Antenna port compatibility signaling

Methods, systems, and devices for wireless communication are described. A user equipment (UE) capable of supporting multiple antenna ports may determine that some combinations of antenna ports can be used simultaneously. The UE may make this determination by evaluating the relationships between the physical antennas and the transmit chains included in the UE. Upon determining that the combinations of antenna ports can be used simultaneously, the UE may send a message to a base station. The message may indicate whether two or more antenna ports can be used at the same time. The UE may communicate simultaneously over one or more antenna ports based on the scheduling information from the base station which takes into account the ability of the combination of antenna ports to be used concurrently.

BACKGROUND

The present Application for patent claims priority to Greek Provisional Patent Application No. 20170100272 by Sundararajan et al., entitled “Antenna Port Compatibility Signaling,” filed Jun. 16, 2017, assigned to the assignee hereof, and expressly incorporated by reference in its entirety.

The following relates generally to wireless communication, and more specifically to antenna port compatibility signaling.

In some cases, a UE may include multiple antenna ports that the UE can use simultaneously to increase communication performance. However, not all combinations of the UE's antenna ports may support simultaneous transmission or reception. For example, a pair of antenna ports may be configured so that simultaneous transmission or reception is not possible. Scheduling of uplink or downlink transmissions by a base station for unsupported combinations of antenna ports may impair reception of the downlink or uplink transmissions.

SUMMARY

The described techniques relate to improved methods, systems, devices, or apparatuses that support antenna port compatibility signaling. A user equipment (UE) with multiple antenna ports may determine which of the antenna ports can be used concurrently and which cannot. For example, the UE may determine that a first combination of antenna ports can be used concurrently but that another combination of antenna ports cannot be used concurrently. The antenna ports that cannot be used concurrently may be constrained by the number of transmit chains available or by the connection of the transmit chains to the physical antennas associated with the antenna ports. After determining the combinations of antenna ports that can and cannot be used concurrently, the UE may convey this information to a base station responsible for scheduling the UE. In some cases, the UE may report a delay constraint for the combinations of antenna ports that cannot be used concurrently. This delay constraint may indicate how long the UE must wait in between using different antenna ports in a combination that does not support concurrent use. The base station may leverage the information from the UE to schedule communications with the UE. For example, the base station may schedule the UE in a manner that takes advantage of the antenna ports that can be used concurrently. The base station may avoid scheduling communications with the UE that require concurrent use of antenna ports that have been reported as incompatible for concurrent use.

A method of wireless communication at a user equipment (UE) having a plurality of antenna ports is described. The method may include identifying a compatibility of at least one antenna port combination of the plurality of antenna ports for coincident use by the UE, transmitting a message to a base station indicating whether two or more antenna ports are available for coincident use based at least in part on the identified compatibility, and communicating with the base station via at least one of the plurality of antenna ports. The at least one of the plurality of antenna ports may be selected based at least in part on the identified compatibility.

An apparatus for wireless communication at a user equipment (UE) having a plurality of antenna ports is described. The apparatus may include means for identifying a compatibility of at least one antenna port combination of the plurality of antenna ports for coincident use by the UE, means for transmitting a message to a base station indicating whether two or more antenna ports are available for coincident use based at least in part on the identified compatibility, and means for communicating with the base station via at least one of the plurality of antenna ports. The at least one of the plurality of antenna ports may be selected based at least in part on the identified compatibility.

Another apparatus for wireless communication at a user equipment (UE) having a plurality of antenna ports is described. The apparatus may include a processor, memory in electronic communication with the processor, and instructions stored in the memory. The instructions may be operable to cause the processor to identify a compatibility of at least one antenna port combination of the plurality of antenna ports for coincident use by the UE, transmit a message to a base station indicating whether two or more antenna ports are available for coincident use based at least in part on the identified compatibility, and communicate with the base station via at least one of the plurality of antenna ports. The at least one of the plurality of antenna ports may be selected based at least in part on the identified compatibility.

A non-transitory computer readable medium for wireless communication at a user equipment (UE) having a plurality of antenna ports is described. The non-transitory computer-readable medium may include instructions operable to cause a processor to identify a compatibility of at least one antenna port combination of the plurality of antenna ports for coincident use by the UE, transmit a message to a base station indicating whether two or more antenna ports are available for coincident use based at least in part on the identified compatibility, and communicate with the base station via at least one of the plurality of antenna ports. The at least one of the plurality of antenna ports may be selected based at least in part on the identified compatibility.

Some examples of the method, apparatus, and non-transitory computer-readable medium described above may further include processes, features, means, or instructions for determining a delay constraint between using antenna ports in the at least one antenna port combination. Some examples of the method, apparatus, and non-transitory computer-readable medium described above may further include processes, features, means, or instructions for transmitting an indication of the delay constraint in the message to the base station.

In some examples of the method, apparatus, and non-transitory computer-readable medium described above, the message indicates a plurality of antenna port combinations and corresponding delay constraints between using antenna ports for each of the plurality of antenna ports combinations. The delay constraint may indicate a duration of time between using antenna ports in the corresponding antenna port combination. In some examples of the method, apparatus, and non-transitory computer-readable medium described above, a zero delay indicates that the at least one antenna port combination is compatible for concurrent use and a non-zero delay indicates that the at least one antenna port combination comprises an antenna port that supports use after expiry of the delay from use of another antenna port of the at least one antenna port combination.

Some examples of the method, apparatus, and non-transitory computer-readable medium described above may further include processes, features, means, or instructions for receiving a scheduling message from the base station indicating an uplink precoder for the at least one of the plurality of antenna ports for communicating with the base station. Some examples of the method, apparatus, and non-transitory computer-readable medium described above may further include processes, features, means, or instructions for applying the uplink precoder to the at least one of the plurality of antenna ports.

Some examples of the method, apparatus, and non-transitory computer-readable medium described above may further include processes, features, means, or instructions for receiving a scheduling message from the base station indicating the at least one of the plurality of antenna ports. Some examples of the method, apparatus, and non-transitory computer-readable medium described above may further include processes, features, means, or instructions for receiving a downlink transmission over the at least one of the plurality of antenna ports. Some examples of the method, apparatus, and non-transitory computer-readable medium described above may further include processes, features, means, or instructions for detecting that the at least one antenna port combination comprises antenna ports that share a transmit chain, wherein identifying the compatibility comprises determining that the at least one antenna port combination is incompatible for coincident use based on the detection.

