some wireless communications systems 100, a slot may further be divided into multiple mini-slots containing one or more symbols. Excluding the cyclic prefix, each symbol period may contain one or more (e.g., N _f) sampling periods. The duration of a symbol period may depend on the subcarrier spacing or frequency band of operation.

A subframe, a slot, a mini-slot, or a symbol may be the smallest scheduling unit (e.g., in the time domain) of the wireless communications system 100 and may be referred to as a transmission time interval (TTI) . In some examples, the TTI duration (e.g., the number of symbol periods in a TTI) may be variable. Additionally or alternatively, the smallest scheduling unit of the wireless communications system 100 may be dynamically selected (e.g., in bursts of shortened TTIs (sTTIs) ) .

Physical channels may be multiplexed on a carrier according to various techniques. A physical control channel and a physical data channel may be multiplexed on a downlink carrier, for example, using one or more of time division multiplexing (TDM) techniques, frequency division multiplexing (FDM) techniques, or hybrid TDM-FDM techniques. A control region (e.g., a control resource set (CORESET) ) for a physical control channel may be defined by a number of symbol periods and may extend across the system bandwidth or a subset of the system bandwidth of the carrier. One or more control regions (e.g., CORESETs) may be configured for a set of the UEs 115. For example, one or more of the UEs 115 may monitor or search control regions for control information according to one or more search space sets, and each search space set may include one or multiple control channel candidates in one or more aggregation levels arranged in a cascaded manner. An aggregation level for a control channel candidate may refer to a number of control channel resources (e.g., control channel elements (CCEs) ) associated with encoded information for a control information format having a given payload size. Search space sets may include common search space sets configured for sending control information to multiple UEs 115 and UE-specific search space sets for sending control information to a specific UE 115.

In some examples, a base station 105 may be movable and therefore provide communication coverage for a moving geographic coverage area 110. In some examples, different geographic coverage areas 110 associated with different technologies may overlap, but the different geographic coverage areas 110 may be supported by the same base station 105. In other examples, the overlapping geographic coverage areas 110 associated with different technologies may be supported by different base stations 105. The wireless communications system 100 may include, for example, a heterogeneous network in which different types of the base stations 105 provide coverage for various geographic coverage areas 110 using the same or different radio access technologies.

The wireless communications system 100 may be configured to support ultra-reliable communications or low-latency communications, or various combinations thereof. For example, the wireless communications system 100 may be configured to support ultra-reliable low-latency communications (URLLC) or mission critical communications. The UEs 115 may be designed to support ultra-reliable, low-latency, or critical functions (e.g., mission critical functions) . Ultra-reliable communications may include private communication or group communication and may be supported by one or more mission critical services such as mission critical push-to-talk (MCPTT) , mission critical video (MCVideo) , or mission critical data (MCData) . Support for mission critical functions may include prioritization of services, and mission critical services may be used for public safety or general commercial applications. The terms ultra-reliable, low-latency, mission critical, and ultra-reliable low-latency may be used interchangeably herein.

In some examples, a UE 115 may also be able to communicate directly with other UEs 115 over a device-to-device (D2D) communication link 135 (e.g., using a peer-to-peer (P2P) or D2D protocol) . One or more UEs 115 utilizing D2D communications may be within the geographic coverage area 110 of a base station 105. Other UEs 115 in such a group may be outside the geographic coverage area 110 of a base station 105 or be otherwise unable to receive transmissions from a base station 105. In some examples, groups of the UEs 115 communicating via D2D communications may utilize a one-to-many (1: M) system in which each UE 115 transmits to every other UE 115 in the group. In some examples, a base station 105 facilitates the scheduling of resources for D2D communications. In other cases, D2D communications are carried out between the UEs 115 without the involvement of a base station 105.

The core network 130 may provide user authentication, access authorization, tracking, Internet Protocol (IP) connectivity, and other access, routing, or mobility functions. The core network 130 may be an evolved packet core (EPC) or 5G core (5GC) , which may include at least one control plane entity that manages access and mobility (e.g., a mobility management entity (MME) , an access and mobility management function (AMF) ) and at least one user plane entity that routes packets or interconnects to external networks (e.g., a serving gateway (S-GW) , a Packet Data Network (PDN) gateway (P-GW) , or a user plane function (UPF) ) . The control plane entity may manage non-access stratum (NAS) functions such as mobility, authentication, and bearer management for the UEs 115 served by the base stations 105 associated with the core network 130. User IP packets may be transferred through the user plane entity, which may provide IP address allocation as well as other functions. The user plane entity may be connected to the network operators IP services 150. The operators IP services 150 may include access to the Internet, Intranet (s) , an IP Multimedia Subsystem (IMS) , or a Packet-Switched Streaming Service.

Some of the network devices, such as a base station 105, may include subcomponents such as an access network entity 140, which may be an example of an access node controller (ANC) . Each access network entity 140 may communicate with the UEs 115 through one or more other access network transmission entities 145, which may be referred to as radio heads, smart radio heads, or transmission/reception points (TRPs) . Each access network transmission entity 145 may include one or more antenna panels. In some configurations, various functions of each access network entity 140 or base station 105 may be distributed across various network devices (e.g., radio heads and ANCs) or consolidated into a single network device (e.g., a base station 105) .

The wireless communications system 100 may operate using one or more frequency bands, typically in the range of 300 megahertz (MHz) to 300 gigahertz (GHz) . Generally, the region from 300 MHz to 3 GHz is known as the ultra-high frequency (UHF) region or decimeter band because the wavelengths range from approximately one decimeter to one meter in length. The UHF waves may be blocked or redirected by buildings and environmental features, but the waves may penetrate structures sufficiently for a macro cell to provide service to the UEs 115 located indoors. The transmission of UHF waves may be associated with smaller antennas and shorter ranges (e.g., less than 100 kilometers) compared to transmission using the smaller frequencies and longer waves of the high frequency (HF) or very high frequency (VHF) portion of the spectrum below 300 MHz.

The wireless communications system 100 may utilize both licensed and unlicensed radio frequency spectrum bands. For example, the wireless communications system 100 may employ License Assisted Access (LAA) , LTE-Unlicensed (LTE-U) radio access technology, or NR technology in an unlicensed band such as the 5 GHz industrial, scientific, and medical (ISM) band. When operating in unlicensed radio frequency spectrum bands, devices such as the base stations 105 and the UEs 115 may employ carrier sensing for collision detection and avoidance. In some examples, operations in unlicensed bands may be based on a carrier aggregation configuration in conjunction with component carriers operating in a licensed band (e.g., LAA) . Operations in unlicensed spectrum may include downlink transmissions, uplink transmissions, P2P transmissions, or D2D transmissions, among other examples.

A base station 105 or a UE 115 may be equipped with multiple antennas, which may be used to employ techniques such as transmit diversity, receive diversity, multiple-input multiple-output (MIMO) communications, or beamforming. The antennas of a base station 105 or a UE 115 may be located within one or more antenna arrays or antenna panels, which may support MIMO operations or transmit or receive beamforming. For example, one or more base station antennas or antenna arrays may be co-located at an antenna assembly, such as an antenna tower. In some examples, antennas or antenna arrays associated with a base station 105 may be located in diverse geographic locations. A base station 105 may have an antenna array with a number of rows and columns of antenna ports that the base station 105 may use to support beamforming of communications with a UE 115. Likewise, a UE 115 may have one or more antenna arrays that may support various MIMO or beamforming operations. Additionally or alternatively, an antenna panel may support radio frequency beamforming for a signal transmitted via an antenna port.

Beamforming, which may also be referred to as spatial filtering, directional transmission, or directional reception, is a signal processing technique that may be used at a transmitting device or a receiving device (e.g., a base station 105, a UE 115) to shape or steer an antenna beam (e.g., a transmit beam, a receive beam) along a spatial path between the transmitting device and the receiving device. Beamforming may be achieved by combining the signals communicated via antenna elements of an antenna array such that some signals propagating at particular orientations with respect to an antenna array experience constructive interference while others experience destructive interference. The adjustment of signals communicated via the antenna elements may include a transmitting device or a receiving device applying amplitude offsets, phase offsets, or both to signals carried via the antenna elements associated with the device. The adjustments associated with each of the antenna elements may be defined by a beamforming weight set associated with a particular orientation (e.g., with respect to the antenna array of the transmitting device or receiving device, or with respect to some other orientation) .

A base station 105 or a UE 115 may use beam sweeping techniques as part of beam forming operations. For example, a base station 105 may use multiple antennas or antenna arrays (e.g., antenna panels) to conduct beamforming operations for directional communications with a UE 115. Some signals (e.g., synchronization signals, reference signals, beam selection signals, or other control signals) may be transmitted by a base station 105 multiple times in different directions. For example, the base station 105 may transmit a signal according to different beamforming weight sets associated with different directions of transmission. Transmissions in different beam directions may be used to identify (e.g., by a transmitting device, such as a base station 105, or by a receiving device, such as a UE 115) a beam direction for later transmission or reception by the base station 105.

Some signals, such as data signals associated with a particular receiving device, may be transmitted by a base station 105 in a single beam direction (e.g., a direction associated with the receiving device, such as a UE 115) . In some examples, the beam direction associated with transmissions along a single beam direction may be determined based on a signal that was transmitted in one or more beam directions. For example, a UE 115 may receive one or more of the signals transmitted by the base station 105 in different directions and may report to the base station 105 an indication of the signal that the UE 115 received with a highest signal quality or an otherwise acceptable signal quality.

In some examples, transmissions by a device (e.g., by a base station 105 or a UE 115) may be performed using multiple beam directions, and the device may use a combination of digital precoding or radio frequency beamforming to generate a combined beam for transmission (e.g., from a base station 105 to a UE 115) . The UE 115 may report feedback that indicates precoding weights for one or more beam directions, and the feedback may correspond to a configured number of beams across a system bandwidth or one or more sub-bands. The base station 105 may transmit a reference signal (e.g., a cell-specific reference signal (CRS) , a channel state information reference signal (CSI-RS) ) , which may be precoded or unprecoded. The UE 115 may provide feedback for beam selection, which may be a precoding matrix indicator (PMI) or codebook-based feedback (e.g., a multi-panel type codebook, a linear combination type codebook, a port selection type codebook) . Although these techniques are described with reference to signals transmitted in one or more directions by a base station 105, a UE 115 may employ similar techniques for transmitting signals multiple times in different directions (e.g., for identifying a beam direction for subsequent transmission or reception by the UE 115) or for transmitting a signal in a single direction (e.g., for transmitting data to a receiving device) .

