Techniques for thermal mitigation and power saving

Methods, systems, and devices for wireless communications are described. A user equipment (UE) may be configured to receive a first configuration indicating for the UE to communicate with the base station using a set of receive ports. The UE may transmit, according to the first configuration in a first time interval associated with a first power state of the UE, sounding reference signals (SRSs) on a set of transmit ports corresponding to the set of receive ports. The UE may then communicate using less than all of the set of transmit ports for the SRSs based on determining to operate in a reduced power state. The UE may then receive, based on communicating using less than all of the set of transmit ports for the SRSs, a second configuration indicating for the UE to communicate with the base station using a first subset of receive ports.

FIELD OF TECHNOLOGY

The present disclosure relates to wireless communications, including techniques for thermal mitigation and power saving.

BACKGROUND

In some wireless communications systems, thermal states (e.g., temperatures) of wireless devices (e.g., UEs) may affect the ability of the wireless devices to efficiently and reliably communicate within the wireless communications systems. For example, a modem baseband and/or a radio frequency transceiver of a UE may be unable to perform wireless communications in cases where a skin temperature (e.g., surface temperature) and/or junction temperature (e.g., substrate temperature) of the UE exceeds certain thermal thresholds. Accordingly, some wireless devices (e.g., UEs) may be configured to implement a variety of thermal mitigation and power savings techniques in order to reduce operating temperatures, conserve power, or both. However, some thermal mitigation techniques and/or power savings techniques are deficient in the context of fifth generation (5G) and New Radio (NR) access technologies.

SUMMARY

The described techniques relate to improved methods, systems, devices, and apparatuses that support techniques for thermal mitigation and power saving. Generally, the described techniques provide for thermal mitigation and power savings at a user equipment (UE). In particular, techniques for sounding reference signal (SRS) antenna switching (SRS-AS) for thermal mitigation and power savings in the context of fifth generation (5G) and New Radio (NR) access technologies. According to some aspects, a UE may be configured to transmit SRSs on a subset of transmit ports corresponding to a subset of receive ports in order to indicate that the UE is to “fallback” to a lower transmission-reception mode. In this regard, the UE may sound SRSs for a subset of receive ports at the UE in order to fallback from a transmission-reception mode using a higher number of receive ports (such as four receive ports (e.g., 1T4R, 2T4R)) to a transmission-reception mode using a lower number of receive ports (such as one or two receive ports (e.g., 1T1R, 2T1R, 1T2R, 2T2R)).

For instance, while operating in a first power state (e.g., normal or full power state, or normal or full operating state), a UE may transmit SRSs on each transmit port corresponding to each receive port at the UE (e.g., sound all four receive ports). Such transmission of SRS on all receive ports is not necessarily simultaneous in the first power state, as antenna switching may be used to transmit alternately on different SRS ports. Subsequently, the UE may determine to operate in a reduced-power state based on identifying high thermal levels (e.g., high temperatures), a low power level (e.g., low battery level), or both. In this regard, the UE may reduce a quantity of transmit ports over which SRSs are transmitted, or completely refrain from transmitting SRSs altogether. On the base station side, the base station may identify that SRSs are not being transmitted/received for at least a subset of the receive ports, and may thereby refrain from scheduling transmissions for the respective receive ports. In this regard, by reducing (or eliminating) a quantity of transmit ports used to transmit SRSs, the UE may induce the base station to reduce a rank (e.g., quantity of layers) associated with wireless communications at the UE, which may thereby reduce power consumption and/or thermal levels at the UE, for example by allowing the UE to disable, turn off, or otherwise deactivate one or more radio frequency transmit chains of the UE.

A method for wireless communication at a UE is described. The method may include receiving, from a base station, a first configuration indicating that the UE is to communicate with the base station using a set of multiple receive ports of the UE, transmitting, according to the first configuration in a first time interval associated with a first power state of the UE, SRSs on a set of multiple transmit ports corresponding to the set of multiple receive ports, communicating with the base station during a second time interval following the first time interval using less than all of the set of multiple transmit ports for the SRSs based on the UE determining to operate in a second power state lower than the first power state, and receiving, from the base station based on communicating with the base station using less than all of the set of multiple transmit ports for the SRSs, a second configuration indicating for the UE to communicate with the base station using a first subset of receive ports of the set of multiple receive ports.

An apparatus for wireless communication at a UE is described. The apparatus may include a processor, memory in electronic communication with the processor, and instructions stored in the memory. The instructions may be executable by the processor to cause the apparatus to receive, from a base station, a first configuration indicating that the UE is to communicate with the base station using a set of multiple receive ports of the UE, transmit, according to the first configuration in a first time interval associated with a first power state of the UE, SRSs on a set of multiple transmit ports corresponding to the set of multiple receive ports, communicate with the base station during a second time interval following the first time interval using less than all of the set of multiple transmit ports for the SRSs based on the UE determining to operate in a second power state lower than the first power state, and receive, from the base station based on communicating with the base station using less than all of the set of multiple transmit ports for the SRSs, a second configuration indicating for the UE to communicate with the base station using a first subset of receive ports of the set of multiple receive ports.

Another apparatus for wireless communication at a UE is described. The apparatus may include means for receiving, from a base station, a first configuration indicating that the UE is to communicate with the base station using a set of multiple receive ports of the UE, means for transmitting, according to the first configuration in a first time interval associated with a first power state of the UE, SRSs on a set of multiple transmit ports corresponding to the set of multiple receive ports, means for communicating with the base station during a second time interval following the first time interval using less than all of the set of multiple transmit ports for the SRSs based on the UE determining to operate in a second power state lower than the first power state, and means for receiving, from the base station based on communicating with the base station using less than all of the set of multiple transmit ports for the SRSs, a second configuration indicating for the UE to communicate with the base station using a first subset of receive ports of the set of multiple receive ports.

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 receive, from a base station, a first configuration indicating that the UE is to communicate with the base station using a set of multiple receive ports of the UE, transmit, according to the first configuration in a first time interval associated with a first power state of the UE, SRSs on a set of multiple transmit ports corresponding to the set of multiple receive ports, communicate with the base station during a second time interval following the first time interval using less than all of the set of multiple transmit ports for the SRSs based on the UE determining to operate in a second power state lower than the first power state, and receive, from the base station based on communicating with the base station using less than all of the set of multiple transmit ports for the SRSs, a second configuration indicating for the UE to communicate with the base station using a first subset of receive ports of the set of multiple receive ports.

In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, communicating with the base station using less than all of the set of multiple transmit ports for the SRSs may include operations, features, means, or instructions for refraining from transmitting SRSs on all transmit ports of the set of multiple transmit ports, where receiving the second configuration may be based on the UE refraining from transmitting SRSs on all of the transmit ports.

In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, communicating with the base station using less than all of the set of multiple transmit ports for the SRSs may include operations, features, means, or instructions for transmitting, during the second time interval, SRSs on a subset of transmit ports of the set of multiple transmit ports, where receiving the second configuration may be based on transmitting the SRSs on the subset of transmit ports.

Some examples of the method, apparatuses, and non-transitory computer-readable medium described herein may further include operations, features, means, or instructions for determining one or more parameters associated with the set of multiple receive ports and selecting the subset of transmit ports of the set of multiple transmit ports corresponding to a subset of receive ports of the set of multiple receive ports based on the one or more parameters, where transmitting the SRSs on the subset of transmit ports may be based on the selecting.

In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, the one or more parameters associated with the set of multiple receive ports include a received signal strength indicator (RSSI) metric, a reference signal received power (RSRP) metric, a reference signal received quality (RSRQ) metric, a signal-to-noise ratio (SNR), a signal-to-interference plus noise ratio (SINR), or any combination thereof.

In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, the set of multiple transmit ports includes four transmit ports, and the subset of transmit ports includes one or two transmit ports.

Some examples of the method, apparatuses, and non-transitory computer-readable medium described herein may further include operations, features, means, or instructions for determining to operate in the second power state based on determining that a thermal state at the UE may be greater than or equal to a threshold thermal state, where communicating with the base station using less than all of the set of multiple transmit ports for the SRSs may be based on determining that the thermal state at the UE may be greater than or equal to the threshold thermal state.

In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, the thermal state includes a skin temperate of the UE, a junction temperature of the UE, or both.

Some examples of the method, apparatuses, and non-transitory computer-readable medium described herein may further include operations, features, means, or instructions for determining to operate in the second power state based on determining that a power level at the UE satisfies a threshold power level, where communicating with the base station using less than all of the set of multiple transmit ports for the SRSs may be based on determining that the power level at the UE satisfies the threshold power level.

In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, the power level satisfies the threshold power level when the power level may be less than or equal to the threshold power level.

In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, the power level includes a battery level of the UE.

Some examples of the method, apparatuses, and non-transitory computer-readable medium described herein may further include operations, features, means, or instructions for transmitting, to the base station, a channel state feedback (CSF) report based on the UE determining to operate in the second power state, where receiving the second configuration may be based on transmitting the CSF report and communicating with the base station using less than all of the set of multiple transmit ports for the SRSs.

Some examples of the method, apparatuses, and non-transitory computer-readable medium described herein may further include operations, features, means, or instructions for determining a rank associated with communications with the base station using one or more receive ports of the set of multiple receive ports and selectively adjusting the determined rank to generate an adjusted rank less than the determined rank based on the UE determining to operate in the second power state, where the CSF report includes an indication of the adjusted rank.

Some examples of the method, apparatuses, and non-transitory computer-readable medium described herein may further include operations, features, means, or instructions for determining a channel quality indicator (CQI) associated with communications with the base station using one or more receive ports of the set of multiple receive ports and selectively adjusting the determined CQI to generate an adjusted CQI less than the determined CQI based on the UE determining to operate in the second power state, where the CSF report includes an indication of the adjusted CQI.

Some examples of the method, apparatuses, and non-transitory computer-readable medium described herein may further include operations, features, means, or instructions for transmitting, to the base station, a capability report including an indication of one or more transmission-reception modes supported by the UE, where receiving the first configuration may be based on transmitting the capability report.

In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, the one or more transmission-reception modes include a transmission-reception mode indicating one transmission port and four reception ports for the UE, a transmission-reception mode indicating two transmission ports and four reception ports for the UE, or both.

In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, selectively adjusting one or more parameters associated with a second subset of receive ports of the set of multiple receive ports based on receiving the second configuration.

In some examples of the method, apparatuses, and non-transitory computer-readable medium described herein, the one or more parameters may be associated with a low-noise amplifier (LNA) for the second subset of receive ports, a phase shifter for the second subset of receive ports, or both.

DETAILED DESCRIPTION

In some wireless communications systems, thermal states (e.g., temperatures) of wireless devices (e.g., user equipments (UEs)) may affect the ability of the wireless devices to efficiently and reliably communicate within the wireless communications systems. For example, a modem baseband and/or a radio frequency transceiver of a UE may be unable to perform wireless communications in cases where a skin temperature Tskin(e.g., surface temperature) and/or junction temperature Tj(e.g., substrate temperature) of the UE exceeds certain thermal thresholds (e.g., if Tskin>43° C., and/or Tj>95° C.). Accordingly, some wireless devices (e.g., UEs) may be configured to implement a variety of thermal mitigation and power savings techniques in order to reduce operating temperatures (e.g., Tskin, Tj), conserve power, or both. For example, in the context of long-term evolution (LTE) communications which utilize carrier aggregation techniques, a UE may conserve power and reduce operating temperatures by dropping carriers associated with secondary cells. For instance, the UE may report poor channel quality indicators associated with carriers of secondary cells in order to induce the base station to stop scheduling transmissions on the indicated carriers, thereby resulting in the carriers being dropped at the UE. By reducing the quantity of carriers which are monitored at the UE, power consumption may be reduced, and operating temperatures at the UE may be reduced. However, as compared to LTE radio access technologies which utilize multiple carrier aggregation, fifth generation (5G) and New Radio (NR) radio access technologies may utilize a single component carrier. In this regard, techniques used for thermal mitigation and power savings used in LTE access technologies may not be usable for 5G and NR access technologies, for example when the UE is operating in a standalone mode of operation.

Accordingly, techniques for thermal mitigation and power savings at a UE are disclosed. In particular, techniques for sounding reference signal antenna switching (SRS-AS) for thermal mitigation and power savings in the context of NR and 5G access technologies are described. According to some aspects, a UE may be configured to transmit SRSs on a subset of transmit ports corresponding to a subset of receive ports in order to indicate that the UE is to “fallback” to a lower transmission-reception mode. In this regard, the UE may sound SRSs for a subset of receive ports at the UE in order to fallback from a transmission-reception mode using a higher number of receive ports (such as four receive ports (e.g., 1T4R, 2T4R)) to a transmission-reception mode using a lower number of receive ports (such as one or two receive ports (e.g., 1T1R, 2T1R, 1T2R, 2T2R)).

For example, while operating in a first power state (e.g., normal power state, or normal operating state), a UE may transmit SRSs on each transmit port corresponding to each receive port at the UE (e.g., sound all four receive ports). Such transmission of SRS on all receive ports is not necessarily simultaneous in the first power state, as antenna switching may be used to transmit alternately on different SRS ports. Subsequently, the UE may determine to operate in a reduced-power state based on identifying high thermal levels (e.g., high temperatures), a low power level (e.g., low battery level), or both. In this regard, the UE may reduce a quantity of transmit ports over which SRSs are transmitted, or completely refrain from transmitting SRSs altogether. On the base station side, the base station may identify that SRSs are not being transmitted or received for at least a subset of the receive ports, and may thereby refrain from scheduling transmissions for the respective receive ports. In this regard, by reducing (or eliminating) a quantity of transmit ports used to transmit SRSs, the UE may induce the base station to reduce a rank (e.g., quantity of layers) associated with wireless communications at the UE, which may thereby reduce power consumption and/or thermal levels at the UE, for example by allowing the UE to disable, turn off, or otherwise deactivate one or more radio frequency transmit chains of the UE.