Some examples of the method, apparatus, and non-transitory computer-readable medium described above may further include processes, features, means, or instructions for detecting that the at least one antenna port combination comprises antenna ports with independent transmit chains. In some examples, identifying the compatibility comprises determining that the at least one antenna port combination is compatible for coincident use based on the detection. Some examples of the method, apparatus, and non-transitory computer-readable medium described above may further include processes, features, means, or instructions for determining a ratio of transmit chains to physical antennas for the at least one antenna port combination, wherein the identifying is based on the ratio.

Some examples of the method, apparatus, and non-transitory computer-readable medium described above may further include processes, features, means, or instructions for detecting that a first antenna port and a second antenna port of the at least one antenna port combination share a physical antenna. In some examples, identifying the compatibility comprises determining that the at least one antenna port combination is compatible for coincident use based on the detection.

Some examples of the method, apparatus, and non-transitory computer-readable medium described above may further include processes, features, means, or instructions for detecting that a first antenna port and a second antenna port of the at least one antenna port combination do not share a physical antenna. In some examples, identifying the compatibility comprises determining that the at least one antenna port combination is incompatible for coincident use based on the detection.

Some examples of the method, apparatus, and non-transitory computer-readable medium described above may further include processes, features, means, or instructions for detecting that a number of physical antennas associated with the at least one antenna port combination are co-located on an antenna panel. In such examples, identifying the compatibility is based on the detection.

In some examples of the method, apparatus, and non-transitory computer-readable medium described above, the message comprises a compatible port set indicating that two or more antenna ports are available for concurrent use. In some examples of the method, apparatus, and non-transitory computer-readable medium described above, the compatibility of compatible port set is indicated via a bit-map or matrix.

In some examples of the method, apparatus, and non-transitory computer-readable medium described above, the message comprises an incompatible port set indicating that the at least one antenna port combination is incompatible for concurrent use. In some examples of the method, apparatus, and non-transitory computer-readable medium described above, the message comprises a compatible port set indicating a first set of antenna port combinations that are compatible for concurrent use and an incompatible port set indicating a second set of antenna port combinations that are incompatible for concurrent use.

In some examples of the method, apparatus, and non-transitory computer-readable medium described above, the message may include an indication of a number of antenna ports available for coincident use.

DETAILED DESCRIPTION

Some wireless communications may involve a user equipment (UE) using multiple antenna ports concurrently. For example, in New Radio (NR), a UE may use multiple antenna ports (e.g., uplink transmission ports) concurrently to send multiple precoded sounding reference signals (SRS) on the same symbol. Or the UE may use multiple antenna ports at once when communicating over multiple layers (e.g., rank>1) using multiple-input-multiple-output (MIMO) techniques. In some cases, a UE's implementation or design may constrain which antenna ports can be used at the same time, if any, and thus whether any two or more antenna ports may be available for coincident use. For example, some antenna ports may not be used together if they share a transmit chain. Also, some combinations of antenna ports may not support concurrent use if the number of transmit chains is greater than the number of physical antennas associated with the antenna ports. For a combination of antenna ports that cannot be used concurrently, there may be constraints on the time needed between using the antenna ports in the combination. For example, in a two-port combination, there may be a delay in between using the first port and using the second port.

If a base station scheduling a UE is unaware that the UE is subject to such constraints, the base station may attempt to schedule the UE in a manner that cannot be implemented by the UE. For example, the base station may schedule the UE to communicate concurrently over a combination of antenna ports that do not support concurrent use. Additionally or alternatively, the base station may schedule the UE in a manner that fails to take advantage of the UE's ability to communicate over some antenna ports concurrently. For example, the base station may schedule (e.g., in a reference signal configuration message) the UE to transmit multiple SRS across several different transmit time intervals (TTIs), rather than in the same TTI. Thus, a base station's lack of knowledge of the UE's capabilities may impair communications and reduce efficiency.

According to the techniques described herein, a UE may determine which combinations of its antenna ports are compatible for concurrent use and which are not. The UE may send this information to a serving base station. For example, the UE may send a message that indicates a) the antenna port combinations that are compatible for concurrent use and/or b) the antenna port combinations that are incompatible for concurrent use. In some examples, the message may indicate a threshold number, where any combination up to the threshold number of antenna ports is compatible for concurrent use but any combination with more than the threshold number of antenna ports is not compatible for concurrent use. In some cases, the UE may also convey the delay constraint value for each combination of antenna ports that is incompatible for concurrent use. However, the UE may refrain from sending extraneous information to the serving base station, such as the implementation details which caused the constraints to arise. For example, the UE may refrain from sending the base station indications of the antenna-to-port mapping used by the UE or the number of transmit chains available at the UE.

Based on the information from the UE, the base station may incorporate the constraints of the UE into its scheduling decisions. For example, the base station may select a precoder for the UE that allows the UE to simultaneously use a combination of antenna ports that are compatible for concurrent use. In another example, the base station may avoid selecting a precoder for the UE that requires the UE to simultaneously use a combination of antenna ports that are incompatible for concurrent use. The base station may make these selections without knowing the implementation details associated with the UE's constraints.

FIG. 1illustrates an example of a wireless communications system100in accordance with various aspects of the present disclosure. The wireless communications system100includes base stations105, UEs115, and a core network130. In some examples, the wireless communications system100may be a Long Term Evolution (LTE), LTE-Advanced (LTE-A) network, or a New Radio (NR) network. In some cases, wireless communications system100may support enhanced broadband communications, ultra-reliable (i.e., mission critical) communications, low latency communications, and communications with low-cost and low-complexity devices. A UE115may be capable of communicating using multiple antenna ports, but not all combinations of antenna ports may be support simultaneous use. A UE115may determine which antenna port combinations are compatible for concurrent use and indicate these combinations to a base station105. The base station105may take the compatibly of the antenna ports into account when scheduling communications with the UE115.