A receiving device (e.g., a UE 115) may try multiple receive configurations (e.g., directional listening) when receiving various signals from the base station 105, such as synchronization signals, reference signals, beam selection signals, or other control signals. For example, a receiving device may try multiple receive directions by receiving via different antenna subarrays, by processing received signals according to different antenna subarrays, by receiving according to different receive beamforming weight sets (e.g., different directional listening weight sets) applied to signals received at multiple antenna elements of an antenna array, or by processing received signals according to different receive beamforming weight sets applied to signals received at multiple antenna elements of an antenna array, any of which may be referred to as “listening” according to different receive configurations or receive directions. In some examples, a receiving device may use a single receive configuration to receive along a single beam direction (e.g., when receiving a data signal) . The single receive configuration may be aligned in a beam direction determined based on listening according to different receive configuration directions (e.g., a beam direction determined to have a highest signal strength, highest signal-to-noise ratio (SNR) , or otherwise acceptable signal quality based on listening according to multiple beam directions) .

Wireless communications systems are widely deployed to provide various types of communication content such as voice, video, packet data, messaging, broadcast, and so on. These systems may be multiple-access systems capable of supporting communication with multiple users by sharing the available system resources (e.g., time, frequency, and power) . A wireless network, for example a wireless local area network (WLAN) , such as a Wi-Fi (i.e., Institute of Electrical and Electronics Engineers (IEEE) 802.11) network may include an access point (AP) that may communicate with one or more wireless or mobile devices. The AP may be coupled to a network, such as the Internet, and may enable a mobile device to communicate via the network (or communicate with other devices coupled to the access point) . A wireless device may communicate with a network device bi-directionally. For example, in a WLAN, a device may communicate with an associated AP via downlink (e.g., the communication link from the AP to the device) and uplink (e.g., the communication link from the device to the AP) . A wireless personal area network (PAN) , which may include a Bluetooth connection, may provide for short range wireless connections between two or more paired wireless devices. For example, wireless devices such as cellular phones may utilize wireless PAN communications to exchange information such as audio signals with wireless headsets.

In some examples, a UE 115 may receive a configuration of a reference signal resource set (e.g., an SRS resource set) associated with an antenna switching usage type. The UE 115 may receive a reference signal resource indicator (e.g., an SRS resource indicator (SRI) ) associated with a codebook-based uplink transmission. The UE 115 may select a resource of the reference signal resource set for transmitting a reference signal (e.g., an SRS) based on receiving the reference signal resource indicator. The UE 115 may transmit the reference signal over the resource of the reference signal resource set. In some cases, the UE 115 may transmit a codebook-based uplink transmission based on transmitting the reference signal over the resource.

FIG. 2 illustrates an example of a wireless communications system 200 that supports sounding reference signal usage enhancements in accordance with aspects of the present disclosure. In some examples, wireless communications system 200 may implement aspects of wireless communication system 100. For instance, base station 105-a may be an example of a base station 105 as described with reference to FIG. 1 and UE 115-a may be an example of a UE 115 as described with reference to FIG. 1.

In some cases, base station 105-a may configure UE 115-a with one or more sounding reference signal (SRS) resource sets. For instance, base station 105-a may transmit a configuration 205 to UE 115-a indicating the one or more SRS resource sets. Base station 105-a may transmit the configuration 205 via RRC or DCI, and may transmit indicators for transmission of aperiodic SRS or periodic (e.g., semi-persistent) SRS using configuration 205 via RRC or DCI. Base station 105-a may configure UE 115-a with multiple resources, which may be grouped into SRS resource sets depending on the use case or usage type (e.g., antenna switching, codebook-based, non-codebook based, beam management) .

Each SRS resource set may contain a set of SRS resources over which UE 115-a may transmit an SRS. UE 115-a and base station 105-a may support SRS resources that span 1, 2, or 4 adjacent symbols with up to a predefined number of ports (e.g., 4) per SRS resource. Up to a predefined number of SRS resource sets (e.g., 2) may be configured for SRS sounding with antenna switching. Each port of an SRS resource may be sounded in each symbol. In some cases, UE 115-a may transmit an SRS in the last 6 symbols of a slot (e.g., symbols 8 through 13) and may do so after transmitting a physical uplink shared channel (PUSCH) transmission in that slot. The SRS transmitted over an SRS resource may be a wideband SRS or a subband SRS, where a bandwidth of each SRS may be a multiple of 4 physical resource blocks (PRBs) .

In some cases, UE 115-a may be configured to use (e.g., may be physically present at the UE or enabled) a number of transmit antennas as well as a number of receive antennas. UE 115-a may use up to the number of transmit antennas to transmit signals and may use up to the number of receive antennas to receive signals. In some cases, the number of transmit antennas versus the number of receive antennas may be given by xTyR, where x may be equal to the number of transmit antennas and y may be equal to the number of receive antennas. For instance, 1T1R may correspond to UE 115-a having or being configured to use 1 transmit antenna and 1 receive antenna.

Performing SRS antenna switching may involve UE 115-a transmitting SRS to base station 105-a over the transmit antennas and base station 105-a exploiting channel reciprocity to perform downlink beamforming for a time division duplexed (TDD) channel. For instance, base station 105-a may receive the SRS, may perform uplink channel estimation, and may exploit channel reciprocity to determine a downlink channel estimation from the uplink channel estimation. Base station 105-a may use the downlink channel estimation for downlink beamforming. SRS resource sets whose resources are used for antenna switching may be said to have an antenna switching usage type. Generally, SRS antenna switching may be supported if the number of transmit x≤y for xTyR (e.g., 1T2R, 2T4R, 1T4R, 1T4R/2T4R, or T=R) . The number of SRS resources in an SRS resource set for antenna switching may be given by x/y. For example an antenna switching SRS resource set for a UE configured with 1T4R may have four SRS resources.

For codebook-based transmissions, UE 115-a may be configured with a single SRS resource set (e.g., SRS-ResourceSet) with usage type set to ‘codebook. ’ Base station 105-a may transmit an SRI 210 to indicate an SRS resource within the configured SRS resource set, where the SRI 210 may have one or more bits. The maximum number of configured SRS resources for codebook-based transmission may have a predefined value (e.g., 2) . Performing codebook-based SRS communications may involve UE 115-a transmitting an SRS to base station 105-a to be used for uplink sounding. Based on measurements on the configured SRS, base station 105-a may sound the channel and may determine a suitable rank and precoder matrix. Determining the rank and precoder matrix may enable base station 105-a to perform PUSCH scheduling and/or to perform beamforming to receive a PUSCH transmission. When performing codebook-based SRS communications, UE 115-a may be configured for transmission of at least one multi-port SRS. In some cases, UE 115-a may utilize multiple SRS beams, where each SRS beam may correspond to a different device antenna panel with different directions, and where each panel may include a set of antenna elements corresponding to antenna ports of each multi-port SRS. SRS resource sets whose resources are used for codebook-based SRS communications may be said to have a codebook usage type.

Typically, each SRS resource set may map to mutually exclusive resources. For instance, SRS resource sets associated with an antenna switching usage type (e.g., configured with usage type set to antenna switching, referred to as antenna switching SRS resource sets) may have resources that differ from SRS resource sets with a codebook usage type (e.g., configured with usage type set to codebook, referred to as codebook SRS resource sets) . According to various aspects, codebook SRS resource sets may be merged with antenna switching SRS resource sets. Merging may involve setting a codebook SRS resource set to be a virtual set that maps to an antenna switching SRS resource set. In such cases, the virtual set may have resources that are a subset of the antenna switching SRS resource set. Merging the resource sets may decrease a number of configurations for SRS or a total number of resources used for transmitting SRSs, which may enable base station 105-a to more flexibly schedule resources for other types of transmissions or transmissions from other UEs.

Base station 105-a may transmit an SRI 210 to differentiate between whether an SRS 215 received over resources that the virtual set maps to is associated a codebook SRS 215 (e.g., an SRS 215 used for codebook-based uplink communications) or an antenna switching SRS 215 (e.g , an SRS 215 used for antenna switching) . If base station 105-a transmits an SRI 210 to UE 115-a and receives a corresponding SRS 215, base station 105-a may determine that the SRS 215 is a codebook SRS 215 If base station 105-a does not transmit an SRI 210 to UE 115-a and receives an SRS 215, base station 105-a may determine that the SRS 215 is an antenna switching SRS 215. Additionally or alternatively, the base station 105-a may send an explicit indicator for transmission of an SRS 215 for antenna switching (e.g., periodic or aperiodic) .

Additionally, base station 105-a may use the SRI 210 to indicate which SRS resource set or which resource of an SRS resource set over which to transmit a codebook SRS 215. In one example, if x=y for xTyR, UE 115-a may use the SRI 210 to select between one of multiple antenna switching SRS resource sets. For instance, for 1T1R, if UE 115-a receives a one-bit SRI 210, UE 115-a may select between a first antenna switching SRS resource set and a second antenna switching SRS resource set based on a value of the bit. If the bit is a ‘0’ , UE 115-a may transmit a codebook SRS 215 over a resource of the first antenna switching SRS resource set (e.g., which may have one SRS resource) and if the bit is a ‘1’ , UE 115-a may transmit a codebook SRS 215 over a resource of the second antenna switching SRS resource set (e.g., which may also have one SRS resource) . Additional bits may be used to select between more than two SRS resources. More details about this method may be described with reference to FIGs. 3A and 3B.

