Techniques for indicating sounding reference signal resources

Abstract

Methods, systems, and devices for wireless communications are described. A user equipment (UE) may send a capability message indicating a first number of one or more transmit antennas supported by the UE for antenna switching and a second number of ports supported for uplink transmission, the second number exceeding the first number of the one or more transmit antennas. The UE may receive a sounding reference signal (SRS) configuration based on the capability message, the SRS configuration indicating a mapping between each SRS resource or SRS resource group and a corresponding bit sequence in a set of bit sequences. The UE may receive a control message including one or more bit sequences in the set of bit sequences indicating one or more SRS resources or SRS resource groups based on the mapping. The UE may send one or more SRS signals based on the control message.

Description

Technical Field

[0001] The following relates to wireless communications, including techniques for indicating sounding reference signal (SRS) resources. Background Art

[0002] Wireless communication systems are widely deployed to provide various types of communication content such as voice, video, packet data, messaging, broadcast, etc. These systems can support communication with multiple users by sharing 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, advanced LTE (LTE-A) systems, or LTE-A Pro systems, and fifth generation (5G) systems that may be referred to as new radio (NR) systems. These systems may employ techniques 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 multiple access (DFT-S-OFDM). A wireless multiple access communication system may include one or more base stations or one or more network access nodes, each of which simultaneously supports communication with multiple communication devices, which may be referred to as user equipment (UE).

[0003] In some wireless communication systems, a UE may be configured with a sounding reference signal (SRS) resource set for the UE to send SRS transmissions, where each SRS resource set may be allocated to a specific use case (e.g., antenna switching, codebook-based, non-codebook-based, beam management). In some cases, in order to reduce SRS overhead, a single SRS resource set may be used for multiple use cases, such as SRS transmission for antenna switching and codebook-based SRS transmission. The base station may indicate to the UE which SRS resources in the SRS resource set the UE should use for SRS transmission, such as SRS transmission according to a specific use case. In some cases, the base station may indicate the SRS resources via an SRS resource indicator (SRI). However, conventional techniques for indicating SRS resources may be flawed. Summary of the Invention

[0004] The described technology relates to improved methods, systems, devices and apparatuses that support technology for indicating sounding reference signal (SRS) resources. In general, the described technology provides a user equipment (UE) with a reduction in configuration overhead and resources associated with performing SRS transmission. In some cases, the described technology can support merged SRS resource sets so that SRS resources in one or more merged SRS resource sets can be used for multiple different SRS use cases (e.g., antenna switching, codebook-based, non-codebook-based, beam management). In some cases, the described technology can support indicating to the UE SRS resources within one or more merged SRS resource sets to be used for SRS transmission, where the SRS resources can be configured for a specific SRS use case. Each SRS use case can be associated with a different number of ports, transmit antennas and / or receive antennas for performing the SRS use case. In order to take into account the different antenna and / or port configurations for each use case, the indication of the configured SRS resources can be based on the SRS use case associated with the configured SRS resources.

[0005] For example, a UE may send a capability message indicating a first number of one or more transmit antennas supported by the UE for antenna switching and a second number of ports supported for uplink transmission, the second number exceeding the first number of the one or more transmit antennas. The UE may receive an SRS configuration based on the capability message, the SRS configuration indicating a mapping between each SRS resource group in at least a subset of a set of SRS resource groups and a corresponding bit sequence in a set of bit sequences. The UE may receive a control message based on the mapping, the control message including a first bit sequence in the set of bit sequences indicating a first SRS resource group in the subset of the set of SRS resource groups. Based on the control message, the UE may send a first SRS in a first SRS resource in the first SRS resource group based on the control message, and send a second SRS in a second SRS resource in the first SRS resource group based on the control message.

[0006] In another example, the UE may send a capability message indicating a first number of one or more transmit antennas supported by the UE for antenna switching and a second number of ports supported for uplink transmission, the second number exceeding the first number of transmit antennas. The UE may receive an SRS configuration based on the capability message, the SRS configuration indicating a mapping between each SRS resource in an SRS resource set and a corresponding bit sequence in a bit sequence set. The UE may receive a control message based on the mapping, the control message including: a first bit sequence in the bit sequence set indicating a first SRS resource in the SRS resource set, and a second bit sequence in the bit sequence set indicating a second SRS resource in the SRS resource set. The UE may send a first SRS in the first SRS resource based on the first bit sequence indicated in the control message, and send a second SRS in the second SRS resource based on the second bit sequence indicated in the control message.

[0007] A method for wireless communication at a UE is described. The method may include: sending a capability message indicating a first number of one or more transmit antennas supported by the UE for antenna switching and a second number of ports supported for uplink transmission, the second number exceeding the first number of the one or more transmit antennas; receiving an SRS configuration based on the capability message, the SRS configuration indicating a mapping between each SRS resource group in at least a subset of a set of SRS resource groups and a corresponding bit sequence in a set of bit sequences; receiving a control message based on the mapping, the control message including a first bit sequence in the set of bit sequences indicating a first SRS resource group in the subset of the set of SRS resource groups; sending a first SRS in a first SRS resource in the first SRS resource group based on the control message; and sending a second SRS in a second SRS resource in the first SRS resource group based on the control message.

[0008] A device for wireless communication at a UE is described. The device may include a processor, a memory coupled to the processor, and instructions stored in the memory. The instructions may be executed by the processor to cause the device to: send a capability message indicating a first number of one or more transmit antennas supported by the UE for antenna switching and a second number of ports supported for uplink transmission, the second number exceeding the first number of the one or more transmit antennas; receive an SRS configuration based on the capability message, the SRS configuration indicating a mapping between each SRS resource group in at least a subset of a set of SRS resource groups and a corresponding bit sequence in a set of bit sequences; receive a control message based on the mapping, the control message including a first bit sequence in the set of bit sequences indicating a first SRS resource group in the subset of the set of SRS resource groups; send a first SRS in a first SRS resource in the first SRS resource group based on the control message; and send a second SRS in a second SRS resource in the first SRS resource group based on the control message.

[0009] Another apparatus for wireless communication at a UE is described. The apparatus may include components for: sending a capability message indicating a first number of one or more transmit antennas supported by the UE for antenna switching and a second number of ports supported for uplink transmission, the second number exceeding the first number of the one or more transmit antennas; receiving an SRS configuration based on the capability message, the SRS configuration indicating a mapping between each SRS resource group in at least a subset of a set of SRS resource groups and a corresponding bit sequence in a set of bit sequences; receiving a control message based on the mapping, the control message including a first bit sequence in the set of bit sequences indicating a first SRS resource group in the subset of the set of SRS resource groups; sending a first SRS in a first SRS resource in the first SRS resource group based on the control message; and sending a second SRS in a second SRS resource in the first SRS resource group based on the control message.

[0010] A non-transitory computer-readable medium storing code for wireless communication at a UE is described. The code may include instructions executable by a processor to: send a capability message indicating a first number of one or more transmit antennas supported by the UE for antenna switching and a second number of ports supported for uplink transmission, the second number exceeding the first number of the one or more transmit antennas; receive an SRS configuration based on the capability message, the SRS configuration indicating a mapping between each SRS resource group in at least a subset of a set of SRS resource groups and a corresponding bit sequence in a set of bit sequences; receive a control message based on the mapping, the control message including a first bit sequence in the set of bit sequences indicating a first SRS resource group in the subset of the set of SRS resource groups; send a first SRS in a first SRS resource in the first SRS resource group based on the control message; and send a second SRS in a second SRS resource in the first SRS resource group based on the control message.

[0011] In some examples of the methods, apparatus, and non-transitory computer-readable media described herein, receiving the SRS configuration may also include operations, features, components, or instructions for receiving the SRS configuration indicating a mapping table indicating a mapping between each SRS resource group in at least the subset of the set of SRS resource groups and a corresponding bit sequence in the set of bit sequences.

[0012] In some examples of the methods, apparatus, and non-transitory computer-readable media described herein, receiving the SRS configuration may also include operations, features, components, or instructions for receiving the SRS configuration indicating the number of configuration ports for antenna switching and the number of configuration ports for uplink transmission, wherein the mapping may be based on the number of configuration ports for antenna switching and the number of configuration ports for uplink transmission.

[0013] In some examples of the methods, apparatus, and non-transitory computer-readable media described herein, receiving the SRS configuration indicating the mapping may also include operations, features, components, or instructions for receiving the SRS configuration indicating a mapping between each SRS group in the set of SRS resource groups and a corresponding bit sequence in the set of bit sequences.

[0014] In some examples of the methods, apparatus, and non-transitory computer-readable media described herein, sending the capability message may also include operations, features, components, or instructions for sending the capability message indicating a third number of one or more receive antennas supported for antenna switching, the SRS configuration being based on the third number of receive antennas supported for antenna switching.

[0015] In some examples of the methods, apparatus, and non-transitory computer-readable media described herein, the third number of one or more receive antennas exceeds the first number of one or more transmit antennas.

[0016] In some examples of the methods, apparatus, and non-transitory computer-readable media described herein, receiving the control message may also include operations, features, components, or instructions for receiving a downlink control information message including the first bit sequence.

[0017] In some examples of the methods, apparatus, and non-transitory computer-readable media described herein, each SRS resource group includes a single SRS resource in the SRS resource group.

[0018] In some examples of the methods, apparatus, and non-transitory computer-readable media described herein, receiving the SRS configuration may also include operations, features, components, or instructions for receiving the SRS configuration indicating a codebook SRS configuration.

[0019] In some examples of the methods, apparatus, and non-transitory computer-readable media described herein, each bit sequence in the set of bit sequences includes a single bit.

[0020] A method for wireless communication at a UE is described. The method may include: sending a capability message indicating a first number of one or more transmit antennas supported by the UE for antenna switching and a second number of ports supported for uplink transmission, the second number exceeding the first number of transmit antennas; receiving an SRS configuration based on the capability message, the SRS configuration indicating a mapping between each SRS resource in an SRS resource set and a corresponding bit sequence in a bit sequence set; receiving a control message based on the mapping, the control message including a first bit sequence in the bit sequence set indicating a first SRS resource in the SRS resource set and a second bit sequence in the bit sequence set indicating a second SRS resource in the SRS resource set; sending a first SRS in the first SRS resource based on the first bit sequence indicated in the control message; and sending a second SRS in the second SRS resource based on the second bit sequence indicated in the control message.

[0021] A device for wireless communication at a UE is described. The device may include a processor, a memory coupled to the processor, and instructions stored in the memory. The instructions may be executed by the processor to cause the device to: send a capability message, the capability message indicating a first number of one or more transmit antennas supported by the UE for antenna switching and a second number of ports supported for uplink transmission, the second number exceeding the first number of transmit antennas; receive an SRS configuration based on the capability message, the SRS configuration indicating a mapping between each SRS resource in an SRS resource set and a corresponding bit sequence in a bit sequence set; receive a control message based on the mapping, the control message including a first bit sequence in the bit sequence set indicating a first SRS resource in the SRS resource set and a second bit sequence in the bit sequence set indicating a second SRS resource in the SRS resource set; send a first SRS in the first SRS resource based on the first bit sequence indicated in the control message; and send a second SRS in the second SRS resource based on the second bit sequence indicated in the control message.

[0022] Another apparatus for wireless communication at a UE is described. The apparatus may include components for: sending a capability message indicating a first number of one or more transmit antennas supported by the UE for antenna switching and a second number of ports supported for uplink transmission, the second number exceeding the first number of transmit antennas; receiving an SRS configuration based on the capability message, the SRS configuration indicating a mapping between each SRS resource in an SRS resource set and a corresponding bit sequence in a bit sequence set; receiving a control message based on the mapping, the control message including a first bit sequence in the bit sequence set indicating a first SRS resource in the SRS resource set and a second bit sequence in the bit sequence set indicating a second SRS resource in the SRS resource set; sending a first SRS in the first SRS resource based on the first bit sequence indicated in the control message; and sending a second SRS in the second SRS resource based on the second bit sequence indicated in the control message.

[0023] A non-transitory computer-readable medium storing code for wireless communication at a UE is described. The code may include instructions executable by a processor to: send a capability message indicating a first number of one or more transmit antennas supported by the UE for antenna switching and a second number of ports supported for uplink transmission, the second number exceeding the first number of transmit antennas; receive an SRS configuration based on the capability message, the SRS configuration indicating a mapping between each SRS resource in an SRS resource set and a corresponding bit sequence in a bit sequence set; receive a control message based on the mapping, the control message including a first bit sequence in the bit sequence set indicating a first SRS resource in the SRS resource set and a second bit sequence in the bit sequence set indicating a second SRS resource in the SRS resource set; send a first SRS in the first SRS resource based on the first bit sequence indicated in the control message; and send a second SRS in the second SRS resource based on the second bit sequence indicated in the control message.

[0024] In some examples of the methods, apparatus, and non-transitory computer-readable media described herein, receiving the SRS configuration may also include operations, features, components, or instructions for receiving the SRS configuration indicating a codebook SRS configuration.

[0025] In some examples of the methods, apparatus, and non-transitory computer-readable media described herein, receiving the SRS configuration may also include operations, features, components, or instructions for receiving the SRS configuration indicating a mapping table corresponding to the mapping, wherein the corresponding bit sequence indicates a corresponding index to the mapping table.

[0026] In some examples of the methods, apparatus, and non-transitory computer-readable media described herein, sending the capability message may also include operations, features, components, or instructions for sending the capability message indicating a third number of one or more receive antennas supported for antenna switching, the SRS configuration being based on the third number of receive antennas supported for antenna switching.

[0027] In some examples of the methods, apparatus, and non-transitory computer-readable media described herein, the third number of one or more receive antennas exceeds the first number of one or more transmit antennas.

[0028] In some examples of the methods, apparatus, and non-transitory computer-readable media described herein, receiving the control message may also include operations, features, components, or instructions for receiving a downlink control information message including the first bit sequence and the second bit sequence.

[0029] A method for wireless communication at a base station is described. The method may include: receiving a capability message from a UE, the capability message indicating a first number of one or more transmit antennas supported by the UE for antenna switching and a second number of ports supported for uplink transmission, the second number exceeding the first number of the one or more transmit antennas; sending an SRS configuration based on the capability message, the SRS configuration indicating a mapping between each SRS resource group in at least a subset of a set of SRS resource groups and a corresponding bit sequence in a set of bit sequences; sending a control message based on the mapping, the control message including a first bit sequence in the set of bit sequences indicating a first SRS resource group in the subset of the set of SRS resource groups; receiving a first SRS in a first SRS resource in the first SRS resource group based on the control message; and receiving a second SRS in a second SRS resource in the first SRS resource group based on the control message.

[0030] An apparatus for wireless communication at a base station is described. The apparatus may include a processor, a memory coupled to the processor, and instructions stored in the memory. The instructions may be executed by the processor to cause the apparatus to: receive a capability message from a UE, the capability message indicating a first number of one or more transmit antennas supported by the UE for antenna switching and a second number of ports supported for uplink transmission, the second number exceeding the first number of the one or more transmit antennas; send an SRS configuration based on the capability message, the SRS configuration indicating a mapping between each SRS resource group in at least a subset of a set of SRS resource groups and a corresponding bit sequence in a set of bit sequences; send a control message based on the mapping, the control message including a first bit sequence in the set of bit sequences indicating a first SRS resource group in the subset of the set of SRS resource groups; receive a first SRS in a first SRS resource in the first SRS resource group based on the control message; and receive a second SRS in a second SRS resource in the first SRS resource group based on the control message.

[0031] Another apparatus for wireless communication at a base station is described. The apparatus may include components for: receiving a capability message from a UE, the capability message indicating a first number of one or more transmit antennas supported by the UE for antenna switching and a second number of ports supported for uplink transmission, the second number exceeding the first number of the one or more transmit antennas; sending an SRS configuration based on the capability message, the SRS configuration indicating a mapping between each SRS resource group in at least a subset of a set of SRS resource groups and a corresponding bit sequence in a set of bit sequences; sending a control message based on the mapping, the control message including a first bit sequence in the set of bit sequences indicating a first SRS resource group in the subset of the set of SRS resource groups; receiving a first SRS in a first SRS resource in the first SRS resource group based on the control message; and receiving a second SRS in a second SRS resource in the first SRS resource group based on the control message.

[0032] A non-transitory computer-readable medium storing code for wireless communication at a base station is described. The code may include instructions executable by a processor to: receive a capability message from a UE, the capability message indicating a first number of one or more transmit antennas supported by the UE for antenna switching and a second number of ports supported for uplink transmission, the second number exceeding the first number of the one or more transmit antennas; send an SRS configuration based on the capability message, the SRS configuration indicating a mapping between each SRS resource group in at least a subset of a set of SRS resource groups and a corresponding bit sequence in a set of bit sequences; send a control message based on the mapping, the control message including a first bit sequence in the set of bit sequences indicating a first SRS resource group in the subset of the set of SRS resource groups; receive a first SRS in a first SRS resource in the first SRS resource group based on the control message; and receive a second SRS in a second SRS resource in the first SRS resource group based on the control message.

[0033] In some examples of the methods, apparatus, and non-transitory computer-readable media described herein, sending the SRS configuration may also include operations, features, components, or instructions for sending the SRS configuration indicating a mapping table indicating a mapping between each SRS resource group in at least the subset of the set of SRS resource groups and a corresponding bit sequence in the set of bit sequences.

[0034] In some examples of the methods, apparatus, and non-transitory computer-readable media described herein, sending the SRS configuration may also include operations, features, components, or instructions for sending the SRS configuration indicating the number of configuration ports for antenna switching and the number of configuration ports for uplink transmission, wherein the mapping may be based on the number of configuration ports for antenna switching and the number of configuration ports for uplink transmission.

[0035] In some examples of the methods, apparatus, and non-transitory computer-readable media described herein, sending the SRS configuration indicating the mapping may also include operations, features, components, or instructions for sending the SRS configuration indicating a mapping between each SRS group in the set of SRS resource groups and a corresponding bit sequence in the set of bit sequences.

[0036] In some examples of the methods, apparatus, and non-transitory computer-readable media described herein, receiving the capability message may also include operations, features, components, or instructions for receiving the capability message indicating a third number of one or more receive antennas supported for antenna switching, the SRS configuration being based on the third number of receive antennas supported for antenna switching.

[0037] In some examples of the methods, apparatus, and non-transitory computer-readable media described herein, the third number of one or more receive antennas exceeds the first number of one or more transmit antennas.

[0038] In some examples of the methods, apparatus, and non-transitory computer-readable media described herein, sending the control message may also include operations, features, components, or instructions for sending a downlink control information message including the first bit sequence.