In some cases, a UE may be configured to spoof (e.g., fake) channel state feedback (CSF) reports to the base station in addition to performing SRS-AS in order to further induce the base station to reduce a rank associated with wireless communications at the UE. For example, in addition to refraining from transmitting SRSs on transmit ports associated with receive ports, the UE may additionally report poor channel quality indicators associated with wireless communications at the respective receive ports in order to induce the base station to refrain from scheduling transmissions at the respective receive ports. In some aspects, the techniques disclosed herein may be used to reduce a rank of wireless communications at a UE in the context of NR communications, which may thereby result in reduced power consumption and therefore reduced temperatures at the UE. Such thermal mitigation techniques may be applied in the context of wireless communications within multiple frequency ranges of NR communications (e.g., FR1, FR2, or both).

Aspects of the disclosure are initially described in the context of wireless communications systems. Additional aspects of the disclosure are described in the context of example communications schemes and an example process flow. Aspects of the disclosure are further illustrated by and described with reference to apparatus diagrams, system diagrams, and flowcharts that relate to techniques for thermal mitigation and power saving.

In some wireless communications systems (e.g., wireless communications system100), base stations105may utilize SRS-AS to measure channel quality (e.g., measure rank and/or channel quality indicators (CQIs)) between UEs115and the base stations105. Moreover, the base stations105may configure UEs115to operate in one or more transmission-reception modes (e.g., 1T4R, 2T4R), where SRS-AS is performed in the respective transmission-reception modes by transmitting SRSs on a single antenna port in a circular (e.g., “round robin”) fashion. For example, in the context of a 1T4R transmission-reception mode, a UE115may be configured to use one transmit antenna port and four receive antenna ports in a first power state (e.g., normal or default power state). Comparatively, in the context of a 2T4R transmission-reception mode, a UE115may be configured to use two transmit antenna ports and four receive antenna ports in the first power state (e.g., normal or default power state),

The UEs115of the wireless communications system100may support techniques for thermal mitigation and power savings at the UEs115. In particular, the UEs115of the wireless communications system100may be configured to perform SRS-AS techniques for thermal mitigation and power savings in the context of NR and 5G access technologies in order to induce the base stations105of the wireless communications system100to reduce a rank (e.g., reduce a quantity of layers) associated with wireless communications at the UEs115. In this regard, by inducing the base stations105to reduce a rank of wireless communications, techniques described herein may enable the UEs115to deactivate receive ports at the UEs115, enter lower power states, reduce power consumption at the UEs115, and reduce temperatures at the UEs115.

For example, while operating in a first power state (e.g., normal power state, or normal operating state), a UE115of the wireless communications system100may transmit SRSs on each transmit port corresponding to each receive port at the UE115(e.g., sound all four receive ports). Such transmission of SRS on all receive ports is not necessarily simultaneous in the first power state, as antenna switching may be used to transmit alternately on different SRS ports. Subsequently, the UE115may determine to operate in a reduced-power state based on identifying high thermal levels (e.g., high temperatures), a low power level (e.g., low battery level), or both. In this regard, the UE115may reduce a quantity of transmit ports over which SRSs are transmitted, or completely refrain from transmitting SRSs altogether. From the perspective of the base station105, the base station105may identify that SRSs are not being transmitted/received for at least a subset of the receive ports, and may thereby refrain from scheduling transmissions for the respective receive ports. In this regard, by reducing (or eliminating) a quantity of transmit ports used to transmit SRSs, the UE115may induce the base station to reduce a rank (e.g., quantity of layers) associated with wireless communications at the UE115, which may thereby reduce power consumption and/or thermal levels at the UE115, for example by allowing the UE115to disable, turn off, or otherwise deactivate one or more radio frequency transmit chains of the UE115.

In some cases, a UE115may be configured to spoof (e.g., fake) CSF reports to the base station105in addition to performing SRS-AS in order to further induce the base station105to reduce a rank associated with wireless communications at the UE115. For example, in addition to refraining from transmitting SRSs on transmit ports associated with receive ports, the UE115may additionally report poor channel quality indicators associated with wireless communications at the respective receive ports in order to induce the base station105to refrain from scheduling transmissions at the respective receive ports. In some aspects, the techniques disclosed herein may be used to reduce a rank of wireless communications at a UE in the context of NR communications, which may thereby result in reduced power consumption and therefore reduced temperatures at the UE.

The techniques described herein may enable UEs115of the wireless communications system100to reduce a power state at the UEs115, correspondingly reducing a power consumption at the UEs115and reducing a temperature at the UEs115. In particular, techniques described herein may enable the UEs115to perform SRS-AS in which the UEs115refrain from transmitting SRSs and/or transmit SRSs using a subset of transmit ports in order to induce a base station105to reduce a rank of scheduled transmissions. In this regard, by inducing the base station105to reduce a rank of scheduled transmissions, the UEs115may be able to deactivate one or more receive ports at the UEs115, thereby enabling the UEs115to enter a lower power state, reduce power consumption, and reduce a temperature at the UEs115. Such thermal mitigation and power savings techniques may enable the UEs115to reduce power consumption at both modem baseband and radio frequency transceiver components of the UEs115.

FIG. 2illustrates an example of a wireless communications system200that supports techniques for thermal mitigation and power saving in accordance with aspects of the present disclosure. In some examples, wireless communications system200may implement aspects of wireless communications system100. The wireless communications system200may include a UE115-aand a base station105-a, which may be examples of UEs115and base stations105described with reference toFIG. 1.

The UE115-aand the base station105-aof the wireless communications system200may communicate with one another via a communication link205. The communication link205may include an example of a link between two UEs115(e.g., a sidelink communication link, or PC5 link). In this regard, the communication link205may include a bi-directional links which supports both uplink and downlink transmissions.

In some aspects, the UE115-aand the base station105-aof the wireless communications system200may support techniques for thermal mitigation and power savings at the UE115-a. In particular, the UE115-aof the wireless communications system200may be configured to perform SRS-AS techniques for thermal mitigation and power savings in the context of NR and 5G access technologies in order to induce the base station105of the wireless communications system200to reduce a rank (e.g., reduce a quantity of layers) associated with wireless communications at the UE115-a. In this regard, by inducing the base station105-ato reduce a rank of wireless communications, techniques described herein may enable the UE115-ato deactivate receive ports at the UE115-a, enter a lower power state, reduce power consumption at the UE115-a, and reduce temperatures at the UE115-a.

For example, the UE115-amay transmit a capability report210to the base station105-a. In some aspects, the capability report210may include an indication of one or more transmission-reception modes supported by the UE115-a. For example, the capability report210may indicate that the UE115-asupports a transmission-reception mode including one transmission port and four reception ports (e.g., 1T4R), a transmission-reception mode including two transmission ports and four reception ports (e.g., 2T4R), or both. The UE115-amay be configured to supports any quantity or type of transmission-reception modes including any quantity of transmission ports, any quantity of reception ports, or both.

In some aspects, the base station105-amay transmit an indication of a first configuration220-afor communications between the UE115-aand the base station105-a. The first configuration220-amay indicate one or more parameters associated with wireless communications between the UE115-aand the base station105-aincluding a transmission-reception mode which is to be used at the UE115-a, a quantity of transmission ports and/or reception ports to be used by the UE115-a, or both. For example, the first configuration220-amay indicate that the UE115-ais to use one or more transmission-reception modes which was indicated in the capability report210. The first configuration220-amay be indicated to the UE115-avia a control message (e.g., radio resource control (RRC) message, downlink control information (DCI) message, MAC-CE message).

In some aspects, the first configuration220-amay indicate that the UE115-ais to communicate with the base station105-ausing a set of receive ports of the UE115-a. For example, the capability report210may indicate that the UE115-asupports a 1T4R transmission-reception mode (e.g., a transmission-reception mode including a set of four receive ports). In this example, the first configuration220-amay indicate that the UE115-ais to communicate with the base station105-ausing the set of four receive ports of the UE115-a.

In some aspects, the UE115-amay transmit SRSs225-aon a set of transmit ports corresponding to the set of receive ports associated with the first configuration220-a. In this regard, the UE115-amay transmit the SRSs225-aaccording to the first configuration220-a. In some cases, the UE115-amay transmit the SRSs225-aduring a first time interval associated with a first power state of the UE115-a. In some aspects, the base station105-amay be configured to measure a channel quality (e.g., determine a CQI and/or rank) associated with communications between the UE115-aand the base station105-abased on the received SRSs225-a. In some aspects, the UE115-amay transmit the SRSs225-abased on transmitting the capability report210, receiving the first configuration220-a, or both.

For example, the first configuration220-amay indicate that the UE115-ais to communicate with the base station105-ausing a set of four receive ports of the UE115-a. In some aspects, each receive port of the set of receive ports may be associated with (e.g., correspond to) a respective transmit port at the UE115-a. In other words, a first receive port may correspond to a first transmit port, a second receive port may correspond to a second transmit port, a third receive port may correspond to a third transmit port, and a fourth receive port may correspond to a fourth transmit port. In this example, the UE115-amay transmit the SRSs225-aaccording to the first configuration220-aby transmitting the SRSs225-aon the set of transmit ports (e.g., four transmit ports) corresponding to the set of receive ports (e.g., four receive ports) indicated in the first configuration220-a.

In some aspects, the UE115-amay transmit the SRSs225-ain a first time interval (e.g., first TTI, first slot, first subframe) associated with a first power state of the UE115-a(e.g., normal or default power state). Additionally, the UE115-amay receive one or more signals (e.g., reference signals) from the base station105-ausing (e.g., according to) the first configuration220-a. For example, in cases where the first configuration220-aindicates that the UE115-ais to communicate with the base station105-ausing a set of four receive ports, the UE115-amay receive signals from the base station105-ausing each receive port of the set of four receive ports. In this example, the UE115-amay be configured to decode four layers of downlink transmissions (e.g., four layers of physical downlink shared channel (PDSCH) transmissions) using the four receive ports.

In some aspects, the UE115-amay determine to operate in the second power state that is lower than the first power state. In other words, the UE115-amay determine to operate in the second power state (e.g., reduced power state) that is lower than the first power state. In this regard, the UE115-amay determine that one or more trigger conditions for transitioning to a reduced power state have been satisfied.

The UE115-amay determine to operate in the second power state based on any quantity of parameters or characteristics including, but not limited to, a thermal state (e.g., temperature) at the UE115-a, a power level (e.g., battery level) at the UE115-a, or both. For example,FIG. 1illustrates a graph which shows a thermal state (e.g., temperature, Tskin, Tj) at the UE115-aover time. As may be shown inFIG. 1, a thermal state (e.g., temperature) at the UE115-amay increase over time due to communications or processing carried out at the UE115-a, external temperatures or heat sources (e.g., direct sunlight, body heat), or any combination thereof.

In some aspects, the UE115-amay be configured to transition from a first power state (e.g., normal or default power state) to a second power state (e.g., reduced power state) based on comparing a thermal state at the UE115-ato one or more threshold thermal states. In particular, the UE115-amay determine to operate in the second power state based on determining that a thermal state at the UE115-asatisfies a threshold thermal state. In some cases, a thermal state at the UE115-amay satisfy the threshold thermal state if the thermal state is greater than or equal to the threshold thermal state.

For example, as shown inFIG. 1, the thermal state (e.g., Tskin, Tj) of the UE115-amay become equal or greater than a threshold thermal state T thresh at time Tj. In this example, the UE115-amay determine to operate in the second power state at time T1based on determining that the thermal state of the UE115-ais greater than or equal to the threshold thermal state. It is noted herein that different metrics of a thermal state may be associated with different threshold thermal states. For instance, a skin temperature Tskinat the UE115-amay be associated with a threshold skin temperature Tthresh,skin, such that the UE115-adetermines to operate in the second power state based on determining that Tskin≥Tthresh,skin. By way of another example, a junction temperature Tskinat the UE115-amay be associated with a threshold junction temperature Tthresh,jsuch that the UE115-adetermines to operate in the second power state based on determining that Tj≥Tthresh,j.

By way of another example, the UE115-amay determine to operate in the second power state based on determining that a power level (PUE) at the UE115-asatisfies a threshold power level (Pthresh). The power level of the UE115-amay include, but is not limited to, a battery level of the UE115-a. In some cases, the power level may satisfy the threshold power level if the power level is less than or equal to the threshold power level. In this regard, the UE115-amay determine to operate in the second power state based on determining that the power level of the UE115-ais less than or equal to a threshold power level (e.g., PUE≤Pthresh).

In some aspects, the UE115-amay determine one or more parameters associated with the set of receive ports of the UE115-a. Parameters associated with the set of receive ports may include, but are not limited to, a received signal strength indicator (RSSI) metric, a reference signal received power (RSRP) metric, a reference signal received quality (RSRQ) metric, a SNR, a SINR, or any combination thereof. In some aspects, the UE115-amay determine the parameters of the receive ports based on transmitting the capability report210, receiving the first configuration220-a, communicating with the base station105-aaccording to the first configuration220-a(e.g., transmitting SRSs225-a), or any combination thereof.

