Patent Description:
The following relates generally to wireless communication, and more specifically to antenna switch scheduling in a multi-antenna user equipment (UE).

Wireless communications systems, as are for example described in <CIT>, <CIT> and <CIT>, are widely deployed to provide various types of communication content such as voice, video, packet data, messaging, broadcast, and so on. Examples of such multiple-access systems include fourth generation (<NUM>) systems such as E-UTRA, or Long Term Evolution (LTE) or LTE-Advanced (LTE-A), systems, and fifth generation (<NUM>) systems which may be referred to as New Radio (NR) systems. These systems may employ technologies such as code division multiple access (CDMA), time division multiple access (TDMA), frequency division multiple access (FDMA), orthogonal frequency division multiple access (OFDMA), or discrete Fourier transform-spread-OFDM (DFT-S-OFDM).

Generally, base stations and UEs communicate via transmissions on forward and reverse links. A forward link (or downlink) refers to the communication link from a base station to a UE, and the reverse link (or uplink) refers to the communication link
from the UE to the base station. The forward and/or reverse links may be established via single-in-single-out (SISO), multiple-in-single-out (MISO), or a multiple-in-multiple-out (MIMO) system. In devices utilizing multiple antennas, algorithms may exist for switching between antennas to achieve a desired performance (e.g., to switch from using a certain antenna that may be blocked by how a device is held). Moreover, some UEs may be configured to communicate with base stations using multiple radio access technologies, such as in an E-UTRA New Radio - Dual Connectivity (EN-DC) mode.

The described techniques relate to improved methods, systems, devices, or apparatuses that support antenna switch scheduling in a multi-antenna user equipment (UE).

A method of wireless communication in a multi-antenna UE is described. The method may include communicating with a base station using a first antenna, determining to switch from the first antenna to a second antenna for communicating with the base station, determining a silence window in which communication with the base station is suspended, scheduling the switch from the first antenna to the second antenna to occur during the silence window, and switching from the first antenna to the second antenna during the silence window.

A multi-antenna UE is described. The UE may include a first antenna, a second antenna, a processor, memory coupled to the processor, and instructions stored in the memory. The instructions may be executable by the processor to cause the UE to communicate with a base station using the first antenna, determine to switch from the first antenna to the second antenna for communicating with the base station, determine a silence window in which communication with the base station is suspended, schedule the switch from the first antenna to the second antenna to occur during the silence window, and switch from the first antenna to the second antenna during the silence window.

An apparatus for wireless communication is described. The apparatus may include means for communicating with a base station using a first antenna, means for determining to switch from the first antenna to a second antenna for communicating with the base station, means for determining a silence window in which communication with the base station is suspended, means for scheduling the switch from the first antenna to the second antenna to occur during the silence window, and means for switching from the first antenna to the second antenna during the silence window.

A non-transitory computer readable medium storing code for wireless communication is described. The code may include instructions executable by a processor to communicate with a base station using a first antenna, determine to switch from the first antenna to a second antenna for communicating with the base station, determine a silence window in which communication with the base station is suspended, schedule the switch from the first antenna to the second antenna to occur during the silence window, and switch from the first antenna to the second antenna during the silence window.

Various aspects of the disclosure provide techniques for scheduling antenna switching in a multi-antenna user equipment (UE). In one aspect, a UE may determine to switch from a first antenna to a second antenna in communicating with a base station. Switching from one antenna to another antenna may involve suspending communication to avoid damaging components (e.g., front end components such as a power amplifier) of the UE and/or to change settings (e.g., antenna switched diversity (ASDIV) configurations) of components. Suspending communication during a connection with a base station may result in communication delays and/or outages. In an aspect, the UE may determine whether an upcoming silence window is available and may schedule the antenna switch to occur during the silence window. In some aspects, scheduling an antenna switch may reduce outages or loss of connection due to transmission and/or reception suspension or blanking.

Aspects of the disclosure are initially described in the context of a wireless communications system. Aspects of the disclosure are further illustrated by and described with reference to apparatus diagrams, timeline diagrams, system diagrams, and flowcharts that relate to antenna switch scheduling in a multi-antenna UE.

<FIG> illustrates an example of a wireless communications system <NUM> that supports antenna switch scheduling in a multi-antenna UE in accordance with various aspects of the present disclosure. The wireless communications system <NUM> includes base stations <NUM>, UEs <NUM>, and a core network <NUM>. In some aspects, the wireless communications system <NUM> may be a Long Term Evolution (LTE) network, an LTE-Advanced (LTE-A) network, or a New Radio (NR) network. In some cases, wireless communications system <NUM> may support enhanced broadband communications, ultra-reliable (e.g., mission critical) communications, low latency communications, or communications with low-cost and low-complexity devices.

In some aspects, each base station <NUM> may provide communication coverage for a macro cell, a small cell, a hot spot, or other types of cells, or various combinations thereof. In some aspects, a base station <NUM> may be movable and therefore provide communication coverage for a moving geographic coverage area <NUM>. In some aspects, different geographic coverage areas <NUM> associated with different technologies may overlap, and overlapping geographic coverage areas <NUM> associated with different technologies may be supported by the same base station <NUM> or by different base stations <NUM>. The wireless communications system <NUM> may include, for example, a heterogeneous LTE/LTE-A or NR network in which different types of base stations <NUM> provide coverage for various geographic coverage areas <NUM>.

In some aspects, a carrier may support multiple cells, and different cells may be configured according to different protocol types (e.g., machine-type communication (MTC), narrowband Internet-of-Things (NB-IoT), enhanced mobile broadband (eMBB), or others) that may provide access for different types of devices.

In some aspects, a UE <NUM> may also refer to a wireless local loop (WLL) station, an Internet of Things (IoT) device, an Internet of Everything (IoE) device, or an MTC device, or the like, which may be implemented in various articles such as appliances, vehicles, meters, or the like.

In some aspects, M2M communication or MTC may include communications from devices that integrate sensors or meters to measure or capture information and relay that information to a central server or application program that can make use of the information or present the information to humans interacting with the program or application.