[0039] In some examples of the methods, apparatus, and non-transitory computer-readable media described herein, each SRS resource group includes a single SRS resource in the SRS resource group.

[0040] In some examples of the methods, apparatus, and non-transitory computer-readable media described herein, sending the SRS configuration may also include operations, features, components, or instructions for sending the SRS configuration indicating a codebook SRS configuration.

[0041] In some examples of the methods, apparatus, and non-transitory computer-readable media described herein, each bit sequence in the set of bit sequences includes a single bit.

[0042] A method for wireless communication at a base station is described. The method may include: receiving a capability message from a UE, the capability message indicating a first number of one or more transmit antennas supported by the UE for antenna switching and a second number of ports supported for uplink transmission, the second number exceeding the first number of transmit antennas; sending an SRS configuration based on the capability message, the SRS configuration indicating a mapping between each SRS resource in an SRS resource set and a corresponding bit sequence in a bit sequence set; sending a control message based on the mapping, the control message including: a first bit sequence in the bit sequence set indicating a first SRS resource in the SRS resource set, and a second bit sequence in the bit sequence set indicating a second SRS resource in the SRS resource set; receiving a first SRS in the first SRS resource based on the first bit sequence indicated in the control message; and receiving a second SRS in the second SRS resource based on the second bit sequence indicated in the control message.

[0043] An apparatus for wireless communication at a base station is described. The apparatus may include a processor, a memory coupled to the processor, and instructions stored in the memory. The instructions may be executed by the processor to cause the apparatus to: receive a capability message from a UE, the capability message indicating a first number of one or more transmit antennas supported by the UE for antenna switching and a second number of ports supported for uplink transmission, the second number exceeding the first number of the one or more transmit antennas; send an SRS configuration based on the capability message, the SRS configuration indicating a mapping between each SRS resource group in at least a subset of a set of SRS resource groups and a corresponding bit sequence in a set of bit sequences; send a control message based on the mapping, the control message including a first bit sequence in the set of bit sequences indicating a first SRS resource group in the subset of the set of SRS resource groups; receive a first SRS in a first SRS resource in the first SRS resource group based on the control message; and receive a second SRS in a second SRS resource in the first SRS resource group based on the control message.

[0044] Another apparatus for wireless communication at a base station is described. The apparatus may include components for: receiving a capability message from a UE, the capability message indicating a first number of one or more transmit antennas supported by the UE for antenna switching and a second number of ports supported for uplink transmission, the second number exceeding the first number of the one or more transmit antennas; sending an SRS configuration based on the capability message, the SRS configuration indicating a mapping between each SRS resource group in at least a subset of a set of SRS resource groups and a corresponding bit sequence in a set of bit sequences; sending a control message based on the mapping, the control message including a first bit sequence in the set of bit sequences indicating a first SRS resource group in the subset of the set of SRS resource groups; receiving a first SRS in a first SRS resource in the first SRS resource group based on the control message; and receiving a second SRS in a second SRS resource in the first SRS resource group based on the control message.

[0045] A non-transitory computer-readable medium storing code for wireless communication at a base station is described. The code may include instructions executable by a processor to: receive a capability message from a UE, the capability message indicating a first number of one or more transmit antennas supported by the UE for antenna switching and a second number of ports supported for uplink transmission, the second number exceeding the first number of the one or more transmit antennas; send an SRS configuration based on the capability message, the SRS configuration indicating a mapping between each SRS resource group in at least a subset of a set of SRS resource groups and a corresponding bit sequence in a set of bit sequences; send a control message based on the mapping, the control message including a first bit sequence in the set of bit sequences indicating a first SRS resource group in the subset of the set of SRS resource groups; receive a first SRS in a first SRS resource in the first SRS resource group based on the control message; and receive a second SRS in a second SRS resource in the first SRS resource group based on the control message.

[0046] In some examples of the methods, apparatus, and non-transitory computer-readable media described herein, sending the SRS configuration may also include operations, features, components, or instructions for sending the SRS configuration indicating a codebook SRS configuration.

[0047] In some examples of the methods, apparatus, and non-transitory computer-readable media described herein, sending the SRS configuration may also include operations, features, components, or instructions for sending the SRS configuration indicating a mapping table corresponding to the mapping, wherein the corresponding bit sequence indicates a corresponding index to the mapping table.

[0048] In some examples of the methods, apparatus, and non-transitory computer-readable media described herein, receiving the capability message may also include operations, features, components, or instructions for receiving the capability message indicating a third number of one or more receive antennas supported for antenna switching, the SRS configuration being based on the third number of receive antennas supported for antenna switching.

[0049] In some examples of the methods, apparatus, and non-transitory computer-readable media described herein, the third number of one or more receive antennas exceeds the first number of one or more transmit antennas.

[0050] In some examples of the methods, apparatus, and non-transitory computer-readable media described herein, sending the control message may also include operations, features, components, or instructions for sending a downlink control information message including the first bit sequence and the second bit sequence. BRIEF DESCRIPTION OF THE DRAWINGS

[0051] Figure 1 Illustrated is an example of a wireless communication system supporting techniques for indicating sounding reference signal (SRS) resources in accordance with aspects of the present disclosure.

[0052] Figures 2 to 5 An example of a wireless communication system supporting techniques for indicating SRS resources according to aspects of the present disclosure is illustrated.

[0053] Figure 6 and Figure 7 Illustrated is an example of a process flow supporting techniques for indicating SRS resources according to aspects of the present disclosure.

[0054] Figure 8 and Figure 9 Illustrated is a block diagram of a device supporting techniques for indicating SRS resources according to aspects of the present disclosure.

[0055] Figure 10 A block diagram of a communication manager supporting techniques for indicating SRS resources in accordance with aspects of the present disclosure is shown.

[0056] Figure 11 A diagram of a system including devices supporting techniques for indicating SRS resources according to aspects of the present disclosure is shown.

[0057] Figure 12 and Figure 13 A block diagram of a device supporting techniques for indicating SRS resources according to aspects of the present disclosure is shown.

[0058] Figure 14 A block diagram of a communication manager supporting techniques for indicating SRS resources in accordance with aspects of the present disclosure is shown.

[0059] Figure 15 A diagram is shown of a system including devices supporting techniques for indicating SRS resources in accordance with aspects of the present disclosure.

[0060] Figures 16 to 19 Shown is a flow chart illustrating a method supporting techniques for indicating SRS resources according to aspects of the present disclosure. DETAILED DESCRIPTION

[0061] In some wireless communication systems, a user equipment (UE) may transmit a sounding reference signal (SRS) to a base station during at least one SRS resource so that the base station can determine one or more channel conditions at the UE (e.g., for scheduling uplink transmissions). In some examples, the base station may configure the UE with multiple SRS resources (e.g., aperiodic, semi-persistent, or periodic configurations), which may be grouped into SRS resource sets based on usage (e.g., for antenna switching, codebook-based or non-codebook-based, for beam management, etc.). For example, the UE may perform an SRS antenna switching operation to implement downlink beamforming in a time division duplex (TDD) band by utilizing channel reciprocity (e.g., the channel response may be the same in both directions). In addition, SRS antenna switching may be used for uplink sounding (e.g., for physical uplink shared channel scheduling and / or beamforming). During the antenna switching operation, the base station may configure multiple SRS resource sets for the UE, such as up to two SRS resource sets. In some other examples, such as for codebook-based transmissions, the base station may configure the UE with a single SRS resource set. It may be beneficial to combine the use of downlink channel state information (CSI) acquisition and uplink codebook selection during antenna switching operations to reduce signaling overhead associated with SRS transmission, resulting in large pools or SRS resources within one or more SRS resource sets. However, antenna switching operations and codebook-based transmissions may use different numbers of SRS resources within an SRS resource set based on the number of ports, receive antennas, and / or transmit antennas utilized for each use case, and conventional techniques for indicating which SRS resources to use (e.g., an SRS resource indicator (SRI) field) may not currently allow for large pools of SRS resources.

[0062] In order to indicate to the UE which resources are used for SRS transmission for a specific use case, the UE may be configured with a mapping between SRS resources or SRS resource groups within an SRS resource set and a bit sequence (such as an SRI bit sequence). In some cases, the mapping may be based on the capabilities of the UE. The UE may receive a control message including one or more SRI bit sequences and determine one or more SRS resources configured by the UE for SRS transmission based on the mapping. In a first example, the SRS resources within the SRS resource set may be grouped, and a lookup table may map the SRI bit field to one of the SRS resource groups. In a second example, the set of groups may be downconverted to a subset of groups, and the lookup table may map the SRI bit field to one of the groups within the subset of groups. In either example, the UE may receive an SRI bit field that may indicate the use of multiple SRS resources included in the group. In some cases, the UE may be configured with a lookup table that may map the SRI bit sequence to the SRS resource so that a multi-bit SRI field indicates one SRS resource. In this way, if multiple SRS resources are configured for the UE for SRS transmission, the UE may receive multiple SRI fields.

[0063] One or more advantages may be achieved by implementing certain aspects of the subject matter described herein. The described techniques may support improvements in SRS transmission by implementing an indication technique for indicating SRS resources allocated for SRS transmission within an SRS resource set. The described techniques may, among other things, reduce signaling overhead, improve reliability, and reduce latency. Consequently, the supported techniques may include improved network operation and, in some examples, increased network efficiency, among other benefits.

[0064] Various aspects of the present disclosure are initially described in the context of a wireless communication system. Various aspects are then described relative to process flows. Various aspects of the present disclosure are further illustrated and described with reference to apparatus diagrams, system diagrams, and flow charts related to techniques for indicating SRS resources.

[0065] Figure 1 An example of a wireless communication system 100 that supports techniques for indicating SRS resources according to aspects of the present disclosure is illustrated. The wireless communication 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 communication 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 communication system 100 may support enhanced broadband communication, ultra-reliable (e.g., mission-critical) communication, low-latency communication, communication with low-cost and low-complexity devices, or any combination thereof, among others.

[0066] Base stations 105 may be dispersed throughout a geographic area to form wireless communication system 100 and may be devices of varying forms or capabilities. Base stations 105 and UEs 115 may communicate wirelessly via one or more communication links 125. Each base station 105 may provide a coverage area 110 over which a UE 115 and base station 105 may establish one or more communication links 125. Coverage area 110 may be an example of a geographic area over which base stations 105 and UEs 115 may support communication of signals according to one or more radio access technologies.

[0067] The UEs 115 may be dispersed throughout the coverage area 110 of the wireless communication system 100, and each UE 115 may be fixed or mobile, or fixed or mobile at different times. The UEs 115 may be devices of different forms or with different capabilities. Figure 1 1. Some example UEs 115 are shown in FIG. 1. The UEs 115 described herein may be capable of communicating with various types of devices, such as other UEs 115, base stations 105, or network devices (e.g., core network nodes, relays, integrated access and backhaul (IAB) nodes, or other network devices), such as Figure 1 shown.

[0068] The base stations 105 can communicate with the core network 130, or with each other, or both. For example, the base stations 105 can interface with the core network 130 via one or more backhaul links 120 (e.g., via S1, N2, N3, or other interfaces). The base stations 105 can communicate with each other via the backhaul links 120 (e.g., via X2, Xn, or other interfaces) directly (e.g., directly between the base stations 105) or indirectly (e.g., via the core network 130), or both. In some examples, the backhaul links 120 can be or include one or more wireless links.

[0069] One or more of the base stations 105 described herein may include or may be referred to by one of ordinary skill in the art as a base transceiver, a radio base station, an access point, a radio transceiver, a NodeB, an eNodeB (eNB), a next generation NodeB or giga-NodeB (any of which may be referred to as a gNB), a Home NodeB, a Home eNodeB, or other suitable terminology.

[0070] In other examples, 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 "device" may also be referred to as a unit, a station, a terminal, or a client. 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, 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 communication (MTC) device, among other examples, which may be implemented in various objects such as home appliances or vehicles, meters, and other examples.

[0071] The UE 115 described herein is capable of communicating with various types of devices, such as other UEs 115, which may sometimes act as relays, as well as base stations 105 and network devices, including macro eNBs or gNBs, small cell eNBs or gNBs, or relay base stations, such as Figure 1 shown.

[0072] The UE 115 and the base station 105 can wirelessly communicate with each other via one or more communication links 125 over one or more carriers. The term "carrier" can refer to a collection of radio spectrum resources having a defined physical layer structure for supporting the communication link 125. For example, a carrier used for the communication link 125 can include a portion of a radio frequency spectrum band (e.g., a bandwidth portion (BWP)) that operates 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 can carry acquisition signaling (e.g., synchronization signals, system information), control signaling to coordinate operations for the carrier, user data, or other signaling. The wireless communication system 100 can use carrier aggregation or multi-carrier operation to support communication with the UE 115. The UE 115 can be configured with multiple downlink component carriers and one or more uplink component carriers according to the carrier aggregation configuration. Carrier aggregation can be used for both frequency division duplex (FDD) and time division duplex (TDD) component carriers.

[0073] The signal waveform transmitted via the carrier may be composed of multiple subcarriers (e.g., using a multicarrier modulation (MCM) technique, such as orthogonal frequency division multiplexing (OFDM) or discrete Fourier transform spread OFDM (DFT-S-OFDM)). In a system employing MCM technology, a resource element may be composed of one symbol period (e.g., the 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). Therefore, the more resource elements received by the UE 115 and the higher the order of the modulation scheme, the higher the data rate of the UE 115 may be. Wireless communication resources may refer to a combination of radio frequency spectrum resources, time resources, and spatial resources (e.g., spatial layers or beams), and the use of multiple spatial layers may further increase the data rate or data integrity used for communication with the UE 115.

[0074] The time interval for the base station 105 or the UE 115 may be expressed as a multiple of a basic time unit, which may be, for example, T s =1 / (Δf max ·N f ) seconds sampling period, where Δf max It can represent the maximum supported subcarrier spacing, and N f The maximum supported Discrete Fourier Transform (DFT) size may be indicated. Time intervals of communication resources 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., in the range 0 to 1023).

[0075] Each frame may include a plurality of consecutively numbered subframes or time slots, and each subframe or time slot may have the same duration. In some examples, the frame may be divided (e.g., in the time domain) into subframes, and each subframe may be further divided into a plurality of time slots. Alternatively, each frame may include a variable number of time slots, and the number of time slots may depend on the subcarrier spacing. Each time slot may include a plurality of symbol periods (e.g., depending on the length of the cyclic prefix preceding each symbol period). In some wireless communication systems 100, the time slot may be further divided into a plurality of mini-time slots containing one or more symbols. In addition to the cyclic prefix, each symbol period may contain one or more (e.g., N subframes). f The duration of a symbol period may depend on the subcarrier spacing or the operating frequency band.

[0076] A subframe, slot, mini-slot, or symbol may be the smallest scheduling unit (e.g., in the time domain) of the wireless communication 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 communication system 100 may be dynamically selected (e.g., in a burst of a shortened TTI (sTTI)).

[0077] Physical channels can be multiplexed on a carrier according to various techniques. Physical control channels and physical data channels can be multiplexed on a downlink carrier, for example, using one or more of time division multiplexing (TDM), frequency division multiplexing (FDM), or hybrid TDM-FDM techniques. A control region (e.g., a control resource set (CORESET)) for physical control channels can be defined by a number of symbol periods and can extend across the system bandwidth of a carrier or a subset of the system bandwidth. One or more control regions (e.g., CORESETs) can be configured for a set of UEs 115. For example, one or more UEs 115 can monitor or search the control region for control information according to one or more search space sets, and each search space set can include one or more control channel candidates at one or more aggregation levels arranged in a cascaded manner. The aggregation level for a control channel candidate can refer to the number of control channel resources (e.g., control channel elements (CCEs)) associated with the coded information for a control information format having a given payload size. A search space set can include a common search space set configured for transmitting control information to multiple UEs 115 and a UE-specific search space set for transmitting control information to a specific UE 115.

[0078] In some examples, base stations 105 can be mobile and, therefore, provide communication coverage for mobile geographic coverage areas 110. In some examples, different geographic coverage areas 110 associated with different technologies can overlap, but the different geographic coverage areas 110 can be supported by the same base station 105. In other examples, overlapping geographic coverage areas 110 associated with different technologies can be supported by different base stations 105. The wireless communication system 100 can include, for example, a heterogeneous network in which different types of base stations 105 provide coverage for various geographic coverage areas 110 using the same or different radio access technologies.

[0079] The wireless communication system 100 can be configured to support ultra-reliable communication or low-latency communication or various combinations thereof. For example, the wireless communication system 100 can be configured to support ultra-reliable low-latency communication (URLLC) or mission-critical communication. UE 115 can be designed to support ultra-reliable, low-latency or critical functions (e.g., mission-critical functions). Ultra-reliable communication can include private communication or group communication and can 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 can include prioritization of services, and mission-critical services can be used for public safety or general commercial applications. The terms ultra-reliable, low-latency, mission-critical, and ultra-reliable low-latency can be used interchangeably herein.

[0080] In some examples, UE 115 can also communicate directly with other UEs 115 via 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 communication can be within the geographic coverage area 110 of base station 105. Other UEs 115 in the group can be outside the geographic coverage area 110 of base station 105 or otherwise unable to receive transmissions from base station 105. In some examples, the group of UEs 115 communicating via D2D communication can utilize a one-to-many (1:M) system, in which each UE 115 transmits to each other UE 115 in the group. In some examples, base station 105 facilitates resource scheduling for D2D communication. In other cases, D2D communication occurs between UEs 115 without involving base station 105.

[0081] 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 a 5G core (5GC), which may include at least one control plane entity (e.g., a mobility management entity (MME), an access and mobility management function (AMF)) that manages access and mobility and at least one user plane entity (e.g., a serving gateway (S-GW), a packet data network (PDN) gateway (P-GW), or a user plane function (UPF)) that routes packets or interconnections to external networks. The control plane entities may manage non-access stratum (NAS) functions associated with the core network 130 for the UE 115 served by the base station 105, such as mobility, authentication, and bearer management. User IP packets may be delivered through the user plane entities, which may provide IP address allocation and other functions. The user plane entities may be connected to the IP services 150 of one or more network operators. IP services 150 may include access to the Internet, intranet(s), IP Multimedia Subsystem (IMS), or packet-switched streaming services.

[0082] Some network devices, such as base stations 105, may include subcomponents such as access network entities 140, which may be examples of access node controllers (ANCs). Each access network entity 140 may communicate with a UE 115 through one or more other access network transmit entities 145, which may be referred to as radio heads, smart radio heads, or transmit / receive points (TRPs). Each access network transmit entity 145 may include one or more antenna panels. In some configurations, the 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., base station 105).

