Techniques for performing an antenna-switching diversity procedure

Various aspects of the present disclosure generally relate to wireless communication. In some aspects, a user equipment (UE) may identify a first timer associated with a first antenna and a second timer associated with a second antenna. The UE may identify an expiration of the first timer associated with the first antenna. The UE may determine, based at least in part on the identified expiration of the first timer, whether a remaining time of the second timer associated with the second antenna is less than a timer threshold. The UE may select, based at least in part on the determination that the remaining time of the second timer is less than the timer threshold, the second antenna. Numerous other aspects are provided.

FIELD OF THE DISCLOSURE

Aspects of the present disclosure generally relate to wireless communication and to techniques and apparatuses for performing an antenna-switching diversity procedure.

DESCRIPTION OF RELATED ART

SUMMARY

In some aspects, a method of wireless communication performed by a user equipment (UE) includes identifying a first timer associated with a first antenna and a second timer associated with a second antenna; identifying an expiration of the first timer associated with the first antenna; determining, based at least in part on the identified expiration of the first timer, whether a remaining time of the second timer associated with the second antenna is less than a timer threshold; and selecting, based at least in part on the determination that the remaining time of the second timer is less than the timer threshold, the second antenna.

In some aspects, the first timer is identified based at least in part on a first measurement associated with the first antenna satisfying a first criterion with respect to a measurement associated with an active antenna, and the second timer is identified based at least in part on a second measurement associated with the second antenna satisfying a second criterion with respect to the first measurement associated with the first antenna.

In some aspects, the method includes identifying a third timer for a third antenna based at least in part on a third measurement associated with the third antenna satisfying a third criterion with respect to the second measurement associated with the second antenna, wherein the third timer expires after an end of the timer threshold.

In some aspects, the method includes performing a transmission via the second antenna after selecting the second antenna.

In some aspects, the timer threshold is adjustable.

In some aspects, a duration associated with the timer threshold begins at the expiration of the first timer.

In some aspects, a UE for wireless communication includes a memory; and one or more processors coupled to the memory, the one or more processors configured to: identify a first timer associated with a first antenna and a second timer associated with a second antenna; identify an expiration of the first timer associated with the first antenna; determine, based at least in part on the identified expiration of the first timer, whether a remaining time of the second timer associated with the second antenna is less than a timer threshold; and select, based at least in part on the determination that the remaining time of the second timer is less than the timer threshold, the second antenna.

In some aspects, the first timer is identified based at least in part on a first measurement associated with the first antenna satisfying a first criterion with respect to a measurement associated with an active antenna, and the second timer is identified based at least in part on a second measurement associated with the second antenna satisfying a second criterion with respect to the first measurement associated with the first antenna.

In some aspects, the one or more processors are further configured to: identify a third timer for a third antenna based at least in part on a third measurement associated with the third antenna satisfying a third criterion with respect to the second measurement associated with the second antenna, wherein the third timer expires after an end of the timer threshold.

In some aspects, the one or more processors are further configured to: perform a transmission via the second antenna after selecting the second antenna.

In some aspects, the timer threshold is adjustable.

In some aspects, a duration associated with the timer threshold begins at the expiration of the first timer.

In some aspects, a non-transitory computer-readable medium storing a set of instructions for wireless communication includes one or more instructions that, when executed by one or more processors of a UE, cause the UE to: identify a first timer associated with a first antenna and a second timer associated with a second antenna; identify an expiration of the first timer associated with the first antenna; determine, based at least in part on the identified expiration of the first timer, whether a remaining time of the second timer associated with the second antenna is less than a timer threshold; and select, based at least in part on the determination that the remaining time of the second timer is less than the timer threshold, the second antenna.

In some aspects, the first timer is identified based at least in part on a first measurement associated with the first antenna satisfying a first criterion with respect to a measurement associated with an active antenna, and the second timer is identified based at least in part on a second measurement associated with the second antenna satisfying a second criterion with respect to the first measurement associated with the first antenna.

In some aspects, the one or more instructions further cause the UE to: identify a third timer for a third antenna based at least in part on a third measurement associated with the third antenna satisfying a third criterion with respect to the second measurement associated with the second antenna, wherein the third timer expires after an end of the timer threshold.

In some aspects, the one or more instructions further cause the UE to: perform a transmission via the second antenna after selecting the second antenna.

In some aspects, the timer threshold is adjustable.

In some aspects, a duration associated with the timer threshold begins at the expiration of the first timer.

In some aspects, an apparatus for wireless communication includes means for identifying a first timer associated with a first antenna and a second timer associated with a second antenna; means for identifying an expiration of the first timer associated with the first antenna; means for determining, based at least in part on the identified expiration of the first timer, whether a remaining time of the second timer associated with the second antenna is less than a timer threshold; and means for selecting, based at least in part on the determination that the remaining time of the second timer is less than the timer threshold, the second antenna.

In some aspects, the first timer is identified based at least in part on a first measurement associated with the first antenna satisfying a first criterion with respect to a measurement associated with an active antenna, and the second timer is identified based at least in part on a second measurement associated with the second antenna satisfying a second criterion with respect to the first measurement associated with the first antenna.

In some aspects, the apparatus includes means for identifying a third timer for a third antenna based at least in part on a third measurement associated with the third antenna satisfying a third criterion with respect to the second measurement associated with the second antenna, wherein the third timer expires after an end of the timer threshold.