In some aspects half-duplex communications may be performed at a reduced peak rate.

In some aspects, base stations <NUM> may interface with the core network <NUM> through backhaul links <NUM> (e.g., via an S1 or other interface).

In some aspects, wireless communications system <NUM> may support millimeter wave (mmW) communications between UEs <NUM> and base stations <NUM>, and EHF antennas of the respective devices may be even smaller and more closely spaced than UHF antennas. In some cases, this may facilitate use of antenna arrays within a UE <NUM> (e.g., for multiple-input multiple-output (MIMO) operations such as spatial multiplexing, or for directional beamforming).

In some aspects, wireless communications system <NUM> may utilize both licensed and unlicensed radio frequency spectrum bands. For example, wireless communications system <NUM> may employ LTE License Assisted Access (LTE-LAA) or LTE-Unlicensed (LTE-U) radio access technology or NR technology in an unlicensed band such as the <NUM> ISM band. In some cases, operations in unlicensed bands may be based on a CA configuration in conjunction with CCs operating in a licensed band.

In some cases, the antennas of a base station <NUM> or UE <NUM> may be located within one or more antennas or antenna arrays, which may support MIMO operations such as spatial multiplexing, or transmit or receive beamforming.

MIMO wireless systems use a transmission scheme between a transmitting device (e.g., a base station <NUM>) and a receiving device (e.g., a UE <NUM>), where both transmitting device and the receiving device are equipped with multiple antennas. MIMO communications may employ multipath signal propagation to increase the utilization of a radio frequency spectrum band by transmitting or receiving different signals via different spatial paths, which may be referred to as spatial multiplexing. The different signals may, for example, be transmitted by the transmitting device via different antennas or different combinations of antennas. Likewise, the different signals may be received by the receiving device via different antennas or different combinations of antennas. Each of the different signals may be referred to as a separate spatial stream, and the different antennas or different combinations of antennas at a given device (e.g., the orthogonal resource of the device associated with the spatial dimension) may be referred to as spatial layers.

Beamforming, which may also be referred to as spatial filtering, directional transmission, or directional reception, is a signal processing technique that may be used at a transmitting device or a receiving device (e.g., a base station <NUM> or a UE <NUM>) to shape or steer an antenna beam (e.g., a transmit beam or receive beam) along a direction between the transmitting device and the receiving device. The adjustment of signals communicated via the antenna elements may include a transmitting device or a receiving device applying certain phase offset, timing advance/delay, or amplitude adjustment to signals carried via each of the antenna elements associated with the device.

In one aspect, a base station <NUM> may multiple use antennas or antenna arrays to conduct beamforming operations for directional communications with a UE <NUM>. For instance, signals may be transmitted multiple times in different directions, which may include a signal being transmitted according to different beamforming weight sets associated with different directions of transmission. A receiving device (e.g., a UE <NUM>, which may be an example of a mmW receiving device) may try multiple receive beams when receiving various signals from the base station <NUM>, such as synchronization signals or other control signals.

Time intervals of a communications resource may be organized according to radio frames each having a duration of <NUM> milliseconds (Tf = <NUM> * Ts). Each frame may include ten subframes numbered from <NUM> to <NUM>, and each subframe may have a duration of <NUM> millisecond. A subframe may be further divided into two slots each having a duration of <NUM> milliseconds, and each slot may contain <NUM> or <NUM> modulation symbol periods (e.g., depending on the length of the cyclic prefix prepended to each symbol period). In some cases a subframe may be the smallest scheduling unit of the wireless communications system <NUM>, and may be referred to as a transmission time interval (TTI).

In some wireless communications systems, a slot may further be divided into multiple mini-slots containing one or more symbols and in some instances, a symbol of a mini-slot or a mini-slot may be the smallest unit of scheduling. Some wireless communications systems may implement slot aggregation in which multiple slots or mini-slots may be aggregated together for communication between a UE <NUM> and a base station <NUM>.

A resource element may consist of one symbol period (e.g., a duration of one modulation symbol) and one subcarrier (e.g., a <NUM> frequency range). A resource block may contain <NUM> consecutive subcarriers in the frequency domain (e.g., collectively forming a "carrier") and, for a normal cyclic prefix in each orthogonal frequency-division multiplexing (OFDM) symbol, <NUM> consecutive OFDM symbol periods in the time domain (<NUM> slot), or <NUM> total resource elements across the frequency and time domains. The number of bits carried by each resource element may depend on the modulation scheme (the configuration of modulation symbols that may be applied during each symbol period). Thus, the more resource elements that a UE <NUM> receives and the higher the modulation scheme (e.g., the higher the number of bits that may be represented by a modulation symbol according to a given modulation scheme), the higher the data rate may be for the UE <NUM>. In MIMO systems, a wireless communications resource may refer to a combination of a radio frequency spectrum band resource, a time resource, and a spatial resource (e.g., spatial layers), and the use of multiple spatial layers may further increase the data rate for communications with a UE <NUM>.

The term "carrier" refers to a set of radio frequency spectrum resources having a defined organizational structure for supporting uplink or downlink communications over a communication link <NUM>. For example, a carrier of a communication link <NUM> may include a portion of a radio frequency spectrum band that may also be referred to as a frequency channel. In some aspects a carrier may be made up of multiple sub-carriers (e.g., waveform signals of multiple different frequencies). A carrier may be organized to include multiple physical channels, where each physical channel may carry user data, control information, or other signaling.

The organizational structure of the carriers may be different for different radio access technologies (e.g., LTE, LTE-A, NR, etc.). In some aspects (e.g., in a carrier aggregation configuration), a carrier may also have acquisition signaling or control signaling that coordinates operations for other carriers.

In some aspects, control information transmitted in a physical control channel may be distributed between different control regions in a cascaded manner (e.g., between a common control region or common search space and one or more UE-specific control regions or UE-specific search spaces).