Base stations105may wirelessly communicate with UEs115via one or more base station antennas. Each base station105may provide communication coverage for a respective geographic coverage area110. Communication links125shown in wireless communications system100may include uplink transmissions from a UE115to a base station105, or downlink transmissions, from a base station105to a UE115. Control information and data may be multiplexed on an uplink channel or downlink according to various techniques. Control information and data may be multiplexed on a downlink channel, for example, using time division multiplexing (TDM) techniques, frequency division multiplexing (FDM) techniques, or hybrid TDM-FDM techniques. In some examples, the control information transmitted during a transmission time interval (TTI) of a downlink channel may be distributed between different control regions in a cascaded manner (e.g., between a common control region and one or more UE-specific control regions).

UEs115may include a communication manager, which may facilitate antenna port compatibility signaling. A UE115may include multiple antenna ports (e.g., uplink transmission ports and downlink transmission ports) associated with a number of physical antennas. Although some combinations of the antenna ports may be used concurrently, the implementation or design of a UE115may prevent other combinations of antenna ports from being used concurrently. For example, the number of transmit chains, or their connection to the UE's physical antennas, may limit which combinations of antenna ports can be used concurrently.

If a base station105is unaware of a UE's analog beamforming constraints, the base station105may inefficiently schedule the UE115for communications, or schedule the UE115for communications that the UE115does not support. In an example of inefficient scheduling, the base station105may schedule the UE115(e.g., in a reference signal configuration message) to send multiple sounding reference signals (SRS) over a corresponding number of symbols when the UE115could have sent the SRS over a single symbol by using multiple antenna ports at once. In an example of unsupported scheduling, the base station105may schedule the UE115to send multiple SRS concurrently over a combination of antenna ports that are not compatible with concurrent use (e.g., the base station105may direct the UE115to use a precoder that the UE115does not support).

According to the techniques described herein, a UE115may identify the compatibility of multiple combinations of antenna ports for coincident use. As used herein, coincident use refers to concurrent use and/or use within a given delay threshold. A combination of antenna ports may be compatible for coincident use if the antenna ports in the combination can be used concurrently or proximately (e.g., one at a time after a delay has elapsed in between use). Additionally or alternatively, the UE115may identify which combinations of antenna ports are incompatible for concurrent or coincident use. The UE115may report the compatibility of the antenna port combinations to a base station105. However, the UE115may not report the implementation details of the UE's transmit chains and physical antennas to the base station105. Thus, overhead signaling may be reduced and the implementation details of the transmit chains and physical antennas may be transparent to the base station105. Using the compatibility information from the UE115, the base station105may schedule communications with the UE115that avoid improper use of incompatible antenna port combinations but take advantage of compatible antenna port combinations.

Wireless communications system100may operate in an ultra-high frequency (UHF) frequency region using frequency bands from 700 MHz to 2600 MHz (2.6 GHz), although some networks (e.g., a wireless local area network (WLAN)) may use frequencies as high as 4 GHz. This region may also be known as the decimeter band, since the wavelengths range from approximately one decimeter to one meter in length. UHF waves may propagate mainly by line of sight, and may be blocked by buildings and environmental features. However, the waves may penetrate walls sufficiently to provide service to UEs115located indoors. Transmission of UHF waves is characterized by smaller antennas and shorter range (e.g., less than 100 km) compared to transmission using the smaller frequencies (and longer waves) of the high frequency (HF) or very high frequency (VHF) portion of the spectrum.

In some cases, wireless communications system100may also utilize extremely high frequency (EHF) portions of the spectrum (e.g., from 30 GHz to 300 GHz). This region may also be known as the millimeter band, since the wavelengths range from approximately one millimeter to one centimeter in length. Thus, EHF antennas may be even smaller and more closely spaced than UHF antennas. In some cases, this may facilitate use of antenna arrays within a UE115(e.g., for directional beamforming). However, EHF transmissions may be subject to even greater atmospheric attenuation and shorter range than UHF transmissions.

Thus, wireless communications system100may support millimeter wave (mmW) communications between UEs115and base stations105. Devices operating in mmW or EHF bands may have multiple physical antennas to allow beamforming. That is, a base station105may use multiple antennas or antenna arrays to conduct beamforming operations for directional communications with a UE115. Beamforming (which may also be referred to as spatial filtering or directional transmission) is a signal processing technique that may be used at a transmitter (e.g., a base station105) to shape and/or steer an overall antenna beam in the direction of a target receiver (e.g., a UE115). This may be achieved by combining elements in an antenna array in such a way that transmitted signals at particular angles experience constructive interference while others experience destructive interference.

Multiple-input multiple-output (MIMO) wireless systems use a transmission scheme between a transmitter (e.g., a base station105) and a receiver (e.g., a UE115), where both transmitter and receiver are equipped with multiple antennas. Some portions of wireless communications system100may use beamforming. For example, base station105may have an antenna array with a number of rows and columns of antenna ports that the base station105may use for beamforming in its communication with UE115. Signals may be transmitted multiple times in different directions (e.g., each transmission may be beamformed differently). A mmW receiver (e.g., a UE115) may try multiple beams (e.g., antenna subarrays) while receiving the synchronization signals.

In some cases, the physical antennas of a base station105or UE115may be located within one or more antenna arrays, which may support beamforming or MIMO operation. One or more base station antennas or antenna arrays may be collocated at an antenna assembly, such as an antenna tower. In some cases, antennas or antenna arrays associated with a base station105may be located in diverse geographic locations. A base station105may multiple use antennas or antenna arrays to conduct beamforming operations for directional communications with a UE115.

Time intervals in LTE or NR may be expressed in multiples of a basic time unit (which may be a sampling period of Ts=1/30,720,000 seconds). Time resources may be organized according to radio frames of length of 10 ms (Tf=307200 Ts), which may be identified by a system frame number (SFN) ranging from 0 to 1023. Each frame may include ten 1 ms subframes numbered from 0 to 9. A subframe may be further divided into two 0.5 ms slots, each of which contains 6 or 7 modulation symbol periods (depending on the length of the cyclic prefix prepended to each symbol). Excluding the cyclic prefix, each symbol contains 2048 sample periods. In some cases the subframe may be the smallest scheduling unit, also known as a TTI. In other cases, a TTI may be shorter than a subframe or may be dynamically selected (e.g., in short TTI bursts or in selected component carriers using short TTIs).