Alternatively, if x<y for xTyR, UE 115-a may use the SRI 210 to select between resources within an antenna switching SRS resource set. For instance, for 1T2R, if UE 115-a receives a one-bit SRI 210, UE 115-a may select between a first SRS resource of the antenna switching SRS resource set and a second SRS resource of the antenna switching SRS resource set based on a value of the bit. If the bit is a ‘0’ , UE 115-a may transmit a codebook SRS 215 over the first SRS resource and if the bit is a ‘1’ , UE 115-a may transmit a codebook SRS 215 over the second SRS resource. Additional bits may be used to select between more than two SRS resources. More details about this method may be described with reference to FIGs. 4A and 4B.

By using the SRI 210 to indicate which SRS resource set or resource of an SRS resource set over which to transmit an SRS associated with the first usage type, the base station and the UE may have a greater number of resources over which the SRS associated with the first usage type may be transmitted.

FIGs. 3A and 3B illustrate examples of switching configurations 300-a and 300-b that support sounding reference signal usage enhancements in accordance with aspects of the present disclosure. In some examples, switching configurations 300-a and 300-b may be implemented by aspects of wireless communication system 100. For instance, switching configurations 300-a and 300-b may represent configurations that a UE 115 may switch between when x=y and depending on an SRI received from a base station 105. In the present example, x and y may equal 1.

Switching configurations 300-a and 300-b may include a codebook SRS resource set 305 and two antenna switching SRS resource sets 310 (e.g., 310-a and 310-b) . Each antenna switching SRS resource set 310 may be mapped to a different resource. For instance, SRS resource set 310-a may be mapped to SRS resource 315-a and SRS resource set 310-b may be mapped to SRS resource 315-b.

In switching configuration 300-a, codebook SRS resource set 305 may map to antenna switching SRS resource set 310-a. That is, the UE may receive SRS resource set 310-a and 310-b with usage type set to antenna switching, and the UE may create codebook SRS resource set 305 as a virtual resource set (e.g., not explicitly received from the base station 105) with a first virtual resource mapped to SRS resource 0 315-a of antenna switching SRS resource set 310-a and a second virtual resource mapped to SRS resource 1 315-b of antenna switching SRS resource set 310-b. As such, when in switching configuration 300-a, a UE 115 may transmit a codebook SRS over SRS resource 315-a. In switching configuration 300-b, codebook SRS resource set 305 may map to antenna switching SRS resource 310-b. As such, when in switching configuration 300-b, the UE 115 may transmit the codebook SRS over SRS resource 315-b.

Whether a UE 115 is in switching configuration 300-a or 300-b may depend on whether an SRI 210 received by the UE 115 indicates to use switching configuration 300-a or 300-b. For instance, if the SRI 210 received by the UE 115 includes a bit and the bit is a ‘0’ , the UE 115 may use switching configuration 300-a. If the bit is a ‘1’ , the UE 115 may use switching configuration 300-b. SRI 210 may have more than one bit to indicate additional switching configurations (e.g., in the case where more than two SRS resources are configured) .

Codebook SRS resource set 305 may be a virtual set that maps to an antenna switching SRS set 310. For two or more antenna switching SRS resource sets 310, each with at least one SRS resource, the SRI field in a DCI may be used to indicate which antenna switching SRS resource set 310 the codebook SRS resource set 305 maps to. The methods as described with reference to FIG. 3 may be used for the case where 1T=1R, 2T=2R, and 4T=4R, where the number of SRS ports for each resource is equal to 1, 2, or 4.

FIGs. 4A and 4B illustrate examples of switching configurations 400-a and 400-b that support sounding reference signal usage enhancements in accordance with aspects of the present disclosure. In some examples, switching configurations 400-a and 400-b may be implemented by aspects of wireless communication system 100. For instance, switching configurations 400-a and 400-b may represent configurations that a UE 115 may switch between when x<y and depending on an SRI received from a base station 105. In the present example, x may equal 1 and y may equal 2.

Switching configurations 400-a and 400-b may include a codebook SRS resource set 405 and antenna switching SRS resource set 410. The antenna switching SRS resource set 410 may include two SRS resources 415-a and 415-b. That is, the UE may receive SRS resource set 410 with usage type set to antenna switching, and the UE may create codebook SRS resource set 405 as a virtual resource set (e.g., not explicitly received from the base station 105) with a first virtual resource mapped to SRS resource 0 415-a and a second virtual resource mapped to SRS resource 1 415-b. In switching configuration 400-a, codebook SRS resource set 405 may map to SRS resource 415-a. As such, when in switching configuration 400-a, a UE 115 may transmit a codebook SRS over SRS resource 415-a. In switching configuration 400-b, codebook SRS resource set 405 may map to SRS resource 415-b. As such, when in switching configuration 400-b, the UE 115 may transmit the codebook SRS over SRS resource 415-b.

Whether a UE 115 is in switching configuration 400-a or 400-b may depend on whether an SRI 210 received by the UE 115 indicates to use switching configuration 400-a or 400-b. For instance, if the SRI 210 received by the UE 115 includes a bit and the bit is a ‘0’ , the UE 115 may use switching configuration 400-a. If the bit is a ‘1’ , the UE 115 may use switching configuration 400-b. SRI 210 may have more than one bit to indicate additional switching configurations (e.g., in the case where more than two SRS resources are configured) .

Where x<y, antenna switching SRS resource set 410 may have multiple resources (e.g., equal to y/x) , where each resource has x ports. In some cases, codebook SRS resource set 405 may be a subset of antenna switching SRS resource set 410. As described above, the codebook SRS resource set 405 may not be explicitly configured by a base station 105, and instead is the base station 105 and UE may apply a rule for subsetting (e.g., how codebook SRS resource set 405 maps to the resources of antenna switching SRS resource set 410) .

One example of such a rule is that SRS resources 415 with the smallest indexes or identifiers (IDs) in antenna switching SRS resource set 410 may be used for codebook-based SRS. For instance, if antenna switching SRS resource set 410 contained more than two resources 415 (e.g., SRS resources 415-a, 415-b, and a third SRS resource with a higher valued ID than SRS resource 415-a and 415-b) and the UE 115 received a one-bit SRI 210, the UE 115 may select between the two lowest indexed SRS resources 415 (e.g., SRS resource 415-a and 415-b, but not the third SRS resource 415) . Another example of such a rule involves a base station 105 using the SRI to indicate with which SRS resource 415 a transmit precoder matrix indicator (TPMI) is associated. Based on receiving the indication, the UE 115 may determine among which subset of the SRS resources 415 of antenna switching SRS resource set 410 the SRS resource 415 is to be selected.

FIG. 5 illustrates an example of a process flow 500 that supports sounding reference signal usage enhancements in accordance with aspects of the present disclosure. In some examples, process flow 500 may implement aspects of wireless communication system 100. For instance, UE 115-b may be an example of a UE 115 as described with reference to FIG. 1 and base station 105-b may be an example of a base station 105 as described with reference to FIG. 1.

At 505, base station 105-b may transmit a configuration of a reference signal resource set (e.g., an SRS resource set) , the reference signal resource set associated with an antenna switching usage type. UE 115-b may receive the configuration of the reference signal resource set. In some cases, the reference signal resource set may include a second resource for transmitting a reference signal. The reference signal resource set may also include more than two resources (e.g., a third resource and a fourth resource) . In some cases, the configuration includes a second reference signal resource set associated with the antenna switching usage type, where the second reference signal resource set includes a second resource for transmitting a reference signal.

At 510, base station 105-b may identify a resource of the reference signal resource set for receiving a reference signal (e.g., an SRS) associated with a codebook-based uplink transmission. Base station 105-b may identify the resource among the resource and a second resource of the reference signal resource set for transmitting the reference signal. Alternatively, base station 105-b may identify the resource among the resource of the reference signal resource set and the second resource of the second reference signal resource set.

At 515, base station 105-b may transmit a reference signal resource indicator associated with a codebook-based uplink transmission. In some cases, base station 105-a may transmit the reference signal resource indicator based on identifying the resource. UE 115-b may receive the reference signal resource indicator. In some cases, the reference signal resource indicator may be indicated via control signaling. The control signaling may be or may include DCI.

At 520, UE 115-b may select a resource (e.g., the resource identified at 510) of the reference signal resource set for transmitting a reference signal based on receiving the reference signal resource indicator. In some cases, selecting the resource may include selecting the resource among a subset of resources of the reference signal resource set, where the subset includes two or more lowest indexed resources of the reference signal resource set, and where the reference signal resource set includes a second resource excluded from the subset. If the reference signal resource set includes the second resource, selecting the resource of the reference signal resource set may involve selecting between the resource and the second resource. If the configuration includes the second reference signal resource set, selecting may involve selecting between the resource of the reference signal resource set and the second resource of the second reference signal resource set.

At 525, UE 115-b may transmit the reference signal over the selected resource of the reference signal resource set. Base station 105-b may receive the reference signal.

At 530, UE 115-b may transmit the codebook-based uplink transmission. In some cases, UE 115-b may transmit the codebook-based uplink transmission based on transmitting the reference signal over the resource at 525. For example, the codebook-based uplink transmission may use precoding (e.g., a TPMI) that is the same as the reference signal, or is configured by the base station 105-b based on receiving the reference signal at 525.

At 535, UE 115-b may transmit a second reference signal. In cases where UE 115-b transmits the second reference signal, the reference signal transmitted at 525 may be transmitted over a first instance of the resource and the second reference signal may be transmitted over a second instance of the resource. Base station 105-b may receive the second reference signal.

At 540, base station 105-b may transmit a downlink transmission based on receiving the second reference signal over the second instance of the resource. UE 115-b may receive the downlink transmission.

FIG. 6 shows a block diagram 600 of a device 605 that supports sounding reference signal usage enhancements in accordance with aspects of the present disclosure. The device 605 may be an example of aspects of a UE 115 as described herein. The device 605 may include a receiver 610, a communication manager 615, and a transmitter 620. The device 605 may also include a processor. Each of these components may be in communication with one another (e.g., via one or more buses) .