A carrier may be associated with a particular bandwidth of the radio frequency spectrum, and in some aspects the carrier bandwidth may be referred to as a "system bandwidth" of the carrier or the wireless communications system <NUM>. For example, the carrier bandwidth may be one of a number of predetermined bandwidths for carriers of a particular radio access technology (e.g., <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, or <NUM>). In some aspects the system bandwidth may refer to a minimum bandwidth unit for scheduling communications between a base station <NUM> and a UE <NUM>. In other aspects a base station <NUM> or a UE <NUM> may also support communications over carriers having a smaller bandwidth than the system bandwidth. In such aspects, the system bandwidth may be referred to as "wideband" bandwidth and the smaller bandwidth may be referred to as a "narrowband" bandwidth. In some aspects of the wireless communications system <NUM>, wideband communications may be performed according to a <NUM> carrier bandwidth and narrowband communications may be performed according to a <NUM> carrier bandwidth.

Devices of the wireless communications system <NUM> (e.g., base stations or UEs <NUM>) may have a hardware configuration that supports communications over a particular carrier bandwidth, or may be configurable to support communications over one of a set of carrier bandwidths. For example, base stations <NUM> or UEs <NUM> may perform some communications according to a system bandwidth (e.g., wideband communications), and may perform some communications according to a smaller bandwidth (e.g., narrowband communications). In some aspects, the wireless communications system <NUM> may include base stations <NUM> and/or UEs that can support simultaneous communications via carriers associated with more than one different bandwidth.

Wireless communications systems such as an NR system may use a combination of licensed shared and unlicensed spectrum bands, among others. The flexibility of eCC symbol duration and subcarrier spacing may allow for the use of eCC across multiple spectrums. In some aspects, NR shared spectrum may increase spectrum utilization and spectral efficiency, specifically through dynamic vertical (e.g., across frequency) and horizontal (e.g., across time) sharing of resources.

In some cases, UE <NUM> may be configured with multiple antennas to communicate with base station <NUM>. In one aspect, UE <NUM> may use a first antenna to communicate with base station <NUM> while a second antenna of UE <NUM> is not used. UE <NUM> may determine to switch to using the second antenna, instead of the first antenna, to communicate with base station <NUM>. UE <NUM> may opportunistically schedule the switch from the first antenna to the second antenna to coincide with a silence window in which communication with base station <NUM> will be suspended. In another aspect, UE <NUM> may communicate with base station <NUM> using multiple antennas simultaneously (e.g., as in downlink MIMO (DL-MIMO) and/or uplink MIMO (UL-MIMO)) while other antennas of UE <NUM> are not used. UE <NUM> may determine to switch to from the used antennas to the unused antennas to communicate with base station <NUM> and may opportunistically schedule the switches to occur during a silence window. Further description of scheduling antenna switching is described below.

<FIG> illustrates a block diagram of various components of a UE <NUM> that supports antenna switch scheduling in accordance with various aspects of the present disclosure. <FIG> is one example configuration of UE <NUM>, and other multi-antenna configurations of UE <NUM> are contemplated to be within the scope of the disclosure. In one aspect, UE <NUM> utilizes ASDIV. UE <NUM> includes a first antenna (ANT1) 205a and a second antenna (ANT2) 205b coupled to a switch component <NUM>. In one aspect, first antenna 205a and second antenna 205b may be in different areas of UE <NUM> (e.g., one at a bottom area of UE <NUM> and one at a top area of UE <NUM>). Although two antennas are depicted, skilled artisans will recognize that more than two antennas may be implemented. Switch <NUM> is operable to couple and decouple first antenna 205a and second antenna 205b to other components of UE <NUM>. Although switch <NUM> is represented by a single block in <FIG>, switch <NUM> may include multiple switches and/or components.

A filter component <NUM> is coupled to switch <NUM> and may be configured to pass signals of selected frequencies. Although filter <NUM> is represented by a single block in <FIG>, filter <NUM> may include multiple filters and/or components. Filter <NUM> may be coupled to a transmit (TX) chain <NUM> that includes one or more power amplifiers <NUM> and other signal conditioning components/circuitry (e.g., mixers, amplifiers, filters) <NUM>. Filter <NUM> may also be coupled to a receive (RX) chain <NUM> that includes one or more low noise amplifiers (LNAs) <NUM> and other signal conditioning components/circuitry (e.g., automatic gain control (AGC), mixers, amplifiers, filters) <NUM>. LNA(s) <NUM> may include built-in AGC functionality. Transmit chain <NUM> and receive chain <NUM> are coupled to one or more processors <NUM> (e. g, a modem). Processor <NUM> is coupled to switch <NUM> (represented by control line <NUM>) and may control switching operations to select an antenna for communication with a base station <NUM>.

In one aspect, UE <NUM> may be configured to operate in a multi-connectivity mode (e.g., an E-UTRA New Radio - Dual Connectivity (EN-DC) mode) in which one or both antennas 205a, 205b are configured to transmit and/or receive signals corresponding to multiple radio access technologies (RATs). In the multi-connectivity mode, UE <NUM> may share switch <NUM> between RATs, and the RATs may either share other front-end components (e.g., filters, amplifiers, mixers) or have separate front-end components or chains. In another aspect, UE <NUM> may be configured to operate in carrier aggregation (CA) mode using multiple carriers. In CA mode, UE <NUM> may share switch <NUM> among carriers and the carriers may either share other front-end components (e.g., filters, amplifiers, mixers) or have separate front-end components or chains.

Processor <NUM> may employ any number of different methodologies for determining the antenna(s) to use for transmitting and/or receiving. In one aspect, processor <NUM> may use communication metrics corresponding to downlink signal conditions, uplink signal conditions, or a combination thereof to determine the antenna(s) to use. In one aspect, processor <NUM> may use receive signal strength metrics (e.g., receive signal strength indicator (RSSI), reference signal receive power (RSRP), reference signal receive quality (RSRQ), or other signal-to-noise (SNR) metrics). In one aspect, processor <NUM> may use UL transmission metrics, such as maximum transmit power limit (MTPL), power headroom (which may vary based on modulation and coding schemes (MCS)), and specific absorption rate (SAR) backoff metrics. In one aspect, processor <NUM> may use communication metrics filtered over time (e.g., an average metric over time). In one aspect, processor <NUM> may determine to switch from one antenna to another antenna when a difference between RSRP (RSRPDelta) of the antennas is greater than a threshold value (e.g., 3dB), when the average RSRPDelta is greater than a threshold, and/or when the MTPL has been reached for some percentage of a time period.