[0083] The wireless communication system 100 can operate using one or more frequency bands typically in the range of 300 megahertz (MHz) to 300 gigahertz (GHz). Typically, the region from 300 MHz to 3 GHz is referred to as the ultra-high frequency (UHF) region or decimeter band because the wavelengths range from approximately 1 decimeter to 1 meter long. UHF waves can be blocked or redirected by buildings and environmental features, but the waves can penetrate the structures used for macro cells sufficiently to provide service to UEs 115 located indoors. Transmissions using UHF waves can be associated with smaller antennas and a shorter range (e.g., less than 100 kilometers) compared to transmissions using the lower frequencies and longer wavelengths of the high frequency (HF) or very high frequency (VHF) portions of the spectrum below 300 MHz.

[0084] The wireless communication system 100 can utilize both licensed and unlicensed radio spectrum bands. For example, the wireless communication system 100 can use 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 an unlicensed radio spectrum band, devices such as the base station 105 and the UE 115 can use carrier sensing for conflict detection and avoidance. In some examples, operations in the unlicensed band can be based on a carrier aggregation configuration (e.g., LAA) in combination with component carriers operating in the licensed band. Operations in the unlicensed spectrum can include downlink transmissions, uplink transmissions, P2P transmissions, or D2D transmissions, etc.

[0085] The base station 105 or 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 the base station 105 or 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 collocated at an antenna assembly such as an antenna tower. In some examples, the antennas or antenna arrays associated with the base station 105 may be located at different geographical locations. The base station 105 may have an antenna array with multiple rows and columns of antenna ports, which the base station 105 may use to support beamforming for communications with the UE 115. Similarly, the UE 115 may have one or more antenna arrays that may support various MIMO or beamforming operations. Additionally or alternatively, the antenna panels may support radio frequency beamforming for signals transmitted via the antenna ports.

[0086] Beamforming (which may also be referred to as spatial filtering, directional transmission, or directional reception) is a signal processing technique that can 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 can be achieved by combining signals communicated via antenna elements of an antenna array so that some signals propagating at a particular orientation relative to the antenna array experience constructive interference, while other signals experience destructive interference. Adjustments to the signals communicated via the antenna elements can include the transmitting device or the receiving device applying an amplitude shift, a phase shift, or both to the signals carried via the antenna elements associated with the device. The adjustments associated with each antenna element can be defined by a set of beamforming weights associated with a particular direction (e.g., relative to the antenna array of the transmitting device or the receiving device, or relative to some other orientation).

[0087] In some wireless communication systems (e.g., wireless communication system 100), UE 115 may be configured to support a combined SRS resource set, such that SRS resources within the combined SRS resource set may be used for a plurality of different SRS usage scenarios (e.g., antenna switching, codebook-based, non-codebook-based, beam management). In this case, base station 105 may indicate to UE 115 the SRS resources within the SRS resource set (e.g., the combined SRS resource set) that UE 115 may use for SRS transmission. The indication may be based on one or more SRS usage scenarios, where each SRS usage scenario may be associated with a different number of ports, transmit antennas, and / or receive antennas for performing the SRS usage scenario.

[0088] For example, UE 115 may send a capability message to base station 105, the capability message indicating a first number of one or more transmit antennas supported by UE 115 for antenna switching and a second number of ports supported for uplink transmission, the second number exceeding the first number of the one or more transmit antennas. UE 115 may receive an SRS configuration based on the capability message, the SRS configuration indicating a mapping between each SRS resource group in at least a subset of a set of SRS resource groups and a corresponding bit sequence in a set of bit sequences. UE 115 may receive a control message based on the mapping, the control message including a first bit sequence in the set of bit sequences indicating a first SRS resource group in the subset of the set of SRS resource groups. Based on the control message, UE 115 may transmit a first SRS in a first SRS resource in the first SRS resource group based on the control message, and transmit a second SRS in a second SRS resource in the first SRS resource group based on the control message.

[0089] In another example, the UE 115 may send a capability message to the base station 105, the capability message indicating a first number of one or more transmit antennas supported by the UE for antenna switching and a second number of ports supported for uplink transmission, the second number exceeding the first number of transmit antennas. The UE 115 may receive an SRS configuration based on the capability message, the SRS configuration indicating a mapping between each SRS resource in the SRS resource set and a corresponding bit sequence in the bit sequence set. The UE 115 may receive a control message based on the mapping, the control message including a first bit sequence in the bit sequence set indicating a first SRS resource in the SRS resource set and a second bit sequence in the bit sequence set indicating a second SRS resource in the SRS resource set. The UE 115 may transmit a first SRS in the first SRS resource based on the first bit sequence indicated in the control message, and may transmit a second SRS in the second SRS resource based on the second bit sequence indicated in the control message.

[0090] Figure 2 An example of a wireless communication system 200 that supports techniques for indicating SRS resources according to aspects of the present disclosure is illustrated. The wireless communication system 200 may include a base station 105-a and a UE 115-a, which may be a reference Figure 1 1. An example of a base station 105 and a UE 115 is described. Base station 105-a may serve geographic coverage area 110a. In some cases, base station 105-a may implement an SRS resource indication procedure. For example, base station 105-a may indicate to UE 115-a one or more SRS resources that UE 115-a may use to send SRS transmissions to base station 105-a. Additionally or alternatively, other wireless devices, such as UE 115 or base station 105, may implement an SRS resource indication procedure and / or receive SRS indications.

[0091] In some cases, such as in a wireless communication system 200 (e.g., an NR communication system), a UE 115-a may communicate with a base station 105-a via one or more communication links 205. For example, the base station 105-a may send control signals (e.g., downlink control information (DCI) messages, radio resource control (RRC) messages, MAC-CE messages, configuration messages) and / or schedule downlink transmissions (e.g., downlink data transmissions, reference signal transmissions) to the UE 115-a via the communication link 205, which may be a downlink communication link. The UE 115-a may send one or more uplink transmissions, such as reference signals (e.g., SRS), to the base station 105-a in uplink configured resources (e.g., SRS resources) via the communication link 205, which may be an uplink communication link.

[0092] In some cases, the base station 105-a may send a sounding reference signal configuration message to configure the UE 115-a with one or more SRS resource sets 215 that the UE 115-a may use to send SRS transmissions to the base station 105-a. For example, the base station 105-a may send a configuration indicating one or more SRS resource sets 215 to the UE 115-a. The base station 105-a may send the configuration via RRC or DCI and may send an indicator via RRC or DCI to use the configuration to send aperiodic SRS or periodic (e.g., semi-persistent) SRS. The base station 105-a may configure the UE 115-a with multiple SRS resources, which may be grouped into SRS resource sets depending on the use case or type of use (e.g., antenna switching, codebook-based, non-codebook-based, beam managed).

[0093] Each SRS resource set 215 may include a set of SRS resources over which UE 115-a may send an SRS. UE 115-a and base station 105-a may support SRS resources that span 1, 2, 4, 8, or 12 adjacent symbols, with each SRS resource having up to a predefined number of ports (e.g., 8). Up to a predefined number of SRS resource sets (e.g., 2) may be configured for SRS detection with antenna switching. Each port of an SRS resource may be detected in each symbol. In some cases, UE 115-a may send an SRS in the last 6 symbols of a time slot (e.g., symbols 8 to 13), and may send an SRS in that time slot after sending a physical uplink shared channel (PUSCH) transmission. The SRS sent over an SRS resource may be a wideband SRS or a subband SRS, where the bandwidth of each SRS may be a multiple of 4 physical resource blocks (PRBs).

[0094] In some embodiments, any symbol or number of symbols within a time slot can be configured as an SRS resource. For example, a time slot can include symbols 0 to 13, which can each be allocated for SRS transmission. One or more SRS resources can be grouped in an SRS resource subset 215. In one example, the base station 105-a can configure symbols 1, 2, 3, and 4 as SRS resources for a first use case (e.g., antenna switching), such that symbols 1, 2, 3, and 4 are included in the same SRS resource set 215, such as SRS resource set 215-a. In another example, the base station 105-a can configure symbol 5 as an SRS resource for a second use case (e.g., codebook-based), such that symbol 5 can be referred to as an SRS resource set 215, such as SRS resource set 215-b.

[0095] 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 and 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 relationship between the number of transmit antennas and 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 example, 1T1R may correspond to UE 115-a having or being configured to use 1 transmit antenna and 1 receive antenna.

[0096] Performing SRS antenna switching may involve the UE 115-a transmitting an SRS to the base station 105-a via a transmit antenna, and the base station 105-a utilizing channel reciprocity to perform downlink beamforming of a time division duplex (TDD) channel. For example, the base station 105-a may receive the SRS, may perform uplink channel estimation, and may employ channel reciprocity to determine a downlink channel estimate based on the uplink channel estimate. The base station 105-a may use the downlink channel estimate for downlink beamforming. An SRS resource set 215 whose resources are used for antenna switching may be referred to as having an antenna switching usage type. In general, if the number xTyR (e.g., 1T2R, 2T4R, 1T4R, 1T4R / 2T4R, or T=R) transmitted for x≤y, then SRS antenna switching may be supported. The number of SRS resources in the SRS resource set used for antenna switching may be given by x / y. For example, the antenna switching SRS resource set 215 for a UE 115 configured with 1T4R may have four SRS resources.

[0097] For codebook based transmission, the UE 115-a may be configured with a single SRS resource set 215 (e.g., SRS-ResourceSet) with a usage type set to "codebook". The base station 105-a may send an SRI to indicate the SRS resources in the configured SRS resource set, where the SRI may have one or more bits. The maximum number of configured SRS resources for codebook based transmission may have a predefined value. When the higher layer parameter ul-FullPowerTransmission is set to full power mode (e.g., full power mode 2), the predefined value may be 4. Performing codebook based SRS communication may involve the UE 115-a sending an SRS to the base station 105-a for uplink sounding. Based on measurements of the configured SRS, the base station 105-a may sound the channel and may determine an appropriate rank and precoder matrix. Determining the rank and precoder matrix may enable the base station 105-a to perform PUSCH scheduling and / or beamforming to receive PUSCH transmissions. When performing codebook-based SRS communication, UE 115-a may be configured to transmit 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 a different orientation, and where each panel may include a set of antenna elements corresponding to an antenna port for each multi-port SRS. An SRS resource set 215 whose resources are used for codebook-based SRS communication may be referred to as having a codebook usage type.

[0098] In general, each SRS resource set 215 can be mapped to mutually exclusive resources. For example, an SRS resource set 215 associated with an antenna switching usage type (e.g., configured to use a type set for antenna switching, referred to as an antenna switching SRS resource set) can have different resources than an SRS resource set 215 with a codebook usage type (e.g., configured to use a type set for codebook, referred to as a codebook SRS resource set), such as SRS resource set 215-a and SRS resource set 215-b. In some embodiments, the codebook SRS resource set 215 can be merged with the antenna switching SRS resource set 215. The merging can include setting the codebook SRS resource set 215 to a subset of the SRS resources within the antenna switching SRS resource set 215. For example, the SRS resource set 215-a can be a combined resource set that can be used for antenna switching and codebook-based SRS. Merging the SRS resource sets 215 may reduce the number of SRS configurations or the total number of resources used to transmit SRS, which may enable the base station 105 - a to more flexibly schedule resources for other types of transmissions or transmissions from other UEs.

[0099] Base station 105-a may send an SRI to distinguish whether the SRS within the combined SRS resource set 215-a is allocated to codebook SRS (e.g., SRS for codebook-based uplink communication) or antenna switching SRS (e.g., SRS for antenna switching). If base station 105-a sends an SRI to UE 115-a and receives the corresponding SRS, base station 105-a may determine that the SRS is codebook SRS. If base station 105-a does not send an SRI to UE 115-a and receives the SRS, base station 105-a may determine that the SRS is antenna switching SRS. Additionally or alternatively, base station 105-a may send an explicit indicator for SRS transmission for antenna switching (e.g., periodic or aperiodic).

[0100] In addition, base station 105-a may use the SRI to indicate which SRS resource set 215 or which resource within the SRS resource set 215 on which the codebook SRS is sent. In one example, if x < y for xTyR, UE 115-a may use the SRI 210 to select between resources within the antenna switching SRS resource set. For example, for 1T2R, if UE115-a receives a one-bit SRI 210, UE 115-a may select between the first SRS resource of the antenna switching SRS resource set 215 and the second SRS resource of the antenna switching SRS resource set 215 based on the value of the bit. If the bit is "0", UE 115-a may send the codebook SRS over the first SRS resource, and if the bit is "1", UE 115-a may send the codebook SRS over the second SRS resource. Additional bits may be used to select between more than two SRS resources.

[0101] By using the SRI 210 to indicate which SRS resource set or which resource within the SRS resource set on which the SRS associated with the first usage type is sent, base station 105 and UE 115 may have a greater number of resources on which the SRS associated with the first usage type can be sent. However, UE 115 may be configured with a different number of transmit antennas for antenna switching and PUSCH transmission (e.g., codebook SRS usage). When the number of ports for PUSCH transmission (e.g., 2 ports or 4 ports) is greater than the number of ports for antenna switching, such as in the case where UE 115 is configured with 1T8R for antenna switching and 2 or 4 ports for PUSCH transmission, base station 105 may indicate multiple SRS resources via the SRI. However, traditional configurations of the SRI indicate that the SRI may include 1 bit or 2 bits.

[0102] The UE 115 may be configured with a number z of ports (e.g., a maximum number of ports) for PUSCH transmission and a number x of ports for antenna switching, where z = {1, 2, 4} and x = {1, 2, 4}. In some cases, one or more SRS resource sets (e.g., S>1, set>1, set 1, set 2, ..., set S) may be configured for antenna switching. In the case where more than one set is configured, a subset or all of the sets may be used for codebook-based SRS and antenna switching SRS. The SRS resource set 215 for antenna switching may include a number R of resources, where R = y / x. Each resource may have a number x of ports, and each set may include resources that satisfy The SRS resource set 215 for codebook-based SRS may use multiple SRS resources within the combined SRS resource set 215 based on a value of z (e.g., Nc=ceil(z / x), where Nc may be the number of bits indicating the SRS resources used for codebook-based SRS), wherein all codebook-based ports may be used in multiple SRS resources and multiple symbols within the SRS resource set 215. To indicate which SRS resources within the SRS resource set 215 are allocated for codebook-based SRS, the SRI may be configured to indicate multiple SRS resources, such as more than 2 bits, where the number of bits may be based on Nc=ceil(z / x)).

[0103] In some cases, to indicate which SRS resources within the SRS resource set 215 are allocated for codebook-based SRS, the UE 115 may be configured with a mapping (e.g., via a lookup table) between SRS resources or SRS resource groups within the SRS resource set 215 and bit sequences (such as SRI bit sequences). In some cases, the mapping may be based on the capabilities of the UE 115. The UE 115 may receive a control message including one or more SRI bit sequences and, based on the mapping, determine one or more SRS resources configured by the UE for SRS transmission. In a first example, the SRS resources within the SRS resource set may be grouped, and the lookup table may map an SRI bit field to one of the SRS resource groups. The UE 115-a may receive an SRI bit field that may indicate the use of multiple SRS resources included in the group. The number of SRS resources included in each group may be equal to Nc, so that each group includes the number of SRS resources used for codebook-based SRS. Thus, the base station 105-a may send an SRI field to indicate the SRS resources used for codebook-based SRS. In another example, the set of groups can be downconverted to a subset of groups to reduce the number of groups considered for codebook-based SRS, and a lookup table can map the SRI bit field to one of the groups within the subset of groups. In some cases, the UE can be configured with a lookup table that can map the SRI bit sequence to an SRS resource rather than an SRS resource group, such that a multi-bit SRI field indicates one SRS resource. Thus, if multiple SRS resources are configured for UE 115-a for SRS transmission, UE 115-a can receive multiple SRI fields.

[0104] Figure 3 An example of a wireless communication system 300 that supports techniques for indicating SRS resources according to aspects of the present disclosure is illustrated. The wireless communication system 300 may include a base station 105-b and a UE 115-b, which may be a reference Figure 1 and Figure 2 1. An example of a base station 105 and a UE 115 is depicted. Base station 105-b may serve geographic coverage area 110b. In some cases, base station 105-b may implement an SRS resource indication procedure. For example, base station 105-b may indicate to UE 115-b one or more SRS resources for UE 115-b to use for sending SRS transmissions to base station 105-b. Additionally or alternatively, other wireless devices, such as UE 115 or base station 105, may implement an SRS resource indication procedure and / or receive SRS indications.

[0105] As described herein, UE 115-b may communicate with base station 105-b via one or more communication links 305. For example, base station 105-b may send control messages 310 and / or configuration messages, such as SRS configuration messages, to UE 115-b via communication link 305, which may be a downlink communication link. UE 115-b may send one or more uplink transmissions, such as reference signals (e.g., SRS), in uplink configured resources (e.g., SRS resources) to base station 105-b via communication link 305, which may be an uplink communication link.

[0106] UE 115-b may be configured with a set of SRS resources that may be used for more than one use case, such as antenna switching and codebook-based SRS. In the case where UE 115-b is configured to have more ports for codebook-based SRS (z ports) than the number of transmit antennas for antenna switching SRS (x antennas), and the number of receive antennas for antenna switching (y antennas) is greater than the number of transmit antennas, such as z>x and y>x, UE 115-b may be configured with a lookup table (or some other mapping) that provides an association between SRS resources and SRI bit sequences, where SRI may be configured to include one, two, or more bits. UE 115 may be configured with the lookup table aperiodically or semi-persistently via control signaling, such as RRC signaling (e.g., via a configuration message).

[0107] In some cases, such as Figure 3 In the example depicted in FIG, SRS resources may be grouped, where the number of resources included in the group may be based on the number of ports configured for codebook-based SRS (e.g., as described with respect to FIG). Figure 2As described, the number of SRS resources within each group may be equal to Nc). In some cases, such as a 1T4R configuration for antenna switching, this results in UE 115-b being configured with four SRS resources (within one time slot) for antenna switching SRS. In some cases, UE 115-b may be configured with two SRS resource sets, where each SRS resource set includes two SRS resources. In some cases, one of the two SRS resource sets (e.g., a first SRS resource set) may include one SRS resource, while the other SRS resource set (e.g., a second SRS resource set) may include three bits. In some cases, UE 115-b may be configured with one SRS resource set (e.g., a combined SRS resource subset) including four SRS resources. UE 115-b may be configured to use a subset of the four SRS resources (e.g., in the first SRS resource subset, the second SRS resource subset, or the combined SRS resource subset) for codebook-based SRS. In some cases, UE 115-b may be configured with 2 ports for codebook-based SRS so that UE 115-b may use two SRS resources for codebook-based SRS use. In this way, each SRS resource group may include two SRS resources. In some embodiments, UE 115-a may be configured with a set of SRS groups that covers each combination of SRS resources. For example, a group of four SRS resources and two SRS resources may result in six SRS groups to cover each combination of four SRS resources into two groups. Continuing with this example, UE 115-b may be configured with a first SRS resource group including SRS resources 0 and 1, a second SRS resource group including SRS resources 0 and 2, a third SRS resource group including SRS resources 0 and 3, a fourth SRS resource group including SRS resources 1 and 2, a fifth SRS resource group including SRS resources 1 and 3, and a sixth SRS resource group including SRS resources 2 and 3.