In some aspects, the apparatus includes means for performing a transmission via the second antenna after selecting the second antenna.

In some aspects, the timer threshold is adjustable.

In some aspects, a duration associated with the timer threshold begins at the expiration of the first timer.

DETAILED DESCRIPTION

In some aspects, UE120includes means for identifying a first timer associated with a first antenna and a second timer associated with a second antenna; means for identifying an expiration of the first timer associated with the first antenna; means for determining, based at least in part on the identified expiration of the first timer, whether a remaining time of the second timer associated with the second antenna is less than a timer threshold; and means for selecting, based at least in part on the determination that the remaining time of the second timer is less than the timer threshold, the second antenna. The means for the UE120to perform operations described herein may include, for example, antenna252, demodulator254, MIMO detector256, receive processor258, transmit processor264, TX MIMO processor266, modulator254, controller/processor280, and/or memory282.

In some aspects, the UE120includes means for identifying a third timer for a third antenna based at least in part on a third measurement associated with the third antenna satisfying a third criterion with respect to the second measurement associated with the second antenna, wherein the third timer expires after an end of the timer threshold.

In some aspects, the UE120includes means for performing a transmission via the second antenna after selecting the second antenna.

A UE may conduct data communication with a BS or another wireless device (e.g., another UE) in a wireless network such as an LTE network or a 5G/NR network. To communicate data, the UE may include transmission circuitry and reception circuitry. The transmission circuitry may include, among other components, a plurality of transmission antennas to transmit data during the data communication.

The UE may use a diversity scheme, such as an antenna-switching diversity scheme, to enable a threshold quality associated with the data communication. An antenna-switching diversity scheme is a scheme for switching the active antenna (that is, the antenna used for a particular transmission or reception) based at least in part on conditions associated with the active antenna and/or other antennas. For instance, at a given time, the UE may use a first transmission antenna, from among the plurality of transmission antennas, to transmit a transmission. While transmitting the transmission, the first transmission antenna may experience, for example, antenna blockages (e.g., user hand and/or head obstructing a transmission and/or a reception path associated with an antenna), propagation shadowing effects (e.g., fluctuations in signal power based at least in part on antenna blockages), antenna imbalances, and/or specific absorption rate (SAR) limits (e.g., a regulatory limit to a utilized amount of transmission power). The effects of antenna blockages, propagation shadowing effects, antenna imbalances, and/or SAR limits may be collectively referred to as “antenna degradations.” To mitigate these antenna degradations, the UE may switch to using a second transmission antenna, from among the plurality of transmission antennas, as an active antenna to transmit data based at least in part on an estimation that the second antenna may experience reduced antenna degradation with respect to the first transmission antenna. Additionally, or alternatively, the switching of the transmission antenna can be based at least in part on an antenna order, which specifies an order in which the UE switches from transmission antenna to transmission antenna.

As the environment around the UE varies, the second transmission antenna may experience more antenna degradation, such that a quality associated with the data communication deteriorates below the threshold quality associated with the antenna-switching diversity scheme. In this case, the UE may again switch to using another transmission antenna (e.g., the first transmission antenna, a third transmission antenna, or the like), from among the plurality of transmission antennas, to mitigate effects of the antenna degradation observed while using the second transmission antenna. Thus, an antenna-switching diversity scheme that provides the UE with a flexibility to switch among the plurality of transmission antennas may allow the UE to avoid effects of the antenna degradation and to provide the threshold quality associated with the data communication.

Switching among the plurality of transmission antennas may introduce interruptions in the data communication. For instance, switching from one transmission antenna to another transmission antenna may involve a rearrangement or reconfiguration of components including, for example, a cross-switch that is utilized to transfer transmission signals from a processor to a transmission antenna, and data communication may be suspended during the rearrangement or reconfiguration of the components. As a result, a throughput of the UE may be negatively impacted.

Various aspects of techniques and apparatuses described herein may enable a UE to reduce a number of interruptions in data communication by reducing a number of switching occurrences from one transmission antenna to another in association with an antenna-switching diversity scheme. For example, the UE may use a measured value, such as an RSRP across multiple antennas, to select a best transmission antenna.

In some aspects, the UE may perform the antenna-switching diversity procedure by identifying a first timer associated with a first antenna and a second timer associated with a second antenna, identifying an expiration of the first timer associated with the first antenna, determining, based at least in part on the identified expiration of the first timer, whether a remaining time of the second timer associated with the second antenna is less than a timer threshold, and selecting, based at least in part on the determination that the remaining time of the second timer is less than the timer threshold, the second antenna. In some aspects, the UE may perform the antenna-switching diversity procedure by starting a first hold timer for a first antenna, starting a second hold timer for a second antenna based at least in part on a measurement associated with the second antenna satisfying a threshold with respect to a measurement associated with the first antenna, wherein the second hold timer expires within a given duration of time after an expiration of the first hold timer, and switching to the second antenna based at least in part on the second hold timer expiring within the given duration of time.

In this way, by reducing the number of switching occurrences from one transmission antenna to another, the antenna-switching diversity procedure, described herein, may reduce the number of interruptions in the data communication and provide a threshold quality associated with the data communication. As a result, a throughput enabled by the UE may be improved. Additionally, the UE may avoid performing an amount of processing, associated with rearrangement of components to switch transmission antennas, that would have otherwise occurred using other antenna-switching diversity procedures.