ASDIV may involve suspending current transmissions of transmit chain <NUM> and/or suspending or disabling receive chain <NUM> components during a switch between antennas (e.g., from first antenna 205a to second antenna 205b). Transmissions on transmit chain <NUM> may need to be blanked or suspended to avoid damaging one or more components, such as power amplifier(s) <NUM>. Receive chain <NUM> components, such as LNA(s) <NUM> and AGC components, may need to be suspended or disabled to change AGC and digital controlled variable gain amplifier (DVGA) settings or offsets to account for changing ASDIV configuration settings. In one aspect, processor <NUM> determines whether a silence window will occur in communications with a base station <NUM> and whether to wait for the silence window to switch antennas.

<FIG> illustrates a block diagram of various portions of a UE <NUM> that supports antenna switch scheduling for MIMO (e.g., DL-MIMO, UL-MIMO) applications in accordance with various aspects of the present disclosure. <FIG> is one example configuration of UE <NUM>, and other multi-antenna configurations of UE <NUM> are contemplated to be within the scope of the disclosure. UE <NUM> includes a first antenna (ANT1) 305a, a second antenna (ANT2) 305b, a third antenna (ANT3) 305c, and a fourth antenna (ANT4) 305d coupled to a switch component <NUM>. Although four antennas are depicted, skilled artisans will recognize that more than four antennas may be implemented. In one aspect, the antennas may be in different areas of UE <NUM>. Switch <NUM> is operable to couple and decouple first antenna 305a, second antenna 305b, third antenna 305c and fourth antenna 305d to other components of UE <NUM>. Although switch <NUM> is represented by a single block in <FIG>, switch <NUM> may include multiple switches or components.

In MIMO applications, multiple ones of antennas 305a-305d may transmit and/or receive simultaneously. For example, in UL-MIMO signals for transmission on a first path (or chain) <NUM> may be routed to a first one of antennas 305a-305d and signals for transmission on a second path (or chain) <NUM> may be routed to a second one of antennas 305a-305d. In a DL-MIMO example, signals received on a first one of antennas 305a-305d may be routed to first path <NUM> and signals received on a second one of antennas 305a-305d may be routed to second path <NUM>. First and second paths <NUM> and <NUM> may include various components that are part of transmission and/or receive chains.

UE <NUM> may include one or more processors <NUM> coupled to paths <NUM>, <NUM> and to switch <NUM> via a control line <NUM> to control the routing of paths <NUM>, <NUM> to the various antennas 305a-305d. Processor <NUM> may determine metrics (as described with reference to <FIG>) associated with each antenna 305a-305d and select an antenna for each path <NUM>, <NUM> based on the metrics. Processor <NUM> may also determine to reroute path <NUM> and/or <NUM> to a different antenna based on the metrics. Processor <NUM> may determine to switch antennas for each path <NUM>, <NUM> independently. For example, path <NUM> may be routed to first antenna 305a and path <NUM> may be routed to second antenna 305b, and processor <NUM> may determine to reroute path <NUM> to third antenna 305c while path <NUM> remains routed to second antenna 305b. In one aspect, processor <NUM> determines whether a silence window will occur in communications with a base station <NUM> and whether to wait for the silence window to switch antennas for one or both paths <NUM>, <NUM>.

UE <NUM> of <FIG> may be configured to operate in a multi-connectivity mode (e.g., EN-DC mode) in which one or multiple ones of antennas 205a-205d are configured to transmit and/or receive signals corresponding to multiple RATs. In the multi-connectivity mode, UE <NUM> may share switch <NUM> between RATs, and the RATs may either share other front-end components (e.g., filters, amplifiers, mixers) or have separate front-end components or chains. UE <NUM> of <FIG> may be configured to operate in CA mode in which one or multiple ones of antennas 205a-205d are configured to transmit and/or receive signals corresponding to multiple carriers.

<FIG> is illustrates a timeline diagram <NUM> of operations of UE <NUM> that supports antenna switch scheduling in accordance with aspects of the present disclosure. Timeline <NUM> is one aspect of operations that may be performed by UE <NUM>. Other operations in accordance with the disclosure and other orders of operations may be executed by UE <NUM>. The operations depicted in timeline <NUM> may be performed and/or executed by a processor (e.g., processor <NUM>, processor <NUM>) and switch (e.g., switch <NUM>, switch <NUM>).

At t1, UE <NUM> detects a switch condition by determining to switch communication from a first antenna to a second antenna. For example, a first antenna that is being used to communicate with a base station <NUM> may experience degraded channel conditions (e.g., degraded channel conditions due to blockage by a user's hand or head). A second antenna that is not being used for communication may have better channel conditions than the first antenna (e.g., the second antenna may be in a different location of the UE <NUM> and may experience no or less blockage than the first antenna). In some aspects, UE <NUM> determines communication metrics (e.g., DL and/or UL metrics) associated with its antennas to determine whether to switch from a first antenna to a second antenna to communicate with base station <NUM>. In one aspect, UE <NUM> may use a combination of DL and UL metrics to detect a switch condition.

Some example communication metrics are described with reference to <FIG>. In one aspect, UE <NUM> may determine RSRP metrics for the first and second antennas. The switch condition may correspond to RSRPDelta (or average RSRPDelta) exceeding a threshold. In another aspect, UE <NUM> may determine whether the MTPL for the first antenna has been reached for a threshold percentage of a time period and use this determination in combination with an RSRP determination to detect a switch condition. In some aspects, UE <NUM> may periodically evaluate communication metrics to determine whether to switch antennas and ASDIV configurations. As one example, UE <NUM> may evaluate communication metrics every <NUM>.