The receiver 610 may receive information such as packets, user data, or control information associated with various information channels (e.g., control channels, data channels, and information related to sounding reference signal usage enhancements, etc. ) . Information may be passed on to other components of the device 605. The receiver 610 may be an example of aspects of the transceiver 915 described with reference to FIG. 9. The receiver 610 may utilize a single antenna or a set of antennas.

The communication manager 615 may receive a configuration of a reference signal resource set, the reference signal resource set associated with an antenna switching usage type, receive a reference signal resource indicator associated with a codebook-based uplink transmission, select a resource of the reference signal resource set for transmitting a reference signal based on receiving the reference signal resource indicator, and transmit the reference signal over the resource of the reference signal resource set. The communication manager 615 may be an example of aspects of the communication manager 910 described herein.

The communication manager 615, or its sub-components, may be implemented in hardware, code (e.g., software or firmware) executed by a processor, or any combination thereof. If implemented in code executed by a processor, the functions of the communication manager 615, or its sub-components may be executed by a general-purpose processor, a DSP, an application-specific integrated circuit (ASIC) , a FPGA or other programmable logic device, discrete gate or transistor logic, discrete hardware components, or any combination thereof designed to perform the functions described in the present disclosure.

The communication manager 615, or its sub-components, may be physically located at various positions, including being distributed such that portions of functions are implemented at different physical locations by one or more physical components. In some examples, the communication manager 615, or its sub-components, may be a separate and distinct component in accordance with various aspects of the present disclosure. In some examples, the communication manager 615, or its sub-components, may be combined with one or more other hardware components, including but not limited to an input/output (I/O) component, a transceiver, a network server, another computing device, one or more other components described in the present disclosure, or a combination thereof in accordance with various aspects of the present disclosure.

The transmitter 620 may transmit signals generated by other components of the device 605. In some examples, the transmitter 620 may be collocated with a receiver 610 in a transceiver module. For example, the transmitter 620 may be an example of aspects of the transceiver 915 described with reference to FIG. 9. The transmitter 620 may utilize a single antenna or a set of antennas.

FIG. 7 shows a block diagram 700 of a device 705 that supports sounding reference signal usage enhancements in accordance with aspects of the present disclosure. The device 705 may be an example of aspects of a device 605, or a UE 115 as described herein. The device 705 may include a receiver 710, a communication manager 715, and a transmitter 740. The device 705 may also include a processor. Each of these components may be in communication with one another (e.g., via one or more buses) .

The receiver 710 may receive information such as packets, user data, or control information associated with various information channels (e.g., control channels, data channels, and information related to sounding reference signal usage enhancements, etc. ) . Information may be passed on to other components of the device 705. The receiver 710 may be an example of aspects of the transceiver 915 described with reference to FIG. 9. The receiver 710 may utilize a single antenna or a set of antennas.

The communication manager 715 may be an example of aspects of the communication manager 615 as described herein. The communication manager 715 may include a configuration receiver 720, a resource indicator receiver 725, a resource selector 730, and a reference signal transmitter 735. The communication manager 715 may be an example of aspects of the communication manager 910 described herein.

The configuration receiver 720 may receive a configuration of a reference signal resource set, the reference signal resource set associated with an antenna switching usage type.

The resource indicator receiver 725 may receive a reference signal resource indicator associated with a codebook-based uplink transmission.

The resource selector 730 may select a resource of the reference signal resource set for transmitting a reference signal based on receiving the reference signal resource indicator.

The reference signal transmitter 735 may transmit the reference signal over the resource of the reference signal resource set.

The transmitter 740 may transmit signals generated by other components of the device 705. In some examples, the transmitter 740 may be collocated with a receiver 710 in a transceiver module. For example, the transmitter 740 may be an example of aspects of the transceiver 915 described with reference to FIG. 9. The transmitter 740 may utilize a single antenna or a set of antennas.

FIG. 8 shows a block diagram 800 of a communication manager 805 that supports sounding reference signal usage enhancements in accordance with aspects of the present disclosure. The communication manager 805 may be an example of aspects of a communication manager 615, a communication manager 715, or a communication manager 910 described herein. The communication manager 805 may include a configuration receiver 810, a resource indicator receiver 815, a resource selector 820, a reference signal transmitter 825, an uplink transmission transmitter 830, and a downlink transmission receiver 835. Each of these modules may communicate, directly or indirectly, with one another (e.g., via one or more buses) .

The configuration receiver 810 may receive a configuration of a reference signal resource set, the reference signal resource set associated with an antenna switching usage type. In some cases, the reference signal resource set includes at least a second resource for transmitting the reference signal, and where selecting the resource of the reference signal resource set includes selecting between the resource and the at least the second resource. In some cases, the configuration includes a second reference signal resource set associated with the antenna switching usage type, where the second reference signal resource set includes a second resource for transmitting the reference signal, and where selecting the resource of the reference signal resource set includes selecting between the resource of the reference signal resource set and the second resource of the second reference signal resource set.

The resource indicator receiver 815 may receive a reference signal resource indicator associated with a codebook-based uplink transmission. In some examples, the resource indicator receiver 815 may receive control signaling indicating the reference signal resource indicator. In some cases, the control signaling includes downlink control information.

The resource selector 820 may select a resource of the reference signal resource set for transmitting a reference signal based on receiving the reference signal resource indicator. In some examples, selecting the resource among a subset of resources of the reference signal resource set, where the subset includes two or more lowest indexed resources of the reference signal resource set, and where the reference signal resource set includes a second resource excluded from the subset.

The reference signal transmitter 825 may transmit the reference signal over the resource of the reference signal resource set. In some examples, the reference signal transmitter 825 may transmit a second reference signal over a second instance of the resource of the reference signal resource set. In some cases, one or more ports associated with the second instance of the resource includes one or more ports associated with the second instance of the resource.

The uplink transmission transmitter 830 may transmit a codebook-based uplink transmission based on transmitting the reference signal over the resource.

The downlink transmission receiver 835 may receive a downlink transmission based on transmitting the second reference signal over the second instance of the resource of the reference signal resource set.

FIG. 9 shows a diagram of a system 900 including a device 905 that supports sounding reference signal usage enhancements in accordance with aspects of the present disclosure. The device 905 may be an example of or include the components of device 605, device 705, or a UE 115 as described herein. The device 905 may include components for bi-directional voice and data communications including components for transmitting and receiving communications, including a communication manager 910, a transceiver 915, an antenna 920, memory 925, and a processor 935. These components may be in electronic communication via one or more buses (e.g., bus 940) .

The communication manager 910 may receive a configuration of a reference signal resource set, the reference signal resource set associated with an antenna switching usage type, receive a reference signal resource indicator associated with a codebook-based uplink transmission, select a resource of the reference signal resource set for transmitting a reference signal based on receiving the reference signal resource indicator, and transmit the reference signal over the resource of the reference signal resource set.

The transceiver 915 may communicate bi-directionally, via one or more antennas, wired, or wireless links as described above. For example, the transceiver 915 may represent a wireless transceiver and may communicate bi-directionally with another wireless transceiver. The transceiver 915 may also include a modem to modulate the packets and provide the modulated packets to the antennas for transmission, and to demodulate packets received from the antennas.

In some cases, the wireless device may include a single antenna 920. However, in some cases the device may have more than one antenna 920, which may be capable of concurrently transmitting or receiving multiple wireless transmissions.

The memory 925 may include RAM and ROM. The memory 925 may store computer-readable, computer-executable code 930 including instructions that, when executed, cause the processor to perform various functions described herein. In some cases, the memory 925 may contain, among other things, a BIOS which may control basic hardware or software operation such as the interaction with peripheral components or devices.

The code 930 may include instructions to implement aspects of the present disclosure, including instructions to support wireless communications. The code 930 may be stored in a non-transitory computer-readable medium such as system memory or other type of memory. In some cases, the code 930 may not be directly executable by the processor 935 but may cause a computer (e.g., when compiled and executed) to perform functions described herein.

The processor 935 may include an intelligent hardware device, (e.g., a general-purpose processor, a DSP, a CPU, a microcontroller, an ASIC, an FPGA, a programmable logic device, a discrete gate or transistor logic component, a discrete hardware component, or any combination thereof) . In some cases, the processor 935 may be configured to operate a memory array using a memory controller. In other cases, a memory controller may be integrated into the processor 935. The processor 935 may be configured to execute computer-readable instructions stored in a memory (e.g., the memory 925) to cause the device 905 to perform various functions (e.g., functions or tasks supporting sounding reference signal usage enhancements) .

FIG. 10 shows a block diagram 1000 of a device 1005 that supports sounding reference signal usage enhancements in accordance with aspects of the present disclosure. The device 1005 may be an example of aspects of a base station 105 as described herein. The device 1005 may include a receiver 1010, a communication manager 1015, and a transmitter 1020. The device 1005 may also include a processor. Each of these components may be in communication with one another (e.g., via one or more buses) .

The receiver 1010 may receive information such as packets, user data, or control information associated with various information channels (e.g., control channels, data channels, and information related to sounding reference signal usage enhancements, etc. ) . Information may be passed on to other components of the device 1005. The receiver 1010 may be an example of aspects of the transceiver 1320 described with reference to FIG. 13. The receiver 1010 may utilize a single antenna or a set of antennas.

The communication manager 1015 may transmit a configuration of a reference signal resource set, the reference signal resource set associated with an antenna switching usage type, identify a resource of the reference signal resource set for receiving a reference signal associated with a codebook-based uplink transmission, transmit a reference signal resource indicator based on identifying the resource, and receive the reference signal over the resource of the reference signal resource set. The communication manager 1015 may be an example of aspects of the communication manager 1310 described herein.

The communication manager 1015, or its sub-components, may be implemented in hardware, code (e.g., software or firmware) executed by a processor, or any combination thereof. If implemented in code executed by a processor, the functions of the communication manager 1015, or its sub-components may be executed by a general-purpose processor, a DSP, an application-specific integrated circuit (ASIC) , a FPGA or other programmable logic device, discrete gate or transistor logic, discrete hardware components, or any combination thereof designed to perform the functions described in the present disclosure.