FIG.3is a diagram illustrating an example300of a UE associated with performing an antenna-switching diversity procedure, in accordance with the present disclosure.FIG.3shows a UE120capable of conducting data communication in a wireless network, such as an LTE network or a 5G/NR network. The UE120may conduct the data communication with a BS or another wireless device (e.g., another UE). The UE120may include one or more UEs discussed elsewhere herein, such as, for example, the UE discussed with respect toFIG.2.

To conduct the data communication, the UE120may include transmission circuitry and reception circuitry. The transmission circuitry may include, among other components, a plurality of transmission antennas and the reception circuitry may include, among other components, a plurality of reception antennas. A transmission antenna is an antenna used for transmitting a signal. A reception antenna is an antenna used for receiving a signal. As shown inFIG.3, the UE120may include, for example, four antennas: Ant 1, Ant 2, Ant 3, and Ant 4. In some aspects, an antenna may include a single antenna that is used for transmission and/or reception, such as associated with one or more of respective transmission circuitry or reception circuitry. In some aspects, Ant 1 may include a Tx ant 1 and an Rx ant 1, Ant 2 may include a Tx ant 2 and an Rx ant 2, Ant 3 may include a Tx ant 3 and an Rx ant 3, and/or Ant 4 may include a Tx ant 4 and an Rx ant 4. In some aspects, at a given time, the UE120may use a single transmission antenna to transmit data during the data communication. The in-use single transmission antenna may also be referred to as an active transmission antenna. For instance, as shown inFIG.3, Tx ant 1, associated with Ant 1, may be the active transmission antenna and each of Tx ant 2, Tx ant 3, and Tx ant 4 may be an inactive transmission antenna. For simplicity, if an antenna includes a single antenna that is used as a transmit antenna and a receive antenna, the antenna is referred to as a transmission antenna when performing transmission and a reception antenna when performing reception. The transmission antennas and/or the reception antennas may include one or more antennas discussed elsewhere herein including, for example, antennas252athrough252rdiscussed above with respect toFIG.2. In some aspects, the UE120may use multiple transmission antennas to transmit data concurrently during the data communication.

In some aspects, a transmission antenna may be associated with a reception antenna such that the transmission antenna and the reception antenna form a transmission-reception antenna pair (Tx-Rx ant pair). For instance, Tx ant 1 and Rx ant 1 may form a Tx-Rx ant pair 1, Tx ant 2 and Rx ant 2 may form a Tx-Rx ant pair 2, Tx ant 3 and Rx ant 3 may form a Tx-Rx ant pair 3, and Tx ant 4 and Rx ant 4 may form a Tx-Rx ant pair 4.

In some aspects, a reception antenna may be configured to receive one or more reference signals that enable the UE120to estimate a condition associated with a performance of an associated transmission antenna. In some aspects, a reception antenna may be placed adjacent to the associated transmission antenna to configure the reception antenna to receive the one or more reference signals that enable the UE120to estimate a condition associated with a performance of the associated transmission antenna. For instance, as shown inFIG.3, Rx ant 3 may be placed adjacent to Tx ant 3 to configure Rx ant 3 to receive reference signals that enable the UE120to estimate a condition associated with a performance of Tx ant 3. In some aspects, a reception antenna may receive reference signals, and may determine a measurement such as an RSRP associated with the associated transmission antenna. The determined measurement may enable the UE120to estimate, for example, an amount of antenna degradation associated with the transmission antenna. The measurement performed on the received reference signal may be useful to determine the antenna degradation associated with the transmission antenna because the reference signal and transmissions via the transmission antenna may generally be expected to encounter similar channel conditions (sometimes referred to as channel reciprocity). In some aspects, the measurement may include, for example, a signal-to-noise ratio (SNR), an RSSI, an amount of power headroom, an amount of power consumed per unit of time associated with using a transmission antenna, and/or the like.

In some aspects, each reception antenna may periodically receive the reference signals to enable the UE120to periodically estimate an amount of antenna degradation associated with each transmission antenna. Based at least in part on the estimated amount of antenna degradations associated with each transmission antenna, the UE120may perform an antenna-switching diversity procedure. In some aspects, as discussed in further detail with respect toFIGS.4-7, the antenna-switching diversity procedure may include switching from using a given transmission antenna (also referred to as an active transmission antenna) to using another transmission antenna (also referred to as a candidate transmission antenna) when one or more antenna degradations observed while using the active transmission antenna may result in a quality associated with the data communication deteriorating below a threshold quality.

The number and arrangement of antennas shown inFIG.3are provided as an example. For instance, there may be additional antennas (e.g., five or more) or fewer antennas (e.g., two or three) than those shown inFIG.3. In some aspects, the transmission and reception antennas may be arranged differently than shown inFIG.3. Furthermore, a transmission antenna and a reception antenna shown inFIG.3may be implemented within a single component, or a single transmission antenna or a single reception antenna shown inFIG.3may be implemented as multiple, distributed components.

FIG.4is a diagram illustrating an example400associated with performing an antenna-switching diversity procedure, in accordance with the present disclosure. As shown inFIG.4, events associated with the antenna-switching diversity procedure may be plotted along a timeline charted on a horizontal axis, which represents time. The antenna-switching diversity procedure may be performed by a UE120(not shown inFIG.4) capable of conducting data communication. The UE120may include one or more UEs discussed elsewhere herein, such as, for example, the UE120discussed with respect toFIG.2and/or the UE120discussed with respect toFIG.3.