At t2, UE <NUM> determines whether a silence window <NUM> will occur and whether to schedule the antenna switch to take place during silence window <NUM>. In <FIG>, t2 is depicted as occurring some time after t1 (the switch detection). However, the operations of t2 may occur directly after detecting a switch condition or simultaneously with detecting a switch condition. Silence window <NUM> may correspond to various different types of time durations in which communications between UE <NUM> and base station <NUM> will be suspended. According to the invention, silence window <NUM> corresponds to a measurement gap duration. In some aspects, UE <NUM> may be configured to operate in a multi-connectivity mode or CA mode, and silence window <NUM> may correspond to a time duration in which communication with base station(s) <NUM> is suspended for multiple RATs or multiple carriers. A silence window may be determined using various techniques including by analyzing control information or parameters determined by UE <NUM> or signaled to UE <NUM> from a network.

In some scenarios, the channel conditions of a first antenna that is being used for communications with base station <NUM> may be degraded to a point where UE <NUM> may determine to switch to a second antenna before waiting for silence window <NUM>. For example, the channel conditions related to the first antenna may be such that UE <NUM> may lose connection with base station <NUM> before silence window <NUM> occurs. UE <NUM> may use the communication metrics (e.g., DL and/or UL metrics) to determine whether to wait for silence window <NUM> to switch antennas. In one aspect, UE <NUM> compares communication metrics to a first threshold at t1 to determine whether to switch antennas and compares the communication metrics to a second threshold at t2 to determine whether to wait for silence window <NUM> to switch antennas. In an aspect, the communication metrics may correspond to RSRPDelta and the first threshold may correspond to a first dB level (e.g., <NUM> dB) and the second threshold may correspond to a second dB level greater than the first dB level (e.g., <NUM> dB greater than the first dB level, or <NUM> dB). UE <NUM> may determine to switch antennas, and wait for silence window <NUM> to switch, if RSRPDelta exceeds the first threshold but does not exceed the second threshold. If RSRPDelta exceeds the first and second thresholds, UE <NUM> may switch antennas without waiting for silence window <NUM> to do so.

UE <NUM> also factors in the length of time between detecting a switch condition and the start of silence window (e.g., from t1 to t3) to determine whether to wait for silence window <NUM> to switch. If the length of time between t1 and t3 exceeds a threshold time, UE <NUM> determines to switch before silence window <NUM>. UE <NUM> uses a combination of communication metrics and time metrics to determine whether to wait for silence window <NUM> to switch. In an aspect, UE <NUM> compares communication metrics to thresholds (a first threshold and a second threshold) and
compare the time until the next silence window <NUM> to determine whether to wait for silence window <NUM> to switch.

The switch from a first antenna to a second antenna may not occur instantaneously. Instead, various settings and/or offsets may need to change and signals to components may need to be suspended in preparation to switch, which may take some time. The length of time from initiating the switch (e.g., suspending signals, initiating the change of settings) to completing the switch of antennas may be referred to as a switch duration. UE <NUM> may compare the switch duration to a silence duration, which corresponds to a length of time of silence window <NUM> (e.g., the length of time between t3 and t6), to determine whether silence duration of silence window <NUM> is long enough to accommodate the switch (e.g., whether the silence duration is equal to or greater than the switch duration). If the silence duration is greater than or equal to the switch duration, UE <NUM> may schedule the switch to occur during the silence duration.

As depicted in <FIG>, UE <NUM> determines to schedule the antenna switch to occur during silence window <NUM>, which starts at t3 and ends at t6. UE <NUM> begins to switch from a first antenna to a second antenna at t4 and ends the switch at t5. Although t4 is depicted in <FIG> as occurring after t3, t4 may coincide with t3. That is, UE <NUM> may begin the antenna switch at the start of silence window <NUM>.

In <FIG>, silence windows (e.g., as described with reference to <FIG>) correspond to measurement gaps such as gaps 505a, 505b and 505c. In some aspects, gaps 505a-505c may correspond to per-UE measurement gaps. Gaps 505a-505c may occur periodically such as every <NUM>, <NUM>, <NUM> or other periodicities. In multi-connectivity scenarios, such as EN-DC, or CA scenarios measurement gaps may correspond to common measurement gaps (e.g., shared measurement gaps) for the multiple RATs or the multiple carriers. At t1, UE <NUM> detects a switch condition by determining to switch communication from a first antenna to a second antenna. As depicted in <FIG>, t1 occurs after first gap 505a.

At t2, UE <NUM> determines whether second gap 505b will occur and whether to schedule the antenna switch to take place during second gap 505b. UE <NUM> may analyze various factors (e.g., described with reference to <FIG>), such as communication metrics, a silence duration (e.g., the duration of gap 505b), a switch duration, and a length of time between the switch detection and the start of second gap 505b to determine whether to schedule the antenna switch during second gap 505b.

As depicted in <FIG>, UE <NUM> determines to schedule the antenna switch to occur during second gap 505b, which starts at t3 and ends at t6. UE <NUM> begins to switch from a first antenna to a second antenna at t4 and ends the switch at t5. Although t4 is depicted in <FIG> as occurring after t3, t4 may coincide with t3. That is, UE <NUM> may begin the antenna switch at the start of second gap 505b. The antenna switch during second gap 505b may include changing ASDIV configurations. In an aspect, prior to second gap 505b the ASDIV configuration may be a first configuration (e.g., ASDIV config-<NUM>) and after second gap 505b the ASDIV configuration may be a second configuration (e.g., ASDIV config-<NUM>). The ASDIV configuration change may be scheduled to occur during second gap 505b and may preempt other changes or measurements during second gap 505b.

In <FIG>, a silence window (e.g., as described with reference to <FIG>) corresponds to a DRX and/or DTX (e.g., CDRX) OFF or sleep duration <NUM> in a DRX cycle. DRX OFF duration <NUM> may occur periodically according to the DRX cycle and may follow a DRX ON or awake duration 610a. As shown in <FIG>, the DRX cycle spans from t1 to t7 with ON duration 610a spanning from t1 to t4 and OFF duration <NUM> spanning from t4 to t7. At t2, UE <NUM> detects a switch condition by determining to switch communication from a first antenna to a second antenna. As depicted in <FIG>, t2 occurs during ON duration 610a.