For example, in cases where the first configuration220-aindicates that the UE115-ais to communicate with the base station105-ausing a set of four receive ports, the UE115-amay receive signals from the base station105-ausing each receive port of the set of four receive ports. In this example, the UE115-amay perform measurements (e.g., RSSI measurements, RSRP measurements, RSRQ measurements, SNR measurements, SINR measurements) on signals received using each of the respective receive ports. In this regard, the UE115-amay be configured to determine relative strengths or qualities of signals received using each of the respective receive ports.

In some aspects, the UE115-amay be configured to select a subset of receive ports of the set of receive ports of the UE115-a. More particularly, the UE115-amay be configured to select a subset of receive ports of the UE115-a, and may be configured to select a subset of transmit ports corresponding to the selected subset of receive ports of the UE115-a. In some aspects, the UE115-amay be configured to select the set of receive ports of the UE115-abased on the determined parameters of the receive ports, based on determining to operate in the second power state, or both.

For example, the UE115-amay be configured to select a subset of receive ports from the set of receive ports which may be associated with a highest signal strength or quality. For instance, in cases where the first configuration220-ais associated with four receive ports, the UE115-amay be configured to select a subset of receive ports (e.g., one or two receive ports) which are associated with the highest RSSI metrics, the highest RSRP metrics, the highest RSRQ metrics, the highest SNRs, the highest SINRs, or any combination thereof. Furthermore, the UE115-amay be configured to select a subset of transmit ports which correspond to the selected subset of receive ports. For instance, in cases where the UE115-aselects a first receive port and a second receive port out of the set of four receive ports, the UE115-amay additionally be configured to select a first transmit port corresponding to the first receive port and a second transmit port corresponding to the second receive port.

In some aspects, the UE115-amay communicate with the base station105-ausing less than all of the set of transmit ports for SRSs225-bduring a second time interval (e.g., second TTI, second slot, second subframe) following the first time interval. In some aspects, the UE115-amay communicate with the base station105-ausing less than all of the set of transmit ports for SRSs225-bbased on transmitting the capability report210, receiving the first configuration220-a, communicating with the base station105-aaccording to the first configuration220-a(e.g., transmitting SRSs225-a), determining to operate in the second power state, determining the parameters associated with the set of receive ports, selecting the subset of receive and/or transmit ports, or any combination thereof.

For example, the UE115-amay communicate with the base station105-ausing less than all of the set of transmit ports for SRSs225-bduring a second time interval based on determining that a thermal state at the UE115-asatisfies a threshold thermal state (e.g., based on Tskin≥Tthresh,skin, Tj≥Tthresh,j) at time T1. Additionally or alternatively, the UE115-amay communicate with the base station105-ausing less than all of the set of transmit ports for SRSs225-bduring a second time interval based on determining that a power level at the UE115-asatisfies a threshold power level (e.g., based on PUE≤Pthresh), or any combination thereof.

In some aspects, the UE115-amay communicate with the base station105-ausing less than all of the set of transmit ports for SRSs225-bin order to induce the base station105-ainto scheduling transmissions at the UE115-awhich are associated with a lower rank (e.g., reduced quantity of layers). In turn, by inducing the base station105-ato schedule transmissions which are associated with a lower rank, the UE115-amay be able to adjust an operational state of one or more receive ports (e.g., deactivate one or more receive ports) of the UE115-ain order to reduce a power consumption at the UE115-a, thereby reducing a thermal state at the UE115-a. Accordingly, in some cases, the UE115-amay communicate with the base station105-ausing less than all of the set of transmit ports for SRSs225-bbased on determining to operate in the second power state (e.g., based on determining to operate in the second power state at time T1) in order to reduce power consumption, conserve a power level (e.g., battery level), and reduce a thermal state (e.g., reduce Tskin, Tj) at the UE115-a.

For example, the UE115-amay be configured to refrain from transmitting SRSs225-bon all transmit ports of a set of transmit ports at the UE115-aduring the second time interval. For instance, in cases where the UE115-aincludes a set of four receive ports, and therefore a set of four transmit ports corresponding to the four receive ports, the UE115-amay refrain from transmitting SRSs225-bon each transmit port of the set of four transmit ports. In this regard, the UE115-amay wholly refrain from transmitting any SRSs225-bon the set of transmit ports.

By way of another example, the UE115-amay be configured to transmit SRSs225-bon a subset of transmit ports of the set of transmit ports at the UE115-aduring the second time interval. For instance, in cases where the UE115-aincludes a set of four receive ports, and therefore a set of four transmit ports corresponding to the four receive ports, the UE115-amay transmit SRSs225-bon one, two, or three transmit ports of the set of four transmit ports. In this regard, the UE115-amay refrain from transmitting SRSs225-bon one or more transmit ports of the set of transmit ports.

As noted previously herein, In the base station105-amay be configured to measure a channel quality (e.g., determine a CQI and/or rank) associated with communications between the UE115-aand the base station105-abased on the received SRSs225-a,225-b. In this regard, communicating with the base station105-ausing less than all the transmit ports for SRSs225-b(e.g., refraining from transmitting SRSs225-b, transmitting SRSs225-busing a subset of transmit ports) may result in different estimations of channel quality at the base station105-a, which may be used to induce the base station105-ato reduce a quantity of layers associated with scheduled transmissions.

Moreover, the quantity of transmit ports of the subset of transmit ports on which the SRSs225-bare transmitted may be based on a level of reduction of desired power consumption and/or thermal mitigation at the UE115-a. In particular, reducing the quantity of transmit ports on which the SRSs225-bare transmitted may induce the base station105-ato reduce the rank of scheduled transmissions, thereby corresponding to larger reductions in power consumption at the UE115-a. In this regard, completely refraining from transmitting SRSs225-bon the set of transmit ports may be associated with larger reductions in power consumption at the UE115-a. Similarly, transmitting SRSs225-bon a single transmit port may result in a further reduction of a rank of scheduled transmissions as compared to transmitting SRSs225-bon two transmit ports, and may therefore result in larger reductions of power consumption at the UE115-a. Therefore, the quantity of transmit ports on which the UE115-atransmits SRSs225-bmay be based on a desired level of reduction of power consumption at the UE115-a.

In some cases, in addition to performing SRS-AS techniques in which the UE115-areduces a quantity of transmit ports on which SRSs225-bare transmitted, the UE115-amay additionally adjust parameters reported to the base station105-avia a CSF report230in order to further induce the base station105-ato reduce a rank (e.g., quantity of layers) associated with transmissions scheduled at the UE115-a. In this regard, the UE115-amay use a combination of SRS-AS techniques and CSF spoofing techniques in order to reduce a rank of scheduled transmissions, and therefore reduce power consumption and reduce temperatures (e.g., Tskin, Tj) at the UE115-a.

For example, the UE115-amay determine a rank, a CQI, or both, associated with communications between the UE115-aand the base station105-ausing one or more receive ports. In some aspects, the UE115-amay determine the rank and/or CQI associated with communications with the base station105-ausing one or more receive ports based on determining to operate in the second power state. Upon determining the rank and/or CQI associated with communications between the UE115-aand the base station105-a, the UE115-amay selectively adjust the determined rank, the determined CQI, or both. In some aspects, the UE115-amay selectively adjust the determined rank and/or the determined CQI based on determining to operate in the second power state.

The UE115-amay be configured to selectively adjust the rank and/or CQI in order to further induce the base station105-ato reduce a rank (e.g., quantity of layers) associated with transmissions scheduled at the UE115-a, which may result in reduced power consumption and reduced temperatures at the UE115-a. For example, the UE115-amay determine a rank associated with communications with the base station105-ausing the set of receive ports by determining that it may support up to four layers of communications (e.g., rank4). In this example, the UE115-amay selectively adjust the determined rank to generate an adjusted rank which is less than the determined rank (e.g., rank3, rank2, rank1). The adjusted rank may subsequently be reported to the base station105-avis a CSF report230in order to induce the base station105-ato reduce a rank associated with transmissions scheduled at the UE115-abased on the adjusted rank.

By way of another example, the UE115-amay determine a CQI associated with communications with the base station105-ausing the set of receive ports of the UE115-a. In this example, the UE115-amay selectively adjust the determined CQI to generate an adjusted CQI which is less than the determined CQI (e.g., lower quality CQI). In this regard, the UE115-amay be configured to artificially adjust a determined rank and/or a determined CQI in order to reduce a quantity of layers of communications scheduled at the UE115-a.

Subsequently, the UE115-amay transmit a CSF report230to the base station105-a. In some aspects, the CSF report230may include an indication of the adjusted rank, the adjusted CQI, or both. In this regard, the UE115-amay transmit the CSF report230based determining to operate in the second power state and selectively adjusting the determined rank and/or determined CQI.

In some aspects, the UE115-amay selectively adjust the rank and/or CQI which is reported to the base station105-aat450via the CSF report230in order to induce the base station105-ato reduce a quantity of layers associated with transmissions scheduled at the UE115-a. For instance, by reporting the adjusted rank (e.g., lowered rank) to the base station105-avia the CSF report230, the base station105-amay be configured to determine that the UE115-ais not capable of supporting higher quantities of layers, and may therefore reduce the rank of transmissions scheduled at the UE115-abase on the adjusted rank. Similarly, by reporting the adjusted CQI (e.g., lowered CQI) to the base station105-avia the CSF report230, the base station105-amay be configured to determine that the UE115-ais experiencing poor CQI, and may therefore reduce the rank of transmissions scheduled at the UE115-abase on the adjusted CQI.

In some aspects, the UE115-amay use a combination of CSF spoofing techniques and SRS-AS techniques in order to induce the base station105-ato reduce a rank (e.g., quantity of layers) associated with transmissions scheduled at the UE115-a. For example, according to some conventional techniques, the UE115-amay perform CSF spoofing techniques in which the UE115-areports selectively adjusted (e.g., selectively reduced) rank and/or CQI to the base station105-avia a CSF report230. However, in some cases, instead of simply reducing the rank of scheduled transmissions based on the adjusted rank and/or CQIs, the base station105-amay instead instruct the UE115-ato transmit SRSs so that the base station105-amay directly determine the rank and/or CQI of wireless communications between the UE115-aand the base station105-a. In such cases, if the UE115-awere not to perform the SRS-AS techniques described herein, the base station105-amay determine that the adjusted rank and/or CQI values reported to the base station105-bare inaccurate, and may therefore refrain from reducing the rank of scheduled transmissions. Accordingly, some techniques described herein may use a combination of CSF spoofing techniques and SRS-AS techniques to increase the likelihood that the base station105-amay be induced into reducing a rank of transmissions scheduled at the UE115-a.

In some aspects, the UE115-amay receive an indication of a second configuration220-bfrom the base station105-a. As noted previously herein, the second configuration220-bmay indicate one or more parameters associated with wireless communications between the UE115-aand the base station105-aincluding a transmission-reception mode which is to be used at the UE115-a, a quantity of transmission ports and/or reception ports to be used by the UE115-a, or both. For example, the second configuration220-bmay indicate for the UE115-ato communicate with the base station105-ausing a first subset of receive ports of the set of receive ports at the UE115-a. The second configuration220-bmay be indicated to the UE115-avia a control message (e.g., RRC message, DCI message, MAC-CE message).

In some aspects, the UE115-amay receive the second configuration220-bbased on communicating with the base station105-ausing less than all the transmit ports for the SRSs225-b, receiving the CSF report230, or both. For example, the UE115-amay receive the second configuration220-bbased on refraining from transmitting the SRSs225-bon all the transmit ports of the UE115-a(e.g., refraining from transmitting any SRSs225-b). By way of another example, the UE115-amay receive the second configuration220-bbased on transmitting SRSs on a subset of transmit ports corresponding to a subset of receive ports of the UE115-a. Furthermore, in some cases, the UE115-amay receive the second configuration220-bbased on communicating with the base station105-ausing less than all the transmit ports for SRSs225-bin conjunction with reporting the selectively adjusted (e.g., selectively reduced) rank and/or CQI to the base station105-avia the CSF report230.

In some aspects, the second configuration220-bmay indicate for the UE115-ato communicate with the base station105-ausing a first subset of receive ports of the set of receive ports at the UE115-a. In this regard, the second configuration220-bmay reduce a quantity of receive ports used at the UE115-arelative to the first configuration220-a. For example, the first configuration220-amay indicate for the UE115-ato use a set of four receive ports at the UE115-a. Subsequently, the UE115-amay transmit the SRSs225-busing a first transmit port and a second transmit port corresponding to a first receive port and a second receive port, respectively. In this example, the second configuration220-bmay indicate for the UE115-ato use the first receive port and the second receive port corresponding to the first transmit port and the second transmit port. In this regard, the second configuration220-bmay reduce a quantity of receive ports used by the UE115-afrom four receive ports to two receive ports (e.g., 2Rx fallback).

Accordingly, the UE115-amay be configured to implement receive port fallback (e.g., 2Rx fallback, 1Rx fallback) to reduce power consumption at the UE115-bby refraining from transmitting SRSs225-baltogether, transmitting SRSs225-busing a subset of transmit ports corresponding to a subset of receive ports, transmitting the CSF report including selectively adjusted rank values, CQI values, or any combination thereof.