[0108] The lookup table may include each group and an SRI bit sequence associated with each group (e.g., a unique SRI bit sequence in the lookup table). The number of bits included in the SRI bit field may be based on the number of groups for which UE 115-b is configured, where the number of bits in the table may be the same so that the same number of bits is used to indicate each SRS resource group in the table. For example, UE 115-a may be configured with six SRS groups, each with a unique identifier (e.g., an SRI bit sequence). An SRI bit sequence comprising 3 bits may provide 6 different bit combinations to uniquely identify each SRS resource group. The base station 105-a may send one or more SRI bit fields to UE 115-b via a control message 310 (such as a DCI message), where the number of bits included in the SRI bit field may be an appropriate number of bits to uniquely indicate which SRS resource group within the configured table UE 115-b may be used for codebook-based SRS transmission.

[0109] In some cases, the configuration of the mapping (e.g., the (multiple) lookup tables that the base station 105-b sends to the UE 115-b) may be based on the capabilities of the UE 115-b. For example, prior to mapping, the UE 115-b may be configured to or may be requested to send the capabilities of the UE 115-b to the base station 105-b via one or more capabilities messages. The capabilities message may indicate the antenna switching configuration (e.g., xTyR) with which the UE 115-b is configured, so that the UE 115-b may indicate the number of transmit and receive antennas that the UE 115-b may use for antenna-switched SRS. The capabilities message may also include the number of ports that the UE 115-b may use for codebook-based SRS. In some cases, the base station 105-b may obtain this information from another source (e.g., another base station 105), or the base station 105-b may configure the UE 115-b with the antenna switching configuration (e.g., xTyR) and / or the codebook-based configuration (e.g., z-ports), and may indicate this configuration to the UE 115-b. Thus, in this case, UE 115-b may not send a capability message to base station 105-b.

[0110] For example, UE 115-b may receive a configuration message from base station 105-b indicating a mapping between an SRS bit field and an SRS resource group. The configuration message may also indicate the SRS resources included in each SRS resource group. The configuration message may indicate that a first SRS resource group is associated with SRI 000, a second SRS resource group is associated with SRI 001, a third SRS resource group is associated with SRI 010, a fourth SRS resource group is associated with SRI 011, a fifth SRS resource group is associated with SRI 100, and a sixth SRS resource group is associated with SRI 101.

[0111] Upon receiving the configuration message, the base station 105-b may send a control message 310 including at least one SRS bit field to indicate which SRS resource group the transmitted precoding matrix indicator (TPMI) is associated with. For example, the UE 115-b may receive the control message 310 including the SRI bit sequence 010. The UE 115-b may use information included in the configuration message (such as a lookup table) to determine that the SRI bit sequence 010 is associated with the third SRS resource group. The UE 115-b may also use the information included in the configuration message to determine that the third SRS resource group includes SRS resource 0 and SRS resource 3, where SRS resources 0 and 3 may be included in the same SRS resource set or different SRS resource sets. In this way, the UE 115-b may use SRS resources 0 and 3 to send codebook-based SRS transmissions.

[0112] Tables 1 through 5 illustrate examples of lookup tables for various situations. The values ​​included in Tables 1 through 5 are merely examples, such that the values ​​and order of the groups, the resources within the groups, or the association between the SRI bit sequences and the SRS resources may be different and based on pre-configuration or configuration by the base station 105. For example, Table 1 may be an example lookup table for a UE 115 configured with a 1T4R antenna configuration for antenna switching SRS and two ports for codebook-based SRS, as shown in FIG. Figure 3 As described in the example shown. In this way, UE 115 can divide the four SRS resources into groups of two resources, resulting in six SRS resource groups. In some cases, UE 115 can send a capability message to base station 105, which indicates the number of transmit antennas and / or receive antennas that UE 115 can support for antenna switching SRS, and / or indicates the number of ports that UE 115 can support based on codebook SRS. In some cases, UE 115 can receive an SRS configuration that includes one or more mapping tables and indicates the number of configured ports for antenna switching and the number of configured ports for uplink transmission, wherein the mapping between SRS resources (or SRS groups) is based on the number of configured ports for antenna switching and the number of configured ports for uplink transmission (e.g., based on codebook SRS). An SRI bit sequence comprising three bits can be used to distinguish the six groups, wherein, for example, an SRI bit sequence of 010 can indicate SRS resources 1 and 3.

[0113]

[0114] Table 1

[0115] Table 2 may be an example lookup table for a UE 115 configured with a 2T6R (e.g., x=2 and y=6) antenna configuration for antenna switching SRS and four ports (e.g., z=4) for codebook-based SRS. Thus, the UE 115 may divide three SRS resources (e.g., R=y / x, where 6 / 2 equals three SRS resources) into two resource groups (e.g., Nc=ceil(z / x), where ceil(4 / 2) equals two SRS resources), resulting in three SRS resource groups (e.g., ). The mapping between the SRS resource groups and the SRI bit sequences can be based on the capabilities of UE 115, or based on a configuration message from base station 105 indicating the number of ports that UE 115 can use for antenna switching SRS and the number of ports that UE 115 can use for uplink transmission (e.g., codebook-based SRS), or a combination thereof. A two-bit SRI bit sequence can be used to distinguish the three groups, where, for example, an SRI bit sequence of 00 (or 0) can indicate SRS resources 0 and 1.

[0116]

[0117]

[0118] Table 2

[0119] Table 3 may be an example lookup table for a UE 115 configured with a 1T6R (e.g., x=1 and y=6) antenna configuration for antenna switching SRS and two ports or four ports (e.g., z=2 or z=4) for codebook-based SRS. In one case, the UE 115 may divide six SRS resources (e.g., R=y / x, where 6 / 1 equals six SRS resources) into groups of two resources for the two-port case (e.g., Nc=ceil(z / x), where ceil(2 / 1) equals two SRS resources), resulting in fifteen SRS resource groups (e.g., C6). 2 =15). In another case, UE 115 may divide six SRS resources (e.g., R = y / x, where 6 / 1 equals six SRS resources) into groups of four resources for the case of four ports (e.g., Nc = ceil(z / x), where ceil(4 / 1) equals four SRS resources), resulting in fifteen SRS resource groups (e.g., In either case, the fifteen groups can be distinguished using a four-bit SRI bit sequence. Based on the capabilities of UE 115 (e.g., the number of receive antennas, transmit antennas, and / or the number of ports configured for UE 115) and signaling from base station 105 (e.g., the base station can indicate the antenna and / or port configuration), UE 115 can determine whether to use the two-port column or the four-port column of the table. In some cases, Table 3 can be divided into two different tables based on the number of ports.

[0120]

[0121] Table 3

[0122] Table 4 may be an example lookup table for a UE 115 configured with a 2T8R (e.g., x=2 and y=8) antenna configuration for antenna switching SRS and four ports (e.g., z=4) for codebook-based SRS. Thus, the UE 115 may divide four SRS resources (e.g., R=y / x, where 8 / 2 equals four SRS resources) into two resource groups (e.g., Nc=ceil(z / x), where ceil(4 / 2) equals two SRS resources), resulting in six SRS resource groups (e.g., C4). 2 =6). The mapping between the SRS resource groups and the SRI bit sequences can be based on the capabilities of UE 115, or based on a configuration message from base station 105 indicating the number of ports that UE 115 can use for antenna switching SRS and the number of ports that UE 115 can use for uplink transmission (e.g., codebook-based SRS), or a combination thereof. The SRI bit sequence comprising three bits can be used to distinguish the six groups.

[0123]

[0124] Table 4

[0125] Table 5 may be an example lookup table for a UE 115 configured with a 1T8R (e.g., x=1 and y=8) antenna configuration for antenna switching SRS and two ports or four ports (e.g., z=2 or z=4) for codebook-based SRS. In one case, the UE 115 may divide eight SRS resources (e.g., R=y / x, where 8 / 1 equals eight SRS resources) into groups of two resources for the two-port case (e.g., Nc=ceil(z / x), where ceil(2 / 1) equals two SRS resources), resulting in 28 SRS resource groups (e.g., In this case, the 28 groups may be distinguished using an SRI bit sequence comprising five bits. In another case, the UE 115 may divide the 8 SRS resources (e.g., R=y / x, where 8 / 1 equals 8 SRS resources) into groups of 4 resources for a 4-port case (e.g., Nc=ceil(z / x), where ceil(4 / 1) equals 4 SRS resources), resulting in 70 SRS resource groups (e.g., In this case, a 7-bit SRI bit sequence can be used to distinguish the 70 groups. Based on the capabilities of UE 115 (e.g., the number of receive antennas, transmit antennas, and / or the number of ports configured for UE 115) and signaling from base station 105 (e.g., the base station can indicate the antenna and / or port configuration), UE 115 can determine whether to use the two-port column or the four-port column of the table. In some cases, Table 5 can be divided into two different tables based on the number of ports.

[0126]

[0127] Table 5

[0128] Figure 4 An example of a wireless communication system 400 that supports techniques for indicating SRS resources according to aspects of the present disclosure is illustrated. The wireless communication system 400 may include a base station 105-c and a UE 115-c, which may be reference Figures 1 to 3 10. An example of a base station 105 and a UE 115 is described. Base station 105-c may serve geographic coverage area 110c. In some cases, base station 105-c may implement an SRS resource indication procedure. For example, base station 105-c may indicate to UE 115-c one or more SRS resources for UE 115-c to use for sending SRS transmissions to base station 105-c. Additionally or alternatively, other wireless devices, such as UE 115 or base station 105, may implement an SRS resource indication procedure and / or receive SRS indications.

[0129] As described herein, a UE 115-c may communicate with a base station 105-c via one or more communication links 405. For example, the base station 105-c may send a control message 410 and / or a configuration message, such as an SRS configuration message, to the UE 115-c via the communication link 405, which may be a downlink communication link. The UE 115-c may send one or more uplink transmissions, such as a reference signal (e.g., an SRS), in uplink configured resources (e.g., SRS resources) to the base station 105-c via the communication link 405, which may be an uplink communication link.

[0130] As reference Figure 3 As described, the UE 115 may receive an SRS configuration, such as a lookup table or mapping that provides an association between SRS resources and SRI bit sequences, where the SRI may be configured to include one, two, or more bits. Figure 3 In the described example, SRS resources may be grouped such that a single SRS bit sequence may indicate an SRS resource group comprising multiple SRS resources. The more groups a UE 115 is configured with, the more SRI bits will be included in the SRI bit sequence. In some cases, SRS resource groups may be down-selected to reduce SRI overhead.

[0131] In some cases, UE 115-c may be configured with all groups, such as according to reference Figure 3 Described example. The base station 105-c may select a subset of SRS resource groups from the complete set of SRS resource groups and may aperiodically or semi-persistently send an indication of the subset 415 to the UE 115-c via a control message 410, such as through RRC or MAC-CE signaling. For example, the UE 115-c may receive the indication of the subset 415 via a DCI message (e.g., dynamically) indicating a change to the subset 415 having the same time slot index as the SRS transmission. In some cases, the indication of the subset 415 may be included in a configuration message, and in some cases, the configuration message may include the complete set of groups and a mapping associated with the complete set and an indication of the subset 415 of the group. In some cases, the UE 115-c may receive the complete set and the subset 415 in two different configuration messages. For example, the UE 115-c may be initially configured with the complete set of SRS groups and may perform SRS transmission based on the complete set configuration. The UE 115-c may receive an indication of the subset 415 and use the subset 415 for SRS transmission. In some cases, the UE 115-c may receive the full set and the subset 415 in the same different configuration message, and the UE 115-c may store the mapping and information associated with the full set and the subset 415. The UE 115-c may then receive a message from the base station 105-c aperiodically, semi-persistently, or dynamically (e.g., via RRC, MAC-CE, or DCI) indicating whether the UE 115-c should use the full set or the subset 415 for SRS transmission.

[0132] In some cases, UE 115 may send a capability message to base station 105 that indicates the number of transmit antennas and / or receive antennas for which UE 115 can support antenna switching SRS, and / or indicates the number of ports for which UE 115 can support codebook-based SRS. In some cases, UE 115 may receive an SRS configuration that includes one or more mapping tables and indicates the number of configured ports for antenna switching and the number of configured ports for uplink transmission, wherein mapping between SRS resources (or SRS groups) is based on the number of configured ports for antenna switching and the number of configured ports for uplink transmission (e.g., codebook-based SRS).

[0133] like Figure 4 As shown, UE 115-c may be configured with a 1T4R antenna configuration for antenna switching SRS and two ports for codebook-based SRS, as shown in FIG. Figure 3 As described in the example shown. Thus, the UE 115 can divide the four SRS resources into groups of two resources, resulting in six SRS resource groups. The six groups (e.g., Group I to Group VI) can be distinguished using an SRI bit sequence comprising three bits. The base station 105-c can determine to select two of the six groups downward. For example, the base station 105-c can select a subset 415 comprising Group I and Group II. Since the number of groups that must be distinguished by the SRI bit sequence is reduced, the number of bits included in the SRI bit sequence is reduced. For example, in order to distinguish the original six groups, the base station 105-c must include three bits in the SRI bit sequence. However, with only two groups to distinguish, the SRI bit sequence can include only one bit. Thus, the configuration message 410 including an indication of the subset 415 can also include a mapping associated with the subset 415, so that each group in the subset 415 is mapped to the SRI bit sequence. For example, UE 115-c may receive a mapping indicating that group I of subset 415 is mapped to SRI bit sequence 0 and group II of subset 415 is mapped to SRI bit sequence 1. The number of groups included in down-selected subset 415 is not restricted, such that base station 105-c may select any number of groups from the complete set to be included in subset 415. Furthermore, base station 105-c may select the groups to be included in subset 415 in any order, such that the groups included in subset 415 may be from anywhere within the complete set.

[0134] Thus, upon receiving an indication of the subset 415 and a mapping associated with the subset 415, the UE 115-c may receive a first control message 410a from the base station 105-c including an SRI bit sequence 0. The UE 115-c may determine, based on the SRI bit sequence and the indicated mapping, to use SRS resources within group I (e.g., SRS resources 0 and 1) for SRS transmission (e.g., codebook-based SRS). In another example, the UE 115-c may receive a second control message 410b from the base station 105-c including an SRI bit sequence 1. The UE 115-c may determine, based on the SRI bit sequence and the indicated mapping, to use SRS resources within group II (e.g., SRS resources 0 and 2) for SRS transmission (e.g., codebook-based SRS).

[0135] Tables 6 and 7 may indicate another example of downward selection. UE 115-c may be configured with 1T8R for antenna switching and two ports for codebook-based SRS. Thus, base station 105-c may configure UE 115-c with an SRS resource group configuration according to Table 6, which includes 28 groups and utilizes five bits to distinguish these groups. Base station 105-c may determine to downwardly select a subset of 8 groups from the set of 28. Base station 105-c may select any 8 groups within the 28, where the selection of the subset may be based on available resources, etc. In the example shown in Table 7, base station 105-c may select the first 8 groups from Table 6. Thus, base station 105-c may distinguish eight groups instead of 28 groups, and base station 105-c may use a 3-bit SRI bit sequence instead of a 5-bit SRI bit sequence. Thus, SRI overhead may be reduced. The new bit sequence (e.g., subset bit sequence) may be based on the original bit sequence (e.g., full set sequence).

[0136]

[0137]

[0138] Figure 5An example of a wireless communication system 500 that supports techniques for indicating SRS resources in accordance with aspects of the present disclosure is illustrated. The wireless communication system 500 may include a base station 105-d and a UE 115-d, which may be examples of a base station 105 and a UE 115. The base station 105-d may serve a geographic coverage area 110d. In some cases, the base station 105-d may implement an SRS resource indication procedure. For example, the base station 105-d may indicate to the UE 115-d one or more SRS resources for the UE 115-d to use for sending SRS transmissions to the base station 105-d. Additionally or alternatively, other wireless devices, such as the UE 115 or the base station 105, may implement an SRS resource indication procedure and / or receive SRS indications.

[0139] As described herein, a UE 115-d may communicate with a base station 105-d via one or more communication links 505. For example, the base station 105-d may send control signals and / or configuration messages, such as an SRS configuration message, to the UE 115-d via the communication link 505, which may be a downlink communication link. The UE 115-d may send one or more uplink transmissions, such as a reference signal (e.g., an SRS), in uplink configured resources (e.g., SRS resources) to the base station 105-d via the communication link 505, which may be an uplink communication link.

[0140] In some embodiments, the base station 105 may configure the mapping between individual SRS resources and SRI bit sequences, rather than as in the reference Figure 3 and Figure 4 The mapping between the SRS resource groups and the SRI bit sequences is configured as described above. The number of bits included in each mapped SRI bit sequence may be based on the number of SRS resources that the UE 115 is configured to use for antenna switching. For example, the UE 115-d may be configured with a 1T8R antenna configuration for antenna switching SRS. Thus, the UE 115-d may use 8 SRS resources (e.g., SRS resources 0 to 7) for antenna switching SRS and / or codebook-based SRS, and the base station 105-d may distinguish the 8 SRS resources via the SRI bit sequence. A 3-bit bit sequence may be utilized to associate a unique bit sequence with each SRS resource.

[0141] The base station 105-c may aperiodically or semi-statically send a configuration, such as a lookup table including a mapping between SRS resources and a 3-bit SRI bit sequence, to the UE 115-d via a control message 510, such as an RRC message. The base station 105-d may then send another control message, such as a DCI message, including the SRI bit sequence to the UE 115-d. The UE 115-d may identify the SRI bit sequence and use the configured lookup table to determine which SRS resource is associated with the identified SRI bit sequence. In some cases, the control message may include multiple SRI bit sequences to indicate multiple SRS resources. For example, the control message 510 may include an SRI bit sequence 000 and an SRI bit sequence 001. The UE 115-d may determine that the SRI bit sequence 000 is associated with SRS resource 0 and that the SRI bit sequence 001 is associated with SRS resource 1. Thus, the UE 115-b may use SRS resources 0 and 1 to send a codebook-based SRS transmission. In some cases, the base station 105 - d may configure up to three SRS resources for codebook-based SRS transmission to reduce the number of SRI bit sequences, thereby reducing the number of bits included in the control message 510 .