At t3, UE <NUM> determines whether to schedule the antenna switch to take place during OFF duration <NUM>. UE <NUM> may analyze various factors (e.g., described with reference to <FIG>), such as communication metrics, a silence duration (e.g., the length of OFF duration <NUM>), a switch duration, and a length of time between the switch detection and the start of OFF duration <NUM> to determine whether to schedule the antenna switch during OFF duration <NUM>. In one aspect, UE <NUM> may schedule the antenna switch to occur during OFF duration <NUM> if the time between detecting the switch condition and the start of OFF duration <NUM> is <NUM> or less.

As depicted in <FIG>, UE <NUM> determines to schedule the antenna switch to occur during OFF duration <NUM>. UE <NUM> begins to switch from a first antenna to a second antenna at t5 and ends the switch at t6. Although t5 is depicted in <FIG> as occurring after t4 (the start of OFF duration <NUM>), t5 may coincide with t4. That is, UE <NUM> may begin the antenna switch at the start of OFF duration <NUM>. Once UE <NUM> finishes the antenna switch at t6, UE <NUM> may sleep for the remainder of OFF duration <NUM>. The antenna switch during OFF duration <NUM> may include changing ASDIV configurations. In an aspect, during ON duration 610a the ASDIV configuration may be a first configuration (e.g., ASDIV config-<NUM>) and during an ON duration 610b the ASDIV configuration may be a second configuration (e.g., ASDIV config-<NUM>).

<FIG> is illustrates a timeline diagram <NUM> of operations of UE <NUM> that supports antenna switch scheduling in a multi-connectivity mode in accordance with aspects of the present disclosure. Timeline <NUM> is one aspect of operations that may be performed by UE <NUM>. Other operations in accordance with the disclosure and other orders of operations may be executed by UE <NUM>. The operations depicted in timeline <NUM> may be performed and/or executed by a processor (e.g., processor <NUM>, processor <NUM>) and switch (e.g., switch <NUM>, switch <NUM>).

In <FIG>, a silence window <NUM> corresponds to overlapping portions of a DRX OFF duration 705a of a first RAT (RAT1) and a DRX OFF duration 705b of a second RAT (RAT2). In a multi-connectivity mode, such as an EN-DC mode, DRX cycles of the different RATs may not be synchronized in time and may have ON and/or OFF durations of different lengths. UE <NUM> may determine DRX cycle information for each RAT and identify portions of DRX OFF durations that overlap in time based on the information.

At t1, UE <NUM> detects a switch condition by determining to switch communication from a first antenna to a second antenna. At t2, UE <NUM> determines whether to schedule the antenna switch to take place during silence window <NUM>, which corresponds to the overlapping portions of OFF durations 705a and 705b. UE <NUM> may analyze various factors (e.g., described with reference to <FIG>), such as communication metrics, a silence duration (e.g., the duration of silence window <NUM>), a switch duration, and a length of time between the switch detection and the start of silence window <NUM> to determine whether to schedule the antenna switch during silence window <NUM>. In one aspect, UE <NUM> may schedule the antenna switch to occur during silence window <NUM> if the time between detecting the switch condition and the start of silence window <NUM> is <NUM> or less.

As depicted in <FIG>, UE <NUM> determines to schedule the antenna switch to occur during silence window <NUM>. UE <NUM> begins to switch from a first antenna to a second antenna at t4 and ends the switch at t5. Although t4 is depicted in <FIG> as occurring after t3 (the start of silence window <NUM>), t4 may coincide with t3. That is, UE <NUM> may begin the antenna switch at the start of silence window <NUM>. Once UE <NUM> finishes the antenna switch at t5, UE <NUM> may sleep for the remainder of silence window <NUM> (e.g., until t6).

In <FIG>, a silence window corresponds to a silence interval <NUM> that may occur in a voice type or voice related service. During voice related services, a voice activity factor may correspond to an average time that voice is communicated between users. In one aspect, the voice activity factor may be around <NUM>%. During inactivity a voice vocoder may send a silence indicator descriptor (SID) vocoder packet 810a at the beginning of a silence occasion and may send other SID packets (e.g., packet 810b) at selected intervals (e.g., every <NUM>). Silence interval <NUM> may correspond to the time between SID packets 810a and 810b.

At t0, UE <NUM> may determine that an active service is a voice related service. At t1, UE <NUM> may determine (e.g., through a voice activity detection algorithm) that a condition is met to enter a voice silence period or occasion and may start to send SID packet 810a at t3. Although t3 is depicted in <FIG> as occurring after t1, t3 may coincide with t1. That is, SID packet 810a may be sent immediately when the voice activity detection algorithm detects silence.

At t2, UE <NUM> detects a switch condition by determining to switch communication from a first antenna to a second antenna. At t2, UE <NUM> determines whether to schedule the antenna switch to take place during silence interval <NUM>. UE <NUM> may analyze various factors (e.g., described with reference to <FIG>), such as communication metrics, a silence duration (e.g., the duration of silence interval <NUM>), a switch duration, and a length of time between the switch detection and the start of silence interval <NUM> to determine whether to schedule the antenna switch during silence interval <NUM>. Although t2 is depicted as occurring after t1, UE <NUM> may detect a switch condition at the same time as detecting voice silence or before detecting voice silence. In one aspect, UE <NUM> may detect a switch condition before detecting voice silence and may wait for a selected time period to detect voice silence. If voice silence is not detected within the selected time period, UE <NUM> may begin the antenna switch. If voice silence is detected within the selected time period, UE <NUM> may determine to schedule the antenna switch to occur during silence interval <NUM>.

As depicted in <FIG>, UE <NUM> determines to schedule the antenna switch to occur during silence interval <NUM>. UE <NUM> begins to switch from a first antenna to a second antenna at t5 and ends the switch at t6 before the communication of the next SID packet 810b at t7. Although t5 is depicted in <FIG> as occurring after t4 (the end of SID packet 810a), t5 may coincide with t4. That is, UE <NUM> may begin the antenna switch immediately after communication of SID packet 810a.