In some aspects, the UE115-amay selectively adjust one or more parameters associated with a second subset of receive ports of the UE115-a. In some aspects, the UE115-amay selectively adjust the one or more parameters associated with the second subset of receive ports in order to operate in the second power state (e.g., reduced power state). Parameters associated with the second subset of receive ports which may be adjusted may include parameters associated with low-noise amplifiers (LNAs), phase shifters, or both. In some cases, the UE115-amay selectively adjust one or more parameters associated with the second subset of receive ports in order to adjust an operational state (e.g., deactivate) the second subset of receive ports, which may thereby reduce power consumption and/or temperate at the UE115-a. In some aspects, the UE115-amay selectively adjust the parameters associated with the second subset of receive ports based on receiving the second configuration220-bat450.

For example, as noted previously herein, the first configuration220-amay indicate for the UE115-ato use a set of four receive ports at the UE115-a(e.g., first receive port, second receive port, third receive port, fourth receive port). Subsequently, the second configuration220-bmay indicate for the UE115-ato use the second receive port and the fourth receive port based on identifying that SRSs225-bwere not transmitted/received, based on identifying that the SRSs225-bwere transmitted using a subset of transmit ports, based on the CSF report230, or any combination thereof. Thus, first subset of receive ports indicated by the second configuration220-bmay include the second and fourth receive ports. In this example, the UE115-amay selectively adjust parameters associated with the first and third receive ports (e.g., a second subset of receive ports) in order to reduce a power consumption of the first and third receive ports. For instance, the UE115-amay deactivate the first and third receive ports by selectively adjusting parameters associated with LNAs, phase shifters, and/or other components of the first and third receive ports.

By inducing the base station105-ato transmit the second configuration220-bwhich instructs the UE115-ato communicate using a subset of receive ports, the techniques described herein may be used by the UE115-ato effectively reduce a rank of transmissions scheduled at the UE115-a. Therefore, by effectively reducing a rank of scheduled transmissions, techniques described herein may enable the UE115-ato deactivate a subset of receive ports, which may enable the UE115-ato enter a lower operational power state, reduce power consumption at the UE115-a, and reduce a temperature (e.g., reduce Tskinand/or Tj) at the UE115-a. Such power savings techniques may enable the UE115-ato reduce power consumption at both a modem baseband of the UE115-aand a radio frequency transceiver of the UE115-a.

Subsequently, the UE115-amay communicate with the base station105-aaccording to the second configuration220-b. In this regard, the UE115-amay communicate with the base station105-aby receiving signals using the first subset of receive ports indicated in the second configuration220-b. Moreover, the UE115-amay communicate with the base station105-aby transmitting SRSs225using a subset of transmit ports corresponding to the first subset of receive ports indicated in the second configuration220-b. Accordingly, the UE115-amay communicate with the base station105-aaccording to the second configuration220-busing a lower quantity of layers (e.g., reduced rank) as compared to communications which were carried out according to the first configuration220-a.

The UE115-amay communicate base station105-aaccording to the second configuration220-bbased on receiving the second configuration220-b, selectively adjusting the parameters associated with the second subset of receive ports, or both. For example, the second configuration220-bmay indicate for the UE115-ato use a first subset of receive ports including a first receive port and a third receive port. Subsequently, the UE115-amay deactivate a second receive port and a fourth receive port in order to enter the second power state (e.g., reduced power state). In this example, the UE115-amay communicate with the base station105-aaccording to the second configuration220-bby receiving downlink transmissions from the base station105-ausing the first and third receive ports. In this example, the UE115-amay be configured to decode two layers of downlink transmissions (e.g., two layers of PDSCH transmissions) using the first and third receive ports.

In some aspects, the UE115-amay subsequently induce the base station105-ato increase a quantity of layers associated with transmissions scheduled at the UE115-a. For example, while communicating with the base station105-baccording to the second configuration220-b, the UE115-amay subsequently determine that it may return to the first power state (e.g., the default power state, or other power state) which is higher than the second power state. The UE115-amay determine to return the first power state based on determining that the thermal state of the UE115-ano longer satisfies the threshold thermal state (e.g., based on determining Tskin<Tthresh,skin, and/or Tj<Tthresh,j) or another thermal state, based on determining that the power level (e.g., battery level) of the UE115-ano longer satisfies the threshold power level (e.g., based on determining PUE>Pthresh), or both.

For example, as shown in the graph illustrated inFIG. 2, the UE115-amay implement thermal mitigation and power savings techniques at some time after time T1(e.g., based on a thermal state T satisfying a threshold thermal state Tthresh), as described previously herein. The UE115-amay then transition to the second power state at some time after time T1, which may reduce a thermal state (e.g., reduce a temperature) of the UE115-b. In this example, the UE115-amay determine that it may switch back to the first power state (e.g., normal or default power state) based on identifying that a thermal state of the UE115-afails to satisfy the threshold thermal state, based on identifying that the thermal state satisfies a different threshold thermal state, or both.

For example, referring to the graph illustrated inFIG. 2, the UE115-amay determine to operate in (e.g., return to) the first thermal state based on identifying that the thermal state (e.g., Tskin, Tj) fails to satisfy the threshold thermal state (Tthresh). For instance, the UE115-amay determine to operate in (e.g., return to) the first thermal state based on identifying that the thermal state is less than the threshold thermal state (e.g., operate in first power state if Tskin<Tthresh, or Tj<Tthresh).

By way of another example, continuing with reference to the graph illustrated inFIG. 2, the UE115-amay determine to operate in (e.g., return to) the first thermal state based on identifying that the thermal state (e.g., Tskin, Tj) satisfies a second threshold thermal state (Tthresh,2) which is different from (e.g., lower than) the threshold thermal state Tthresh. In some cases, the thermal state at the UE115-amay satisfy the second threshold thermal state if the thermal state is less than or equal to the second thermal state. For instance, the UE115-amay determine to operate in (e.g., return to) the first thermal state based on identifying that the thermal state at the UE115-ais less than or equal to the second threshold thermal state (e.g., operate in first power sate if Tskin≤Tthresh,2, or Tj≤Tthresh,2). By comparing the thermal state at the UE115-ato the second thermal state Tthresh,2which is lower than the first thermal state Tthresh, the thermal mitigation techniques described herein may ensure that the UE115-ahas an opportunity to sufficiently cool before the UE115-areturns to the first power state (e.g., normal or default power state).

Upon determining that the UE115-ais to operate in the first power state, the UE115-amay transmit SRSs25using an increased quantity of transmit ports corresponding to an increased quantity of receive ports. For example, in cases where the second configuration220-bincludes two receive ports (e.g., 2Rx), the UE115-amay transmit SRSs using four transmit ports corresponding to the four receive ports (e.g., 4Rx) in order to induce the base station105-ato increase the quantity of layers associated with transmissions scheduled at the UE115-a. Additionally or alternatively, the UE115-amay transmit a CSF report230which indicates a higher rank and/or higher CQI (e.g., rank4) in order to further induce the base station105-ato increase the quantity of layers associated with transmissions scheduled at the UE115-a.

The UE115-amay implement the power-savings techniques described herein for a limited duration of time until such power-savings techniques are no longer necessary. In other words, the UE115-amay implement the techniques described herein to reduce the power level at the UE115-a, correspondingly reducing a power consumption and/or temperature of the UE115-a. Subsequently, when the temperature (e.g., Tskin, Tj) of the UE115-afalls below a threshold temperature (e.g., Tthresh,skin, Tthresh,j, Tthresh,2) and/or when the power level (e.g., PUE, battery level) of the UE115-arises above the threshold power level (e.g., Pthresh), the UE115-amay transmit SRSs225and/or transmit a CSF report230in order to return to the first power state and/or the first configuration220-a.

The techniques described herein may enable the UE115-ato reduce a power state at the UE115-a, correspondingly reducing a power consumption at the UE115-aand reducing a temperature at the UE115-a. In particular, techniques described herein may enable the UE115-ato perform SRS-AS in which the UE115-arefrains from transmitting SRSs225-band/or transmits SRSs225-busing a subset of transmit ports in order to induce the base station105-ato reduce a rank of scheduled transmissions. In this regard, by inducing the base station105-ato reduce a rank of scheduled transmissions, the UE115-amay be able to deactivate one or more receive ports at the UE115-a, thereby enabling the UE115-ato enter a lower power state, reduce power consumption, and reduce a temperature at the UE115-a. Such thermal mitigation and power savings techniques may enable the UE115-ato reduce power consumption at both modem baseband and radio frequency transceiver components of the UE115-a.

FIGS. 3A and 3Billustrate examples of a communication scheme300-aand a communication scheme300-b, respectively, that support techniques for thermal mitigation and power saving in accordance with aspects of the present disclosure. In some examples, the communication scheme300-aand/or communication scheme300-bmay implement, or be implemented by, aspects of wireless communications system100, wireless communications system200, or both.

In some aspects,FIGS. 3A and 3Bmay illustrate components of a UE115-b, which may include examples of UEs115shown and described with reference toFIGS. 1 and 2. In some aspects, the UE115-bmay include a set of receive ports305including one or more receive ports315. For example, the UE115-bmay include a set of receive ports305including a first receive port315-a, a second receive port315-b, a third receive port315-c, and a fourth receive port315-d(e.g., 4Rx). Similarly, the UE115-bmay include a set of transmit ports310including one or more transmit ports320. For example, the UE115-bmay include a set of transmit ports310including a first transmit port320-a, a second transmit port320-b, a third transmit port320-c, and a fourth transmit port320-d(e.g., 4Tx). In this regard, the UE115-bmay be configured to support multiple transmission-reception modes (e.g., 1T4R, 2T4R, etc.). It is noted herein, however, that the UE115-bmay include any quantity of receive ports315and/or any quantity of transmit ports320in order to support additional transmission-reception modes.

In some aspects, each receive port315of the set of receive ports305may correspond to a transmit port320of the set of transmit ports310, and vice versa. For example, the first receive port315-amay correspond to the first transmit port320-a, the second receive port315-bmay correspond to the second transmit port320-b, the third receive port315-cmay correspond to the third transmit port320-c, and the fourth receive port315-dmay correspond to the fourth transmit port320-d. In some aspects, each of the respective transmit ports320may be configured to sound SRSs (e.g., transmit SRSs) for each of the respective corresponding receive ports315(e.g., first transmit port320-asounds SRSs for first receive port315-a, second transmit port320-bsounds SRSs for second receive port315-b, and the like).

According to some implementations, the UE115-bmay be configured to communicate with a base station105according to a first configuration using the set of receive ports305during a first time interval, and may subsequently communicate with the base station105using less than all of the set of transmit ports310for SRSs during a second time interval in order to induce the base station105to reduce a rank of transmissions scheduled at the UE115-b.

For example, while operating in a first power state (e.g., normal or default power state), the UE115-amay receive an indication of a first configuration for communications between the UE115-band the base station105. The first configuration may indicate one or more parameters associated with wireless communications between the UE115-band the base station105including a transmission-reception mode which is to be used at the UE115-b, a quantity of transmission ports320and/or reception ports315to be used by the UE115-b, or both. For example, the first configuration may indicate that the UE115-bis to communicate with the base station105using each receive port315of the set of receive ports305of the UE115-c(e.g., indicate 4Rx).

Subsequently, as shown in a communications configuration325-aillustrated inFIG. 3A, and a communications configuration325-billustrated inFIG. 3B, the UE115-bmay communicate with the base station105-baccording to the first configuration during a first time interval330-a(e.g., first TTI, first slot, first subframe). For instance, in cases where the first configuration indicates for the UE115-bto communicate with the base station105using all four receive ports315of the set of receive ports305, the UE115-bmay transmit, during the first time interval330-a, SRSs on each transmit port320of the set of transmit ports310corresponding to each receive port315of the set of receive ports305. For instance, as shown in communications configurations325-aand325-b, the UE115-amay transmit SRSs using each of the first transmit port320-a, the second transmit port320-b, the third transmit port320-c, and the fourth transmit port320-d.

The SRSs transmitted according to the first configuration in the first time interval330-aare shown as being transmitted at different times within the first time interval330-a. However, in additional or alternative cases, the SRSs transmitted (e.g., sounded) in the first time interval330-amay be transmitted such that they at least partially overlap with one another in the time domain. In this regard, the SRSs may be transmitted according to different modulation schemes, within different frequency bands (e.g., different carriers, different component carriers), or any combination thereof, such that the transmission of two or more SRSs at least partially overlap with one another in the time domain. For example, the UE115-bmay transmit a first SRS via the first transmit port320-aand a second SRS via the second transmit port320-b. In this example, the first SRS may be transmitted on a first carrier and the second SRS may be transmitted on a second carrier, where the first SRS and the second SRS at least partially overlap in the time domain.

At some time during or after the first time interval330-a, the UE115-amay determine to operate in a second power state that is lower than the first power state. In other words, the UE115-bmay determine to operate in the second power state (e.g., reduced power state) that is lower than the first power state based on determining that one or more trigger conditions for transitioning to a reduced power state have been satisfied. As noted previously herein, the UE115-bmay determine to operate in the second power state based on any quantity of parameters or characteristics including, but not limited to, a thermal state at the UE115-b, a power level (e.g., battery level) at the UE115-b, or both.

In some aspects, upon determining to operate in the second power state, the UE115-bmay communicate with the base station105within a second time interval330-bfollowing the first time interval330-ausing less than all of the transmit ports320for SRSs. For example, as shown in the communications configuration325-aillustrated inFIG. 3A, the UE115-bmay refrain from transmitting SRSs on all transmit ports320of the set of transmit ports310during the second time interval330-b. As such, in some examples, the UE115-amay completely refrain from transmitting SRSs during the second time interval330-b.