The UE120may include a processor to perform the antenna-switching diversity procedure. The processor may include one or more processors discussed elsewhere herein, such as, for example, the processor components discussed above with respect toFIG.2. The processor of the UE120may be coupled to transmission circuitry and reception circuitry included in the UE120. The transmission circuitry may include a plurality of transmission antennas and the reception circuitry may include a plurality of reception antennas. The plurality of transmission antennas may include one or more antennas discussed elsewhere herein, such as, for example, transmission antennas Tx ant 1, Tx ant 2, Tx ant 3, and Tx ant 4 discussed above with respect toFIG.3and/or antennas252athrough252rdiscussed above with respect toFIG.2. Similarly, the plurality of reception antennas may include one or more antennas discussed elsewhere herein, such as, for example, reception antennas Rx ant 1, Rx ant 2, Rx ant 3, and Rx ant 4 discussed above with respect toFIG.3and/or antennas252athrough252rdiscussed above with respect toFIG.2.

The antenna-switching diversity procedure may include switching from using an active transmission antenna to using one or more of candidate transmission antennas when an amount of antenna degradation observed while using the active transmission antenna may result in, for example, a quality associated with the data communication deteriorating below a threshold quality. In some aspects, as discussed above with respect toFIG.3, the UE120may periodically estimate the amount of antenna degradation associated with each transmission antenna. Based at least in part on the estimated amount of antenna degradation associated with each transmission antenna, the UE120may switch from using the active transmission antenna to using one of the candidate transmission antennas.

In some aspects, the UE120may initiate the antenna-switching diversity procedure based at least in part on determining that an amount of antenna degradation associated with the active transmission antenna may be higher than an amount of antenna degradation associated with a first candidate transmission antenna. For instance, the UE120may initiate the antenna-switching diversity procedure based at least in part on received reference signals indicating that an RSRP associated with the first candidate transmission antenna is greater than an RSRP associated with the active transmission antenna by at least a first threshold amount (which may be expressed as “RSRP_Threshold”). In some aspects, the first candidate transmission antenna may include one or more antennas. In one example, the first threshold amount may be 3 dBm. In some aspects, the first threshold amount may be adjustable by the UE120.

To initiate the antenna-switching diversity procedure, as shown by reference number410, the UE120may start, at time T1, a first hold timer (Thold, first) associated with the first candidate transmission antenna (e.g., Tx ant 1) based at least in part on determining that an RSRP (e.g., −70 dBm) associated with the first candidate transmission antenna (e.g., Tx ant 1) is greater than an RSRP (e.g., −80 dBm) associated with the active transmission antenna (e.g., Tx ant 4) by at least the first threshold amount. The first hold timer (Thold, first) may while the RSRP (e.g., −70 dBm) associated with the first candidate transmission antenna (e.g., Tx ant 1) remains greater than the RSRP (e.g., −80 dBm) associated with the active transmission antenna (e.g., Tx ant 4) by at least the first threshold amount (e.g., 3 dBm). In some aspects, the first hold timer may be adjustable by the UE120.

While the first hold timer (Thold, first) is running, the UE120may determine that an RSRP associated with a second candidate transmission antenna (e.g., Tx ant 2) is greater than the RSRP associated with the first candidate transmission antenna (e.g., Tx ant 1) by at least a second threshold amount (e.g., 3 dBm). In some aspects, the second threshold amount may be the same as the first threshold amount. In some other aspects, the second threshold amount may be different with respect to the first threshold amount. For instance, the second threshold amount may be greater than the first threshold amount to ensure that a delay in switching to a candidate transmission antenna is implemented when obtaining an optimized increase in a quality associated with the data communication. In some aspects, the second threshold amount may be adjustable by the UE120. In some aspects, the second candidate transmission antenna may include one or more antennas.

As shown by reference number420, the UE120may start, at time T2, a second hold timer (Thold, second) associated with the second candidate transmission antenna (e.g., Tx ant 2) based at least in part on determining that the RSRP (e.g., −65 dBm) associated with the second candidate transmission antenna (e.g., Tx ant 2) is greater than the RSRP (e.g., −70 dBm) associated with the first candidate transmission antenna (e.g., Tx ant 1) by at least the second threshold amount. The second hold timer (Thold, second) may run while the RSRP (e.g., −65 dBm) associated with the second candidate transmission antenna (e.g., Tx ant 2) remains greater than the RSRP (e.g., −70 dBm) associated with the first candidate transmission antenna (e.g., Tx ant 1) by at least the second threshold amount (e.g., 3 dBm). In some aspects, a length of the second hold timer may be adjustable by the UE120. In some aspects, a length of the second hold timer may be the same as a length of the first hold timer.

In some examples, while the first hold timer (Thold, first) is running, the UE120may determine that an RSRP associated with a third candidate transmission antenna (e.g., Tx ant 3) is greater than the RSRP associated with the second candidate transmission antenna (e.g., Tx ant 2) by at least a third threshold amount. In some aspects, the third threshold amount may be the same as the second threshold amount. In some other aspects, the third threshold amount may be different than the first threshold amount and/or the second threshold amount. For instance, the third threshold amount may be greater than the first threshold amount and/or the second threshold amount to ensure that a delay in switching to a candidate transmission antenna is implemented when obtaining an optimized increase in the quality associated with the data communication. In some aspects, the third threshold amount may be adjustable by the UE120. In some aspects, the third candidate transmission antenna may include one or more antennas.