The communication manager 1015, or its sub-components, may be physically located at various positions, including being distributed such that portions of functions are implemented at different physical locations by one or more physical components. In some examples, the communication manager 1015, or its sub-components, may be a separate and distinct component in accordance with various aspects of the present disclosure. In some examples, the communication manager 1015, or its sub-components, may be combined with one or more other hardware components, including but not limited to an input/output (I/O) component, a transceiver, a network server, another computing device, one or more other components described in the present disclosure, or a combination thereof in accordance with various aspects of the present disclosure.

The transmitter 1020 may transmit signals generated by other components of the device 1005. In some examples, the transmitter 1020 may be collocated with a receiver 1010 in a transceiver module. For example, the transmitter 1020 may be an example of aspects of the transceiver 1320 described with reference to FIG. 13. The transmitter 1020 may utilize a single antenna or a set of antennas.

FIG. 11 shows a block diagram 1100 of a device 1105 that supports sounding reference signal usage enhancements in accordance with aspects of the present disclosure. The device 1105 may be an example of aspects of a device 1005, or a base station 115 as described herein. The device 1105 may include a receiver 1110, a communication manager 1115, and a transmitter 1140. The device 1105 may also include a processor. Each of these components may be in communication with one another (e.g., via one or more buses) .

The receiver 1110 may receive information such as packets, user data, or control information associated with various information channels (e.g., control channels, data channels, and information related to sounding reference signal usage enhancements, etc. ) . Information may be passed on to other components of the device 1105. The receiver 1110 may be an example of aspects of the transceiver 1320 described with reference to FIG. 13. The receiver 1110 may utilize a single antenna or a set of antennas.

The communication manager 1115 may be an example of aspects of the communication manager 1015 as described herein. The communication manager 1115 may include a configuration transmitter 1120, a resource identifier 1125, a resource indicator transmitter 1130, and a reference signal receiver 1135. The communication manager 1115 may be an example of aspects of the communication manager 1310 described herein.

The configuration transmitter 1120 may transmit a configuration of a reference signal resource set, the reference signal resource set associated with an antenna switching usage type.

The resource identifier 1125 may identify a resource of the reference signal resource set for receiving a reference signal associated with a codebook-based uplink transmission.

The resource indicator transmitter 1130 may transmit a reference signal resource indicator based on identifying the resource.

The reference signal receiver 1135 may receive the reference signal over the resource of the reference signal resource set.

The transmitter 1140 may transmit signals generated by other components of the device 1105. In some examples, the transmitter 1140 may be collocated with a receiver 1110 in a transceiver module. For example, the transmitter 1140 may be an example of aspects of the transceiver 1320 described with reference to FIG. 13. The transmitter 1140 may utilize a single antenna or a set of antennas.

FIG. 12 shows a block diagram 1200 of a communication manager 1205 that supports sounding reference signal usage enhancements in accordance with aspects of the present disclosure. The communication manager 1205 may be an example of aspects of a communication manager 1015, a communication manager 1115, or a communication manager 1310 described herein. The communication manager 1205 may include a configuration transmitter 1210, a resource identifier 1215, a resource indicator transmitter 1220, a reference signal receiver 1225, an uplink transmission receiver 1230, and a downlink transmission transmitter 1235. Each of these modules may communicate, directly or indirectly, with one another (e.g., via one or more buses) .

The configuration transmitter 1210 may transmit a configuration of a reference signal resource set, the reference signal resource set associated with an antenna switching usage type. In some cases, the reference signal resource set includes at least a second resource for transmitting the reference signal, and where the resource of the reference signal resource set is identified among the resource and the at least the second resource. In some cases, the configuration includes a second reference signal resource set associated with the antenna switching usage type, where the second reference signal resource set includes a second resource for transmitting the reference signal, and where the resource of the reference signal resource set is identified among the resource of the reference signal resource set and the second resource of the second reference signal resource set.

The resource identifier 1215 may identify a resource of the reference signal resource set for receiving a reference signal associated with a codebook-based uplink transmission. In some examples, identifying the resource among a subset of the reference signal resource set, where the subset includes two or more lowest indexed resources of the reference signal resource set, and where the reference signal resource set includes a second resource excluded from the subset.

The resource indicator transmitter 1220 may transmit a reference signal resource indicator based on identifying the resource. In some examples, the resource indicator transmitter 1220 may transmit control signaling indicating the reference signal resource indicator. In some cases, the control signaling includes downlink control information.

The reference signal receiver 1225 may receive the reference signal over the resource of the reference signal resource set. In some examples, the reference signal receiver 1225 may receive a second reference signal over a second instance of the resource of the reference signal resource set.

The uplink transmission receiver 1230 may receive a codebook-based uplink transmission based on receiving the reference signal over the resource.

The downlink transmission transmitter 1235 may transmit a downlink transmission based on transmitting the second reference signal over the second instance of the resource of the reference signal resource set.

FIG. 13 shows a diagram of a system 1300 including a device 1305 that supports sounding reference signal usage enhancements in accordance with aspects of the present disclosure. The device 1305 may be an example of or include the components of device 1005, device 1105, or a base station 105 as described herein. The device 1305 may include components for bi-directional voice and data communications including components for transmitting and receiving communications, including a communication manager 1310, a network communications manager 1315, a transceiver 1320, an antenna 1325, memory 1330, a processor 1340, and an inter-station communications manager 1345. These components may be in electronic communication via one or more buses (e.g., bus 1350) .

The communication manager 1310 may transmit a configuration of a reference signal resource set, the reference signal resource set associated with an antenna switching usage type, identify a resource of the reference signal resource set for receiving a reference signal associated with a codebook-based uplink transmission, transmit a reference signal resource indicator based on identifying the resource, and receive the reference signal over the resource of the reference signal resource set.

The network communications manager 1315 may manage communications with the core network (e.g., via one or more wired backhaul links) . For example, the network communications manager 1315 may manage the transfer of data communications for client devices, such as one or more UEs 115.

The transceiver 1320 may communicate bi-directionally, via one or more antennas, wired, or wireless links as described above. For example, the transceiver 1320 may represent a wireless transceiver and may communicate bi-directionally with another wireless transceiver. The transceiver 1320 may also include a modem to modulate the packets and provide the modulated packets to the antennas for transmission, and to demodulate packets received from the antennas.

In some cases, the wireless device may include a single antenna 1325. However, in some cases the device may have more than one antenna 1325, which may be capable of concurrently transmitting or receiving multiple wireless transmissions.

The memory 1330 may include RAM and ROM. The memory 1330 may store computer-readable, computer-executable code 1335 including instructions that, when executed, cause the processor to perform various functions described herein. In some cases, the memory 1330 may contain, among other things, a BIOS which may control basic hardware or software operation such as the interaction with peripheral components or devices.

The code 1335 may include instructions to implement aspects of the present disclosure, including instructions to support wireless communications. The code 1335 may be stored in a non-transitory computer-readable medium such as system memory or other type of memory. In some cases, the code 1335 may not be directly executable by the processor 1340 but may cause a computer (e.g., when compiled and executed) to perform functions described herein.

The processor 1340 may include an intelligent hardware device, (e.g., a general-purpose processor, a DSP, a CPU, a microcontroller, an ASIC, an FPGA, a programmable logic device, a discrete gate or transistor logic component, a discrete hardware component, or any combination thereof) . In some cases, the processor 1340 may be configured to operate a memory array using a memory controller. In other cases, a memory controller may be integrated into the processor 1340. The processor 1340 may be configured to execute computer-readable instructions stored in a memory (e.g., the memory 1330) to cause the device 1305 to perform various functions (e.g., functions or tasks supporting sounding reference signal usage enhancements) .

The inter-station communications manager 1345 may manage communications with other base station 105, and may include a controller or scheduler for controlling communications with UEs 115 in cooperation with other base stations 105. For example, the inter-station communications manager 1345 may coordinate scheduling for transmissions to UEs 115 for various interference mitigation techniques such as beamforming or joint transmission. In some examples, the inter-station communications manager 1345 may provide an X2 interface within an LTE/LTE-A wireless communication network technology to provide communication between base stations 105.

FIG. 14 shows a flowchart illustrating a method 1400 that supports sounding reference signal usage enhancements in accordance with aspects of the present disclosure. The operations of method 1400 may be implemented by a UE 115 or its components as described herein. For example, the operations of method 1400 may be performed by a communication manager as described with reference to FIGs. 6 through 9. In some examples, a UE may execute a set of instructions to control the functional elements of the UE to perform the described functions. Additionally or alternatively, a UE may perform aspects of the described functions using special-purpose hardware.

At 1405, the UE may receive a configuration of a reference signal resource set, the reference signal resource set associated with an antenna switching usage type. Receiving the configuration may involve the UE identifying time-frequency resources over which the configuration is transmitted, demodulating a transmission over those time-frequency resources, and decoding the demodulated transmission to obtain bits indicating the configuration. The operations of 1405 may be performed according to the methods described herein. In some examples, aspects of the operations of 1405 may be performed by a configuration receiver as described with reference to FIGs. 6 through 9.

At 1410, the UE may receive a reference signal resource indicator associated with a codebook-based uplink transmission. The UE may receive the reference signal resource indicator by identifying time-frequency resources over which DCI is to be transmitted, demodulating a transmission over those time-frequency resources, and decoding the demodulated transmission to obtain bits indicating the DCI, where the DCI may contain the reference signal resource indicator. The operations of 1410 may be performed according to the methods described herein. In some examples, aspects of the operations of 1410 may be performed by a resource indicator receiver as described with reference to FIGs. 6 through 9.

At 1415, the UE may select a resource of the reference signal resource set for transmitting a reference signal based on receiving the reference signal resource indicator. Performing the selecting may involve the UE identifying multiple reference signal resource sets associated with the antenna switching usage type and selecting one of them. Additionally or alternatively, performing the selecting may involve the UE identifying resources of a single reference signal resource set and selecting one of the resources. The operations of 1415 may be performed according to the methods described herein. In some examples, aspects of the operations of 1415 may be performed by a resource selector as described with reference to FIGs. 6 through 9.