A resource element may consist of one symbol period and one subcarrier (e.g., a 15 KHz frequency range). A resource block may contain 12 consecutive subcarriers in the frequency domain and, for a normal cyclic prefix in each OFDM symbol, 7 consecutive OFDM symbols in the time domain (1slot), or84resource elements. The number of bits carried by each resource element may depend on the modulation scheme (the configuration of symbols that may be selected during each symbol period). Thus, the more resource blocks that a UE receives and the higher the modulation scheme, the higher the data rate may be.

In some cases, wireless communications system100may utilize enhanced component carriers (eCCs). An eCC may be characterized by one or more features including: wider bandwidth, shorter symbol duration, shorter TTIs, and modified control channel configuration. In some cases, an eCC may be associated with a carrier aggregation configuration or a dual connectivity configuration (e.g., when multiple serving cells have a suboptimal or non-ideal backhaul link). An eCC may also be configured for use in unlicensed spectrum or shared spectrum (where more than one operator is allowed to use the spectrum). An eCC characterized by wide bandwidth may include one or more segments that may be utilized by UEs115that are not capable of monitoring the whole bandwidth or prefer to use a limited bandwidth (e.g., to conserve power).

In some cases, an eCC may utilize a different symbol duration than other CCs, which may include use of a reduced symbol duration as compared with symbol durations of the other CCs. A shorter symbol duration is associated with increased subcarrier spacing. A device, such as a UE115or base station105, utilizing eCCs may transmit wideband signals (e.g., 20, 40, 60, 80 MHz, etc.) at reduced symbol durations (e.g., 16.67 microseconds). A TTI in eCC may consist of one or multiple symbols. In some cases, the TTI duration (that is, the number of symbols in a TTI) may be variable.

A shared radio frequency spectrum band may be utilized in an NR shared spectrum system. For example, an NR shared spectrum may utilize any combination of licensed, shared, and unlicensed spectrums, among others. The flexibility of eCC symbol duration and subcarrier spacing may allow for the use of eCC across multiple spectrums. In some examples, 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.

FIG. 2illustrates an example of a wireless communications system200for antenna port compatibility signaling in accordance with various aspects of the present disclosure. Wireless communications system200includes base station105-aand UE115-a, which may be examples of the corresponding devices described with reference toFIG. 1. Base station105-amay communicate with wireless devices inside coverage area110-a; for example, base station105-amay communicate with UE115-aover a wireless channel via a communication link. Base station105-aand UE115-amay be capable of communicating over multiple antenna ports simultaneously. According to the techniques described herein, UE115-amay inform base station105-aof the antenna ports that support simultaneous communication and/or of those that do not.

Base station105-amay include multiple antennas205(e.g., n antennas). For example, base station105-amay include antenna205-a, antenna205-b, and antenna205-c. UE115-amay also include multiple antennas210. For example, UE115-amay include antenna210-a,210-b, and210-c. Each antenna may be coupled with processing circuitry, which may include one or more transmit chains and/or one or more receive chains. Although shown with the same number of antennas, base station105-aand UE115-amay include different numbers of antennas. In some cases, an antenna may be associated with multiple transmit or receive chains, or multiple antennas may share a transmit or receive chain. UE115-amay define multiple antenna ports, which may be mapped to precoders that are associated with multiple physical antennas210.

In some cases, UE115-amay employ MIMO techniques in which UE115-auses multiple antenna ports to receive communications from base station105-a, which also uses multiple antenna ports to transmit. MIMO may use a technique called spatial division multiplexing that takes advantage of the multiple transmit and receive chains to send multiple streams of data simultaneously on the same wireless channel, thereby increasing data rate and overall throughput. In some cases, base station105-aand/or UE115-amay use beamforming to send a MIMO transmission. For example, base station105-amay send a beamformed transmission215to UE115-a. Prior to sending a beamformed transmission over a channel, base station105-amay gather information about the channel. Base station105-a(as beamformer) may use the information to determine a beamforming steering matrix that is used to direct transmissions towards the UE as the target device(s). The transmissions may be directed by applying weights to antennas within an antenna array (e.g., as defined by the beamforming matrix) so that constructive and destructive interference focuses the energy of the transmission in a particular direction.

In some cases, an application may call for multiple antenna ports (e.g., multiple uplink transmission ports) to be used at once. For example, base station105-amay instruct UE115-ato send multiple precoded SRS on the same symbol. Or multiple antenna ports may be used simultaneously to implement uplink MIMO with rank>1 (e.g., multiple layers). But some or all antenna ports may not be configured for simultaneous use. According to the techniques described herein, UE115-amay determine which antenna ports support simultaneous use and send a message that indicates these antenna ports to base station105-a. In some examples, the message may include an indication of a number of antenna ports available for coincident use. For example, the message may include an indication that no antenna ports are available for coincident use, an indication that two antenna ports are available for coincident use, or an indication that some other number of antenna ports are available for coincident use. Based on the antenna port information, base station105-amay assign scheduling resources and precoders to UE115-a. UE115-amay communicate according to the scheduling assignment(s) from base station105-a.

FIG. 3illustrates an example of a transmitter300for use in antenna port compatibility signaling in accordance with various aspects of the present disclosure. Transmitter300may be part of a base station105or UE115, which may be examples of the corresponding devices described with reference toFIG. 1. Transmitter300may be part of a transceiver that includes a receiver with which the transmitter may share a number of physical antennas315. The physical antennas315may be associated with antenna ports, some of which may be constrained from concurrent use due to, e.g., shared processing circuitry such as transmit chains320. A UE115may detect which combinations of antenna ports are prohibited from concurrent use (e.g., incompatible for simultaneous use) and report these combinations to a base station105. Additionally or alternatively, the UE115may detect which antenna port combinations are compatible for concurrent use and report these combinations to the base station105.