In some aspects, as shown by reference number430, the UE120may start, at time T3, a third hold timer (Thold, third) associated with a third candidate transmission antenna (e.g., Tx ant 3) based at least in part on determining that the RSRP (e.g., −60 dBm) associated with the third candidate transmission antenna (e.g., Tx ant 3) is greater than the RSRP (−65 dBm) associated with the second candidate transmission antenna (e.g., Tx ant 2) by at least the third threshold amount. The third hold timer (Thold, third) may run while the RSRP (e.g., −60 dBm) associated with the third candidate transmission antenna (e.g., Tx ant 3) remains greater than the RSRP (−65 dBm) associated with the second candidate transmission antenna (e.g., Tx ant 2) by at least the third threshold amount. In some aspects, a length of the third hold timer may be adjustable by the UE120. In some aspects, a length of the third hold timer may be the same as a length of the first hold timer and/or a length of the second hold timer.

At reference number440, the UE120may identify, at time TS, a delta hold timer (Thold, delta) associated with a given duration of time. In some aspects, the UE120may identify the delta hold timer (Thold, delta) at substantially an end of the first hold timer (Thold, first), such as at TS. The delta hold timer (Thold, delta) may expire at time TΔ, as shown by reference number450. The given duration of time may be configurable by the UE120. In other words, the time TΔmay be a configurable limit in time. In some aspects, the time TΔmay limit consideration of candidate transmission antennas being considered for the antenna-switching diversity procedure based at least in part on a valid hold timer that expires before a difference between time TΔand a time TS. For example, the UE120may filter out an antenna (e.g., may not consider the antenna) as a candidate transmission antenna based at least in part on the antenna's hold timer expiring after TΔ. The time TSmay refer to a time when the first hold timer (Thold, first) expires.

In some aspects, the given duration of time for the delta hold timer (Thold, delta) may be preset (e.g., in an initial configuration of the UE120, in initial connection or onboarding) and may be adjustable by the UE120. For instance, the given duration of time may be set to a value sufficient for the UE120to determine whether the UE120should switch to the first candidate transmission antenna (e.g., Tx ant 1), to the second candidate transmission antenna (e.g., Tx ant 2), or to the third candidate transmission antenna (e.g., Tx ant 3). In some aspects, the given duration of time may be 640 ms. In some aspects, the given duration of time may be in units of milliseconds.

As shown, at time TS, the UE120may switch to the second candidate transmission antenna based at least in part on the second hold timer (Thold, second) expiring within the given duration of time of the delta hold timer (Thou, delta) and based at least in part on the RSRP associated with the second candidate transmission antenna (e.g., Tx ant 2) being greater than the RSRP associated with the first candidate transmission antenna (e.g., Tx ant 1) by the second threshold amount.

In some aspects, the UE120may avoid switching, at time TSand after Thold,thirdhas expired, to the third candidate transmission antenna based at least in part on the third hold timer (Thold, third) expiring after TΔ. For example, the UE may determine not to switch to the third candidate transmission antenna based at least in part on the third hold timer expiring after the end of the given duration of time of the delta hold timer. In some aspects (not shown inFIG.4), the UE120may switch to the first candidate transmission antenna (e.g., Tx ant 1) based at least in part on the second hold timer (Thold, second) expiring after TΔ(e.g., the end of the given duration of time of the delta hold timer (Thold, delta)) and based at least in part on the third hold timer (Thou, third) expiring after TΔ(e.g., the end of the given duration of time of the delta hold timer (Thold, delta)). In some aspects, in a situation where both the second hold timer (Thold, second) and the third hold timer (Thold, third) expire within the given duration of time of the delta hold timer (Thold, delta) (not shown inFIG.4), the UE120may switch to the third candidate transmission antenna based at least in part on the RSRP associated with the third candidate transmission antenna being greater than the RSRP associated with the second candidate transmission antenna.

In some aspects, the UE120may determine the length of the first hold timer (Thold, first) to be, for example, 1000 milliseconds, the length of the second hold timer (Thold, second) to be, for example, 1000 milliseconds, the length of the third hold timer (Thom, third) to be, for example, 1000 milliseconds, and/or the given duration of time of the delta hold timer (Thold, delta) to be, for example, 640 milliseconds.

In some aspects, the antenna-switching diversity procedure, described herein, may include switching from using the active transmission antenna to using a candidate transmission antenna when (i) an RSRP associated with the candidate transmission antenna is greater than an RSRP associated with the active antenna by at least a threshold amount and (ii) a hold timer associated with the candidate antenna expires within a given duration of time (e.g., a delta hold timer).

By implementing the delta hold timer (Thold, delta), the UE120may switch to the second candidate transmission antenna, to mitigate the antenna degradation observed while using the active transmission antenna to transmit data, without previously switching to the first candidate transmission antenna. In this way, the UE120may reduce a number of switching occurrences from one transmission antenna to another. Reducing the number of switching occurrences enables fewer interruptions during the data communication, thereby improving a throughput enabled by the UE120. Also, by switching to the second candidate transmission antenna, whose RSRP may be greater than the RSRP of the active transmission antenna by a plurality of threshold amounts, the UE120may provide an optimized increase in the quality associated with the data communication.