At 1420, the UE may transmit the reference signal over the resource of the reference signal resource set. Transmitting the reference signal may involve the UE selecting the resource at 1415, modulating the reference signal, and transmitting the modulated reference signal over the resource. The operations of 1420 may be performed according to the methods described herein. In some examples, aspects of the operations of 1420 may be performed by a reference signal transmitter as described with reference to FIGs. 6 through 9.

FIG. 15 shows a flowchart illustrating a method 1500 that supports sounding reference signal usage enhancements in accordance with aspects of the present disclosure. The operations of method 1500 may be implemented by a UE 115 or its components as described herein. For example, the operations of method 1500 may be performed by a communication manager as described with reference to FIGs. 6 through 9. In some examples, a UE may execute a set of instructions to control the functional elements of the UE to perform the described functions. Additionally or alternatively, a UE may perform aspects of the described functions using special-purpose hardware.

At 1505, the UE may receive a configuration of a reference signal resource set, the reference signal resource set associated with an antenna switching usage type. Receiving the configuration may involve the UE identifying time-frequency resources over which the configuration is transmitted, demodulating a transmission over those time-frequency resources, and decoding the demodulated transmission to obtain bits indicating the configuration. The operations of 1505 may be performed according to the methods described herein. In some examples, aspects of the operations of 1505 may be performed by a configuration receiver as described with reference to FIGs. 6 through 9.

At 1510, the UE may receive a reference signal resource indicator associated with a codebook-based uplink transmission. The UE may receive the reference signal resource indicator by identifying time-frequency resources over which DCI is to be transmitted, demodulating a transmission over those time-frequency resources, and decoding the demodulated transmission to obtain bits indicating the DCI, where the DCI may contain the reference signal resource indicator. The operations of 1510 may be performed according to the methods described herein. In some examples, aspects of the operations of 1510 may be performed by a resource indicator receiver as described with reference to FIGs. 6 through 9.

At 1515, the UE may select a resource of the reference signal resource set for transmitting a reference signal based on receiving the reference signal resource indicator. Performing the selecting may involve the UE identifying multiple reference signal resource sets associated with the antenna switching usage type and selecting one of them. Additionally or alternatively, performing the selecting may involve the UE identifying resources of a single reference signal resource set and selecting one of the resources. The operations of 1515 may be performed according to the methods described herein. In some examples, aspects of the operations of 1515 may be performed by a resource selector as described with reference to FIGs. 6 through 9.

At 1520, the UE may transmit the reference signal over the resource of the reference signal resource set. Transmitting the reference signal may involve the UE selecting the resource at 1515, modulating the reference signal, and transmitting the modulated reference signal over the resource. The operations of 1520 may be performed according to the methods described herein. In some examples, aspects of the operations of 1520 may be performed by a reference signal transmitter as described with reference to FIGs. 6 through 9.

At 1525, the UE may transmit the codebook-based uplink transmission based on transmitting the reference signal over the resource. Transmitting the codebook-based uplink transmission may involve the UE identifying time-frequency resources over which the codebook-based uplink transmission is to be transmitted, encoding bits associated with the codebook-based uplink transmission, and modulating the encoded bits over the identified time-frequency resources. The operations of 1525 may be performed according to the methods described herein. In some examples, aspects of the operations of 1525 may be performed by an uplink transmission transmitter as described with reference to FIGs. 6 through 9.

FIG. 16 shows a flowchart illustrating a method 1600 that supports sounding reference signal usage enhancements in accordance with aspects of the present disclosure. The operations of method 1600 may be implemented by a UE 115 or its components as described herein. For example, the operations of method 1600 may be performed by a communication manager as described with reference to FIGs. 6 through 9. In some examples, a UE may execute a set of instructions to control the functional elements of the UE to perform the described functions. Additionally or alternatively, a UE may perform aspects of the described functions using special-purpose hardware.

At 1605, the UE may receive a configuration of a reference signal resource set, the reference signal resource set associated with an antenna switching usage type. Receiving the configuration may involve the UE identifying time-frequency resources over which the configuration is transmitted, demodulating a transmission over those time-frequency resources, and decoding the demodulated transmission to obtain bits indicating the configuration. The operations of 1605 may be performed according to the methods described herein. In some examples, aspects of the operations of 1605 may be performed by a configuration receiver as described with reference to FIGs. 6 through 9.

At 1610, the UE may receive a reference signal resource indicator associated with a codebook-based uplink transmission. The UE may receive the reference signal resource indicator by identifying time-frequency resources over which DCI is to be transmitted, demodulating a transmission over those time-frequency resources, and decoding the demodulated transmission to obtain bits indicating the DCI, where the DCI may contain the reference signal resource indicator. The operations of 1610 may be performed according to the methods described herein. In some examples, aspects of the operations of 1610 may be performed by a resource indicator receiver as described with reference to FIGs. 6 through 9.

At 1615, the UE may select a resource of the reference signal resource set for transmitting a reference signal based on receiving the reference signal resource indicator. Performing the selecting may involve the UE identifying multiple reference signal resource sets associated with the antenna switching usage type and selecting one of them. Additionally or alternatively, performing the selecting may involve the UE identifying resources of a single reference signal resource set and selecting one of the resources. The operations of 1615 may be performed according to the methods described herein. In some examples, aspects of the operations of 1615 may be performed by a resource selector as described with reference to FIGs. 6 through 9.

At 1620, the UE may transmit the reference signal over a first instance of the resource of the reference signal resource set. Transmitting the reference signal may involve the UE selecting the resource at 1615, modulating the reference signal, and transmitting the modulated reference signal over the first instance of the resource. The operations of 1620 may be performed according to the methods described herein. In some examples, aspects of the operations of 1620 may be performed by a reference signal transmitter as described with reference to FIGs. 6 through 9.

At 1625, the UE may transmit a second reference signal over a second instance of the resource of the reference signal resource set. Transmitting the reference signal may involve the UE selecting the resource at 1615, modulating the second reference signal, and transmitting the modulated second reference signal over the second instance of the resource. The operations of 1625 may be performed according to the methods described herein. In some examples, aspects of the operations of 1625 may be performed by a reference signal transmitter as described with reference to FIGs. 6 through 9.

At 1630, the UE may receive a downlink transmission based on transmitting the second reference signal over the second instance of the resource of the reference signal resource set. Receiving the downlink transmission may involve the UE identifying time-frequency resources over which the downlink transmission is transmitted, demodulating a transmission over those time-frequency resources, and decoding the demodulated transmission to obtain bits indicating the downlink transmission. The operations of 1630 may be performed according to the methods described herein. In some examples, aspects of the operations of 1630 may be performed by a downlink transmission receiver as described with reference to FIGs. 6 through 9.

FIG. 17 shows a flowchart illustrating a method 1700 that supports sounding reference signal usage enhancements in accordance with aspects of the present disclosure. The operations of method 1700 may be implemented by a base station 105 or its components as described herein. For example, the operations of method 1700 may be performed by a communication manager as described with reference to FIGs. 10 through 13. In some examples, a base station may execute a set of instructions to control the functional elements of the base station to perform the described functions. Additionally or alternatively, a base station may perform aspects of the described functions using special-purpose hardware.

At 1705, the base station may transmit a configuration of a reference signal resource set, the reference signal resource set associated with an antenna switching usage type. Transmitting the configuration may involve the base station identifying time-frequency resources over which the configuration is to be transmitted, encoding bits associated with the configuration, and modulating the encoded bits over the identified time-frequency resources. The operations of 1705 may be performed according to the methods described herein. In some examples, aspects of the operations of 1705 may be performed by a configuration transmitter as described with reference to FIGs. 10 through 13.

At 1710, the base station may identify a resource of the reference signal resource set for receiving a reference signal associated with a codebook-based uplink transmission. Performing the identifying may involve the base station identifying multiple reference signal resource sets associated with the antenna switching usage type and selecting one of them. Additionally or alternatively, performing the identifying may involve the base station identifying resources of a single reference signal resource set and selecting one of the resources. The operations of 1710 may be performed according to the methods described herein. In some examples, aspects of the operations of 1710 may be performed by a resource identifier as described with reference to FIGs. 10 through 13.

At 1715, the base station may transmit a reference signal resource indicator based on identifying the resource. Transmitting the reference signal resource indicator may involve the base station identifying time-frequency resources over which a DCI containing the reference signal resource indicator is to be transmitted, encoding bits associated with the DCI, and modulating the encoded bits over the identified time-frequency resources. The operations of 1715 may be performed according to the methods described herein. In some examples, aspects of the operations of 1715 may be performed by a resource indicator transmitter as described with reference to FIGs. 10 through 13.

At 1720, the base station may receive the reference signal over the resource of the reference signal resource set. Receiving the reference signal may involve the base station identifying time-frequency resources over which the reference signal is transmitted and demodulating a transmission over those time-frequency resources. The operations of 1720 may be performed according to the methods described herein. In some examples, aspects of the operations of 1720 may be performed by a reference signal receiver as described with reference to FIGs. 10 through 13.

It should be noted that the methods described herein describe possible implementations, and that the operations and the steps may be rearranged or otherwise modified and that other implementations are possible. Further, aspects from two or more of the methods may be combined.

Although aspects of an LTE, LTE-A, LTE-A Pro, or NR system may be described for purposes of example, and LTE, LTE-A, LTE-A Pro, or NR terminology may be used in much of the description, the techniques described herein are applicable beyond LTE, LTE-A, LTE-A Pro, or NR networks. For example, the described techniques may be applicable to various other wireless communications systems such as Ultra Mobile Broadband (UMB) , Institute of Electrical and Electronics Engineers (IEEE) 802.11 (Wi-Fi) , IEEE 802.16 (WiMAX) , IEEE 802.20, Flash-OFDM, as well as other systems and radio technologies not explicitly mentioned herein.

Information and signals described herein 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 description may be represented by voltages, currents, electromagnetic waves, magnetic fields or particles, optical fields or particles, or any combination thereof.