[0142] In some embodiments, the base station 105-c may select a subset of the full set of SRS resources to further reduce SRI overhead. For example, the base station 105-c may select and configure a mapping of up to three SRS resources out of eight SRS resources. This allows fewer bits to be used in the SRI bit sequence to distinguish SRS resources.

[0143] In some cases, UE 115 may send a capability message to base station 105 that indicates the number of transmit antennas and / or receive antennas for which UE 115 can support antenna switching SRS, and / or indicates the number of ports for which UE 115 can support codebook-based SRS. In some cases, UE 115 may receive an SRS configuration that includes one or more mapping tables and indicates the number of configured ports for antenna switching and the number of configured ports for uplink transmission, wherein mapping between SRS resources (or SRS groups) is based on the number of configured ports for antenna switching and the number of configured ports for uplink transmission (e.g., codebook-based SRS).

[0144] Figure 6An example of a process flow 600 supporting techniques for indicating SRS resources according to aspects of the present disclosure is illustrated. The process flow 600 may illustrate an example SRS indication and SRS transmission process. For example, a base station 105-e may indicate to a UE 115-e one or more SRS resources for the UE 115-e to use for sending SRS transmissions to the base station 105-e. The base station 105-e and the UE 115-e may be reference Figures 1 to 5 Examples of corresponding wireless devices are described. In some cases, instead of base station 105-e implementing the SRS indication process, a different type of wireless device (e.g., UE 115 or other network device) can indicate SRS resources and / or perform the SRS transmission process. The following alternative examples can be implemented, where some of the operations are performed in a different order than described or not performed at all. In some cases, the operations may include additional features not mentioned below, or further operations may be added.

[0145] At 605, the UE 115-e may send a capability message to the base station 105-e, the capability message indicating a first number of one or more transmit antennas supported by the UE for antenna switching and a second number of ports supported for uplink transmission, the second number exceeding the first number of the one or more transmit antennas. In some embodiments, the UE 115-e may send the capability message indicating a third number of one or more receive antennas supported for antenna switching, the SRS configuration being based at least in part on the third number of receive antennas supported for antenna switching. The third number of one or more receive antennas exceeds the first number of one or more transmit antennas. Based on the capability message, the base station 105-b may determine a number of resource sets and a number of SRS resource groups for SRS sounding and codebook-based sounding of the SRS for antenna switching, and may determine the mapping between SRI bit sequences and SRS resource groups.

[0146] At 610, the UE 115-e may receive an SRS configuration from the base station 105-e based at least in part on the capability message, the SRS configuration indicating a mapping between each SRS resource group in at least a subset of a plurality of SRS resource groups and a corresponding bit sequence in a plurality of bit sequences. In some cases, the UE 115-e may receive the SRS configuration indicating a mapping table indicating a mapping between each SRS resource group in at least the subset of the plurality of SRS resource groups and the corresponding bit sequence in the plurality of bit sequences. In some cases, the UE 115-e may receive the SRS configuration indicating a number of configured ports for antenna switching and a number of configured ports for uplink transmission, wherein the mapping is based at least in part on the number of configured ports for antenna switching and the number of configured ports for uplink transmission (e.g., a codebook-based SRS). In some cases, the UE 115-e may receive the SRS configuration indicating a mapping between each SRS group in the plurality of SRS resource groups and a corresponding bit sequence in the plurality of bit sequences. For example, UE 115-e may receive a configuration message from base station 105-e indicating a configuration such as a reference Figure 3 and Figure 4 The mapping tables of Tables 1 to 7 described above may be based on the configuration of the UE 115 and / or based on a configuration message from the base station 105-e, which indicates the number of ports that the base station 105-e has allocated to the UE 115-e for antenna switching SRS and the number of ports that the base station 105-e has allocated to the UE 115-e for codebook-based SRS.

[0147] In some cases, the UE 115-e may receive the SRS configuration indicating a codebook SRS configuration. Each SRS resource group may include a single SRS resource in the SRS resource group. Each bit sequence in the plurality of bit sequences may include a single bit.

[0148] At 615, the UE 115-e may receive a control message from the base station 105-e based at least in part on the mapping, the control message including a first bit sequence from the plurality of bit sequences indicating a first SRS resource group in the subset of the plurality of SRS resource groups. In some cases, the UE 115-e may receive a downlink control information message including the first bit sequence.

[0149] At 620 , the UE 115 - e may send a first SRS to the base station 105 - e in a first SRS resource in the first SRS resource group based at least in part on the control message.

[0150] At 625 , the UE 115 - e may send a second SRS to the base station 105 - e in a second SRS resource in the first set of SRS resources based at least in part on the control message.

[0151] Figure 7 An example of a process flow 700 supporting techniques for indicating SRS resources according to aspects of the present disclosure is illustrated. The process flow 700 may illustrate an example SRS indication and SRS transmission process. For example, a base station 105-f may indicate to a UE 115-f one or more SRS resources for the UE 115-f to use for sending SRS transmissions to the base station 105-f. The base station 105-f and the UE 115-f may be reference Figures 1 to 6 Examples of corresponding wireless devices are described. In some cases, instead of base station 105-f implementing the SRS indication process, a different type of wireless device (e.g., UE 115 or other network device) can indicate SRS resources and / or perform the SRS transmission process. The following alternative examples can be implemented, with some operations performed in a different order than described or not performed at all. In some cases, the operations may include additional features not mentioned below, or further operations may be added.

[0152] At 705, UE 115-f may send a capability message to base station 105-f, the capability message indicating a first number of one or more transmit antennas supported by the UE for antenna switching and a second number of ports supported for uplink transmission, the second number exceeding the first number of transmit antennas. In some embodiments, UE 115-f may send the capability message indicating a third number of one or more receive antennas supported for antenna switching, the SRS configuration being based at least in part on the third number of receive antennas supported for antenna switching. The third number of one or more receive antennas exceeds the first number of one or more transmit antennas. Based on the capability message, base station 105-b may determine a number of resource sets and a number of SRS resource groups for SRS sounding and codebook-based sounding of SRS for antenna switching, and may determine a mapping between SRI bit sequences and SRS resource groups.

[0153] At 710, the UE 115-f may receive an SRS configuration based at least in part on the capability message, the SRS configuration indicating a mapping between each of the plurality of SRS resources and a corresponding bit sequence in the plurality of bit sequences. In some cases, the UE 115-f may receive the SRS configuration indicating a codebook SRS configuration. In some cases, the UE 115-f may receive the SRS configuration indicating a mapping table corresponding to the mapping, wherein the corresponding bit sequence indicates a corresponding index to the mapping table. For example, the UE 115-f may receive a configuration message from the base station 105-f indicating a mapping table such as a reference bit sequence. Figure 5 A mapping table of tables described, wherein the mapping table can be based on the configuration of UE 115 and / or based on a configuration message from base station 105-f, which indicates the number of ports that base station 105-f has allocated to UE 115-f for antenna switching SRS and the number of ports that base station 105-f has allocated to UE 115-f for codebook-based SRS.

[0154] At 715, UE 115-f may receive a control message from base station 105-f based at least in part on the mapping, the control message including a first bit sequence in the plurality of bit sequences indicating a first SRS resource in the plurality of SRS resources and a second bit sequence in the plurality of bit sequences indicating a second SRS resource in the plurality of SRS resources. In some cases, UE 115-c may receive a downlink control information message including the first bit sequence and the second bit sequence.

[0155] At 720 , UE 115 - f may send a first SRS to base station 105 - f in the first SRS resource based at least in part on the first bit sequence indicated in the control message.

[0156] At 725 , UE 115 - f may send a second SRS to base station 105 - f in the second SRS resource based at least in part on the second bit sequence indicated in the control message.

[0157] Figure 8 A block diagram 800 is shown of a device 805 that supports techniques for indicating SRS resources according to aspects of the present disclosure. The device 805 can be an example of aspects of the UE 115 as described herein. The device 805 can include a receiver 810, a communication manager 815, and a transmitter 820. The device 805 can also include a processor. Each of these components can communicate with each other directly or indirectly (e.g., via one or more buses).

[0158] The receiver 810 may receive information associated with various information channels (e.g., a control channel, a data channel, and information related to a technique for indicating SRS resources, etc.), such as packets, user data, or control information. The information may be delivered to other components of the device 805. The receiver 810 may be a reference Figure 11 Examples of various aspects of the transceiver 1120 are described. The receiver 810 may utilize a single antenna or a collection of antennas.

[0159] The communication manager 815 can: send a capability message indicating a first number of one or more transmit antennas supported by the UE for antenna switching and a second number of ports supported for uplink transmission, the second number exceeding the first number of the one or more transmit antennas; receive an SRS configuration based on the capability message, the SRS configuration indicating a mapping between each SRS resource group in at least a subset of the SRS resource group set and a corresponding bit sequence in the bit sequence set; receive a control message based on the mapping, the control message including a first bit sequence in the bit sequence set indicating a first SRS resource group in the subset of the SRS resource group set; send a first SRS in a first SRS resource in the first SRS resource group based on the control message; and send a second SRS in a second SRS resource in the first SRS resource group based on the control message. The communication manager 815 may also: send a capability message indicating a first number of one or more transmit antennas supported by the UE for antenna switching and a second number of ports supported for uplink transmission, the second number exceeding the first number of transmit antennas; receive an SRS configuration based on the capability message, the SRS configuration indicating a mapping between each SRS resource in the SRS resource set and a corresponding bit sequence in the bit sequence set; receive a control message based on the mapping, the control message including a first bit sequence in the bit sequence set indicating a first SRS resource in the SRS resource set and a second bit sequence in the bit sequence set indicating a second SRS resource in the SRS resource set; send a first SRS in the first SRS resource based on the first bit sequence indicated in the control message; and send a second SRS in the second SRS resource based on the second bit sequence indicated in the control message. The communication manager 815 may be an example of aspects of the communication manager 1110 described herein.

[0160] The communication manager 815 or its subcomponents may be implemented in hardware, in 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 815 or its subcomponents may be controlled by a general-purpose processor, a digital signal processor (DSP), an application-specific integrated circuit (ASIC), a field-programmable gate array (FPGA) or other programmable logic device designed to perform the functions described in this disclosure, discrete gate or transistor logic, discrete hardware components, or any combination thereof.

[0161] The communication manager 815 or its subcomponents can be physically located in different locations, including being distributed so that portions of the functionality are implemented by one or more physical components at different physical locations. In some examples, according to various aspects of the present disclosure, the communication manager 815 or its subcomponents can be separate and distinct components. In some examples, according to various aspects of the present disclosure, the communication manager 815 or its subcomponents can be combined with one or more other hardware components, including but not limited to input / output (I / O) components, a transceiver, a network server, another computing device, one or more other components described in the present disclosure, or a combination thereof.

[0162] The transmitter 820 can transmit signals generated by other components of the device 805. In some examples, the transmitter 820 can be collocated with the receiver 810 in a transceiver module. For example, the transmitter 820 can be a reference Figure 11 Examples of various aspects of the transceiver 1120 are described. The transmitter 820 may utilize a single antenna or a collection of antennas.

[0163] The communication manager 815 as described herein can be implemented to achieve one or more potential advantages. One embodiment can allow the device 805 to more efficiently schedule SRS transmissions to be sent by the device 805. For example, the device 805 can be configured with a single set of SRS resources that can be used for multiple different SRS use cases, and the device 805 can receive reliable indications of which SRS resources within the set of SRS resources to use for certain SRS transmissions (e.g., for certain SRS use cases).

[0164] Based on implementing the SRS configuration and transmission techniques described herein, the processor of the UE 115 (e.g., as described in reference Figure 11 As described, controlling the receiver 810, transmitter 820, or transceiver 1120) can improve the reliability and efficiency of communicating reference signals between the UE 115 and one or more base stations and determining channel properties based on the reference signals.

[0165] Figure 9A block diagram 900 is shown of a device 905 that supports techniques for indicating SRS resources according to aspects of the present disclosure. The device 905 can be an example of aspects of the device 805 or UE 115 as described herein. The device 905 can include a receiver 910, a communication manager 915, and a transmitter 945. The device 905 can also include a processor. Each of these components can communicate with each other directly or indirectly (e.g., via one or more buses).

[0166] The receiver 910 may receive information associated with various information channels (e.g., a control channel, a data channel, and information related to a technique for indicating SRS resources, etc.), such as packets, user data, or control information. The information may be delivered to other components of the device 905. The receiver 910 may be a reference Figure 11 Examples of aspects of the described transceiver 1120. The receiver 910 may utilize a single antenna or a collection of antennas.

[0167] The communication manager 915 may be an example of aspects of the communication manager 815 described herein. The communication manager 915 may include a capability message manager 920, an SRS configuration manager 925, a bit sequence reception manager 930, a first SRS transmission manager 935, and a second SRS transmission manager 940. The communication manager 915 may be an example of aspects of the communication manager 1110 described herein.

[0168] The capability message manager 920 may send a capability message indicating a first number of one or more transmit antennas supported by the UE for antenna switching and a second number of ports supported for uplink transmission, the second number exceeding the first number of the one or more transmit antennas. The SRS configuration manager 925 may receive an SRS configuration based on the capability message, the SRS configuration indicating a mapping between each SRS resource group in at least a subset of the SRS resource group set and a corresponding bit sequence in the bit sequence set. The bit sequence reception manager 930 may receive a control message based on the mapping, the control message including a first bit sequence in the bit sequence set indicating a first SRS resource group in the subset of the SRS resource group set. The first SRS transmission manager 935 may transmit a first SRS in a first SRS resource in the first SRS resource group based on the control message. The second SRS transmission manager 940 may transmit a second SRS in a second SRS resource in the first SRS resource group based on the control message.

[0169] The capability message manager 920 may send a capability message indicating a first number of one or more transmit antennas supported by the UE for antenna switching and a second number of ports supported for uplink transmission, the second number exceeding the first number of transmit antennas. The SRS configuration manager 925 may receive an SRS configuration based on the capability message, the SRS configuration indicating a mapping between each SRS resource in an SRS resource set and a corresponding bit sequence in a bit sequence set. The bit sequence reception manager 930 may receive a control message based on the mapping, the control message including a first bit sequence in the bit sequence set indicating a first SRS resource in the SRS resource set and a second bit sequence in the bit sequence set indicating a second SRS resource in the SRS resource set. The first SRS transmission manager 935 may transmit a first SRS in the first SRS resource based on the first bit sequence indicated in the control message. The second SRS transmission manager 940 may transmit a second SRS in the second SRS resource based on the second bit sequence indicated in the control message.

[0170] The transmitter 945 can transmit signals generated by other components of the device 905. In some examples, the transmitter 945 can be collocated with the receiver 910 in a transceiver module. For example, the transmitter 945 can be a reference Figure 11 Examples of various aspects of the transceiver 1120 are described. The transmitter 945 can utilize a single antenna or a collection of antennas.

[0171] Figure 10 A block diagram 1000 is shown of a communication manager 1005 that supports techniques for indicating SRS resources in accordance with aspects of the present disclosure. The communication manager 1005 can be an example of aspects of the communication manager 815, the communication manager 915, or the communication manager 1110 described herein. The communication manager 1005 can include a capability message manager 1010, an SRS configuration manager 1015, a bit sequence reception manager 1020, a first SRS transmission manager 1025, a second SRS transmission manager 1030, a mapping table reception manager 1035, and a port configuration manager 1040. Each of these modules can communicate with each other directly or indirectly (e.g., via one or more buses).

[0172] The capability message manager 1010 may send a capability message indicating a first number of one or more transmit antennas supported by the UE for antenna switching and a second number of ports supported for uplink transmission, the second number exceeding the first number of the one or more transmit antennas. The SRS configuration manager 1015 may receive an SRS configuration based on the capability message, the SRS configuration indicating a mapping between each SRS resource group in at least a subset of a set of SRS resource groups and a corresponding bit sequence in a set of bit sequences. The bit sequence reception manager 1020 may receive a control message based on the mapping, the control message including a first bit sequence in the set of bit sequences indicating a first SRS resource group in the subset of the set of SRS resource groups. The first SRS transmission manager 1025 may transmit a first SRS in a first SRS resource in the first SRS resource group based on the control message. The second SRS transmission manager 1030 may transmit a second SRS in a second SRS resource in the first SRS resource group based on the control message.

[0173] The mapping table receiving manager 1035 may receive the SRS configuration indicating a mapping table, the mapping table indicating a mapping between each SRS resource group in at least the subset of the set of SRS resource groups and a corresponding bit sequence in the set of bit sequences. The port configuration manager 1040 may receive the SRS configuration indicating the number of configured ports for antenna switching and the number of configured ports for uplink transmission, wherein the mapping is based on the number of configured ports for antenna switching and the number of configured ports for uplink transmission.

[0174] In some examples, the SRS configuration manager 1015 may receive the SRS configuration indicating a mapping between each SRS group in the set of SRS resource groups and a corresponding bit sequence in the set of bit sequences.

[0175] In some examples, the capability message manager 1010 may send the capability message indicating a third number of one or more receive antennas supported for antenna switching, the SRS configuration being based on the third number of receive antennas supported for antenna switching. In some cases, the third number of one or more receive antennas exceeds the first number of one or more transmit antennas.

[0176] In some examples, the bit sequence reception manager 1020 may receive a downlink control information message including the first bit sequence. In some cases, each SRS resource group includes a single SRS resource in the SRS resource group. In some examples, the SRS configuration manager 1015 may receive an SRS configuration indicating a codebook SRS configuration. In some cases, each bit sequence in the set of bit sequences includes a single bit.

[0177] The capability message manager 1010 may send a capability message indicating a first number of one or more transmit antennas supported by the UE for antenna switching and a second number of ports supported for uplink transmission, the second number exceeding the first number of transmit antennas. The SRS configuration manager 1015 may receive an SRS configuration based on the capability message, the SRS configuration indicating a mapping between each SRS resource in an SRS resource set and a corresponding bit sequence in a bit sequence set. The bit sequence reception manager 1020 may receive a control message based on the mapping, the control message including a first bit sequence in the bit sequence set indicating a first SRS resource in the SRS resource set and a second bit sequence in the bit sequence set indicating a second SRS resource in the SRS resource set. The first SRS transmission manager 1025 may transmit a first SRS in the first SRS resource based on the first bit sequence indicated in the control message. The second SRS transmission manager 1030 may transmit a second SRS in the second SRS resource based on the second bit sequence indicated in the control message.