The below pseudocode illustrates an example process relating to example400. In the below pseudocode, /* and */ delimit code comments. For example, /* ABC */ is a code comment of “ABC.” Lines of code are numbered sequentially.

1/* set of all antennas is {A, B, C, D} whereby antenna D iscurrent Tx antenna*/2/* antenna_other is one or two antennas from subset {A, B, C} */3/* antenna_other and antenna_A are not current Tx antenna */4/* antenna_A is first candidate antenna with valid Tholdfirst toexpire */5IF Tholdexpired for antenna_A /* expired means Tholdtimer hasexpired and we are waiting for next switching occasion*/6IF antenna_other Thold== active /*means Tholdvalid or running*/7IF ( antenna_other(RSRP) − antenna_A(RSRP) ) >RSRP_Threshold8IF Tholdantenna_other =< Thold_delta /*Thold_delta isconfigurable parameter that is stored in UE non-volatile memory,should less than or equal to Thold*/9SET new Tx antenna as antenna_other /*antenna_other is filtered based on Thold_delta criteria*/10ELSE11SET new Tx antenna as antenna_A12END13END14END15END

In the above pseudocode, Tholdfor antenna_A may correspond to Thold, firstof example400. Tholdfor antenna_other (which is expressed as “Tholdantenna_other” and as “antenna_other Thold”) may correspond to Thold, secondof example400. Thold_deltamay correspond to Thold, deltaof example400. RSRP_Threshold may correspond to the second threshold amount of example400.

FIG.5is a diagram illustrating an example process500performed, for example, by a UE, in accordance with the present disclosure. Example process500is an example where the UE (e.g., UE120) performs operations associated with techniques for performing an antenna-switching diversity procedure.

As shown inFIG.5, in some aspects, process500may include identifying a first timer associated with a first antenna and a second timer associated with a second antenna (block510). For example, the UE (e.g., using identification component608, depicted inFIG.6) may identify a first timer associated with a first antenna and a second timer associated with a second antenna, as described above. In some aspects, the first timer is referred to herein as a first hold timer (e.g., Thold, firstofFIG.4) and the second timer is referred to herein as a second hold timer (e.g., Thold, secondofFIG.4). The first antenna is referred to herein as a first candidate antenna. The second antenna is referred to herein as a second candidate antenna. In some aspects, the first antenna may include one or more antennas. In some aspects, the second antenna may include one or more antennas.

As further shown inFIG.5, in some aspects, process500may include identifying an expiration of the first timer associated with the first antenna (block520). For example, the UE (e.g., using identification component608, depicted inFIG.6) may identify an expiration of the first timer associated with the first antenna (e.g., at a time TS), as described above. As another example, the UE may determine that the first timer has expired.

As further shown inFIG.5, in some aspects, process500may include determining, based at least in part on the identified expiration of the first timer, whether a remaining time of the second timer associated with the second antenna is less than a timer threshold (block530). For example, the UE (e.g., using determination component610, depicted inFIG.6) may determine, based at least in part on the identified expiration of the first timer, whether a remaining time of the second timer associated with the second antenna is less than a timer threshold, as described above. In some aspects, the timer threshold is associated with a time illustrated inFIG.4as TΔbased at least in part on a delta hold timer (e.g., Thold, deltaofFIG.4). For example, the timer threshold may be determined as a time at which the delta hold timer ends.

As further shown inFIG.5, in some aspects, process500may include selecting, based at least in part on the determination that the remaining time of the second timer is less than the timer threshold, the second antenna (block540). For example, the UE (e.g., using selection component612, depicted inFIG.6) may select, based at least in part on the determination that the remaining time of the second timer is less than the timer threshold, the second antenna, as described above. The UE may use the second antenna as a transmission antenna.

In a first aspect, the first timer is identified based at least in part on a first measurement associated with the first antenna satisfying a first criterion with respect to a measurement associated with an active antenna, and the second timer is identified based at least in part on a second measurement associated with the second antenna satisfying a second criterion with respect to the first measurement associated with the first antenna. In some aspects, the first criterion and the second criterion may be based at least in part on threshold amounts, such as the first threshold amount and the second threshold amount described in connection withFIG.4. For example, the first criterion may be that a difference between the first measurement and the measurement associated with the active antenna is greater than the first threshold amount. For example, the second criterion may be that a difference between the second measurement and the first threshold is greater than the second threshold amount. It should be noted that the first timer can be identified at a different time than the second timer (e.g., separately from one another), as illustrated inFIG.4.

In a second aspect, alone or in combination with the first aspect, process500includes identifying a third timer for a third antenna based at least in part on a third measurement associated with the third antenna satisfying a third criterion with respect to the second measurement associated with the second antenna, wherein the third timer expires after an end of the timer threshold. In some aspects, the third criterion may be based at least in part on a threshold amount, such as the third threshold amount described in connection withFIG.4. For example, the third criterion may be that a difference between the third measurement and the first measurement (or, in some aspects, the second measurement) is greater than the third threshold amount. The third timer may be Thold, third. In this example, the UE may filter out the third antenna based at least in part on the third timer expiring after an end of the timer threshold.

In a third aspect, alone or in combination with one or more of the first and second aspects, process500includes performing a transmission via the second antenna after selecting the second antenna.