Transmitter300may include two pairs of physical antennas315, each of which may share a different transmit chain320. For example, antenna315-aand antenna315-bmay share transmit chain320-aand antenna315-cand antenna315-dmay share transmit chain320-b. Thus, four physical antennas315may be managed using two transmit chains320. A transmit chain320may connect to one physical antenna315at a time via switching circuitry325(e.g., transmit chain320-amay switch between physical antennas315-aand315-band transmit chain320-bmay switch between physical antennas315-cand315-d). Because the transmit chains320are shared, simultaneous use of physical antennas315-aand315-bis not supported and simultaneous use of physical antennas315-cand315-dis not supported. For example, when transmit chain320-ais connected to physical antenna315-a, simultaneous connection to physical antenna315-bis not supported. Although two pairs of two physical antennas315are shown, any number of physical antennas may be included in transmitter300. Similarly, any number of transmit chains320may be used and the relationship between the transmit chains320and the physical antennas may vary.

An antenna port may be defined by coefficients (e.g., complex weights) applied to one or more physical antennas. For example, a port may be defined as [u1 0 u2 0], where ‘u1’ is the complex weight applied to physical antenna315-aand ‘u2’ is the complex weight applied to physical antenna315-c(in this example a complex weight of zero is applied to physical antennas315-band315-d). A transmitter300may apply precoding for a signal to be transmitted via one or more ports via a precoder330. The complex weights for the physical antennas according to the antenna ports may be applied by the transmit chains320or the precoder3330. For example, precoder330may apply a precoder such as [a 0 b 0] to a combination of fours ports (e.g., port 1, port 2, port 3, and port 4), which means that a precoding weight ‘a’ is applied to port 1, a precoding weight ‘b’ is applied to port 3, and no precoding weight is applied to ports 2 and 4. The precoder330and/or the transmit chains320may then apply the complex weights assigned to each physical antenna for the antenna ports. Thus, an antenna port may be mapped to a precoder and may involve more than one physical antenna315. The beamforming and precoding weights may be real or complex and may be selected to facilitate beamforming and/or MIMO communications.

In some cases, the antenna ports that are supported by a transmitter300may be constrained by the configuration of the transmitter300(e.g., sharing the transmit chains320between multiple physical antennas315may preclude some antenna ports from being used concurrently or coincidently). For instance, an antenna port of [u1 u2 0 0] is not supported by the transmitter300because the antenna port requires physical antennas315-aand315-bto be used concurrently, which is not possible given the limitations of transmit chain320-a. Similarly, an antenna port [0 0 u1 u2] may not be supported by the transmitter300because it requires concurrent use of physical antennas315-cand315-d, which cannot be used simultaneously.

The configuration of transmitter300may also impose constraints on which antenna ports are compatible for simultaneous use. For example, antenna port [u1 0 0 0] may be used simultaneously with antenna port [0 0 0 u2] (because the combination involves physical antennas315-aand315-c) but not antenna port [0 u2 0 0] (because the combination involves physical antennas315-aand315-b). Accordingly, precoder [a 0 0 b] may be supported by transmitter300but precoder [a b 0 0] may not be supported by transmitter300(because precoder [a b 0 0] ultimately applies precoding weights ‘a’ and ‘b’ to physical antennas315-aand315-b, which cannot be used simultaneously). Thus, a UE115may determine which antenna ports support simultaneous use by evaluating the connectivity between the associated physical antennas315and transmit chains320. Because a UE115may be constrained from using certain antenna ports at all, or certain combinations of antenna ports concurrently, a UE115may be prevented from arbitrarily applying beamforming or precoding weights to the four physical antennas315.

According to the techniques described herein, a UE115may detect (e.g., by evaluating the hardware configuration of transmitter300) whether certain physical antennas315can be used concurrently, if any, and thus whether two or more antenna ports are available for coincident use. For example, the UE115may detect that the following pairs of physical antennas can be used concurrently:315-aand315-c,315-aand315-d,315-band315-c, and315-band315-d. The UE115may also detect that certain physical antennas315cannot be used concurrently (e.g.,315-aand315-b,315-cand315-d). In some cases, the UE115may indicate to the base station which pairs of physical antennas315are compatible for concurrent use and/or which pairs of physical antennas315are incompatible for concurrent use. The UE115may use the physical antenna information to determine that certain antenna ports are not available for use by the UE115and may report these ports to a base station105. For example, the UE115may send a message to the base station105indicating that port [u1 u2 0 0] and port [0 0 u1 u2] are not supported by the UE115. Additionally or alternatively, the UE115may send a message to the base station105indicating the antenna ports that are supported by the UE115(e.g., antenna ports [u1 0 0 u2], [u1 0 u2 0], [0 u1 u2 0], and [0 u1 0 u2]). A base station may use the antenna port information to identify precoders that are not supported by the UE115(e.g., precoder [a b 0 0]).

The UE115may also detect that certain antenna port combinations do not support concurrent use and may report these combinations to the base station105. For example, the UE115may send a message to the base station105indicating that antenna port combination [u1 0 u2 0] cannot be used concurrently with antenna port combination [0 v1 0 v2]. Additionally or alternatively, the UE115may send a message to the base station105indicating the antenna ports that are compatible for concurrent use. After informing the base station105of the compatibility of antenna port combinations, the UE115may receive scheduling information from the base station105. The scheduling information may include which precoder to use for an uplink transmission. The UE115may apply the precoder to the appropriate ports and simultaneously send signals to the base station105over the physical antennas315corresponding to those ports.

In some cases, a UE115may determine that a combination of antenna ports supports proximate use (e.g., even if they do not support concurrent use). For example, UE115may determine that antenna port [u1 0 u2 0] can be used after antenna port [0 v1 0 v2] if an appropriate duration of time has elapsed in between use. The duration of time may be a delay constraint (e.g., the minimum delay or duration of time required by the UE115between use of the antenna ports) that is based on hardware limitations associated with switching between the two antenna ports. In some examples, the UE115may send a message to the base station105indicating a) the combination of antenna ports that supports proximate use and b) the corresponding delay associated with that combination of antenna ports, where a zero delay may mean that the antenna port combination can be used concurrently. The base station105may take this information into account when making scheduling decisions for the UE115.

FIG. 4illustrates an example of a receiver400for use in antenna port compatibility signaling in accordance with various aspects of the present disclosure. Receiver400may be part of a base station105or UE115, which may be examples of the corresponding devices described with reference toFIG. 1. Receiver400may be part of a transceiver, which may include a transmitter such as transmitter300. Receiver400may include a number of physical antennas315that may be associated with antenna ports, some of which may be constrained from concurrent use due to, e.g., shared processing circuitry such as receive chains320. A UE115may detect which combinations of antenna ports are prohibited from concurrent use (e.g., incompatible for simultaneous use) and report these combinations to a base station105. Additionally or alternatively, the UE115may detect which antenna port combinations are compatible for concurrent use and report these combinations to the base station105.