[0178] In some examples, the SRS configuration manager 1015 may receive the SRS configuration indicating a codebook SRS configuration. In some examples, the mapping table reception manager 1035 may receive the SRS configuration indicating a mapping table corresponding to the mapping, wherein the corresponding bit sequence indicates a corresponding index to the mapping table.

[0179] In some examples, the capability message manager 1010 may send the capability message indicating a third number of one or more receive antennas supported for antenna switching, the SRS configuration being based on the third number of receive antennas supported for antenna switching. In some cases, the third number of one or more receive antennas exceeds the first number of one or more transmit antennas.

[0180] In some examples, the bit sequence reception manager 1020 may receive a downlink control information message including the first bit sequence and the second bit sequence.

[0181] Figure 11A diagram of a system 1100 including a device 1105 supporting techniques for indicating SRS resources according to aspects of the present disclosure is shown. The device 1105 may be an example of, or include components of, the device 805, device 905, or UE 115 described herein. The device 1105 may include components for two-way voice and data communications, including components for sending and receiving communications, including a communications manager 1110, an I / O controller 1115, a transceiver 1120, an antenna 1125, a memory 1130, and a processor 1140. These components may be in electronic communication via one or more buses (e.g., bus 1145).

[0182] The communication manager 1110 may: send a capability message indicating a first number of one or more transmit antennas supported by the UE for antenna switching and a second number of ports supported for uplink transmission, the second number exceeding the first number of the one or more transmit antennas; receive an SRS configuration based on the capability message, the SRS configuration indicating a mapping between each SRS resource group in at least a subset of the SRS resource group set and a corresponding bit sequence in the bit sequence set; receive a control message based on the mapping, the control message including a first bit sequence in the bit sequence set indicating a first SRS resource group in the subset of the SRS resource group set; send a first SRS in a first SRS resource in the first SRS resource group based on the control message; and send a second SRS in a second SRS resource in the first SRS resource group based on the control message. The communication manager 1110 can also: send a capability message indicating a first number of one or more transmitting antennas supported by the UE for antenna switching and a second number of ports supported for uplink transmission, the second number exceeding the first number of transmitting antennas; receive an SRS configuration based on the capability message, the SRS configuration indicating a mapping between each SRS resource in the SRS resource set and a corresponding bit sequence in the bit sequence set; receive a control message based on the mapping, the control message including a first bit sequence in the bit sequence set indicating a first SRS resource in the SRS resource set, and a second bit sequence in the bit sequence set indicating a second SRS resource in the SRS resource set; send a first SRS in the first SRS resource based on the first bit sequence indicated in the control message; and send a second SRS in the second SRS resource based on the second bit sequence indicated in the control message.

[0183] I / O controller 1115 can manage input and output signals for device 1105. I / O controller 1115 can also manage peripheral devices that are not integrated into device 1105. In some cases, I / O controller 1115 can represent a physical connection or port to an external peripheral device. In some cases, I / O controller 1115 can utilize a controller such as 1105. In some cases, the I / O controller 1115 may represent or interact with a modem, keyboard, mouse, touch screen, or similar device. In some cases, the I / O controller 1115 may be implemented as part of the processor. In some cases, a user may interact with the device 1105 via the I / O controller 1115 or via hardware components controlled by the I / O controller 1115.

[0184] As described above, transceiver 1120 can communicate bidirectionally via one or more antennas, wired or wireless links. For example, transceiver 1120 can represent a wireless transceiver and can communicate bidirectionally with another wireless transceiver. Transceiver 1120 can also include a modem to modulate packets and provide the modulated packets to the antenna for transmission, and demodulate packets received from the antenna.

[0185] In some cases, a wireless device may include a single antenna 1125. However, in some cases, a device may have more than one antenna 1125, which may be capable of sending or receiving multiple wireless transmissions concurrently.

[0186] Memory 1130 may include random access memory (RAM) and read-only memory (ROM). Memory 1130 may store computer-readable, computer-executable code 1135 including instructions that, when executed, cause the processor to perform the various functions described herein. In some cases, memory 1130 may include, among other things, an I / O system (BIOS), which may control basic hardware or software operations, such as interacting with peripheral components or devices.

[0187] The processor 1140 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, discrete gate or transistor logic components, discrete hardware components, or any combination thereof). In some cases, the processor 1140 may be configured to operate the memory array using a memory controller. In other cases, the memory controller may be integrated into the processor 1140. The processor 1140 may be configured to execute computer-readable instructions stored in a memory (e.g., memory 1130) to cause the device 1105 to perform various functions (e.g., functions or tasks supporting techniques for indicating SRS resources).

[0188] The code 1135 may include instructions for implementing various aspects of the present disclosure, including instructions for supporting wireless communications. The code 1135 may be stored in a non-transitory computer-readable medium such as system memory or other types of memory. In some cases, the code 1135 may not be directly executed by the processor 1140, but may cause the computer (e.g., when compiled and executed) to perform the functions described herein.

[0189] Figure 12 A block diagram 1200 is shown of a device 1205 supporting techniques for indicating SRS resources according to aspects of the present disclosure. The device 1205 may be an example of aspects of the base station 105 described herein. The device 1205 may include a receiver 1210, a communication manager 1215, and a transmitter 1220. The device 1205 may also include a processor. Each of these components may communicate with each other directly or indirectly (e.g., via one or more buses).

[0190] The receiver 1210 may receive information associated with various information channels (e.g., control channels, data channels, and information related to techniques for indicating SRS resources, etc.), such as packets, user data, or control information. The information may be delivered to other components of the device 1205. The receiver 1210 may be a reference Figure 15 Examples of various aspects of the transceiver 1520 are described. The receiver 1210 may utilize a single antenna or a collection of antennas.

[0191] The communication manager 1215 can: receive a capability message from the UE, the capability message indicating a first number of one or more transmitting antennas supported by the UE for antenna switching and a second number of ports supported for uplink transmission, the second number exceeding the first number of the one or more transmitting antennas; send an SRS configuration based on the capability message, the SRS configuration indicating a mapping between each SRS resource group in at least a subset of the SRS resource group set and a corresponding bit sequence in the bit sequence set; send a control message based on the mapping, the control message including a first bit sequence in the bit sequence set indicating a first SRS resource group in the subset of the SRS resource group set; receive a first SRS in a first SRS resource in the first SRS resource group based on the control message; and receive a second SRS in a second SRS resource in the first SRS resource group based on the control message. The communication manager 1215 may also: receive a capability message from a UE, the capability message indicating a first number of one or more transmit antennas supported by the UE for antenna switching and a second number of ports supported for uplink transmission, the second number exceeding the first number of transmit antennas; send an SRS configuration based on the capability message, the SRS configuration indicating a mapping between each SRS resource in an SRS resource set and a corresponding bit sequence in a bit sequence set; send a control message based on the mapping, the control message including a first bit sequence in the bit sequence set indicating a first SRS resource in the SRS resource set and a second bit sequence in the bit sequence set indicating a second SRS resource in the SRS resource set; receive a first SRS in the first SRS resource based on the first bit sequence indicated in the control message; and receive a second SRS in the second SRS resource based on the second bit sequence indicated in the control message. The communication manager 1215 may be an example of aspects of the communication manager 1510 described herein.

[0192] The communication manager 1215 or its subcomponents may be implemented by 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 1215 or its subcomponents may be performed by a general-purpose processor, a DSP, an application-specific integrated circuit (ASIC), an FPGA or other programmable logic device designed to perform the functions described in this disclosure, discrete gate or transistor logic, discrete hardware components, or any combination thereof.

[0193] The communication manager 1215 or its subcomponents can be physically located in a variety of locations, including being distributed so that portions of the functionality are implemented by one or more physical components at different physical locations. In some examples, the communication manager 1215 or its subcomponents can be separate and distinct components according to various aspects of the present disclosure. In some examples, according to various aspects of the present disclosure, the communication manager 1215 or its subcomponents can be combined with one or more other hardware components, including but not limited to input / output (I / O) components, a transceiver, a network server, another computing device, one or more other components described in the present disclosure, or a combination thereof.

[0194] Transmitter 1220 can transmit signals generated by other components of device 1205. In some examples, transmitter 1220 can be collocated with receiver 1210 in a transceiver module. For example, transmitter 1220 can be a reference Figure 15 Examples of various aspects of the transceiver 1520 are described. The transmitter 1220 can utilize a single antenna or a collection of antennas.

[0195] Figure 13 A block diagram 1300 is shown of a device 1305 supporting techniques for indicating SRS resources according to aspects of the present disclosure. The device 1305 can be an example of aspects of the device 1205 or base station 105 as described herein. The device 1305 can include a receiver 1310, a communication manager 1315, and a transmitter 1345. The device 1305 can also include a processor. Each of these components can communicate with each other directly or indirectly (e.g., via one or more buses).

[0196] The receiver 1310 may receive information associated with various information channels (e.g., control channels, data channels, and information related to techniques for indicating SRS resources, etc.), such as packets, user data, or control information. The information may be delivered to other components of the device 1305. The receiver 1310 may be a reference Figure 15 Examples of various aspects of the transceiver 1520 are described. The receiver 1310 may utilize a single antenna or a collection of antennas.

[0197] The communication manager 1315 can be an example of aspects of the communication manager 1215 described herein. The communication manager 1315 can include a capability message component 1320, an SRS configuration component 1325, a bit sequence transmission component 1330, a first SRS reception component 1335, and a second SRS reception component 1340. The communication manager 1315 can be an example of aspects of the communication manager 1510 described herein.

[0198] The capability message component 1320 may receive a capability message from a UE, the capability message indicating a first number of one or more transmit antennas supported by the UE for antenna switching and a second number of ports supported for uplink transmission, the second number exceeding the first number of the one or more transmit antennas. The SRS configuration component 1325 may transmit an SRS configuration based on the capability message, the SRS configuration indicating a mapping between each SRS resource group in at least a subset of the set of SRS resource groups and a corresponding bit sequence in the set of bit sequences. The bit sequence transmission component 1330 may transmit a control message based on the mapping, the control message including a first bit sequence in the set of bit sequences indicating a first SRS resource group in the subset of the set of SRS resource groups. The first SRS reception component 1335 may receive a first SRS in a first SRS resource in the first SRS resource group based on the control message. The second SRS reception component 1340 may receive a second SRS in a second SRS resource in the first SRS resource group based on the control message.

[0199] The capability message component 1320 may receive a capability message from a UE, the capability message indicating a first number of one or more transmit antennas supported by the UE for antenna switching and a second number of ports supported for uplink transmission, the second number exceeding the first number of transmit antennas. The SRS configuration component 1325 may transmit an SRS configuration based on the capability message, the SRS configuration indicating a mapping between each SRS resource in the SRS resource set and a corresponding bit sequence in the bit sequence set. The bit sequence transmission component 1330 may transmit a control message based on the mapping, the control message including a first bit sequence in the bit sequence set indicating a first SRS resource in the SRS resource set and a second bit sequence in the bit sequence set indicating a second SRS resource in the SRS resource set. The first SRS reception component 1335 may receive a first SRS in the first SRS resource based on the first bit sequence indicated in the control message. The second SRS reception component 1340 may receive a second SRS in the second SRS resource based on the second bit sequence indicated in the control message.

[0200] Transmitter 1345 can transmit signals generated by other components of device 1305. In some examples, transmitter 1345 can be collocated with receiver 1310 in a transceiver module. For example, transmitter 1345 can be a reference Figure 15 Examples of various aspects of the transceiver 1520 are described. The transmitter 1345 can utilize a single antenna or a collection of antennas.

[0201] Figure 14A block diagram 1400 is shown of a communication manager 1405 that supports techniques for indicating SRS resources in accordance with aspects of the present disclosure. The communication manager 1405 can be an example of aspects of the communication manager 1215, the communication manager 1315, or the communication manager 1510 described herein. The communication manager 1405 can include a capability message component 1410, an SRS configuration component 1415, a bit sequence transmission component 1420, a first SRS reception component 1425, a second SRS reception component 1430, a mapping table transmission component 1435, and a port configuration component 1440. Each of these modules can communicate with each other directly or indirectly (e.g., via one or more buses).

[0202] The capability message component 1410 may receive a capability message from a UE, the capability message indicating a first number of one or more transmit antennas supported by the UE for antenna switching and a second number of ports supported for uplink transmission, the second number exceeding the first number of the one or more transmit antennas. The SRS configuration component 1415 may transmit an SRS configuration based on the capability message, the SRS configuration indicating a mapping between each SRS resource group in at least a subset of the set of SRS resource groups and a corresponding bit sequence in the set of bit sequences. The bit sequence transmission component 1420 may transmit a control message based on the mapping, the control message including a first bit sequence in the set of bit sequences indicating a first SRS resource group in the subset of the set of SRS resource groups. The first SRS reception component 1425 may receive a first SRS in a first SRS resource in the first SRS resource group based on the control message. The second SRS reception component 1430 may receive a second SRS in a second SRS resource in the first SRS resource group based on the control message.

[0203] The mapping table sending component 1435 can send the SRS configuration indicating a mapping table, the mapping table indicating a mapping between each SRS resource group in at least the subset of the set of SRS resource groups and the corresponding bit sequence in the set of bit sequences. The port configuration component 1440 can send the SRS configuration indicating the number of configured ports for antenna switching and the number of configured ports for uplink transmission, wherein the mapping can be based on the number of configured ports for antenna switching and the number of configured ports for uplink transmission.

[0204] In some examples, the SRS configuration component 1415 can transmit the SRS configuration indicating a mapping between each SRS group in the set of SRS resource groups and a corresponding bit sequence in the set of bit sequences.

[0205] In some examples, capability message component 1410 can receive the capability message indicating a third number of one or more receive antennas supported for antenna switching, the SRS configuration being based on the third number of receive antennas supported for antenna switching. In some cases, the third number of one or more receive antennas exceeds the first number of one or more transmit antennas.

[0206] In some examples, the bit sequence transmitting component 1420 may transmit a downlink control information message including the first bit sequence.

[0207] In some cases, each SRS resource group includes a single SRS resource in the SRS resource group. In some examples, SRS configuration component 1415 can send the SRS configuration indicating the codebook SRS configuration. In some cases, each bit sequence in the set of bit sequences includes a single bit.

[0208] The capability message component 1410 may receive a capability message from a UE, the capability message indicating a first number of one or more transmit antennas supported by the UE for antenna switching and a second number of ports supported for uplink transmission, the second number exceeding the first number of transmit antennas. The SRS configuration component 1415 may transmit an SRS configuration based on the capability message, the SRS configuration indicating a mapping between each SRS resource in an SRS resource set and a corresponding bit sequence in a bit sequence set. The bit sequence transmission component 1420 may transmit a control message based on the mapping, the control message including a first bit sequence in the bit sequence set indicating a first SRS resource in the SRS resource set and a second bit sequence in the bit sequence set indicating a second SRS resource in the SRS resource set. The first SRS reception component 1425 may receive a first SRS in the first SRS resource based on the first bit sequence indicated in the control message. The second SRS reception component 1430 may receive a second SRS in the second SRS resource based on the second bit sequence indicated in the control message.

[0209] In some examples, SRS configuration component 1415 may transmit the SRS configuration indicating a codebook SRS configuration.

[0210] In some examples, the mapping table transmitting component 1435 may transmit the SRS configuration indicating a mapping table corresponding to the mapping, wherein the corresponding bit sequence indicates a corresponding index to the mapping table.

[0211] In some examples, capability message component 1410 can receive the capability message indicating a third number of one or more receive antennas supported for antenna switching, the SRS configuration being based on the third number of receive antennas supported for antenna switching. In some cases, the third number of one or more receive antennas exceeds the first number of one or more transmit antennas.

[0212] In some examples, the bit sequence transmitting component 1420 may transmit a downlink control information message including the first bit sequence and the second bit sequence.

[0213] Figure 15 A diagram of a system 1500 including a device 1505 supporting techniques for indicating SRS resources according to aspects of the present disclosure is shown. The device 1505 can be an example of, or include components of, the device 1205, device 1305, or base station 105 described herein. The device 1505 can include components for two-way voice and data communications, including components for sending and receiving communications, including a communication manager 1510, an I / O controller 1515, a transceiver 1520, an antenna 1525, a memory 1530, a processor 1540, and an inter-station communication manager 1545. These components can communicate electronically via one or more buses (e.g., bus 1550).

[0214] The communication manager 1510 may: receive a capability message from a UE, the capability message indicating a first number of one or more transmit antennas supported by the UE for antenna switching and a second number of ports supported for uplink transmission, the second number exceeding the first number of the one or more transmit antennas; send an SRS configuration based on the capability message, the SRS configuration indicating a mapping between each SRS resource group in at least a subset of the SRS resource group set and a corresponding bit sequence in a bit sequence set; send a control message based on the mapping, the control message including a first bit sequence in the bit sequence set indicating a first SRS resource group in the subset of the SRS resource group set; receive a first SRS in a first SRS resource in the first SRS resource group based on the control message; and receive a second SRS in a second SRS resource in the first SRS resource group based on the control message. The communication manager 1510 can also: receive a capability message from the UE, the capability message indicating a first number of one or more transmitting antennas supported by the UE for antenna switching and a second number of ports supported for uplink transmission, the second number exceeding the first number of transmitting antennas; send an SRS configuration based on the capability message, the SRS configuration indicating a mapping between each SRS resource in the SRS resource set and a corresponding bit sequence in the bit sequence set; send a control message based on the mapping, the control message including: a first bit sequence in the bit sequence set indicating a first SRS resource in the SRS resource set, and a second bit sequence in the bit sequence set indicating a second SRS resource in the SRS resource set; receive a first SRS in the first SRS resource based on the first bit sequence indicated in the control message; and receive a second SRS in the second SRS resource based on the second bit sequence indicated in the control message.

[0215] The network communications manager 1515 may manage communications with the core network (eg, via one or more wired backhaul links). For example, the network communications manager 1515 may manage the delivery of data communications for client devices such as one or more UEs 115.

[0216] The transceiver 1520 can communicate bidirectionally via one or more antennas, wired or wireless links as described above. For example, the transceiver 1520 can represent a wireless transceiver and can communicate bidirectionally with another wireless transceiver. The transceiver 1520 can also include a modem to modulate packets and provide the modulated packets to the antenna for transmission, as well as demodulate packets received from the antenna.

[0217] In some cases, a wireless device may include a single antenna 1525. However, in some cases, the device may have more than one antenna 1525, which may be capable of sending or receiving multiple wireless transmissions simultaneously.

[0218] Memory 1530 may include RAM, ROM, or a combination thereof. Memory 1530 may store computer-readable code 1535 including instructions that, when executed by a processor (e.g., processor 1540), cause the device to perform various functions described herein. In some cases, memory 1530 may include, among other things, a BIOS that controls basic hardware or software operations, such as interacting with peripheral components or devices.