The various illustrative blocks and components described in connection with the disclosure herein may be implemented or performed with a general-purpose processor, a DSP, an ASIC, a CPU, an 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 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, multiple microprocessors, one or more microprocessors in conjunction with a DSP core, or any other such configuration) .

The functions described herein may be implemented in hardware, software executed by a processor, firmware, or any combination thereof. If implemented in software executed by a processor, the functions may be stored on or transmitted over as one or more instructions or code on a computer-readable medium. Other examples and implementations are within the scope of the disclosure and appended claims. For example, due to the nature of software, functions described herein may be implemented using software executed by a processor, hardware, firmware, hardwiring, or combinations of any of these. Features implementing functions may also be physically located at various positions, including being distributed such that portions of functions are implemented at different physical locations.

Computer-readable media includes both non-transitory computer storage media and communication media including any medium that facilitates transfer of a computer program from one place to another. A non-transitory storage medium may be any available medium that may be accessed by a general-purpose or special purpose computer. By way of example, and not limitation, non-transitory computer-readable media may include random-access memory (RAM) , read-only memory (ROM) , electrically erasable programmable ROM (EEPROM) , flash memory, compact disk (CD) ROM or other optical disk storage, magnetic disk storage or other magnetic storage devices, or any other non-transitory medium that may be used to carry or store desired program code means in the form of instructions or data structures and that may be accessed by a general-purpose or special-purpose computer, or a general-purpose or special-purpose processor. Also, any connection is 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, digital subscriber line (DSL) , or wireless technologies such as infrared, radio, and microwave, then the coaxial cable, fiber optic cable, twisted pair, DSL, or wireless technologies such as infrared, radio, and microwave are included in the definition of computer-readable medium. Disk and disc, as used herein, include CD, laser disc, optical disc, digital versatile disc (DVD) , floppy disk and Blu-ray disc where disks usually reproduce data magnetically, while discs reproduce data optically with lasers. Combinations of the above are also included within the scope of computer-readable media.

As used herein, including in the claims, “or” as used in a list of items (e.g., a list of items prefaced by a phrase such as “at least one of” or “one or more of” ) indicates an inclusive 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) . Also, as used herein, the phrase “based on” shall not be construed as a reference to a closed set of conditions. For example, an example step that is described as “based on condition A” may be based on both a condition A and a condition B without departing from the scope of the present disclosure. In other words, as used herein, the phrase “based on” shall be construed in the same manner as the phrase “based at least in part on. ”

In the appended figures, similar components or features may have the same reference label. Further, various components of the same type may be distinguished by following the reference label by a dash and a second label that distinguishes among the similar components. If just the first reference label is used in the specification, the description is applicable to any one of the similar components having the same first reference label irrespective of the second reference label, or other subsequent reference label.

The description set forth herein, in connection with the appended drawings, describes example configurations and does not represent all the examples that may be implemented or that are within the scope of the claims. The term “example” used herein means “serving as an example, instance, or illustration, ” and not “preferred” or “advantageous over other examples. ” The detailed description includes specific details for the purpose of providing an understanding of the described techniques. These techniques, however, may be practiced without these specific details. In some instances, known structures and devices are shown in block diagram form in order to avoid obscuring the concepts of the described examples.

The description herein is provided to enable a person having ordinary skill in the art to make or use the disclosure. Various modifications to the disclosure will be apparent to a person having ordinary skill in the art, and the generic principles defined herein may be applied to other variations without departing from the scope of the disclosure. Thus, the disclosure is not limited to the examples and designs described herein, but is to be accorded the broadest scope consistent with the principles and novel features disclosed herein.

Claims

A method for wireless communication, comprising:

receiving a configuration of a reference signal resource set, the reference signal resource set associated with an antenna switching usage type;

receiving a reference signal resource indicator associated with a codebook-based uplink transmission;

selecting a resource of the reference signal resource set for transmitting a reference signal based at least in part on receiving the reference signal resource indicator; and

transmitting the reference signal over the resource of the reference signal resource set.
The method of claim 1, further comprising:

transmitting the codebook-based uplink transmission based at least in part on transmitting the reference signal over the resource.
The method of claim 2, wherein the reference signal resource set comprises at least a second resource for transmitting the reference signal, and wherein selecting the resource of the reference signal resource set comprises selecting between the resource and the at least the second resource.
The method of claim 2, wherein the configuration comprises a second reference signal resource set associated with the antenna switching usage type, wherein the second reference signal resource set comprises a second resource for transmitting the reference signal, and wherein selecting the resource of the reference signal resource set comprises selecting between the resource of the reference signal resource set and the second resource of the second reference signal resource set.
The method of claim 1, wherein the resource over which the reference signal is transmitted comprises a first instance of the resource, and further comprising:

transmitting a second reference signal over a second instance of the resource of the reference signal resource set; and

receiving a downlink transmission based at least in part on transmitting the second reference signal over the second instance of the resource of the reference signal resource set.
The method of claim 5, wherein one or more ports associated with the second instance of the resource comprises one or more ports associated with the second instance of the resource.
The method of claim 1, wherein selecting the resource comprises:

selecting the resource among a subset of resources of the reference signal resource set, wherein the subset comprises two or more lowest indexed resources of the reference signal resource set, and wherein the reference signal resource set comprises a second resource excluded from the subset.
The method of claim 1, wherein receiving the reference signal resource indicator comprises:

receiving control signaling indicating the reference signal resource indicator.
The method of claim 8, wherein the control signaling comprises downlink control information.
The method of claim 1, wherein the reference signal is a sounding reference signal.
A method for wireless communications, comprising:

transmitting a configuration of a reference signal resource set, the reference signal resource set associated with an antenna switching usage type;

identifying a resource of the reference signal resource set for receiving a reference signal associated with a codebook-based uplink transmission;

transmitting a reference signal resource indicator based at least in part on identifying the resource; and

receiving the reference signal over the resource of the reference signal resource set.
The method of claim 11, further comprising:

receiving the codebook-based uplink transmission based at least in part on receiving the reference signal over the resource.
The method of claim 12, wherein the reference signal resource set comprises at least a second resource for transmitting the reference signal, and wherein the resource of the reference signal resource set is identified among the resource and the at least the second resource.
The method of claim 12, wherein the configuration comprises a second reference signal resource set associated with the antenna switching usage type, wherein the second reference signal resource set comprises a second resource for transmitting the reference signal, and wherein the resource of the reference signal resource set is identified among the resource of the reference signal resource set and the second resource of the second reference signal resource set.
The method of claim 11, wherein the resource over which the reference signal is received comprises a first instance of the resource, and further comprising:

receiving a second reference signal over a second instance of the resource of the reference signal resource set; and

transmitting a downlink transmission based at least in part on transmitting the second reference signal over the second instance of the resource of the reference signal resource set.
The method of claim 11, wherein identifying the resource comprises:

identifying the resource among a subset of the reference signal resource set, wherein the subset comprises two or more lowest indexed resources of the reference signal resource set, and wherein the reference signal resource set comprises a second resource excluded from the subset.
The method of claim 11, wherein transmitting the reference signal resource indicator comprises:

transmitting control signaling indicating the reference signal resource indicator.
The method of claim 17, wherein the control signaling comprises downlink control information.
The method of claim 11, wherein the reference signal is a sounding reference signal.
An apparatus for wireless communication, comprising:

a processor,

memory in electronic communication with the processor, and

instructions stored in the memory and executable by the processor to cause the apparatus to:

receive a configuration of a reference signal resource set, the reference signal resource set associated with an antenna switching usage type;

receive a reference signal resource indicator associated with a codebook-based uplink transmission

select a resource of the reference signal resource set for transmitting a reference signal based at least in part on receiving the reference signal resource indicator; and

transmit the reference signal over the resource of the reference signal resource set.
The apparatus of claim 20, wherein the instructions are further executable by the processor to cause the apparatus to:

transmit the codebook-based uplink transmission based at least in part on transmitting the reference signal over the resource.
The apparatus of claim 21, wherein the reference signal resource set comprises at least a second resource for transmitting the reference signal, and wherein selecting the resource of the reference signal resource set comprises selecting between the resource and the at least the second resource.
The apparatus of claim 21, wherein the configuration comprises a second reference signal resource set associated with the antenna switching usage type, wherein the second reference signal resource set comprises a second resource for transmitting the reference signal, and wherein selecting the resource of the reference signal resource set comprises selecting between the resource of the reference signal resource set and the second resource of the second reference signal resource set.
The apparatus of claim 20, wherein the resource over which the reference signal is transmitted comprises a first instance of the resource, and the instructions are further executable by the processor to cause the apparatus to:

transmit a second reference signal over a second instance of the resource of the reference signal resource set; and

receive a downlink transmission based at least in part on transmitting the second reference signal over the second instance of the resource of the reference signal resource set.
The apparatus of claim 24, wherein one or more ports associated with the second instance of the resource comprises one or more ports associated with the second instance of the resource.
The apparatus of claim 20, wherein the instructions to select the resource are executable by the processor to cause the apparatus to:

select the resource among a subset of resources of the reference signal resource set, wherein the subset comprises two or more lowest indexed resources of the reference signal resource set, and wherein the reference signal resource set comprises a second resource excluded from the subset.
The apparatus of claim 20, wherein the instructions to receive the reference signal resource indicator are executable by the processor to cause the apparatus to:

receive control signaling indicating the reference signal resource indicator.
The apparatus of claim 27, wherein the control signaling comprises downlink control information.
The apparatus of claim 20, wherein the reference signal is a sounding reference signal.
An apparatus for wireless communications, comprising:

a processor,

memory in electronic communication with the processor, and

instructions stored in the memory and executable by the processor to cause the apparatus to:

transmit a configuration of a reference signal resource set, the reference signal resource set associated with an antenna switching usage type;

identify a resource of the reference signal resource set for receiving a reference signal associated with a codebook-based uplink transmission;

transmit a reference signal resource indicator based at least in part on identifying the resource; and