By refraining from transmitting SRSs on all transmit ports320of the set of transmit ports320during the second time interval330-b, as shown in the communications configuration325-a, the UE115-bmay be configured to induce the base station105to reduce rank (e.g., reduce a quantity of layers) associated with transmissions scheduled at the UE115-b. Accordingly, by inducing the base station105to reduce the rank and/or quantity of layers of scheduled transmissions, techniques described herein may enable the UE115-bto enter the second power state (e.g., lower power state) by turning off, deactivating, or otherwise disabling one or more receive ports315of the set of receive ports305. Therefore, by enabling the UE115-bto deactivate one or more receive ports315and operate in the second power state, techniques described herein may enable the UE115-bto reduce a thermal state (e.g., skin temperature, junction temperature) at the UE115-c, reduce power consumption, and conserve power.

For example, by refraining from transmitting SRSs in the second time interval330-b, the UE115-bmay induce the base station to reduce scheduled transmissions to a rank two (e.g., two layers), thereby enabling the UE115-bto disable two receive ports315of the set of receive ports305(e.g., 2Rx fallback). By way of another example, by refraining from transmitting SRSs in the second time interval330-b, the UE115-bmay induce the base station to reduce scheduled transmissions to a rank one (e.g., one layer), thereby enabling the UE115-bto disable three receive ports315of the set of receive ports305(e.g., 1Rx fallback).

In additional or alternative implementations, the UE115-bmay be configured to induce the base station105to reduce a rank of scheduled transmissions by transmitting SRSs on a subset of transmit ports320. For example, as shown in the communications configuration325-billustrated inFIG. 3B, the UE115-bmay transmit SRSs, during the second time interval, using less than all the transmit ports320of the set of transmit ports310. For instance, as shown inFIG. 3B, the UE115-bmay transmit a first SRS via the second transmit port320-band a second SRS via the fourth transmit port320-dduring the second time interval330-b(e.g., refrain from transmitting SRSs on the first transmit port320-aand the third transmit port320-c).

By transmitting SRSs on less than all transmit ports320of the set of transmit ports320during the second time interval330-b, as shown in the communications configuration325-a, the UE115-bmay be configured to induce the base station105to reduce rank (e.g., reduce a quantity of layers) associated with transmissions scheduled at the UE115-b. Accordingly, by inducing the base station105to reduce the rank and/or quantity of layers of scheduled transmissions, techniques described herein may enable the UE115-bto enter the second power state (e.g., lower power state) by turning off, deactivating, or otherwise disabling one or more receive ports315of the set of receive ports305. Therefore, by enabling the UE115-bto deactivate one or more receive ports315and operate in the second power state, techniques described herein may enable the UE115-bto reduce a thermal state (e.g., skin temperature, junction temperature) at the UE115-c, reduce power consumption, and conserve power.

In some aspects, the UE115-bmay be configured to select which transmit ports320will be used to transmit SRSs during the second time interval330-bbased on one or more parameters associated with the set of receive ports305, the set of transmit ports310, or both. Parameters associated with the set of receive ports305may include, but are not limited to, an RSSI metric, an RSRP metric, an RSRQ metric, a SNR, a SINR, or any combination thereof.

For example, in cases where the first configuration indicates that the UE115-bis to communicate with the base station105using each receive port310of the set of receive ports305, the UE115-bmay receive signals from the base station105using each receive port310of the set of receive ports305. In this example, the UE115-bmay perform measurements (e.g., RSSI measurements, RSRP measurements, RSRQ measurements, SNR measurements, SINR measurements) on signals received using each of the respective receive ports310. In this regard, the UE115-bmay be configured to determine relative strengths or qualities of signals received using each of the respective receive ports310.

Subsequently, the UE115-bmay be configured to select a subset of receive ports310of the set of receive ports305. In some aspects, the UE115-bmay be configured to select the subset of receive ports310of the UE115-bbased on the determined parameters of the respective receive ports310. In some cases, the UE115-bmay select a subset of receive ports310which are associated with a higher signal strengths, higher signal qualities, or both. Subsequently, the UE115-bmay transmit the SRSs within the second time interval330-busing a subset of transmit ports320which correspond to the determined subset of receive ports315.

For example, in cases where the first configuration is associated with each of the set of receive ports305, the UE115-bmay determine that the second receive port315-band the fourth receive port315-dmay be associated with the highest RSSI metrics, the highest RSRP metrics, the highest RSRQ metrics, the highest SNRs, the highest SINRs, or any combination thereof. In this regard, the UE115-bmay select that the second and fourth receive ports315for inclusion within the subset of receive ports315. The UE115-bmay be further configured to select a subset of transmit ports320which correspond to the selected subset of receive ports315. For instance, in cases where the UE115-cselects the second receive port315-band the forth receive port315-dfor inclusion within the subset of receive ports315, the UE115-bmay additionally be configured to select the second transmit port320-bcorresponding to the second receive port315-band the fourth transmit port320-dcorresponding to the fourth receive port315-d. Subsequently, as shown in communications configuration325-b, the UE115-bmay then transmit SRSs within the second time interval using the second transmit port320-band the fourth transmit port320-d.

FIG. 4illustrates an example of a process flow400that supports techniques for thermal mitigation and power saving in accordance with aspects of the present disclosure. In some examples, process flow400may implement, or be implemented by, aspects of wireless communications system100, wireless communications system200, communications schemes300-aand300-b, or any combination thereof. For example, the process flow400may illustrate a UE115-ctransmitting SRSs according to a first configuration, determining to operate in a reduced power state, communicating with a base station105-busing less than all transmit ports for SRSs, and receiving a second configuration for wireless communications with the base station105-b, as described with reference toFIGS. 1-3. In some cases, process flow400may include a UE115-cand a base station105-b, which may be examples of corresponding devices as described herein.

At405, the UE115-cmay transmit a capability report to the base station105-b. In some aspects, the capability report may include an indication of one or more transmission-reception modes supported by the UE115-c. For example, the capability report may indicate that the UE115-csupports a transmission-reception mode including one transmission port and four reception ports (e.g., 1T4R), a transmission-reception mode including two transmission ports and four reception ports (e.g., 2T4R), or both. The UE115-cmay be configured to supports any quantity or type of transmission-reception modes including any quantity of transmission ports, any quantity of reception ports, or both.

At410, the base station105-bmay transmit an indication of a first configuration for communications between the UE115-cand the base station105-b. The first configuration may indicate one or more parameters associated with wireless communications between the UE115-cand the base station105-bincluding a transmission-reception mode which is to be used at the UE115-c, a quantity of transmission ports and/or reception ports to be used by the UE115-c, or both. For example, the first configuration may indicate that the UE115-cis to use one or more transmission-reception modes which was indicated in the capability report transmitted at405. The first configuration may be indicated to the UE115-cvia a control message (e.g., RRC message, DCI message, MAC-CE message).

In some aspects, the first configuration may indicate that the UE115-cis to communicate with the base station105-busing a set of receive ports of the UE115-c. For example, the capability report transmitted by the UE115-cmay indicate that the UE115-csupports a 1T4R transmission-reception mode (e.g., a transmission-reception mode including a set of four receive ports). In this example, the first configuration may indicate that the UE115-cis to communicate with the base station105-busing the set of four receive ports of the UE115-c.

At415, the UE115-cmay transmit SRSs on a set of transmit ports corresponding to the set of receive ports associated with the first configuration. In this regard, the UE115-cmay transmit SRSs according to the first configuration indicated at410. In some cases, the UE115-cmay transmit the SRSs at415during a first time interval associated with a first power state of the UE115-a. In some aspects, the base station105-bmay be configured to measure a channel quality (e.g., determine a CQI and/or rank) associated with communications between the UE115-cand the base station105-bbased on the received SRSs. In some aspects, the UE115-cmay transmit the SRSs at415based on transmitting the capability report at405, receiving the first configuration at410, or both.

For example, the first configuration may indicate that the UE115-cis to communicate with the base station105-busing a set of four receive ports of the UE115-c. As noted previously herein, each receive port of the set of receive ports may be associated with (e.g., correspond to) a respective transmit port at the UE115-c. In other words, a first receive port may correspond to a first transmit port, a second receive port may correspond to a second transmit port, a third receive port may correspond to a third transmit port, and a fourth receive port may correspond to a fourth transmit port. In this example, the UE115-cmay transmit the SRSs at415according to the first configuration by transmitting the SRSs on the set of transmit ports (e.g., four transmit ports) corresponding to the set of receive ports (e.g., four receive ports) indicated in the first configuration.

In some aspects, the UE115-cmay transmit the SRSs at415in a first time interval (e.g., first TTI, first slot, first subframe) associated with a first power state of the UE115-c(e.g., normal or default power state). In some cases, the UE115-cmay communicate with the base station105-bwhile operating in the first power state (e.g., default power state) until one or more trigger conditions for transitioning to a second power state (e.g., lower or reduced power state) are satisfied. As described previously herein, the first power state may be associated with a higher power consumption level as compared to the second power state.

Additionally, the UE115-cmay receive one or more signals (e.g., reference signals) from the base station105-busing (e.g., according to) the first configuration. For example, in cases where the first configuration indicates that the UE115-cis to communicate with the base station105-busing a set of four receive ports, the UE115-cmay receive signals from the base station105-busing each receive port of the set of four receive ports. In this example, the UE115-cmay be configured to decode four layers of downlink transmissions (e.g., four layers of PDSCH transmissions) using the four receive ports.

At420, the UE115-cmay determine to operate in the second power state that is lower than the first power state. In other words, the UE115-cmay determine to operate in the second power state (e.g., reduced power state) that is lower than the first power state. In this regard, the UE115-cmay determine that one or more trigger conditions for transitioning to a reduced power state have been satisfied.

The UE115-cmay determine to operate in the second power state based on any quantity of parameters or characteristics including, but not limited to, a thermal state at the UE115-c, a power level (e.g., battery level) at the UE115-c, or both. For example, the UE115-cmay determine to operate in the second power state based on determining that a thermal state at the UE115-csatisfies a threshold thermal state (Tthresh). In some cases, the thermal state may satisfy the threshold thermal state if the thermal state is greater than or equal to the threshold thermal state. Moreover, the thermal state may include, but is not limited to, a skin temperature (Tskin) of the UE115-c, a junction temperature (Tj) of the UE115-c, or both. In this regard, the UE115-cmay determine to operate in the second power state based on determining that the skin temperature of the UE115-cis greater than or equal to a threshold skin temperature (e.g., Tskin≥Tthresh,skin), based on determining that the junction temperature of the UE115-cis greater than or equal to a threshold junction temperature (e.g., Tj≥Tthresh,j), or both.

By way of another example, the UE115-cmay determine to operate in the second power state based on determining that a power level (PUE) at the UE115-csatisfies a threshold power level (Pthresh). The power level of the UE115-cmay include, but is not limited to, a battery level of the UE115-c. In some cases, the power level may satisfy the threshold power level if the power level is less than or equal to the threshold power level. In this regard, the UE115-cmay determine to operate in the second power state based on determining that the power level of the UE115-cis less than or equal to a threshold power level (e.g., PUE≤Pthresh).

At425, the UE115-cmay determine one or more parameters associated with the set of receive ports of the UE115-c. Parameters associated with the set of receive ports may include, but are not limited to, an RSSI metric, an RSRP metric, an RSRQ metric, a SNR, a SINR, or any combination thereof. In some aspects, the UE115-cmay determine the parameters of the receive ports at425based on transmitting the capability report at405, receiving the first configuration at410, communicating with the base station105-baccording to the first configuration at415, or any combination thereof.

For example, in cases where the first configuration indicates that the UE115-cis to communicate with the base station105-busing a set of four receive ports, the UE115-cmay receive signals from the base station105-busing each receive port of the set of four receive ports. In this example, the UE115-cmay perform measurements (e.g., RSSI measurements, RSRP measurements, RSRQ measurements, SNR measurements, SINR measurements) on signals received using each of the respective receive ports. In this regard, the UE115-cmay be configured to determine relative strengths or qualities of signals received using each of the respective receive ports.

At430, the UE115-cmay be configured to select a subset of receive ports of the set of receive ports of the UE115-c. More particularly, the UE115-cmay be configured to select a subset of receive ports of the UE115-c, and may be configured to select a subset of transmit ports corresponding to the selected subset of receive ports of the UE115-c. In some aspects, the UE115-cmay be configured to select the set of receive ports of the UE115-cbased on the parameters of the receive ports determined at425.

For example, the UE115-cmay be configured to select a subset of receive ports from the set of receive ports which may be associated with a highest signal strength or quality. For instance, in cases where the first configuration is associated with four receive ports, the UE115-cmay be configured to select a subset of receive ports (e.g., one or two receive ports) which are associated with the highest RSSI metrics, the highest RSRP metrics, the highest RSRQ metrics, the highest SNRs, the highest SINRs, or any combination thereof. Furthermore, the UE115-cmay be configured to select a subset of transmit ports which correspond to the selected subset of receive ports. For instance, in cases where the UE115-cselects a first receive port and a second receive port out of the set of four receive ports, the UE115-cmay additionally be configured to select a first transmit port corresponding to the first receive port and a second transmit port corresponding to the second receive port.

At435, the UE115-cmay communicate with the base station105-busing less than all of the set of transmit ports for SRSs during a second time interval (e.g., second TTI, second slot, second subframe) following the first time interval. In some aspects, the UE115-cmay communicate with the base station105-busing less than all of the set of transmit ports for SRSs at425based on transmitting the capability report at405, receiving the first configuration at410, communicating with the base station105-baccording to the first configuration at415, determining to operate in the second power state at420, determining the parameters associated with the set of receive ports at425, selecting the subset of receive and/or transmit ports at430, or any combination thereof.