[0219] Processor 1540 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, discrete gate or transistor logic components, discrete hardware components, or any combination thereof). In some cases, processor 1540 may be configured to operate a memory array using a memory controller. In some cases, the memory controller may be integrated into processor 1540. Processor 1540 may be configured to execute computer-readable instructions stored in a memory (e.g., memory 1530) to cause device 1505 to perform various functions (e.g., functions or tasks supporting techniques for indicating SRS resources).

[0220] The inter-site communication manager 1545 can manage communications with other base stations 105 and can include a controller or scheduler for controlling communications with the UE 115 in coordination with the other base stations 105. For example, the inter-site communication manager 1545 can coordinate the scheduling of transmissions to the UE 115 for various interference mitigation techniques such as beamforming or joint transmission. In some examples, the inter-site communication manager 1545 can provide an X2 interface within an LTE / LTE-A wireless communication network technology to provide communications between the base stations 105.

[0221] The code 1535 may include instructions for implementing various aspects of the present disclosure, including instructions for supporting wireless communications. The code 1535 may be stored in a non-transitory computer-readable medium such as system memory or other types of memory. In some cases, the code 1535 may not be directly executed by the processor 1540, but may cause a computer (e.g., when compiled and executed) to perform the functions described herein.

[0222] Figure 16A flow chart illustrating a method 1600 for supporting techniques for indicating SRS resources according to aspects of the present disclosure is shown. The operations of the method 1600 may be implemented by a UE 115 or components thereof as described herein. For example, the operations of the method 1600 may be implemented by reference to Figures 8 to 11 In some examples, the UE may execute an instruction set to control the functional elements of the UE to perform the functions described below. Additionally or alternatively, the UE may use dedicated hardware to perform various aspects of the functions described below.

[0223] At 1605, the UE may send a capability message indicating a first number of one or more transmit antennas supported by the UE for antenna switching and a second number of ports supported for uplink transmission, the second number exceeding the first number of the one or more transmit antennas. 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 capability message manager, as described with reference to Figures 8 to 11 described.

[0224] At 1610, the UE may receive an SRS configuration based on the capability message, the SRS configuration indicating a mapping between each SRS resource group in at least a subset of the set of SRS resource groups and a corresponding bit sequence in the set of bit sequences. 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 an SRS configuration manager, as described with reference to Figures 8 to 11 described.

[0225] At 1615, the UE may receive a control message based on the mapping, the control message including a first bit sequence in the set of bit sequences indicating a first SRS resource group in the subset of the set of SRS resource groups. 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 bit sequence reception manager, as described with reference to Figures 8 to 11 described.

[0226] At 1620, the UE may transmit a first SRS in a first SRS resource in the first SRS resource group based on the control message. 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 first SRS transmission manager, as described with reference to Figures 8 to 11 described.

[0227] At 1625, the UE may transmit a second SRS in a second SRS resource in the first SRS resource group based on the control message. 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 second SRS transmission manager, as described with reference to FIG. Figures 8 to 11 described.

[0228] Figure 17 A flow chart illustrating a method 1700 for supporting techniques for indicating SRS resources according to aspects of the present disclosure is shown. The operations of the method 1700 may be implemented by a UE 115 or components thereof as described herein. For example, the operations of the method 1700 may be implemented by reference to Figures 8 to 11 In some examples, the UE may execute an instruction set to control the functional elements of the UE to perform the functions described below. Additionally or alternatively, the UE may use dedicated hardware to perform various aspects of the functions described below.

[0229] At 1705, the UE may send a capability message indicating a first number of one or more transmit antennas supported by the UE for antenna switching and a second number of ports supported for uplink transmission, the second number exceeding the first number of transmit antennas. 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 capability message manager, as described with reference to Figures 8 to 11 described.

[0230] At 1710, the UE may receive an SRS configuration based on the capability message, the SRS configuration indicating a mapping between each SRS resource in the SRS resource set and a corresponding bit sequence in the bit sequence set. 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 an SRS configuration manager, as described with reference to FIG. Figures 8 to 11 described.

[0231] At 1715, the UE may receive a control message based on the mapping, the control message including a first bit sequence in the bit sequence set indicating a first SRS resource in the SRS resource set, and a second bit sequence in the bit sequence set indicating a second SRS resource in the SRS resource set. 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 bit sequence reception manager, as described with reference to Figures 8 to 11 described.

[0232] At 1720, the UE may transmit a first SRS in the first SRS resource based on the first bit sequence indicated in the control message. 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 first SRS transmission manager, as described in reference to Figures 8 to 11 described.

[0233] At 1725, the UE may transmit a second SRS in the second SRS resource based on the second bit sequence indicated in the control message. The operations of 1725 may be performed according to the methods described herein. In some examples, aspects of the operations of 1725 may be performed by a second SRS transmission manager, as described with reference to FIG. Figures 8 to 11 described.

[0234] Figure 18 A flow chart illustrating a method 1800 for supporting techniques for indicating SRS resources according to aspects of the present disclosure is shown. The operations of the method 1800 may be implemented by a base station 105 or components thereof as described herein. For example, the operations of the method 1800 may be implemented by reference to Figures 12 to 15 In some examples, the base station may execute an instruction set to control the functional elements of the base station to perform the functions described below. Additionally or alternatively, the base station may use dedicated hardware to perform various aspects of the functions described below.

[0235] At 1805, the base station may receive a capability message from a UE, the capability message indicating a first number of one or more transmit antennas supported by the UE for antenna switching and a second number of ports supported for uplink transmission, the second number exceeding the first number of the one or more transmit antennas. The operations of 1805 may be performed according to the methods described herein. In some examples, aspects of the operations of 1805 may be performed by a capability message component, as described with reference to Figures 12 to 15 described.

[0236] At 1810, the base station may send an SRS configuration based on the capability message, the SRS configuration indicating a mapping between each SRS resource group in at least a subset of the set of SRS resource groups and a corresponding bit sequence in the set of bit sequences. The operations of 1810 may be performed according to the methods described herein. In some examples, aspects of the operations of 1810 may be performed by an SRS configuration component, as described with reference to Figures 12 to 15 described.

[0237] At 1815, the base station may send a control message based on the mapping, the control message including a first bit sequence in the set of bit sequences indicating a first SRS resource group in the subset of the set of SRS resource groups. The operations of 1815 may be performed according to the methods described herein. In some examples, aspects of the operations of 1815 may be performed by a bit sequence sending component, such as with reference to Figures 12 to 15 described.

[0238] At 1820, the base station may receive a first SRS in a first SRS resource in the first SRS resource group based on the control message. The operations of 1820 may be performed according to the methods described herein. In some examples, aspects of the operations of 1820 may be performed by a first SRS receiving component, as described with reference to Figures 12 to 15 Descriptive.

[0239] At 1825, the base station may receive a second SRS in a second SRS resource in the first SRS resource group based on the control message. The operations of 1825 may be performed according to the methods described herein. In some examples, aspects of the operations of 1825 may be performed by a second SRS receiving component, as described with reference to Figures 12 to 15 described.

[0240] Figure 19 A flow chart illustrating a method 1900 for supporting techniques for indicating SRS resources according to aspects of the present disclosure is shown. The operations of the method 1900 may be implemented by a base station 105 or components thereof as described herein. For example, the operations of the method 1900 may be implemented by reference to Figures 12 to 15 In some examples, the base station may execute an instruction set to control the functional elements of the base station to perform the functions described below. Additionally or alternatively, the base station may use dedicated hardware to perform various aspects of the functions described below.

[0241] At 1905, the base station may receive a capability message from a UE, the capability message indicating a first number of one or more transmit antennas supported by the UE for antenna switching and a second number of ports supported for uplink transmission, the second number exceeding the first number of transmit antennas. The operations of 1905 may be performed according to the methods described herein. In some examples, aspects of the operations of 1905 may be performed by a capability message component, as described with reference to Figures 12 to 15 described.

[0242] At 1910, the base station may send an SRS configuration based on the capability message, the SRS configuration indicating a mapping between each SRS resource in the SRS resource set and a corresponding bit sequence in the bit sequence set. The operations of 1810 may be performed according to the methods described herein. In some examples, aspects of the operations of 1910 may be performed by an SRS configuration component, as described with reference to Figures 12 to 15 described.

[0243] At 1915, the base station may send a control message based on the mapping, the control message including a first bit sequence in the bit sequence set indicating a first SRS resource in the SRS resource set, and a second bit sequence in the bit sequence set indicating a second SRS resource in the SRS resource set. The operations of 1915 may be performed according to the methods described herein. In some examples, aspects of the operations of 1915 may be performed by a bit sequence sending component, such as with reference to Figures 12 to 15 described.

[0244] At 1920, the base station may receive a first SRS in the first SRS resource based on the first bit sequence indicated in the control message. The operations of 1920 may be performed according to the methods described herein. In some examples, aspects of the operations of 1920 may be performed by a first SRS receiving component, as described with reference to Figures 12 to 15 described.

[0245] At 1925, the base station may receive a second SRS in the second SRS resource based on the second bit sequence indicated in the control message. The operations of 1925 may be performed according to the methods described herein. In some examples, aspects of the operations of 1925 may be performed by a second SRS receiving component, as described with reference to Figures 12 to 15 described.

[0246] It should be noted that the methods described herein describe possible implementations, and that operations and steps may be rearranged or otherwise modified, and other implementations are possible. Additionally, aspects from two or more methods may be combined.

[0247] Aspect 1: A method for wireless communication at a UE, comprising: sending a capability message indicating a first number of one or more transmit antennas supported by the UE for antenna switching and a second number of ports supported for uplink transmission, the second number exceeding the first number of the one or more transmit antennas; receiving an SRS configuration based at least in part on the capability message, the SRS configuration indicating a mapping between each SRS resource group in at least a subset of a plurality of SRS resource groups and a corresponding bit sequence in a plurality of bit sequences; receiving a control message based at least in part on the mapping, the control message including a first bit sequence in the plurality of bit sequences indicating a first SRS resource group in the subset of the plurality of SRS resource groups; sending a first SRS in a first SRS resource in the first SRS resource group based at least in part on the control message; and sending a second SRS in a second SRS resource in the first SRS resource group based at least in part on the control message.

[0248] Aspect 2: The method of Aspect 1, wherein receiving the SRS configuration further comprises: receiving the SRS configuration indicating a mapping table, the mapping table indicating the mapping between each SRS resource group in at least the subset of the multiple SRS resource groups and the corresponding bit sequence in the multiple bit sequences.

[0249] Aspect 3: The method of any one of Aspects 1 or 2, wherein receiving the SRS configuration further comprises: receiving the SRS configuration indicating the number of configuration ports for antenna switching and the number of configuration ports for uplink transmission, wherein the mapping is at least partially based on the number of configuration ports for antenna switching and the number of configuration ports for uplink transmission.

[0250] Aspect 4: The method of any one of Aspects 1 to 3, wherein receiving the SRS configuration indicating the mapping further comprises: receiving the SRS configuration indicating a mapping between each SRS group in the multiple SRS resource groups and a corresponding bit sequence in the multiple bit sequences.

[0251] Aspect 5: The method of any one of Aspects 1 to 4, wherein sending the capability message further comprises: sending the capability message indicating a third number of one or more receiving antennas supported for antenna switching, the SRS configuration being at least partially based on the third number of receiving antennas supported for antenna switching.

[0252] Aspect 6: The method of Aspect 5, wherein the third number of one or more receive antennas exceeds the first number of one or more transmit antennas.

[0253] Aspect 7: The method of any one of Aspects 1 to 6, wherein receiving the control message further comprises: receiving a downlink control information message including the first bit sequence.

[0254] Aspect 8: The method of any one of Aspects 1 to 7, wherein each SRS resource group includes a single SRS resource in the SRS resource group.

[0255] Aspect 9: The method of any one of Aspects 1 to 8, wherein receiving the SRS configuration further comprises: receiving the SRS configuration indicating a codebook SRS configuration.

[0256] Aspect 10: The method of any one of Aspects 1 to 9, wherein each bit sequence in the plurality of bit sequences comprises a single bit.

[0257] Aspect 11: A method for performing wireless communication at a UE, comprising: sending a capability message indicating a first number of one or more transmit antennas supported by the UE for antenna switching and a second number of ports supported for uplink transmission, the second number exceeding the first number of transmit antennas; receiving an SRS configuration based at least in part on the capability message, the SRS configuration indicating a mapping between each SRS resource in a plurality of SRS resources and a corresponding bit sequence in a plurality of bit sequences; receiving a control message based at least in part on the mapping, the control message including a first bit sequence in the plurality of bit sequences indicating a first SRS resource in the plurality of SRS resources and a second bit sequence in the plurality of bit sequences indicating a second SRS resource in the plurality of SRS resources; sending a first SRS in the first SRS resource based at least in part on the first bit sequence indicated in the control message; and sending a second SRS in the second SRS resource based at least in part on the second bit sequence indicated in the control message.

[0258] Aspect 12: The method of Aspect 11, wherein receiving the SRS configuration further comprises: receiving the SRS configuration indicating a codebook SRS configuration.

[0259] Aspect 13: The method of any one of Aspects 11 or 12, wherein receiving the SRS configuration further comprises: receiving the SRS configuration indicating a mapping table corresponding to the mapping, wherein the corresponding bit sequence indicates a corresponding index to the mapping table.

[0260] Aspect 14: The method of any one of Aspects 11 to 13, wherein sending the capability message further comprises: sending the capability message indicating a third number of one or more receiving antennas supported for antenna switching, the SRS configuration being at least partially based on the third number of receiving antennas supported for antenna switching.

[0261] Aspect 15: The method of Aspect 14, wherein the third number of one or more receive antennas exceeds the first number of one or more transmit antennas.

[0262] Aspect 16: The method of any one of Aspects 11 to 15, wherein receiving the control message further comprises: receiving a downlink control information message including the first bit sequence and the second bit sequence.

[0263] Aspect 17: A method for wireless communication at a base station, comprising: receiving a capability message from a UE, the capability message indicating a first number of one or more transmit antennas supported by the UE for antenna switching and a second number of ports supported for uplink transmission, the second number exceeding the first number of the one or more transmit antennas; sending an SRS configuration based at least in part on the capability message, the SRS configuration indicating a mapping between each SRS resource group in at least a subset of a plurality of SRS resource groups and a corresponding bit sequence in a plurality of bit sequences; sending a control message based at least in part on the mapping, the control message including a first bit sequence in the plurality of bit sequences indicating a first SRS resource group in the subset of the plurality of SRS resource groups; receiving a first SRS in a first SRS resource in the first SRS resource group based at least in part on the control message; and receiving a second SRS in a second SRS resource in the first SRS resource group based at least in part on the control message.

[0264] Aspect 18: The method of Aspect 17, wherein sending the SRS configuration further comprises: sending the SRS configuration indicating a mapping table, the mapping table indicating a mapping between each SRS resource group in at least the subset of the multiple SRS resource groups and the corresponding bit sequence in the multiple bit sequences.

[0265] Aspect 19: The method of any one of Aspects 17 or 18, wherein sending the SRS configuration further comprises: sending the SRS configuration indicating the number of configuration ports for antenna switching and the number of configuration ports for uplink transmission, wherein the mapping is at least partially based on the number of configuration ports for antenna switching and the number of configuration ports for uplink transmission.

[0266] Aspect 20: The method of any one of Aspects 17 to 19, wherein sending the SRS configuration indicating the mapping further comprises: sending the SRS configuration indicating a mapping between each SRS group in the plurality of SRS resource groups and a corresponding bit sequence in the plurality of bit sequences.

[0267] Aspect 21: The method of any one of Aspects 17 to 20, wherein receiving the capability message further comprises: receiving the capability message indicating a third number of one or more receive antennas supported for antenna switching, the SRS configuration being at least partially based on the third number of receive antennas supported for antenna switching.

[0268] Aspect 22: The method of Aspect 21, wherein the third number of one or more receive antennas exceeds the first number of one or more transmit antennas.

[0269] Aspect 23: The method of any one of Aspects 17 to 22, wherein sending the control message further comprises: sending a downlink control information message including the first bit sequence.

[0270] Aspect 24: The method of any one of Aspects 17 to 23, wherein each SRS resource group includes a single SRS resource in the SRS resource group.

[0271] Aspect 25: The method of any one of Aspects 17 to 24, wherein sending the SRS configuration further comprises: sending the SRS configuration indicating a codebook SRS configuration.

[0272] Aspect 26: The method of any one of Aspects 17 to 25, wherein each bit sequence in the plurality of bit sequences comprises a single bit.

[0273] Aspect 27: A method for wireless communication at a base station, comprising: receiving a capability message from a UE, the capability message indicating a first number of one or more transmit antennas supported by the UE for antenna switching and a second number of ports supported for uplink transmission, the second number exceeding the first number of transmit antennas; sending an SRS configuration based at least in part on the capability message, the SRS configuration indicating a mapping between each SRS resource in a plurality of SRS resources and a corresponding bit sequence in a plurality of bit sequences; sending a control message based at least in part on the mapping, the control message including a first bit sequence in the plurality of bit sequences indicating a first SRS resource in the plurality of SRS resources and a second bit sequence in the plurality of bit sequences indicating a second SRS resource in the plurality of SRS resources; receiving a first SRS in the first SRS resource based at least in part on the first bit sequence indicated in the control message; and receiving a second SRS in the second SRS resource based at least in part on the second bit sequence indicated in the control message.

[0274] Aspect 28: The method of Aspect 27, wherein sending the SRS configuration further comprises: sending the SRS configuration indicating a codebook SRS configuration.

[0275] Aspect 29: The method of any one of Aspects 27 or 28, wherein sending the SRS configuration further comprises: sending the SRS configuration indicating a mapping table corresponding to the mapping, wherein the corresponding bit sequence indicates a corresponding index to the mapping table.

[0276] Aspect 30: The method of any one of Aspects 27 to 29, wherein receiving the capability message further comprises: receiving the capability message indicating a third number of one or more receive antennas supported for antenna switching, the SRS configuration being at least partially based on the third number of receive antennas supported for antenna switching.

[0277] Aspect 31: The method of Aspect 30, wherein the third number of one or more receive antennas exceeds the first number of one or more transmit antennas.

[0278] Aspect 32: The method of any one of Aspects 27 to 31, wherein sending the control message further comprises: sending a downlink control information message including the first bit sequence and the second bit sequence.

[0279] Aspect 33: An apparatus comprising at least one component for performing the method of any one of aspects 1 to 10.