In a fourth aspect, alone or in combination with one or more of the first through third aspects, the timer threshold is adjustable.

In a fifth aspect, alone or in combination with one or more of the first through fourth aspects, a duration associated with the timer threshold (e.g., the given duration of time described with regard toFIG.4) begins at the expiration of the first timer.

In a sixth aspect, alone or in combination with one or more of the first through fifth aspects, identifying a timer may include starting a hold timer for an antenna. The hold timer is described herein as Thold.

In a seventh aspect, alone or in combination with one or more of the first through sixth aspects, starting a hold timer for an antenna may be based at least in part on a determination that a measurement associated with the antenna satisfies a threshold with respect to a measurement associated with another antenna. For example, the threshold may be based at least in part on the first threshold amount, the second threshold amount, or the third threshold amount described herein.

In an eighth aspect, a hold timer for an antenna may expire within a given duration of time (represented by Thold, deltainFIG.4) after an expiration of a hold timer for another antenna, and the antenna may be selected for switching based at least in part on the hold timer for the antenna expiring within the given duration of time.

FIG.6is a block diagram of an example apparatus600for wireless communication. The apparatus600may be a UE, or a UE may include the apparatus600. In some aspects, the apparatus600includes a reception component602and a transmission component604, which may be in communication with one another (for example, via one or more buses and/or one or more other components). As shown, the apparatus600may communicate with another apparatus606(such as a UE, a base station, or another wireless communication device) using the reception component602and the transmission component604. As further shown, the apparatus600may include one or more of an identification component608, a determination component610, or a selection component612, among other examples.

In some aspects, the apparatus600may be configured to perform one or more operations described herein in connection withFIGS.4and5. Additionally, or alternatively, the apparatus600may be configured to perform one or more processes described herein, such as process500ofFIG.5. In some aspects, the apparatus600and/or one or more components shown inFIG.6may include one or more components of the UE described above in connection withFIG.2. Additionally, or alternatively, one or more components shown inFIG.6may be implemented within one or more components described above in connection withFIG.2. Additionally, or alternatively, one or more components of the set of components may be implemented at least in part as software stored in a memory. For example, a component (or a portion of a component) may be implemented as instructions or code stored in a non-transitory computer-readable medium and executable by a controller or a processor to perform the functions or operations of the component.

The reception component602may receive communications, such as reference signals, control information, data communications, or a combination thereof, from the apparatus606. The reception component602may provide received communications to one or more other components of the apparatus600. In some aspects, the reception component602may perform signal processing on the received communications (such as filtering, amplification, demodulation, analog-to-digital conversion, demultiplexing, deinterleaving, de-mapping, equalization, interference cancellation, or decoding, among other examples), and may provide the processed signals to the one or more other components of the apparatus606. In some aspects, the reception component602may include one or more antennas, a demodulator, a MIMO detector, a receive processor, a controller/processor, a memory, or a combination thereof, of the UE described above in connection withFIG.2.

The transmission component604may transmit communications, such as reference signals, control information, data communications, or a combination thereof, to the apparatus606. In some aspects, one or more other components of the apparatus606may generate communications and may provide the generated communications to the transmission component604for transmission to the apparatus606. In some aspects, the transmission component604may perform signal processing on the generated communications (such as filtering, amplification, modulation, digital-to-analog conversion, multiplexing, interleaving, mapping, or encoding, among other examples), and may transmit the processed signals to the apparatus606. In some aspects, the transmission component604may include one or more antennas, a modulator, a transmit MIMO processor, a transmit processor, a controller/processor, a memory, or a combination thereof, of the UE described above in connection withFIG.2. In some aspects, the transmission component604may be collocated with the reception component602in a transceiver.

The identification component608may identify a first timer associated with a first antenna and a second timer associated with a second antenna. In some aspects, the identification component608may include one or more antennas, a demodulator, a MIMO detector, a receive processor, a modulator, a transmit MIMO processor, a transmit processor, a controller/processor, a memory, or a combination thereof, of the UE described above in connection withFIG.2. The identification component608may identify an expiration of the first timer associated with the first antenna. In some aspects, the identification component608may include one or more antennas, a demodulator, a MIMO detector, a receive processor, a modulator, a transmit MIMO processor, a transmit processor, a controller/processor, a memory, or a combination thereof, of the UE described above in connection withFIG.2. The determination component610may determine, based at least in part on the identified expiration of the first timer, whether a remaining time of the second timer associated with the second antenna is less than a timer threshold. In some aspects, the determination component610may include one or more antennas, a demodulator, a MIMO detector, a receive processor, a modulator, a transmit MIMO processor, a transmit processor, a controller/processor, a memory, or a combination thereof, of the UE described above in connection withFIG.2. The selection component612may select, based at least in part on the determination that the remaining time of the second timer is less than the timer threshold, the second antenna. In some aspects, the selection component612may include one or more antennas, a demodulator, a MIMO detector, a receive processor, a modulator, a transmit MIMO processor, a transmit processor, a controller/processor, a memory, or a combination thereof, of the UE described above in connection withFIG.2.

The identification component608may identify a third timer for a third antenna based at least in part on a third measurement associated with the third antenna satisfying a third criterion with respect to the second measurement associated with the second antenna, wherein the third timer expires after an end of the timer threshold. In some aspects, the identification component608may include one or more antennas, a demodulator, a MIMO detector, a receive processor, a modulator, a transmit MIMO processor, a transmit processor, a controller/processor, a memory, or a combination thereof, of the UE described above in connection withFIG.2.