<FIG> shows a block diagram <NUM> of a wireless device <NUM> that supports antenna switch scheduling in a multi-antenna UE in accordance with aspects of the present disclosure. Wireless device <NUM> may be an example of aspects of a user equipment (UE) <NUM> as described herein. Wireless device <NUM> may include receiver <NUM>, UE communications manager <NUM>, and transmitter <NUM>. Wireless device <NUM> may also include a processor. Each of these components may be in communication with or coupled to one another (e.g., via one or more buses).

Receiver <NUM> may receive information such as packets, user data, or control information associated with various information channels (e.g., control channels, data channels, etc.). Information may be passed on to other components of the device. The receiver <NUM> may utilize a single antenna or a set of antennas. Receiver <NUM> may be an example of aspects of components described with reference to <FIG> and <FIG> and the transceiver <NUM> described with reference to <FIG>.

UE communications manager <NUM> and/or at least some of its various sub-components may be implemented in hardware, software executed by a processor, firmware, or any combination thereof. If implemented in software executed by a processor, the functions of the UE communications manager <NUM> and/or at least some of its various sub-components may be executed by a general-purpose processor, a digital signal processor (DSP), an application-specific integrated circuit (ASIC), an field-programmable gate array (FPGA) or other programmable logic device, discrete gate or transistor logic, discrete hardware components, or any combination thereof designed to perform the functions described in the present disclosure. UE communications manager <NUM> and/or at least some of its various sub-components may be physically located at various positions, including being distributed such that portions of functions are implemented at different physical locations by one or more physical devices. In some aspects, UE communications manager <NUM> and/or at least some of its various sub-components may be a separate and distinct component in accordance with various aspects of the present disclosure. In other aspects, UE communications manager <NUM> and/or at least some of its various sub-components may be combined with one or more other hardware components, including but not limited to an I/O component, a transceiver, a network server, another computing device, one or more other components described in the present disclosure, or a combination thereof in accordance with various aspects of the present disclosure. UE communications manager <NUM> may be an example of aspects of the UE communications manager <NUM> described with reference to <FIG>, processor <NUM> described with reference to <FIG>, and/or processor <NUM> described with reference to <FIG>.

UE communications manager <NUM> may determine whether to switch from a first antenna to a second antenna to communicate (e.g., transmit and/or receive) with a base station, determine whether a silence window will occur, determine whether to wait for the silence window to perform the antenna switch, and perform the antenna switch as described herein.

In some aspects, transmitter <NUM> may be collocated with receiver <NUM> in a transceiver module. Transmitter <NUM> may be an example of aspects of the components described with reference to <FIG> and <FIG> and the transceiver <NUM> described with reference to <FIG>. Transmitter <NUM> may utilize a single antenna or a set of antennas.

<FIG> shows a diagram of a system <NUM> including a device <NUM> that supports antenna switch scheduling in a multi-antenna UE in accordance with aspects of the present disclosure. Device <NUM> may be an example of or include the components of wireless device <NUM>, or a UE <NUM> as described herein. Device <NUM> may include components for bi-directional voice and data communications including components for transmitting and receiving communications, including UE communications manager <NUM>, processor <NUM>, memory <NUM>, software <NUM>, transceiver <NUM>, antenna <NUM>, and I/O controller <NUM>. These components may be in electronic communication or coupled to each other via one or more buses (e.g., bus <NUM>). Device <NUM> may communicate wirelessly with one or more base stations <NUM>.

Processor <NUM> may include an intelligent hardware device, (e.g., a general-purpose processor, a DSP, a central processing unit (CPU), a microcontroller, an ASIC, an FPGA, a programmable logic device, a discrete gate or transistor logic component, a discrete hardware component, or any combination thereof). In some cases, processor <NUM> may be configured to operate a memory array using a memory controller. In other cases, a memory controller may be integrated into processor <NUM>. Processor <NUM> may be configured to execute computer-readable instructions stored in a memory to perform various functions (e.g., functions or tasks supporting antenna switch scheduling in a multi-antenna UE).

Memory <NUM> may store computer-readable, computer-executable software <NUM> including instructions that, when executed, cause the processor to perform various functions described herein. In some cases, memory <NUM> may contain, among other things, a basic input/output system (BIOS) which may control basic hardware or software operation such as the interaction with peripheral components or devices.

Software <NUM> may include code to implement aspects of the present disclosure, including code to support antenna switch scheduling in a multi-antenna UE. Software <NUM> may be stored in a non-transitory computer-readable medium such as system memory or other memory. In some cases, software <NUM> may not be directly executable by the processor but may cause a computer (e.g., when compiled and executed) to perform functions described herein.

In an aspect, transceiver <NUM> may represent a wireless transceiver and may communicate bi-directionally with another wireless transceiver. Transceiver <NUM> may also include a modem to modulate the packets and provide the modulated packets to the antennas for transmission, and to demodulate packets from signals received from the antennas.

Device may have more than one antenna <NUM>, which may be capable of concurrently transmitting or receiving multiple wireless transmissions. <FIG> and <FIG> include examples of some of the components or parts that may be included in transceiver <NUM>.

<FIG> shows a flowchart illustrating a method <NUM> for antenna switch scheduling in a multi-antenna UE in accordance with aspects of the present disclosure. The operations of method <NUM> may be implemented by a UE <NUM> or its components as described herein. In an aspect, the operations of method <NUM> may be performed by a UE communications manager as described with reference to <FIG> and <FIG> and/or a processor described with reference to <FIG> and <FIG>. In some aspects, a UE <NUM> may execute a set of codes to control the functional elements of the device to perform the functions described below. Additionally or alternatively, the UE <NUM> may perform aspects of the functions described below using special-purpose hardware.