For example, the UE115-cmay communicate with the base station105-busing less than all of the set of transmit ports for SRSs during a second time interval based on determining that a thermal state at the UE115-csatisfies a threshold thermal state (e.g., based on Tskin≥Tthresh,skin, Tj≥Tthresh,j), based on determining that a power level at the UE115-csatisfies a threshold power level (e.g., based on PUE≤Pthresh), or any combination thereof.

In some aspects, the UE115-cmay communicate with the base station105-busing less than all of the set of transmit ports at435in order to induce the base station105-binto scheduling transmissions at the UE115-cwhich are associated with a lower rank (e.g., reduced quantity of layers). In turn, by inducing the base station105-bto schedule transmissions which are associated with a lower rank, the UE115-cmay be able to adjust an operational state of one or more receive ports (e.g., deactivate one or more receive ports) of the UE115-cin order to reduce a power consumption at the UE115-c, thereby reducing a thermal state at the UE115-c. Accordingly, in some cases, the UE115-cmay communicate with the base station105-busing less than all of the set of transmit ports at435based on determining to operate in the second power state at420in order to reduce power consumption and conserve a power level (e.g., battery level) at the UE115-c.

For example, at435, the UE115-cmay be configured to refrain from transmitting SRSs on all transmit ports of a set of transmit ports at the UE115-cduring the second time interval. For instance, in cases where the UE115-cincludes a set of four receive ports, and therefore a set of four transmit ports corresponding to the four receive ports, the UE115-cmay refrain from transmitting SRSs on each transmit port of the set of four transmit ports. In this regard, the UE115-cmay wholly refrain from transmitting any SRSs on the set of transmit ports.

By way of another example, at435, the UE115-cmay be configured to transmit SRSs on a subset of transmit ports of the set of transmit ports at the UE115-cduring the second time interval. For instance, in cases where the UE115-cincludes a set of four receive ports, and therefore a set of four transmit ports corresponding to the four receive ports, the UE115-cmay transmit SRSs on one, two, or three transmit ports of the set of four transmit ports. In this regard, the UE115-cmay refrain from transmitting SRSs on one or more transmit ports of the set of transmit ports.

In some cases, in addition to performing SRS-AS techniques described in steps405to430of process flow400, the UE115-cmay additionally adjust parameters reported to the base station105-bvia CSF reports in order to further induce the base station105-bto reduce a rank (e.g., quantity of layers) associated with transmissions scheduled at the UE115-c. In this regard, the UE115-cmay use a combination of SRS-AS techniques and CSF report spoofing techniques in order to reduce a rank of scheduled transmissions, and therefore reduce power consumption and reduce temperatures (e.g., Tskin, Tj)) at the UE115-c. This may be further understood with reference to steps440-450of process flow400.

At440, the UE115-cmay determine a rank, a CQI, or both, associated with communications between the UE115-cand the base station105-busing one or more receive ports. In some aspects, the UE115-cmay determine the rank and/or CQI associated with communications with the base station105-busing one or more receive ports based on transmitting the capability report at405, receiving the first configuration at410, communicating with the base station105-baccording to the first configuration at415, determining to operate in the second power state at420, determining the parameters associated with the set of receive ports at425, selecting the subset of receive and/or transmit ports at430, communicating using less than all the transmit ports for SRSs at435, or any combination thereof.

At445, the UE115-cmay selectively adjust the rank and/or the CQI determined at440. In some aspects, the UE115-cmay selectively adjust the determined rank and/or the determined CQI at445based on transmitting the capability report at405, receiving the first configuration at410, communicating with the base station105-baccording to the first configuration at415, determining to operate in the second power state at420, determining the parameters associated with the set of receive ports at425, selecting the subset of receive and/or transmit ports at430, communicating using less than all the transmit ports for SRSs at435, determining the rank and/or CQI at440, or any combination thereof. The UE115-cmay be configured to selectively adjust the rank and/or CQI in order to further induce the base station105-bto reduce a rank (e.g., quantity of layers) associated with transmissions scheduled at the UE115-c, which may result in reduced power consumption and reduced temperatures at the UE115-c.

At450, the UE115-cmay transmit a CSF report to the base station105-b. In some aspects, the CSF report may include an indication of the adjusted rank, the adjusted CQI, or both, which were generated at445. In this regard, the UE115-cmay transmit the CSF report based on transmitting the capability report at405, receiving the first configuration at410, communicating with the base station105-baccording to the first configuration at415, determining to operate in the second power state at420, determining the parameters associated with the set of receive ports at425, selecting the subset of receive and/or transmit ports at430, communicating using less than all the transmit ports for SRSs at435, determining the rank and/or CQI at440, selectively adjusting the determined rank and/or CQI at445, or any combination thereof.

In some aspects, the UE115-cmay selectively adjust the rank and/or CQI which is reported to the base station105-bat450via the CSF report in order to induce the base station105-bto reduce a quantity of layers associated with transmissions scheduled at the UE115-c. For instance, by reporting the adjusted rank (e.g., lowered rank) to the base station105-bvia the CSF report, the base station105-bmay be configured to determine that the UE115-cis not capable of supporting higher quantities of layers, and may therefore reduce the rank of transmissions scheduled at the UE115-cbase on the adjusted rank. Similarly, by reporting the adjusted CQI (e.g., lowered CQI) to the base station105-bvia the CSF report, the base station105-bmay be configured to determine that the UE115-cis experiencing poor CQI, and may therefore reduce the rank of transmissions scheduled at the UE115-cbase on the adjusted CQI.

In some aspects, the UE115-cmay use a combination of CSF spoofing techniques and SRS-AS techniques in order to induce the base station105-bto reduce a rank (e.g., quantity of layers) associated with transmissions scheduled at the UE115-c. For example, according to some conventional techniques, the UE115-cmay perform CSF spoofing techniques in which the UE115-creports selectively adjusted (e.g., selectively reduced) rank and/or CQI to the base station105-bvia a CSF report. However, in some cases, instead of simply reducing the rank of scheduled transmissions based on the adjusted rank and/or CQIs, the base station105-bmay instead instruct the UE115-cto transmit SRSs so that the base station105-bmay directly determine the rank and/or CQI of wireless communications between the UE115-cand the base station105-b. In such cases, if the UE115-cwere not to perform the SRS-AS techniques described herein, the base station105-bmay determine that the adjusted rank and/or CQI values reported to the base station105-bare inaccurate, and may therefore refrain from reducing the rank of scheduled transmissions. Accordingly, some techniques described herein may use a combination of CSF spoofing techniques and SRS-AS techniques to increase the likelihood that the base station105-bmay be induced into reducing a rank of transmissions scheduled at the UE115-c.

At455, the UE115-cmay receive an indication of a second configuration from the base station105-b. As noted previously herein, the second configuration may indicate one or more parameters associated with wireless communications between the UE115-cand the base station105-bincluding a transmission-reception mode which is to be used at the UE115-c, a quantity of transmission ports and/or reception ports to be used by the UE115-c, or both. For example, the second configuration may indicate for the UE115-cto communicate with the base station105-busing a first subset of receive ports of the set of receive ports at the UE115-c. The second configuration may be indicated to the UE115-cvia a control message (e.g., RRC message, DCI message, MAC-CE message).

In some aspects, the UE115-cmay receive the second configuration at455based on communicating with the base station105-busing less than all the transmit ports for SRSs at435, receiving the CSF report at450, or both. For example, the UE115-cmay receive the second configuration at455based on refraining from transmitting SRSs on all the transmit ports of the UE115-cat435. By way of another example, the UE115-cmay receive the second configuration at455based on transmitting SRSs on a subset of transmit ports corresponding to a subset of receive ports of the UE115-cat435. Furthermore, in some cases, the UE115-cmay receive the second configuration at455based on communicating with the base station105-busing less than all the transmit ports for SRSs at435in conjunction with reporting the selectively adjusted (e.g., selectively reduced) rank and/or CQI to the base station105-bvia the CSF report at450.

In some aspects, the second configuration may indicate for the UE115-cto communicate with the base station105-busing a first subset of receive ports of the set of receive ports at the UE115-c. In this regard, the second configuration may reduce a quantity of receive ports used at the UE115-crelative to the first configuration. For example, the first configuration may indicate for the UE115-cto use a set of four receive ports at the UE115-c. Subsequently, at435, the UE115-cmay transmit SRSs using a first transmit port and a second transmit port corresponding to a first receive port and a second receive port, respectively. In this example, the second configuration may indicate for the UE115-cto use the first receive port and the second receive port corresponding to the first transmit port and the second transmit port. In this regard, the second configuration may reduce a quantity of receive ports used by the UE115-cfrom four receive ports to two receive ports.

At460, the UE115-cmay selectively adjust one or more parameters associated with a second subset of receive ports of the UE115-c. In some aspects, the UE115-cmay selectively adjust the one or more parameters associated with the second subset of receive ports in order to operate in the second power state (e.g., reduced power state) determined at430. Parameters associated with the second subset of receive ports which may be adjusted may include parameters associated with LNAs, phase shifters, or both. In some cases, the UE115-cmay selectively adjust one or more parameters associated with the second subset of receive ports in order to adjust an operational state (e.g., deactivate) the second subset of receive ports, which may thereby reduce power consumption and/or temperate at the UE115-c. In some aspects, the UE115-cmay selectively adjust the parameters associated with the second subset of receive ports based on receiving the second configuration at455.

For example, as noted previously herein, the first configuration may indicate for the UE115-cto use a set of four receive ports at the UE115-c(e.g., first receive port, second receive port, third receive port, fourth receive port). Subsequently, at435, the UE115-cmay transmit SRSs using a second transmit port and a fourth transmit port corresponding to the second receive port and the fourth receive port, respectively. In this example, the second configuration may indicate for the UE115-cto use the second receive port and the fourth receive port based on the SRSs received at435. Thus, first subset of receive ports indicated by the second configuration may include the second and fourth receive ports. In this example, the UE115-cmay selectively adjust parameters associated with the first and third receive ports (e.g., a second subset of receive ports) in order to reduce a power consumption of the first and third receive ports. For instance, the UE115-cmay deactivate the first and third receive ports by selectively adjusting parameters associated with LNAs, phase shifters, and/or other components of the first and third receive ports.

By inducing the base station105-bto transmit the second configuration which instructs the UE115-cto communicate using a subset of receive ports, the techniques described herein may be used by the UE115-cto effectively reduce a rank of transmissions scheduled at the UE115-c. Therefore, by effectively reducing a rank of scheduled transmissions, techniques described herein may enable the UE115-cto deactivate a subset of receive ports, which may enable the UE115-cto enter a lower operational power state, reduce power consumption at the UE115-c, and reduce a temperature (e.g., reduce Tskinand/or Tj) at the UE115-c. Such power savings techniques may enable the UE115-cto reduce power consumption at both a modem baseband of the UE115-cand a radio frequency transceiver of the UE115-c.

At465, the UE115-cmay communicate with the base station105-baccording to the second configuration. In this regard, the UE115-cmay communicate with the base station105-bby receiving signals using the first subset of receive ports indicated in the second configuration. Moreover, the UE115-cmay communicate with the base station105-bby transmitting SRSs using a subset of transmit ports corresponding to the first subset of receive ports indicated in the second configuration. Accordingly, the UE115-cmay communicate with the base station105-bat465using a lower quantity of layers (e.g., reduced rank) as compared to communications which were carried out according to the first configuration.

The UE115-cmay communicate base station105-baccording to the second configuration at465based on receiving the second configuration at450, selectively adjusting the parameters associated with the second subset of receive ports at460, or both. For example, the second configuration may indicate for the UE115-cto use a first subset of receive ports including a first receive port and a third receive port. Subsequently, the UE115-cmay deactivate a second receive port and a fourth receive port in order to enter the second power state (e.g., reduced power state). In this example, the UE115-cmay communicate with the base station105-baccording to the second configuration by receiving downlink transmissions from the base station105-busing the first and third receive ports. In this example, the UE115-cmay be configured to decode two layers of downlink transmissions (e.g., two layers of PDSCH transmissions) using the first and third receive ports.

In some aspects, the UE115-cmay subsequently induce the base station105-bto increase a quantity of layers associated with transmissions scheduled at the UE115-c. For example, following the communications at465, the UE115-cmay subsequently determine that it may return to the first power state (e.g., the default power state, or other power state) which is higher than the second power state. The UE115-cmay determine to return the first power state based on determining that the thermal state of the UE115-cno longer satisfies the threshold thermal state (e.g., based on determining Tskin<Tthresh,skin, and/or Tj<Tthresh,j), based on determining that the power level (e.g., battery level) of the UE115-cno longer satisfies the threshold power level (e.g., based on determining PUE>Pthresh), or both.

Continuing with the same example, upon determining that the UE115-cis to operate in the first power state, the UE115-cmay transmit SRSs using an increased quantity of transmit ports corresponding to an increased quantity of receive ports. For example, in cases where the second configuration includes two receive ports (e.g., 2Rx), the UE115-cmay transmit SRSs using four transmit ports corresponding to the four receive ports in order to induce the base station105-bto increase the quantity of layers associated with transmissions scheduled at the UE115-c. Additionally or alternatively, the UE115-cmay transmit a CSF report which indicates a higher rank and/or higher CQI as compared to the rank, CQI, or both, indicated in the CSF report at450in order to further induce the base station105-bto increase the quantity of layers associated with transmissions scheduled at the UE115-c.