[0280] Aspect 34: An apparatus for wireless communication, comprising: a processor; a memory in electronic communication with the processor; and instructions stored in the memory and executable by the processor to cause the apparatus to perform the method of any one of aspects 1 to 10.

[0281] Aspect 35: A non-transitory computer-readable medium storing code for wireless communication, the code comprising instructions executable by a processor to perform the method of any one of aspects 1 to 10.

[0282] Aspect 36: An apparatus comprising at least one component for performing the method of any one of aspects 11 to 16.

[0283] Aspect 37: An apparatus for wireless communication, comprising: a processor; a memory in electronic communication with the processor; and instructions stored in the memory and executable by the processor to cause the apparatus to perform the method of any one of aspects 11 to 16.

[0284] Aspect 38: A non-transitory computer-readable medium storing code for wireless communication, the code comprising instructions executable by a processor to perform the method of any one of aspects 11 to 16.

[0285] Aspect 39: An apparatus comprising at least one component for performing the method of any one of aspects 17 to 26.

[0286] Aspect 40: An apparatus for wireless communication, comprising: a processor; a memory in electronic communication with the processor; and instructions stored in the memory and executable by the processor to cause the apparatus to perform the method of any one of aspects 17 to 26.

[0287] Aspect 41: A non-transitory computer-readable medium storing code for wireless communication, the code comprising instructions executable by a processor to perform the method of any one of aspects 17 to 26.

[0288] Aspect 42: An apparatus comprising at least one component for performing the method of any one of aspects 27 to 32.

[0289] Aspect 43: An apparatus for wireless communication, comprising: a processor; a memory in electronic communication with the processor; and instructions stored in the memory and executable by the processor to cause the apparatus to perform the method of any one of aspects 27 to 32.

[0290] Aspect 44: A non-transitory computer-readable medium storing code for wireless communication, the code comprising instructions executable by a processor to perform the method of any one of aspects 27 to 32.

[0291] Although aspects of LTE, LTE-A, LTE-APro, or NR systems may be described for example purposes, and the terminology of LTE, LTE-A, LTE-APro, or NR may be used in many descriptions, the techniques described herein can be applied beyond LTE, LTE-A, LTE-APro, or NR networks. For example, the techniques described may be applicable to various other wireless communication 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, and other systems and radio technologies not explicitly mentioned herein.

[0292] The 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 referred to throughout this specification may be represented by voltages, currents, electromagnetic waves, magnetic fields or particles, optical fields or particles, or any combination thereof.

[0293] The various illustrative blocks and components described in connection with the disclosure herein may be implemented or performed using 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 DSP and a microprocessor, a plurality of microprocessors, a combination of one or more microprocessors in conjunction with a DSP core, or any other such configuration).

[0294] The functions described herein can be implemented in hardware, software executed by a processor, firmware, or any combination thereof. If implemented in software executed by a processor, the functions can be stored on or transmitted over a computer-readable medium as one or more instructions or codes on a computer-readable medium. Other examples and specific embodiments are within the scope of this disclosure and the appended claims. For example, due to the nature of software, the functions described herein can be implemented using software executed by a processor, hardware, firmware, hard wiring, or any combination thereof. Features that implement the functions can also be physically located in various locations, including being distributed so that parts of the functions are implemented at different physical locations.

[0295] Computer-readable media includes both non-transitory computer storage media and communication media, and communication media includes any medium that is convenient for transferring a computer program from one place to another.Non-transitory storage media can be any available medium that can be accessed by a general or special-purpose computer.As an example and not limitation, non-transitory computer-readable media can include RAM, ROM, electrically erasable programmable ROM (EEPROM), flash memory, compact disc (CD) ROM or other optical disc storage, disk storage or other magnetic storage device, or can be used for carrying or storing required program code components in the form of instructions or data structures and any other non-transitory medium that can be accessed by a general or special-purpose computer or a general or special-purpose processor.Any connection is also properly referred to as computer-readable media.For example, if software is sent from a website, server or other remote source using a coaxial cable, optical cable, twisted pair, digital subscriber line (DSL) or wireless technologies such as infrared, radio and microwave, then coaxial cable, optical cable, twisted pair, DSL or wireless technologies such as infrared, radio and microwave, etc., are all included in the definition of computer-readable media. 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 using lasers. Combinations of the above are also included within the scope of computer-readable media.

[0296] As used herein (including in the claims), "or" as used in a list of items (e.g., a list of items ending with a phrase such as "at least one of" or "one or more of") indicates an inclusive list, so 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). Furthermore, as used herein, the phrase "based on" should not be interpreted as a reference to a closed set of conditions. For example, an exemplary step described as "based on condition A" could be based on both condition A and condition B without departing from the scope of this disclosure. In other words, as used herein, the phrase "based on" should be interpreted in the same manner as the phrase "based at least in part on."

[0297] In the drawings, similar components or features may have the same reference number. In addition, various components of the same type may be distinguished by following the reference number with a dash and a second reference number that distinguishes the similar components. If only the first reference number is used in the specification, the description applies to any similar component having the same first reference number, regardless of the second or subsequent reference numbers.

[0298] The description set forth herein in conjunction with the accompanying drawings describes example configurations and does not represent all examples that may be implemented or within the scope of the claims. The term "example" as used herein means "serving as an example, instance, or illustration," rather than "preferred" or "superior to other examples." The detailed description includes specific details for the purpose of providing an understanding of the described technology. However, these technologies can be practiced without these specific details. In some cases, known structures and devices are shown in block diagram form to avoid obscuring the concepts of the described examples.

[0299] The description herein is provided to enable any person skilled in the art to make or use the present disclosure. Various modifications to the present disclosure will be apparent to those skilled in the art, and the general principles defined herein may be applied to other variations without departing from the scope of the present disclosure. Therefore, the present disclosure is not limited to the examples and designs described herein, but should be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. An apparatus for performing wireless communication at a user equipment (UE), comprising: processor; a memory coupled to the processor; as well as instructions stored in the memory and executable by the processor to cause the apparatus to: sending a capability message indicating a first number of one or more transmit antennas supported by the UE for antenna switching and a second number of ports supported for uplink transmission, the second number exceeding the first number of the one or more transmit antennas; receiving a sounding reference signal configuration based at least in part on the capability message, the sounding reference signal configuration indicating a mapping between each sounding reference signal resource group of at least a subset of a plurality of sounding reference signal resource groups and a corresponding bit sequence of a plurality of bit sequences; receiving a control message based at least in part on the mapping, the control message including a first bit sequence of the plurality of bit sequences indicating a first sounding reference signal resource group in the subset of the plurality of sounding reference signal resource groups; sending a first sounding reference signal in a first sounding reference signal resource in the first sounding reference signal resource group based at least in part on the control message; as well as sending a second sounding reference signal in a second sounding reference signal resource in the first sounding reference signal resource group based at least in part on the control message, The instructions for receiving the sounding reference signal configuration are further executable by the processor to cause the apparatus to: The sounding reference signal configuration is received that indicates a number of configured ports for antenna switching and a number of configured ports for uplink transmission, wherein the mapping is based at least in part on the number of configured ports for antenna switching and the number of configured ports for uplink transmission.

2. The apparatus of claim 1 , wherein the instructions to receive the sounding reference signal configuration are further executable by the processor to cause the apparatus to: The sounding reference signal configuration indicating a mapping table is received, the mapping table indicating the mapping between each sounding reference signal resource group of at least the subset of the plurality of sounding reference signal resource groups and the corresponding bit sequence of the plurality of bit sequences.

3. The apparatus of claim 1 , wherein the instructions to receive the SRS configuration indicating the mapping are further executable by the processor to cause the apparatus to: The sounding reference signal configuration indicating a mapping between each sounding reference signal group of the plurality of sounding reference signal resource groups and a corresponding bit sequence of the plurality of bit sequences is received.

4. The apparatus of claim 1 , wherein the instructions to send the capability message are further executable by the processor to cause the apparatus to: The capability message is sent indicating a third number of one or more receive antennas supported for antenna switching, the sounding reference signal configuration being based at least in part on the third number of receive antennas supported for antenna switching. 5 . The apparatus of claim 4 , wherein the third number of one or more receive antennas exceeds the first number of one or more transmit antennas.

6. The apparatus of claim 1 , wherein the instructions to receive the control message are further executable by the processor to cause the apparatus to: A downlink control information message including the first bit sequence is received.

7. The apparatus of claim 1, wherein each sounding reference signal resource group comprises a single sounding reference signal resource in the sounding reference signal resource group.

8. The apparatus of claim 1 , wherein the instructions to receive the sounding reference signal configuration are further executable by the processor to cause the apparatus to: The sounding reference signal configuration indicating a codebook sounding reference signal configuration is received.

9. The apparatus of claim 1, wherein each bit sequence of the plurality of bit sequences comprises a single bit.

10. An apparatus for wireless communication at an access network entity, comprising: processor; a memory coupled to the processor; as well as instructions stored in the memory and executable by the processor to cause the apparatus to: receiving a capability message from a user equipment (UE), the capability message indicating a first number of one or more transmit antennas supported by the UE for antenna switching and a second number of ports supported for uplink transmission, the second number exceeding the first number of the one or more transmit antennas; transmitting a sounding reference signal configuration based at least in part on the capability message, the sounding reference signal configuration indicating a mapping between each sounding reference signal resource group of at least a subset of a plurality of sounding reference signal resource groups and a corresponding bit sequence of a plurality of bit sequences; sending a control message based at least in part on the mapping, the control message including a first bit sequence of the plurality of bit sequences indicating a first sounding reference signal resource group in the subset of the plurality of sounding reference signal resource groups; receiving a first sounding reference signal in a first sounding reference signal resource in the first sounding reference signal resource group based at least in part on the control message; as well as receiving a second sounding reference signal in a second sounding reference signal resource in the first sounding reference signal resource group based at least in part on the control message, The instructions for sending the sounding reference signal configuration are further executable by the processor to cause the apparatus to: The sounding reference signal configuration is transmitted indicating a number of configured ports for antenna switching and a number of configured ports for uplink transmission, wherein the mapping is based at least in part on the number of configured ports for antenna switching and the number of configured ports for uplink transmission.

11. The apparatus of claim 10, wherein the instructions to send the sounding reference signal configuration are further executable by the processor to cause the apparatus to: The sounding reference signal configuration indicating a mapping table is transmitted, the mapping table indicating the mapping between each sounding reference signal resource group of at least the subset of the plurality of sounding reference signal resource groups and the corresponding bit sequence of the plurality of bit sequences.

12. The apparatus of claim 10 , wherein the instructions to send the sounding reference signal configuration indicating the mapping are further executable by the processor to cause the apparatus to: The sounding reference signal configuration indicating a mapping between each sounding reference signal group in the plurality of sounding reference signal resource groups and a corresponding bit sequence in the plurality of bit sequences is transmitted.

13. The apparatus of claim 10, wherein the instructions to receive the capability message are further executable by the processor to cause the apparatus to: The capability message is received indicating a third number of one or more receive antennas supported for antenna switching, the sounding reference signal configuration being based at least in part on the third number of receive antennas supported for antenna switching.

14. The apparatus of claim 13, wherein the third number of one or more receive antennas exceeds the first number of one or more transmit antennas.

15. The apparatus of claim 10, wherein the instructions to send the control message are further executable by the processor to cause the apparatus to: A downlink control information message including the first bit sequence is sent.

16. The apparatus of claim 10, wherein each sounding reference signal resource group comprises a single sounding reference signal resource in the sounding reference signal resource group.

17. The apparatus of claim 10, wherein the instructions to send the sounding reference signal configuration are further executable by the processor to cause the apparatus to: The sounding reference signal configuration indicating a codebook sounding reference signal configuration is sent.

18. The apparatus of claim 10, wherein each bit sequence of the plurality of bit sequences comprises a single bit.

19. A non-transitory computer-readable medium storing code for wireless communication at a user equipment (UE), the code comprising instructions executable by a processor to: sending a capability message indicating a first number of one or more transmit antennas supported by the UE for antenna switching and a second number of ports supported for uplink transmission, the second number exceeding the first number of the one or more transmit antennas; receiving a sounding reference signal configuration based at least in part on the capability message, the sounding reference signal configuration indicating a mapping between each sounding reference signal resource group of at least a subset of a plurality of sounding reference signal resource groups and a corresponding bit sequence of a plurality of bit sequences; receiving a control message based at least in part on the mapping, the control message including a first bit sequence of the plurality of bit sequences indicating a first sounding reference signal resource group in the subset of the plurality of sounding reference signal resource groups; sending a first sounding reference signal in a first sounding reference signal resource in the first sounding reference signal resource group based at least in part on the control message; as well as sending a second sounding reference signal in a second sounding reference signal resource in the first sounding reference signal resource group based at least in part on the control message, The receiving of the sounding reference signal configuration further includes: The sounding reference signal configuration is received that indicates a number of configured ports for antenna switching and a number of configured ports for uplink transmission, wherein the mapping is based at least in part on the number of configured ports for antenna switching and the number of configured ports for uplink transmission.

20. A method for wireless communication at a user equipment (UE), comprising: sending a capability message indicating a first number of one or more transmit antennas supported by the UE for antenna switching and a second number of ports supported for uplink transmission, the second number exceeding the first number of the one or more transmit antennas; receiving a sounding reference signal configuration based at least in part on the capability message, the sounding reference signal configuration indicating a mapping between each sounding reference signal resource group of at least a subset of a plurality of sounding reference signal resource groups and a corresponding bit sequence of a plurality of bit sequences; receiving a control message based at least in part on the mapping, the control message including a first bit sequence of the plurality of bit sequences indicating a first sounding reference signal resource group in the subset of the plurality of sounding reference signal resource groups; sending a first sounding reference signal in a first sounding reference signal resource in the first sounding reference signal resource group based at least in part on the control message; as well as sending a second sounding reference signal in a second sounding reference signal resource in the first sounding reference signal resource group based at least in part on the control message, The receiving of the sounding reference signal configuration further includes: The sounding reference signal configuration is received that indicates a number of configured ports for antenna switching and a number of configured ports for uplink transmission, wherein the mapping is based at least in part on the number of configured ports for antenna switching and the number of configured ports for uplink transmission.

21. The method of claim 20, wherein receiving the sounding reference signal configuration further comprises: The sounding reference signal configuration indicating a mapping table is received, the mapping table indicating the mapping between each sounding reference signal resource group of at least the subset of the plurality of sounding reference signal resource groups and the corresponding bit sequence of the plurality of bit sequences.

22. The method of claim 20 or 21, wherein receiving the sounding reference signal configuration indicating the mapping further comprises: The sounding reference signal configuration indicating a mapping between each sounding reference signal group of the plurality of sounding reference signal resource groups and a corresponding bit sequence of the plurality of bit sequences is received.

23. The method according to claim 20 or 21, wherein sending the capability message further comprises: The capability message is sent indicating a third number of one or more receive antennas supported for antenna switching, the sounding reference signal configuration being based at least in part on the third number of receive antennas supported for antenna switching.

24. The method of claim 23, wherein the third number of one or more receive antennas exceeds the first number of one or more transmit antennas.

25. The method according to claim 20 or 21, wherein receiving the control message further comprises: A downlink control information message including the first bit sequence is received.

26. The method of claim 20 or 21, wherein each sounding reference signal resource group comprises a single sounding reference signal resource in the sounding reference signal resource group.

27. The method according to claim 20 or 21, wherein receiving the sounding reference signal configuration further comprises: The sounding reference signal configuration indicating a codebook sounding reference signal configuration is received.

28. The method of claim 20 or 21, wherein each bit sequence of the plurality of bit sequences comprises a single bit.

29. A method for wireless communication at an access network entity, comprising: receiving a capability message from a user equipment (UE), the capability message indicating a first number of one or more transmit antennas supported by the UE for antenna switching and a second number of ports supported for uplink transmission, the second number exceeding the first number of the one or more transmit antennas; transmitting a sounding reference signal configuration based at least in part on the capability message, the sounding reference signal configuration indicating a mapping between each sounding reference signal resource group of at least a subset of a plurality of sounding reference signal resource groups and a corresponding bit sequence of a plurality of bit sequences; sending a control message based at least in part on the mapping, the control message including a first bit sequence of the plurality of bit sequences indicating a first sounding reference signal resource group in the subset of the plurality of sounding reference signal resource groups; receiving a first sounding reference signal in a first sounding reference signal resource in the first sounding reference signal resource group based at least in part on the control message; as well as receiving a second sounding reference signal in a second sounding reference signal resource in the first sounding reference signal resource group based at least in part on the control message, The sending of the sounding reference signal configuration further includes: The sounding reference signal configuration is transmitted indicating a number of configured ports for antenna switching and a number of configured ports for uplink transmission, wherein the mapping is based at least in part on the number of configured ports for antenna switching and the number of configured ports for uplink transmission.

30. The method of claim 29, wherein sending the sounding reference signal configuration further comprises: The sounding reference signal configuration indicating a mapping table is transmitted, the mapping table indicating the mapping between each sounding reference signal resource group of at least the subset of the plurality of sounding reference signal resource groups and the corresponding bit sequence of the plurality of bit sequences.

31. The method of claim 29 or 30, wherein sending the sounding reference signal configuration indicating the mapping further comprises: The sounding reference signal configuration indicating a mapping between each sounding reference signal group in the plurality of sounding reference signal resource groups and a corresponding bit sequence in the plurality of bit sequences is transmitted.

32. A non-transitory computer-readable medium storing code for wireless communication at an access network entity, the code comprising instructions executable by a processor to: receiving a capability message from a user equipment (UE), the capability message indicating a first number of one or more transmit antennas supported by the UE for antenna switching and a second number of ports supported for uplink transmission, the second number exceeding the first number of the one or more transmit antennas; transmitting a sounding reference signal configuration based at least in part on the capability message, the sounding reference signal configuration indicating a mapping between each sounding reference signal resource group of at least a subset of a plurality of sounding reference signal resource groups and a corresponding bit sequence of a plurality of bit sequences; sending a control message based at least in part on the mapping, the control message including a first bit sequence of the plurality of bit sequences indicating a first sounding reference signal resource group in the subset of the plurality of sounding reference signal resource groups; receiving a first sounding reference signal in a first sounding reference signal resource in the first sounding reference signal resource group based at least in part on the control message; as well as receiving a second sounding reference signal in a second sounding reference signal resource in the first sounding reference signal resource group based at least in part on the control message, The sending of the sounding reference signal configuration further includes: The sounding reference signal configuration is transmitted indicating a number of configured ports for antenna switching and a number of configured ports for uplink transmission, wherein the mapping is based at least in part on the number of configured ports for antenna switching and the number of configured ports for uplink transmission.

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