receive the reference signal over the resource of the reference signal resource set.
The apparatus of claim 30, wherein the instructions are further executable by the processor to cause the apparatus to:

receive the codebook-based uplink transmission based at least in part on receiving the reference signal over the resource.
The apparatus of claim 31, wherein the reference signal resource set comprises at least a second resource for transmitting the reference signal, and wherein the resource of the reference signal resource set is identified among the resource and the at least the second resource.
The apparatus of claim 31, wherein the configuration comprises a second reference signal resource set associated with the antenna switching usage type, wherein the second reference signal resource set comprises a second resource for transmitting the reference signal, and wherein the resource of the reference signal resource set is identified among the resource of the reference signal resource set and the second resource of the second reference signal resource set.
The apparatus of claim 30, wherein the resource over which the reference signal is received comprises a first instance of the resource, and the instructions are further executable by the processor to cause the apparatus to:

receive a second reference signal over a second instance of the resource of the reference signal resource set; and

transmit a downlink transmission based at least in part on transmitting the second reference signal over the second instance of the resource of the reference signal resource set.
The apparatus of claim 30, wherein the instructions to identify the resource are executable by the processor to cause the apparatus to:

identify the resource among a subset of the reference signal resource set, wherein the subset comprises two or more lowest indexed resources of the reference signal resource set, and wherein the reference signal resource set comprises a second resource excluded from the subset.
The apparatus of claim 30, wherein the instructions to transmit the reference signal resource indicator are executable by the processor to cause the apparatus to:

transmit control signaling indicating the reference signal resource indicator.
The apparatus of claim 36, wherein the control signaling comprises downlink control information.
The apparatus of claim 30, wherein the reference signal is a sounding reference signal.
An apparatus for wireless communication, comprising:

means for receiving a configuration of a reference signal resource set, the reference signal resource set associated with an antenna switching usage type;

means for receiving a reference signal resource indicator associated with a codebook-based uplink transmission;

means for selecting a resource of the reference signal resource set for transmitting a reference signal based at least in part on receiving the reference signal resource indicator; and

means for transmitting the reference signal over the resource of the reference signal resource set.
The apparatus of claim 39, further comprising:

means for transmitting the codebook-based uplink transmission based at least in part on transmitting the reference signal over the resource.
The apparatus of claim 40, wherein the reference signal resource set comprises at least a second resource for transmitting the reference signal, and wherein selecting the resource of the reference signal resource set comprises selecting between the resource and the at least the second resource.
The apparatus of claim 40, wherein the configuration comprises a second reference signal resource set associated with the antenna switching usage type, wherein the second reference signal resource set comprises a second resource for transmitting the reference signal, and wherein selecting the resource of the reference signal resource set comprises selecting between the resource of the reference signal resource set and the second resource of the second reference signal resource set.
The apparatus of claim 39, wherein the resource over which the reference signal is transmitted comprises a first instance of the resource, the apparatus further comprising:

means for transmitting a second reference signal over a second instance of the resource of the reference signal resource set; and

means for receiving a downlink transmission based at least in part on transmitting the second reference signal over the second instance of the resource of the reference signal resource set.
The apparatus of claim 43, wherein one or more ports associated with the second instance of the resource comprises one or more ports associated with the second instance of the resource.
The apparatus of claim 39, wherein the means for selecting the resource comprises:

means for selecting the resource among a subset of resources of the reference signal resource set, wherein the subset comprises two or more lowest indexed resources of the reference signal resource set, and wherein the reference signal resource set comprises a second resource excluded from the subset.
The apparatus of claim 39, wherein the means for receiving the reference signal resource indicator comprises:

means for receiving control signaling indicating the reference signal resource indicator.
The apparatus of claim 46, wherein the control signaling comprises downlink control information.
The apparatus of claim 39, wherein the reference signal is a sounding reference signal.
An apparatus for wireless communications, comprising:

means for transmitting a configuration of a reference signal resource set, the reference signal resource set associated with an antenna switching usage type;

means for identifying a resource of the reference signal resource set for receiving a reference signal associated with a codebook-based uplink transmission;

means for transmitting a reference signal resource indicator based at least in part on identifying the resource; and

means for receiving the reference signal over the resource of the reference signal resource set.
The apparatus of claim 49, further comprising:

means for receiving the codebook-based uplink transmission based at least in part on receiving the reference signal over the resource.
The apparatus of claim 50, wherein the reference signal resource set comprises at least a second resource for transmitting the reference signal, and wherein the resource of the reference signal resource set is identified among the resource and the at least the second resource.
The apparatus of claim 50, wherein the configuration comprises a second reference signal resource set associated with the antenna switching usage type, wherein the second reference signal resource set comprises a second resource for transmitting the reference signal, and wherein the resource of the reference signal resource set is identified among the resource of the reference signal resource set and the second resource of the second reference signal resource set.
The apparatus of claim 49, wherein the resource over which the reference signal is received comprises a first instance of the resource, the apparatus further comprising:

means for receiving a second reference signal over a second instance of the resource of the reference signal resource set; and

means for transmitting a downlink transmission based at least in part on transmitting the second reference signal over the second instance of the resource of the reference signal resource set.
The apparatus of claim 49, wherein the means for identifying the resource comprises:

means for identifying the resource among a subset of the reference signal resource set, wherein the subset comprises two or more lowest indexed resources of the reference signal resource set, and wherein the reference signal resource set comprises a second resource excluded from the subset.
The apparatus of claim 49, wherein the means for transmitting the reference signal resource indicator comprises:

means for transmitting control signaling indicating the reference signal resource indicator.
The apparatus of claim 55, wherein the control signaling comprises downlink control information.
The apparatus of claim 49, wherein the reference signal is a sounding reference signal.
A non-transitory computer-readable medium storing code for wireless communication, the code comprising instructions executable by a processor to:

receive a configuration of a reference signal resource set, the reference signal resource set associated with an antenna switching usage type;

receive a reference signal resource indicator associated with a codebook-based uplink transmission;

select a resource of the reference signal resource set for transmitting a reference signal based at least in part on receiving the reference signal resource indicator; and

transmit the reference signal over the resource of the reference signal resource set.
The non-transitory computer-readable medium of claim 58, wherein the instructions are further executable by the processor to:

transmit the codebook-based uplink transmission based at least in part on transmitting the reference signal over the resource.
The non-transitory computer-readable medium of claim 59, wherein the reference signal resource set comprises at least a second resource for transmitting the reference signal, and wherein selecting the resource of the reference signal resource set comprises selecting between the resource and the at least the second resource.
The non-transitory computer-readable medium of claim 59, wherein the configuration comprises a second reference signal resource set associated with the antenna switching usage type, wherein the second reference signal resource set comprises a second resource for transmitting the reference signal, and wherein selecting the resource of the reference signal resource set comprises selecting between the resource of the reference signal resource set and the second resource of the second reference signal resource set.
The non-transitory computer-readable medium of claim 58, wherein the resource over which the reference signal is transmitted comprises a first instance of the resource, and the instructions are executable by the processor to:

transmit a second reference signal over a second instance of the resource of the reference signal resource set; and

receive a downlink transmission based at least in part on transmitting the second reference signal over the second instance of the resource of the reference signal resource set.
The non-transitory computer-readable medium of claim 62, wherein one or more ports associated with the second instance of the resource comprises one or more ports associated with the second instance of the resource.
The non-transitory computer-readable medium of claim 58, wherein the instructions to select the resource are executable by the processor to:

select the resource among a subset of resources of the reference signal resource set, wherein the subset comprises two or more lowest indexed resources of the reference signal resource set, and wherein the reference signal resource set comprises a second resource excluded from the subset.
The non-transitory computer-readable medium of claim 58, wherein the instructions to receive the reference signal resource indicator are executable by the processor to:

receive control signaling indicating the reference signal resource indicator.
The non-transitory computer-readable medium of claim 65, wherein the control signaling comprises downlink control information.
The non-transitory computer-readable medium of claim 58, wherein the reference signal is a sounding reference signal.
A non-transitory computer-readable medium storing code for wireless communications, the code comprising instructions executable by a processor to:

transmit a configuration of a reference signal resource set, the reference signal resource set associated with an antenna switching usage type;

identify a resource of the reference signal resource set for receiving a reference signal associated with a codebook-based uplink transmission;

transmit a reference signal resource indicator based at least in part on identifying the resource; and

receive the reference signal over the resource of the reference signal resource set.
The non-transitory computer-readable medium of claim 68, wherein the instructions are further executable by the processor to:

receive the codebook-based uplink transmission based at least in part on receiving the reference signal over the resource.
The non-transitory computer-readable medium of claim 69, wherein the reference signal resource set comprises at least a second resource for transmitting the reference signal, and wherein the resource of the reference signal resource set is identified among the resource and the at least the second resource.
The non-transitory computer-readable medium of claim 69, wherein the configuration comprises a second reference signal resource set associated with the antenna switching usage type, wherein the second reference signal resource set comprises a second resource for transmitting the reference signal, and wherein the resource of the reference signal resource set is identified among the resource of the reference signal resource set and the second resource of the second reference signal resource set.
The non-transitory computer-readable medium of claim 68, wherein the resource over which the reference signal is received comprises a first instance of the resource, and the instructions are executable by the processor to:

receive a second reference signal over a second instance of the resource of the reference signal resource set; and

transmit a downlink transmission based at least in part on transmitting the second reference signal over the second instance of the resource of the reference signal resource set.
The non-transitory computer-readable medium of claim 68, wherein the instructions to identify the resource are executable by the processor to:

identify the resource among a subset of the reference signal resource set, wherein the subset comprises two or more lowest indexed resources of the reference signal resource set, and wherein the reference signal resource set comprises a second resource excluded from the subset.
The non-transitory computer-readable medium of claim 68, wherein the instructions to transmit the reference signal resource indicator are executable by the processor to:

transmit control signaling indicating the reference signal resource indicator.
The non-transitory computer-readable medium of claim 74, wherein the control signaling comprises downlink control information.
The non-transitory computer-readable medium of claim 68, wherein the reference signal is a sounding reference signal.