The UE115-cmay implement the power-savings techniques described herein for a limited duration of time until such power-savings techniques are no longer necessary. In other words, the UE115-cmay implement the techniques described herein to reduce the power level at the UE115-c, correspondingly reducing a power consumption and/or temperature of the UE115-c. Subsequently, when the temperature (e.g., Tskin, Tj) of the UE115-cfalls below the threshold temperature (e.g., Tthresh,skin, Tthresh,j) and/or when the power level (e.g., PUE, battery level) of the UE115-crises above the threshold power level (e.g., Pthresh), the UE115-cmay transmit SRSs and/or transmit a CSF report in order to return to the first power state and/or the first configuration.

The techniques described herein may enable the UE115-cto reduce a power state at the UE115-c, correspondingly reducing a power consumption at the UE115-cand reducing a temperature at the UE115-c. In particular, techniques described herein may enable the UE115-cto perform SRS-AS in which the UE115-crefrains from transmitting SRSs and/or transmits SRSs using a subset of transmit ports in order to induce the base station105-bto reduce a rank of scheduled transmissions. In this regard, by inducing the base station105-bto reduce a rank of scheduled transmissions, the UE115-cmay be able to deactivate one or more receive ports at the UE115-c, thereby enabling the UE115-cto enter a lower power state, reduce power consumption, and reduce a temperature at the UE115-c. Such thermal mitigation and power savings techniques may enable the UE115-cto reduce power consumption at both modem baseband and radio frequency transceiver components of the UE115-c.

The receiver510may provide a means for receiving information such as packets, user data, control information, or any combination thereof associated with various information channels (e.g., control channels, data channels, information channels related to techniques for thermal mitigation and power saving). Information may be passed on to other components of the device505. The receiver510may utilize a single antenna or a set of multiple antennas.

The transmitter515may provide a means for transmitting signals generated by other components of the device505. For example, the transmitter515may transmit information such as packets, user data, control information, or any combination thereof associated with various information channels (e.g., control channels, data channels, information channels related to techniques for thermal mitigation and power saving). In some examples, the transmitter515may be co-located with a receiver510in a transceiver module. The transmitter515may utilize a single antenna or a set of multiple antennas.

The communications manager520, the receiver510, the transmitter515, or various combinations thereof or various components thereof may be examples of means for performing various aspects of techniques for thermal mitigation and power saving as described herein. For example, the communications manager520, the receiver510, the transmitter515, or various combinations or components thereof may support a method for performing one or more of the functions described herein.

The communications manager520may support wireless communication at a UE in accordance with examples as disclosed herein. For example, the communications manager520may be configured as or otherwise support a means for receiving, from a base station, a first configuration indicating that the UE is to communicate with the base station using a set of multiple receive ports of the UE. The communications manager520may be configured as or otherwise support a means for transmitting, according to the first configuration in a first time interval associated with a first power state of the UE, SRSs on a set of multiple transmit ports corresponding to the set of multiple receive ports. The communications manager520may be configured as or otherwise support a means for communicating with the base station during a second time interval following the first time interval using less than all of the set of multiple transmit ports for the SRSs based on the UE determining to operate in a second power state lower than the first power state. The communications manager520may be configured as or otherwise support a means for receiving, from the base station based on communicating with the base station using less than all of the set of multiple transmit ports for the SRSs, a second configuration indicating for the UE to communicate with the base station using a first subset of receive ports of the set of multiple receive ports.

By including or configuring the communications manager520in accordance with examples as described herein, the device505(e.g., a processor controlling or otherwise coupled to the receiver510, the transmitter515, the communications manager520, or a combination thereof) may support techniques for reducing a thermal state (e.g., temperature) and/or power consumption the UE115. In particular, techniques described herein may enable the UE115to perform SRS-AS in which the UE115refrains from transmitting SRSs and/or transmits SRSs using a subset of transmit ports in order to induce the base station105to reduce a rank of scheduled transmissions. In this regard, by inducing the base station105to reduce a rank of scheduled transmissions, the UE115may be able to deactivate one or more receive ports at the UE115-c, thereby enabling the UE115-cto enter a lower power state, reduce power consumption, and reduce a temperature at the UE115-c. By reducing a thermal state of the UE115, the efficiency and reliability of wireless communications at the UE115may be improved.

The receiver610may provide a means for receiving information such as packets, user data, control information, or any combination thereof associated with various information channels (e.g., control channels, data channels, information channels related to techniques for thermal mitigation and power saving). Information may be passed on to other components of the device605. The receiver610may utilize a single antenna or a set of multiple antennas.

The transmitter615may provide a means for transmitting signals generated by other components of the device605. For example, the transmitter615may transmit information such as packets, user data, control information, or any combination thereof associated with various information channels (e.g., control channels, data channels, information channels related to techniques for thermal mitigation and power saving). In some examples, the transmitter615may be co-located with a receiver610in a transceiver module. The transmitter615may utilize a single antenna or a set of multiple antennas.

The device605, or various components thereof, may be an example of means for performing various aspects of techniques for thermal mitigation and power saving as described herein. For example, the communications manager620may include a configuration receiving manager625, an SRS transmission manager630, a base station communicating manager635, or any combination thereof. The communications manager620may be an example of aspects of a communications manager520as described herein. In some examples, the communications manager620, or various components thereof, may be configured to perform various operations (e.g., receiving, monitoring, transmitting) using or otherwise in cooperation with the receiver610, the transmitter615, or both. For example, the communications manager620may receive information from the receiver610, send information to the transmitter615, or be integrated in combination with the receiver610, the transmitter615, or both to receive information, transmit information, or perform various other operations as described herein.

The communications manager620may support wireless communication at a UE in accordance with examples as disclosed herein. The configuration receiving manager625may be configured as or otherwise support a means for receiving, from a base station, a first configuration indicating that the UE is to communicate with the base station using a set of multiple receive ports of the UE. The SRS transmission manager630may be configured as or otherwise support a means for transmitting, according to the first configuration in a first time interval associated with a first power state of the UE, SRSs on a set of multiple transmit ports corresponding to the set of multiple receive ports. The base station communicating manager635may be configured as or otherwise support a means for communicating with the base station during a second time interval following the first time interval using less than all of the set of multiple transmit ports for the SRSs based on the UE determining to operate in a second power state lower than the first power state. The configuration receiving manager625may be configured as or otherwise support a means for receiving, from the base station based on communicating with the base station using less than all of the set of multiple transmit ports for the SRSs, a second configuration indicating for the UE to communicate with the base station using a first subset of receive ports of the set of multiple receive ports.

FIG. 7shows a block diagram700of a communications manager720that supports techniques for thermal mitigation and power saving in accordance with aspects of the present disclosure. The communications manager720may be an example of aspects of a communications manager520, a communications manager620, or both, as described herein. The communications manager720, or various components thereof, may be an example of means for performing various aspects of techniques for thermal mitigation and power saving as described herein. For example, the communications manager720may include a configuration receiving manager725, an SRS transmission manager730, a base station communicating manager735, a power state manager740, an CSF report transmitting manager745, a capability report manager750, a receive port manager755, a communications rank manager760, a CQI manager765, or any combination thereof. Each of these components may communicate, directly or indirectly, with one another (e.g., via one or more buses).

The communications manager720may support wireless communication at a UE in accordance with examples as disclosed herein. The configuration receiving manager725may be configured as or otherwise support a means for receiving, from a base station, a first configuration indicating that the UE is to communicate with the base station using a set of multiple receive ports of the UE. The SRS transmission manager730may be configured as or otherwise support a means for transmitting, according to the first configuration in a first time interval associated with a first power state of the UE, SRSs on a set of multiple transmit ports corresponding to the set of multiple receive ports. The base station communicating manager735may be configured as or otherwise support a means for communicating with the base station during a second time interval following the first time interval using less than all of the set of multiple transmit ports for the SRSs based on the UE determining to operate in a second power state lower than the first power state. In some examples, the configuration receiving manager725may be configured as or otherwise support a means for receiving, from the base station based on communicating with the base station using less than all of the set of multiple transmit ports for the SRSs, a second configuration indicating for the UE to communicate with the base station using a first subset of receive ports of the set of multiple receive ports.

In some examples, to support communicating with the base station using less than all of the set of multiple transmit ports for the SRSs, the SRS transmission manager730may be configured as or otherwise support a means for refraining from transmitting SRSs on all transmit ports of the set of multiple transmit ports, where receiving the second configuration is based on the UE refraining from transmitting SRSs on all of the transmit ports.

In some examples, to support communicating with the base station using less than all of the set of multiple transmit ports for the SRSs, the SRS transmission manager730may be configured as or otherwise support a means for transmitting, during the second time interval, SRSs on a subset of transmit ports of the set of multiple transmit ports, where receiving the second configuration is based on transmitting the SRSs on the subset of transmit ports.

In some examples, the receive port manager755may be configured as or otherwise support a means for determining one or more parameters associated with the set of multiple receive ports. In some examples, the receive port manager755may be configured as or otherwise support a means for selecting the subset of transmit ports of the set of multiple transmit ports corresponding to a subset of receive ports of the set of multiple receive ports based on the one or more parameters, where transmitting the SRSs on the subset of transmit ports is based on the selecting. In some examples, the one or more parameters associated with the set of multiple receive ports include a RSSI metric, a RSRP metric, a RSRQ metric, a SNR ratio, a SINR ratio, or any combination thereof.

In some examples, the set of multiple transmit ports includes four transmit ports. In some examples, the subset of transmit ports includes one or two transmit ports.

In some examples, the power state manager740may be configured as or otherwise support a means for determining to operate in the second power state based on determining that a thermal state at the UE is greater than or equal to a threshold thermal state, where communicating with the base station using less than all of the set of multiple transmit ports for the SRSs is based on determining that the thermal state at the UE is greater than or equal to the threshold thermal state. In some examples, the thermal state includes a skin temperate of the UE, a junction temperature of the UE, or both.

In some examples, the power state manager740may be configured as or otherwise support a means for determining to operate in the second power state based on determining that a power level at the UE satisfies a threshold power level, where communicating with the base station using less than all of the set of multiple transmit ports for the SRSs is based on determining that the power level at the UE satisfies the threshold power level. In some examples, the power level satisfies the threshold power level when the power level is less than or equal to the threshold power level. In some examples, the power level includes a battery level of the UE.

In some examples, the CSF report transmitting manager745may be configured as or otherwise support a means for transmitting, to the base station, a CSF report based on the UE determining to operate in the second power state, where receiving the second configuration is based on transmitting the CSF report and communicating with the base station using less than all of the set of multiple transmit ports for the SRSs.

In some examples, the communications rank manager760may be configured as or otherwise support a means for determining a rank associated with communications with the base station using one or more receive ports of the set of multiple receive ports. In some examples, the communications rank manager760may be configured as or otherwise support a means for selectively adjusting the determined rank to generate an adjusted rank less than the determined rank based on the UE determining to operate in the second power state, where the CSF report includes an indication of the adjusted rank.

In some examples, the CQI manager765may be configured as or otherwise support a means for determining a CQI associated with communications with the base station using one or more receive ports of the set of multiple receive ports. In some examples, the CQI manager765may be configured as or otherwise support a means for selectively adjusting the determined CQI to generate an adjusted CQI less than the determined CQI based on the UE determining to operate in the second power state, where the CSF report includes an indication of the adjusted CQI.

In some examples, the capability report manager750may be configured as or otherwise support a means for transmitting, to the base station, a capability report including an indication of one or more transmission-reception modes supported by the UE, where receiving the first configuration is based on transmitting the capability report. In some examples, the one or more transmission-reception modes include a transmission-reception mode indicating one transmission port and four reception ports for the UE, a transmission-reception mode indicating two transmission ports and four reception ports for the UE, or both.

In some examples, the receive port manager755may be configured as or otherwise support a means for selectively adjusting one or more parameters associated with a second subset of receive ports of the set of multiple receive ports based on receiving the second configuration. In some examples, the one or more parameters are associated with a LNA for the second subset of receive ports, a phase shifter for the second subset of receive ports, or both.

The communications manager820may support wireless communication at a UE in accordance with examples as disclosed herein. For example, the communications manager820may be configured as or otherwise support a means for receiving, from a base station, a first configuration indicating that the UE is to communicate with the base station using a set of multiple receive ports of the UE. The communications manager820may be configured as or otherwise support a means for transmitting, according to the first configuration in a first time interval associated with a first power state of the UE, SRSs on a set of multiple transmit ports corresponding to the set of multiple receive ports. The communications manager820may be configured as or otherwise support a means for communicating with the base station during a second time interval following the first time interval using less than all of the set of multiple transmit ports for the SRSs based on the UE determining to operate in a second power state lower than the first power state. The communications manager820may be configured as or otherwise support a means for receiving, from the base station based on communicating with the base station using less than all of the set of multiple transmit ports for the SRSs, a second configuration indicating for the UE to communicate with the base station using a first subset of receive ports of the set of multiple receive ports.

By including or configuring the communications manager820in accordance with examples as described herein, the device805may support techniques for reducing a thermal state (e.g., temperature) and/or power consumption the UE115. In particular, techniques described herein may enable the UE115to perform SRS-AS in which the UE115refrains from transmitting SRSs and/or transmits SRSs using a subset of transmit ports in order to induce the base station105to reduce a rank of scheduled transmissions. In this regard, by inducing the base station105to reduce a rank of scheduled transmissions, the UE115may be able to deactivate one or more receive ports at the UE115-c, thereby enabling the UE115-cto enter a lower power state, reduce power consumption, and reduce a temperature at the UE115-c. By reducing a thermal state of the UE115, the efficiency and reliability of wireless communications at the UE115may be improved, and a batter life of the UE115may be improved.