Receiver400may include physical antenna315-eand physical antenna315-f, which share receive chain405-a, and physical antenna315-gand physical antenna315-h, which share receive chain405-b. The receive chains405may receive signals from the physical antennas315, process aspects of those signals, and pass them on to processing module410for further processing (e.g., decoding, demodulation, etc.). Using switching circuitry415, receive chain405-amay switch between physical antennas315-eand315-fand receive chain405-bmay switch between physical antennas315-gand315-h. Because the receive chains405are shared, simultaneous use of physical antennas315-eand315-fis not supported and simultaneous use of physical antennas315-gand315-his not supported.

A UE115may detect which physical antennas315can be used simultaneously and report this information to a base station105. Additionally or alternatively, the UE115may use this information to determine which antenna ports are supported by receiver400, and of these which can be used concurrently. The UE115may report this antenna port compatibility information to the base station105. For example, the UE115may indicate a set of antenna port combinations that are compatible for concurrent use and thus indicate that two or more antenna ports are available for coincident use. Additionally or alternatively, the UE115may indicate a set of antenna port combinations that are incompatible for concurrent use. In some cases, the UE115may decide which set to send to the base station105based on how many resources each set would consume. For example, the UE115may send the incompatible port set if transmitting the incompatible port set consumes less resources than transmitting the compatible port set. The base station105may schedule communications with the UE115based on the antenna port compatibility information from the UE115.

FIG. 5illustrates an example of UE500for antenna port compatibility signaling in accordance with various aspects of the present disclosure. UE500may be an example of a UE115described with reference toFIG. 1. UE500may include multiple transmit chains320, which may be examples of a transmit chain320described with reference toFIG. 3. UE500also includes physical antenna315-i, physical antenna315-j, physical antenna315-k, and physical antenna315-l. Any transmit chain320can be connected to any one physical antenna315at a time via multiplexor510. Physical antenna315-iand physical antenna315-jmay be co-located on antenna panel505-aand physical antenna315-kand physical antenna315-lmay be co-located on antenna panel505-b. An antenna panel505may include a number of physical antennas315, which may be in close physical proximity. In some instances, the physical antennas315on a panel may share a digital signal input (e.g., via a digital-to-analog converter (DAC)), but may have separate analog beamforming capabilities (independently applied analog beam weights). Thus, an antenna panel505may be used to perform analog beamforming. However, physical antennas315on an antenna panel505may not have independent digital beamforming or have independent precoders applied.

For UE500, four ports may be defined over the four physical antennas315: port 1 (e.g., [u1 u2 0 0]), port 2 (e.g., [0 0 v1 v2]), port 3 (e.g., [0 w1 0 w2]), and port 4 (e.g., [x1 0 x2 0]). Each beamforming weight in a port may correspond to a physical antenna315. In this example, the first beamforming weight corresponds to physical antenna315-i, the second beamforming weight corresponds to physical antenna315-j, the third beamforming weight corresponds to physical antenna315-k, and the fourth beamforming weight corresponds to physical antenna315-l.

While some combinations of the four defined ports may be used concurrently, others may be precluded from simultaneous use due to the ratio of transmit chains320to physical antennas315. This is because a separate transmit chain320must be assigned to a physical antenna315in order to apply a unique beamforming weight to that physical antenna315. Thus, when only one transmit chain320is available, none of the four defined ports are supported by the UE500(because each port uses two physical antennas315). When two transmit chains320are available, such as transmit chain320-cand transmit chain320-d, the four defined antenna ports are supported by the UE500but they can only be used one at a time (e.g., not concurrently), and thus no two or more antennas may be available for coincident use. Put another way, when two of the defined transmit chains320are available, only one antenna port using two physical antennas can be used at a time since each port uses two physical antennas. When three transmit chains320are used, any two of the defined antenna ports that share a physical antenna315can be used concurrently. When four transmit chains320are available, any two of the defined antenna ports can be used concurrently. Thus, a UE500may evaluate the ratio of transmit chains to physical antennas when determining whether antenna port combinations support concurrent use. If the ratio of transmit chains to physical antennas is less than 1, UE500may determine which antenna port combinations support concurrent use by determining whether any of the antenna ports in a combination share a physical antenna.

For example, when three transmit chains320are used (e.g., transmit chain320-c, transmit chain320-d, and transmit chain320-e), port 1 and port 3 can be used concurrently because they share physical antenna315-j. Port 1 and port 4 can be used concurrently because they share physical antenna315-i. Port 2 and port 3 can be used concurrently because they share physical antenna315-l. And port 2 and port 4 can be used concurrently because they share physical antenna315-k. However, port 1 and port 2 cannot be used concurrently and port 3 and port 4 cannot be used concurrently because they do not share a physical antenna315. Thus, UE500may simultaneously use two antenna ports with different precoders as long as the two ports share at least one physical antenna315.

According to the techniques described herein, UE500may determine that the ratio of transmit chains320to physical antennas315prevents simultaneous use of certain antenna ports and report that finding to a base station105. For example, UE500may transmit a message (e.g., an antenna port compatibility message) to the base station105that indicates which of the defined antenna ports can be used concurrently and which cannot be used concurrently. In some cases, the UE500may include a delay constraint with each antenna port combination. The delay constraint may indicate a minimum duration of time for the UE500between use of one of the antenna ports and use of any other antenna port in the antenna port combination.

The base station105that receives the antenna port compatibility message may learn which combinations are compatible for concurrent use and which are not. Based on this information, the base station105may select an uplink precoder to be applied to the antenna ports defined for UE115-b. For example, base station105may select uplink precoder [a 0 b 0], which is supported because antenna port 1 and antenna port 3 are compatible for concurrent use. The base station105may avoid selecting an uplink precoder that requires concurrent use of antenna ports that are incompatible for concurrent use (e.g., the base station105may avoid selecting uplink precoder [a b 0 0], which requires concurrent use of antenna port 1 and antenna port 2).