At block <NUM>, UE <NUM> communiates (e.g., transmit and/or receive signals) with a base station <NUM> using a first antenna. The operations of block <NUM> may be performed according to the methods described herein. In certain examples, aspects of the operations of block <NUM> may be performed by a transceiver, receiver, transmitter, processor, and/or UE communications manager as described herein.

At block <NUM>, UE <NUM> determines to switch from the first antenna to a second antenna for communicating with the base station <NUM>. The operations of block <NUM> may be performed according to the methods described herein. In certain examples, aspects of the operations of block <NUM> may be performed by a UE communications manager and/or a processor as described herein.

At block <NUM>, UE <NUM> determines whether a silence window will occur in which communication with base station <NUM> is suspended. The operations of block <NUM> may be performed according to the methods described herein. In certain examples, aspects of the operations of block <NUM> may be performed by a UE communications manager and/or a processor as described herein.

At block <NUM>, UE <NUM> schedules the switch from the first antenna to the second antenna to occur during the silence window. The operations of block <NUM> may be performed according to the methods described herein. In certain examples, aspects of the operations of block <NUM> may be performed by a UE communications manager and/or a processor as described herein. In one aspect, the operations of block <NUM> may be performed according to the method <NUM> described with reference to <FIG>.

At block <NUM>, UE <NUM> switches from the first antenna to the second antenna during the silence window. The operations of block <NUM> may be performed according to the methods described herein. In certain examples, aspects of the operations of block <NUM> may be performed by a UE communications manager, a processor, a transceiver, a receiver, and/or a transmitter as described herein.

<FIG> shows a flowchart illustrating a method <NUM> for scheduling an antenna switch in a multi-antenna UE in accordance with aspects of the present disclosure. The operations of method <NUM> may be implemented by a UE <NUM> or its components as described herein. In an aspect, the operations of method <NUM> may be performed by a UE communications manager or a processor of a UE <NUM> as described herein. In some aspects, UE <NUM> may execute a set of codes to control the functional elements of the device to perform the functions described below. Additionally or alternatively, UE <NUM> may perform aspects of the functions described below using special-purpose hardware.

At block <NUM>, UE <NUM> determines whether communication metrics associated with its multiple antennas exceed a first threshold that would trigger ASDIV switching. The operations of block <NUM> may be performed according to the methods described herein. Aspects of communication metrics (e.g., RSRPDelta, MPTL) and thresholds (e.g., 3dB) are described above. In certain examples, aspects of the operations of block <NUM> may be performed by a UE communications manager and/or a processor as described herein.

If the communication metrics do not exceed the first threshold at block <NUM>, UE <NUM> ends method <NUM> at block <NUM>. UE <NUM> may repeat method on a periodic basis, such as every <NUM>. If the communication metrics meet or exceed the first threshold at block <NUM>, UE <NUM> compares the communication metrics to a second threshold that is greater than the first threshold at block <NUM>. In certain examples, aspects of the operations of block <NUM> may be performed by a UE communications manager and/or a processor as described herein.

If the communication metrics meet or exceed the second threshold at block <NUM>, UE <NUM> begins the antenna switch, at block <NUM>, without waiting for a silence window. Meeting or exceeding the second threshold may indicate that UE <NUM> may lose connection with base station <NUM> if UE <NUM> waits for a silence window to execute the antenna switch. In certain examples, aspects of the operations of block <NUM> may be performed by a UE communications manager, a processor, a transceiver, a receiver, and/or a transmitter as described herein.

If the communication metrics do not meet or exceed the second threshold at block <NUM>, UE <NUM> compares the amount of time until a silence window occurs to a time threshold and compares the duration or length of time of the silence window (e.g., a silence duration) to the duration or length of time of the antenna switch (e.g., a switch duration) at block <NUM>. The operations of block <NUM> may be performed according to the methods described herein. In certain examples, aspects of the operations of block <NUM> may be performed by a UE communications manager and/or a processor as described herein.

If the amount of time until the silence window meets or exceeds the time threshold or the duration of the silence window is less than the duration of the antenna switch at block <NUM>, UE <NUM> begins the antenna switch, at block <NUM>, without waiting for the silence window. If the amount of time until the silence window is less than the time threshold and the duration of the silence window is greater than or equal to the duration of the antenna switch, UE <NUM> waits for the silence window to switch antennas at block <NUM>. The operations of block <NUM> may be performed according to the methods described herein. In certain examples, aspects of the operations of block <NUM> may be performed by a UE communications manager and/or a processor as described herein.

At block <NUM>, UE <NUM> switches from the first antenna to the second antenna during the silence window. In certain examples, aspects of the operations of block <NUM> may be performed by a UE communications manager, a processor, a transceiver, a receiver, and/or a transmitter as described herein.

Small cells may include pico cells, femto cells, and micro cells according to various aspects.

Other aspects and implementations are within the scope of the disclosure and appended claims.

In some instances, well-known structures and devices are shown in block diagram form in order to avoid obscuring the concepts of the described aspects.

Claim 1:
A method for wireless communication in a multi-antenna user equipment, UE (<NUM>), comprising:
communicating (<NUM>) with a base station using a first antenna;
assessing communication metrics to determine whether to switch from the first antenna to a second antenna;
determining (<NUM>) to switch from the first antenna to the second antenna for communicating with the base station, wherein the determining to switch from the first antenna to the second antenna comprises comparing the communication metrics to a first threshold to determine whether to switch from the first antenna to the second antenna;
determining (<NUM>) a silence window (<NUM>) in which communication with the base station is suspended, wherein the silence window (<NUM>) corresponds to a measurement gap;
comparing the communication metrics to a second threshold to determine whether to wait for the silence window (<NUM>) to perform the switch or to perform the switch before the silence window (<NUM>);
determining a length of time between the determining to switch from the first antenna to the second antenna and a start of the silence window;
comparing the length of time to a threshold time;
scheduling (<NUM>) the switch from the first antenna to the second antenna to occur during the silence window (<NUM>) based at least in part on the comparing of the communication metrics to the second threshold and based at least in part on the length of time being less than the threshold time; and
switching (<NUM>) from the first antenna to the second antenna during the silence window (<NUM>).