FIG. 9shows a flowchart illustrating a method900that supports techniques for thermal mitigation and power saving in accordance with aspects of the present disclosure. The operations of the method900may be implemented by a UE or its components as described herein. For example, the operations of the method900may be performed by a UE115as described with reference toFIGS. 1 through 8. In some examples, a UE may execute a set of instructions to control the functional elements of the UE to perform the described functions. Additionally or alternatively, the UE may perform aspects of the described functions using special-purpose hardware.

At905, the method may include receiving, from a base station, a first configuration indicating that the UE is to communicate with the base station using a set of multiple receive ports of the UE. The operations of905may be performed in accordance with examples as disclosed herein. In some examples, aspects of the operations of905may be performed by a configuration receiving manager725as described with reference toFIG. 7.

At910, the method may include transmitting, according to the first configuration in a first time interval associated with a first power state of the UE, SRSs on a set of multiple transmit ports corresponding to the set of multiple receive ports. The operations of910may be performed in accordance with examples as disclosed herein. In some examples, aspects of the operations of910may be performed by an SRS transmission manager730as described with reference toFIG. 7.

At915, the method may include communicating with the base station during a second time interval following the first time interval using less than all of the set of multiple transmit ports for the SRSs based on the UE determining to operate in a second power state lower than the first power state. The operations of915may be performed in accordance with examples as disclosed herein. In some examples, aspects of the operations of915may be performed by a base station communicating manager735as described with reference toFIG. 7.

At920, the method may include receiving, from the base station based on communicating with the base station using less than all of the set of multiple transmit ports for the SRSs, a second configuration indicating for the UE to communicate with the base station using a first subset of receive ports of the set of multiple receive ports. The operations of920may be performed in accordance with examples as disclosed herein. In some examples, aspects of the operations of920may be performed by a configuration receiving manager725as described with reference toFIG. 7.

At1005, the method may include receiving, from a base station, a first configuration indicating that the UE is to communicate with the base station using a set of multiple receive ports of the UE. The operations of1005may be performed in accordance with examples as disclosed herein. In some examples, aspects of the operations of1005may be performed by a configuration receiving manager725as described with reference toFIG. 7.

At1010, the method may include transmitting, according to the first configuration in a first time interval associated with a first power state of the UE, SRSs on a set of multiple transmit ports corresponding to the set of multiple receive ports. The operations of1010may be performed in accordance with examples as disclosed herein. In some examples, aspects of the operations of1010may be performed by an SRS transmission manager730as described with reference toFIG. 7.

At1015, the method may include refraining from transmitting SRSs on all transmit ports of the set of multiple transmit ports. The operations of1015may be performed in accordance with examples as disclosed herein. In some examples, aspects of the operations of1015may be performed by an SRS transmission manager730as described with reference toFIG. 7.

At1020, the method may include receiving, from the base station based on refraining from transmitting SRSs on all of the transmit ports of the set of multiple transmit ports, a second configuration indicating for the UE to communicate with the base station using a first subset of receive ports of the set of multiple receive ports. The operations of1020may be performed in accordance with examples as disclosed herein. In some examples, aspects of the operations of1020may be performed by a configuration receiving manager725as described with reference toFIG. 7.

FIG. 11shows a flowchart illustrating a method1100that supports techniques for thermal mitigation and power saving in accordance with aspects of the present disclosure. The operations of the method1100may be implemented by a UE or its components as described herein. For example, the operations of the method1100may be performed by a UE115as described with reference toFIGS. 1 through 8. In some examples, a UE may execute a set of instructions to control the functional elements of the UE to perform the described functions. Additionally or alternatively, the UE may perform aspects of the described functions using special-purpose hardware.

At1105, the method may include receiving, from a base station, a first configuration indicating that the UE is to communicate with the base station using a set of multiple receive ports of the UE. The operations of1105may be performed in accordance with examples as disclosed herein. In some examples, aspects of the operations of1105may be performed by a configuration receiving manager725as described with reference toFIG. 7.

At1110, the method may include transmitting, according to the first configuration in a first time interval associated with a first power state of the UE, SRSs on a set of multiple transmit ports corresponding to the set of multiple receive ports. The operations of1110may be performed in accordance with examples as disclosed herein. In some examples, aspects of the operations of1110may be performed by an SRS transmission manager730as described with reference toFIG. 7.

At1115, the method may include transmitting, during the second time interval, SRSs on a subset of transmit ports of the set of multiple transmit ports. The operations of1115may be performed in accordance with examples as disclosed herein. In some examples, aspects of the operations of1115may be performed by an SRS transmission manager730as described with reference toFIG. 7.

At1120, the method may include receiving, from the base station based on transmitting the SRSs on the subset of transmit ports, a second configuration indicating for the UE to communicate with the base station using a first subset of receive ports of the set of multiple receive ports. The operations of1120may be performed in accordance with examples as disclosed herein. In some examples, aspects of the operations of1120may be performed by a configuration receiving manager725as described with reference toFIG. 7.

At1205, the method may include receiving, from a base station, a first configuration indicating that the UE is to communicate with the base station using a set of multiple receive ports of the UE. The operations of1205may be performed in accordance with examples as disclosed herein. In some examples, aspects of the operations of1205may be performed by a configuration receiving manager725as described with reference toFIG. 7.

At1210, the method may include transmitting, according to the first configuration in a first time interval associated with a first power state of the UE, SRSs on a set of multiple transmit ports corresponding to the set of multiple receive ports. The operations of1210may be performed in accordance with examples as disclosed herein. In some examples, aspects of the operations of1210may be performed by an SRS transmission manager730as described with reference toFIG. 7.

At1215, the method may include determining to operate in the second power state based on determining that a thermal state at the UE is greater than or equal to a threshold thermal state. The operations of1215may be performed in accordance with examples as disclosed herein. In some examples, aspects of the operations of1215may be performed by a power state manager740as described with reference toFIG. 7.

At1220, the method may include communicating with the base station during a second time interval following the first time interval using less than all of the set of multiple transmit ports for the SRSs based on the UE determining to operate in a second power state lower than the first power state, where communicating with the base station using less than all of the set of multiple transmit ports for the SRSs is based on determining that the thermal state at the UE is greater than or equal to the threshold thermal state. The operations of1220may be performed in accordance with examples as disclosed herein. In some examples, aspects of the operations of1220may be performed by a base station communicating manager735as described with reference toFIG. 7.

At1225, the method may include receiving, from the base station based on communicating with the base station using less than all of the set of multiple transmit ports for the SRSs, a second configuration indicating for the UE to communicate with the base station using a first subset of receive ports of the set of multiple receive ports. The operations of1225may be performed in accordance with examples as disclosed herein. In some examples, aspects of the operations of1225may be performed by a configuration receiving manager725as described with reference toFIG. 7.

At1305, the method may include receiving, from a base station, a first configuration indicating that the UE is to communicate with the base station using a set of multiple receive ports of the UE. The operations of1305may be performed in accordance with examples as disclosed herein. In some examples, aspects of the operations of1305may be performed by a configuration receiving manager725as described with reference toFIG. 7.

At1310, the method may include transmitting, according to the first configuration in a first time interval associated with a first power state of the UE, SRSs on a set of multiple transmit ports corresponding to the set of multiple receive ports. The operations of1310may be performed in accordance with examples as disclosed herein. In some examples, aspects of the operations of1310may be performed by an SRS transmission manager730as described with reference toFIG. 7.

At1315, the method may include determining to operate in the second power state based on determining that a power level at the UE satisfies a threshold power level. The operations of1315may be performed in accordance with examples as disclosed herein. In some examples, aspects of the operations of1315may be performed by a power state manager740as described with reference toFIG. 7.

At1320, the method may include communicating with the base station during a second time interval following the first time interval using less than all of the set of multiple transmit ports for the SRSs based on the UE determining to operate in a second power state lower than the first power state, where communicating with the base station using less than all of the set of multiple transmit ports for the SRSs is based on determining that the power level at the UE satisfies the threshold power level. The operations of1320may be performed in accordance with examples as disclosed herein. In some examples, aspects of the operations of1320may be performed by a base station communicating manager735as described with reference toFIG. 7.

At1325, the method may include receiving, from the base station based on communicating with the base station using less than all of the set of multiple transmit ports for the SRSs, a second configuration indicating for the UE to communicate with the base station using a first subset of receive ports of the set of multiple receive ports. The operations of1325may be performed in accordance with examples as disclosed herein. In some examples, aspects of the operations of1325may be performed by a configuration receiving manager725as described with reference toFIG. 7.

Aspect 1: A method for wireless communication at a UE, comprising: receiving, from a base station, a first configuration indicating that the UE is to communicate with the base station using a plurality of receive ports of the UE; transmitting, according to the first configuration in a first time interval associated with a first power state of the UE, SRSs on a plurality of transmit ports corresponding to the plurality of receive ports; communicating with the base station during a second time interval following the first time interval using less than all of the plurality of transmit ports for the SRSs based at least in part on the UE determining to operate in a second power state lower than the first power state; and receiving, from the base station based at least in part on communicating with the base station using less than all of the plurality of transmit ports for the SRSs, a second configuration indicating for the UE to communicate with the base station using a first subset of receive ports of the plurality of receive ports.

Aspect 2: The method of aspect 1, wherein communicating with the base station using less than all of the plurality of transmit ports for the SRSs comprises: refraining from transmitting SRSs on all transmit ports of the plurality of transmit ports, wherein receiving the second configuration is based at least in part on the UE refraining from transmitting SRSs on all of the transmit ports.

Aspect 3: The method of any of aspects 1 through 2, wherein communicating with the base station using less than all of the plurality of transmit ports for the SRSs comprises: transmitting, during the second time interval, SRSs on a subset of transmit ports of the plurality of transmit ports, wherein receiving the second configuration is based at least in part on transmitting the SRSs on the subset of transmit ports.

Aspect 4: The method of aspect 3, further comprising: determining one or more parameters associated with the plurality of receive ports; and selecting the subset of transmit ports of the plurality of transmit ports corresponding to a subset of receive ports of the plurality of receive ports based at least in part on the one or more parameters, wherein transmitting the SRSs on the subset of transmit ports is based at least in part on the selecting.

Aspect 5: The method of aspect 4, wherein the one or more parameters associated with the plurality of receive ports comprise a RSSI metric, a RSRP metric, a RSRQ metric, a SNR, a SINR, or any combination thereof.

Aspect 6: The method of any of aspects 3 through 5, wherein the plurality of transmit ports comprises four transmit ports, and the subset of transmit ports comprises one or two transmit ports.

Aspect 7: The method of any of aspects 1 through 6, further comprising: determining to operate in the second power state based at least in part on determining that a thermal state at the UE is greater than or equal to a threshold thermal state, wherein communicating with the base station using less than all of the plurality of transmit ports for the SRSs is based at least in part on determining that the thermal state at the UE is greater than or equal to the threshold thermal state.

Aspect 8: The method of aspect 7, wherein the thermal state comprises a skin temperate of the UE, a junction temperature of the UE, or both.

Aspect 9: The method of any of aspects 1 through 8, further comprising: determining to operate in the second power state based at least in part on determining that a power level at the UE satisfies a threshold power level, wherein communicating with the base station using less than all of the plurality of transmit ports for the SRSs is based at least in part on determining that the power level at the UE satisfies the threshold power level.

Aspect 10: The method of aspect 9, wherein the power level satisfies the threshold power level when the power level is less than or equal to the threshold power level.

Aspect 11: The method of any of aspects 9 through 10, wherein the power level comprises a battery level of the UE.

Aspect 12: The method of any of aspects 1 through 11, further comprising: transmitting, to the base station, a channel state feedback report based at least in part on the UE determining to operate in the second power state, wherein receiving the second configuration is based at least in part on transmitting the channel state feedback report and communicating with the base station using less than all of the plurality of transmit ports for the SRSs.

Aspect 13: The method of aspect 12, further comprising: determining a rank associated with communications with the base station using one or more receive ports of the plurality of receive ports; selectively adjusting the determined rank to generate an adjusted rank less than the determined rank based at least in part on the UE determining to operate in the second power state, wherein the channel state feedback report comprises an indication of the adjusted rank.

Aspect 14: The method of any of aspects 12 through 13, further comprising: determining a CQI associated with communications with the base station using one or more receive ports of the plurality of receive ports; selectively adjusting the determined CQI to generate an adjusted CQI less than the determined CQI based at least in part on the UE determining to operate in the second power state, wherein the channel state feedback report comprises an indication of the adjusted CQI.

Aspect 15: The method of any of aspects 1 through 14, further comprising: transmitting, to the base station, a capability report comprising an indication of one or more transmission-reception modes supported by the UE, wherein receiving the first configuration is based at least in part on transmitting the capability report.

Aspect 16: The method of aspect 15, wherein the one or more transmission-reception modes comprise a transmission-reception mode indicating one transmission port and four reception ports for the UE, a transmission-reception mode indicating two transmission ports and four reception ports for the UE, or both.

Aspect 17: The method of any of aspects 1 through 16, further comprising: selectively adjusting one or more parameters associated with a second subset of receive ports of the plurality of receive ports based at least in part on receiving the second configuration.

Aspect 18: The method of aspect 17, wherein the one or more parameters are associated with a LNA for the second subset of receive ports, a phase shifter for the second subset of receive ports, or both.