In some cases, UE500may detect that several physical antennas315are co-located on the same antenna panel505. For example, UE500may detect that physical antenna315-iand physical antenna315-jare both on antenna panel505-a. UE500may also detect that physical antenna315-kand physical antenna315-lare both on antenna panel505-b. Because the physical antennas315on an antenna panel505share the same analog beamforming, the physical antennas315may not support simultaneous transmission or reception of two different analog beams. However, physical antennas315on different antenna panels505may support simultaneous transmission or reception of two different analog beams. Thus, a UE115with only one antenna panel505may not support simultaneous communication using two different analog beams, but a UE115with multiple antenna panels505(e.g., like UE500) may be able to communicate in such a manner (providing the analog beams are sent using physical antennas315that are on different antenna panels505). UE500may determine which antenna port combinations can be used concurrently based on the location of their associated physical antennas and report that information to a base station105. Thus, the UE500may inform the base station105about constraints in analog beamforming capabilities.

In the millimeter wave context, the UE500may send capability information (to the base station105) that applies to specific beams or beam identifiers (IDs) that may or may not be compatible with each other. For example, UE500may sound a channel using two different beams at different times, but depending on the implementation, the UE500may or may not be able to support simultaneous use of both beams during subsequent data transmissions. For instance, if the two beams require the use of two different panels505that share the same transmit chain320or power amplifier, this may restrict the UE500to using only one of the panels505(and hence only one of the beams) at a given time. In this case, the UE500may update the base station105accordingly using a capability indication that specifies a compatible beam ID set or an incompatible beam ID set.

FIG. 6illustrates an example of a process flow600for antenna port compatibility signaling in accordance with various aspects of the present disclosure. Process flow600may include base station105-band UE115-b. UE115-bmay include a number of physical antennas, transmit chains, and receive chains, and may be associated with multiple antenna ports.

At605, UE115-bmay identify combinations of antenna ports for communication with base station105-b. At610, UE115-bmay determine which of the combinations are compatible for coincident use (e.g., concurrent or proximate use). At615, UE115-bmay transmit a compatibility message to base station105-bindicating the compatibility of the various antenna port combinations. In some cases, the compatibility message includes a compatible port set. The compatible port set may indicate which combinations of antenna ports are compatible for concurrent use (e.g., which antenna ports can be used simultaneously) and thus that two or more antenna ports are available for coincident use. Additionally or alternatively, the compatibility message may include an incompatible port set (e.g., the message may include a combination of compatible and incompatible sets). Additionally, the compatibility message may indicate the combinations of antenna ports that are not compatible for concurrent use but that support proximate use. For example, the compatibility message may include a delay constraint value for each combination of antenna ports. The delay constraint value may indicate the duration of time UE115-bmust wait in between using the antenna ports in the combination. In such a scenario, the delay value may be zero for antenna port combinations that support concurrent use and non-zero for antenna port combinations that support proximate use but not concurrent use.

In some cases, the compatibility message may convey the compatibility of the antenna port sets in a bit-map. The bit-map may indicate whether an antenna port belongs to the compatible port set or the incompatible port set. In some examples, UE115-bmay determine how many antenna ports are in each set and transmit an indication of the set with the fewest number of antenna ports. For example, UE115-bmay transmit an indication of whether two or more antenna ports, or some other number of antenna ports are available for concurrent use. In some cases, an indication of whether two or more antenna ports are available for concurrent use may include an indication of a number of antenna ports available for concurrent use (e.g., zero or one, which may mean that only one antenna port may be used at a time and thus that two or more antenna ports are not available for concurrent use, or some other threshold number of antenna ports (e.g., two, four, or six), where any number of antenna ports up to the threshold number of antenna ports are available for concurrent use and thus indicating that two or more antenna ports are available for concurrent use). In such a scenario, UE115-bmay include an indication in the compatibility message that conveys which set (compatible or incompatible) is being sent. In some examples, the compatibility message may convey the set (e.g., the compatible or incompatible set) in the form of a binary compatibility matrix. For example the ith/jth entry of the matrix may indicate whether port i and port j are compatible. Alternatively, a compatibility matrix may use values that indicate the delay constraint between using each antenna port combination, where a zero delay constraint indicates that the combination supports concurrent use and a positive number indicates a delay (e.g., in TTIs, symbols, slots, microseconds, etc.) between use of antenna ports of the combination.

At620, base station105-bmay determine uplink scheduling for UE115-bbased on the compatibility message. For example, base station105-bmay determine which antenna ports are to send SRS simultaneously and which antenna ports are to send SRS after a delay. Additionally or alternatively, base station105-bmay determine an uplink precoder for use by UE115-b. The precoder may be based on the compatibility message and may indicate the precoding weights that UE115-bis to apply to its antenna ports during an uplink transmission. At625, base station105-bmay transmit a scheduling message to UE115-b. The scheduling message may include an indication of antenna ports to be used for concurrent SRS transmissions and/or an indication of antenna ports to be used for SRS transmissions separated in time (e.g., the scheduling message may be a reference signal configuration message). The scheduling message may additionally or alternatively include an indication of the uplink precoder. At630, UE115-bmay receive and process the scheduling message sent from base station105-b. At635, UE115-bmay transmit an uplink transmission to base station105according to the uplink precoder (e.g., UE115-bmay the uplink precoder to an antenna port combination) and/or according to the SRS scheduling information. In some cases, the uplink transmission includes data. In other cases, the uplink transmission includes SRS.

FIG. 7illustrates an example of a process flow700for antenna port compatibility signaling in accordance with various aspects of the present disclosure. Process flow700may include base station105-cand UE115-c. UE115-cmay include a number of physical antennas, transmit chains, and receive chains, and may be associated with multiple antenna ports.