The transmission component604may perform a transmission via the second antenna after selecting the second antenna. In some aspects, the transmission component604may include one or more antennas, a demodulator, a MIMO detector, a receive processor, a modulator, a transmit MIMO processor, a transmit processor, a controller/processor, a memory, or a combination thereof, of the UE described above in connection withFIG.2.

The number and arrangement of components shown inFIG.6are provided as an example. In practice, there may be additional components, fewer components, different components, or differently arranged components than those shown inFIG.6. Furthermore, two or more components shown inFIG.6may be implemented within a single component, or a single component shown inFIG.6may be implemented as multiple, distributed components. Additionally, or alternatively, a set of (one or more) components shown inFIG.6may perform one or more functions described as being performed by another set of components shown inFIG.6.

FIG.7is a block diagram of an example apparatus700for wireless communication. The apparatus700may be a transmitter, or a transmitter may include the apparatus700. In some aspects, the apparatus700includes a reception component702and a transmission component704, which may be in communication with one another (for example, via one or more buses and/or one or more other components). As shown, the apparatus700may communicate with another apparatus706(such as a UE, a base station, or another wireless communication device) using the reception component702and the transmission component704. As further shown, the apparatus700may include one or more of a configuration component708, among other examples.

The transmission component704may transmit communications, such as reference signals, control information, data communications, or a combination thereof, to the apparatus706. In some aspects, one or more other components of the apparatus706may generate communications and may provide the generated communications to the transmission component704for transmission to the apparatus706. In some aspects, the transmission component704may perform signal processing on the generated communications (such as filtering, amplification, modulation, digital-to-analog conversion, multiplexing, interleaving, mapping, or encoding, among other examples), and may transmit the processed signals to the apparatus706. In some aspects, the transmission component704may include one or more antennas, a modulator, a transmit MIMO processor, a transmit processor, a controller/processor, a memory, or a combination thereof, of the transmitter described above in connection withFIG.2. In some aspects, the transmission component704may be collocated with the reception component702in a transceiver.

In some aspects, the reception component702may receive, among other things, information regarding (i) a timer identified by, for example, the identification component, depicted inFIG.6, (ii) a timer threshold determined by, for example, the determination component610, depicted inFIG.6, and/or (iii) an antenna selected by, for example, the selection component612, depicted inFIG.6. The configuration component708may enable processing of the received information and enable generation and/or provision of configuration information. The transmission component704may transmit the configuration information to, for example, the apparatus706and/or the reception component602, depicted inFIG.6.

The number and arrangement of components shown inFIG.7are provided as an example. In practice, there may be additional components, fewer components, different components, or differently arranged components than those shown inFIG.7. Furthermore, two or more components shown inFIG.7may be implemented within a single component, or a single component shown inFIG.7may be implemented as multiple, distributed components. Additionally, or alternatively, a set of (one or more) components shown inFIG.7may perform one or more functions described as being performed by another set of components shown inFIG.7.

Aspect 1: A method of wireless communication performed by a user equipment (UE), comprising: identifying a first timer associated with a first antenna and a second timer associated with a second antenna; identifying an expiration of the first timer associated with the first antenna; determining, based at least in part on the identified expiration of the first timer, whether a remaining time of the second timer associated with the second antenna is less than a timer threshold; and selecting, based at least in part on the determination that the remaining time of the second timer is less than the timer threshold, the second antenna.

Aspect 2: The method of Aspect 1, wherein the first timer is identified based at least in part on a first measurement associated with the first antenna satisfying a first criterion with respect to a measurement associated with an active antenna, and the second timer is identified based at least in part on a second measurement associated with the second antenna satisfying a second criterion with respect to the first measurement associated with the first antenna.

Aspect 3: The method of Aspect 2, further comprising: identifying a third timer for a third antenna based at least in part on a third measurement associated with the third antenna satisfying a third criterion with respect to the second measurement associated with the second antenna, wherein the third timer expires after an end of the timer threshold.

Aspect 4: The method of Aspect 3, wherein the third antenna is identified prior to selecting the second antenna.

Aspect 5: The method of any of Aspects 1-4, wherein selecting the second antenna further comprises: performing a transmission via the second antenna.

Aspect 6: The method of any of Aspects 1-5, wherein the timer threshold is adjustable.

Aspect 7: The method of any of Aspects 1-6, wherein a duration associated with the timer threshold begins at the expiration of the first timer.

Aspect 8: The method of any of Aspects 1-7, wherein the first timer is identified separately from the second timer.

Aspect 12: A non-transitory computer-readable medium storing code for wireless communication, the code comprising instructions executable by a processor to perform the method of one or more of Aspects 1-8.

As used herein, the term “component” is intended to be broadly construed as hardware, firmware, and/or a combination of hardware and software. As used herein, a processor is implemented in hardware, firmware, and/or a combination of hardware and software. It will be apparent that systems and/or methods described herein may be implemented in different forms of hardware, firmware, and/or a combination of hardware and software. The actual specialized control hardware or software code used to implement these systems and/or methods is not limiting of the aspects. Thus, the operation and behavior of the systems and/or methods were described herein without reference to specific software code—it being understood that software and hardware can be designed to implement the systems and/or methods based, at least in part, on the description herein.