At705, UE115-cmay identify combinations of antenna ports for communication with base station105-c. At710, UE115-cmay determine which of the combinations are compatible for coincident use. At715, UE115-cmay transmit a compatibility message to base station105-cindicating whether two or more antenna ports are available for coincident use based at least in part on the identified compatibility of the various antenna port combinations for coincident use. In some cases, the number of antenna ports available for coincident use (and thus whether antenna ports are available for coincident use) may differ for downlink transmissions versus uplink transmissions at a UE may be different for DL vs. UL. For example, UE115-cmay have a different number of transmit chains than receive chains (e.g., two transmit chains and four receive chains). Accordingly, a compatibility message regarding downlink transmissions (e.g., a compatibility message715) may substantively differ (e.g., may indicate a different number of antenna ports available for coincident use, and thus may differ with respect to indicating whether two or more antenna ports are available for coincident use) from a compatibility message regarding uplink transmissions (e.g., a compatibility message615). At720, base station105-cmay determine downlink scheduling for UE115-c. For example, base station105-cmay determine which antenna ports are to be used to receive a downlink transmission. The downlink scheduling may be based on the compatibility message.

At725, base station105-cmay transmit a scheduling message to UE115-c. The scheduling message may include an indication of antenna ports to be used for a subsequent communication from base station105-c. At730, UE115-cmay receive and process the scheduling message sent from base station105-c. At735, base station105-cmay transmit a downlink transmission to UE115-caccording to the scheduling information. At740, UE115-cmay receive the downlink transmission from base station105-caccording to the scheduling information (e.g., using the antenna ports indicated by the scheduling information).

FIG. 8shows a block diagram800of a wireless device805that supports antenna port capability signaling in accordance with aspects of the present disclosure. Wireless device805may be an example of aspects of a UE115as described herein. Wireless device805may include receiver810, communications manager815, and transmitter820. Wireless device805may also include a processor. Each of these components may be in communication with one another (e.g., via one or more buses).

Receiver810may receive information such as packets, user data, or control information associated with various information channels (e.g., control channels, data channels, and information related to antenna port compatibility signaling, etc.). Receiver810may be an example of a receiver400described with reference toFIG. 4. Receiver810may receive a scheduling message from a base station105. In some examples, the scheduling message may indicate one or more antenna ports for communicating with the base station105. In some examples, the scheduling message may indicate an uplink precoder for one or more antenna ports. Receiver810may also receive a downlink transmission (e.g., over one or more antenna ports, such as those indicated by the scheduling message). Information may be passed on to other components of the device. The receiver810may be an example of aspects of the transceiver1035described with reference toFIG. 10. The receiver810may utilize a single physical antenna or a set of physical antennas as described herein.

Communications manager815may be an example of aspects of the communications manager1015described with reference toFIG. 10. Communications manager815may identify a set of antenna ports associated with the wireless device805for communication with a base station105. The communications manager815may identify the compatibility of antenna port combinations in the set of antenna ports for coincident use by the wireless device805. The communications manager815transmit a message to a base station indicating whether two or more antenna ports are available for coincident use based at least in part on the identified compatibility of the antenna port combinations. The communications manager815may communicate with the base station via one or more of the antenna ports. The antenna port(s) used for communication may be selected based on the identified compatibility.

Transmitter820may transmit signals generated by other components of the device. The transmitter820may be an example of the transmitter300described with reference toFIG. 30. In some examples, the transmitter820may be collocated with a receiver810in a transceiver module. For example, the transmitter820may be an example of aspects of the transceiver1035described with reference toFIG. 10. The transmitter820may utilize a physical single antenna or a set of physical antennas as described herein. In some cases, the transmitter820may receive information from other components of wireless device805. In some examples, the transmitter820may transmit a message to a base station105that indicates the compatibility of one or more antenna port combinations for coincident, concurrent or proximate use.

FIG. 9shows a block diagram900of a wireless device905that supports antenna port compatibility signaling in accordance with aspects of the present disclosure. Wireless device905may be an example of aspects of a UE115or a wireless device805as described with reference toFIG. 8. Wireless device905may include receiver910, communications manager915, and transmitter920. Wireless device905may also include a processor. Each of these components may be in communication with one another (e.g., via one or more buses).

Receiver910may receive information such as packets, user data, or control information associated with various information channels (e.g., control channels, data channels, and information related to antenna port compatibility signaling, etc.). Information may be passed on to other components of the device. The receiver910may be an example of aspects of the transceiver1035described with reference toFIG. 10. The receiver910may utilize a single physical antenna or a set of physical antennas associated with antenna ports.

Communications manager915may be an example of aspects of the communications manager1015described with reference toFIG. 10. Communications manager915may include antenna port administrator925, compatibility identifier930, compatibility signaling coordinator935, uplink/downlink manager940, and hardware monitor945. Each of these modules may communicate, directly or indirectly, with one another (e.g., via one or more buses).

Antenna port administrator925may identify a set of antenna ports associated with the wireless device905. In some cases, antenna port administrator925identify a combination of antenna ports or receive an indication of a combination of antenna ports (e.g., from compatibility identifier930). Antenna port administrator925may determine a delay between using antenna ports in the antenna port combination (e.g., by evaluating the hardware configuration of receiver910or transmitter920). A zero delay may indicate that the antenna port combination is compatible for concurrent use. A non-zero delay may indicate that the antenna port combination includes a first antenna port that supports use after expiry of the delay from use of a second antenna port in the combination.

Compatibility identifier930may identify a compatibility of antenna port combinations for coincident use by the wireless device905. Compatibility identifier930may detect that two antenna ports (e.g., a first antenna port and a second antenna port) in an antenna port combination share a physical antenna. Compatibility identifier930may determine that the antenna port combination is compatible for coincident use based on the detection that the two ports share a physical antenna. In some cases, compatibility identifier930may detect that two antenna ports (e.g., a first antenna port and a second antenna port) in an antenna port combination do not share a physical antenna. In such a scenario, the compatibility identifier930determine that the antenna port combination is incompatible for coincident use based on the detection that the two ports do not share a physical antenna. In some cases, the compatibility identifier930may detect that the antenna port combination includes antenna ports with independent transmit chains. In such cases, the compatibility identifier930may determine that the antenna port combination is compatible for coincident use based on the detection of the independent transmit chains.

Compatibility signaling coordinator935may transmit a message (e.g., to a base station105) indicating whether two or more antenna ports are available for coincident use based at least in part on the identified compatibility of antenna port combinations. In some examples, compatibility signaling coordinator935may transmit an indication of the delay constraint determined by antenna port administrator925in the message. In some cases, the message indicates a set of antenna port combinations and a corresponding delay constraint for each. The delay constraint may indicate a duration of time between using antenna ports in the corresponding antenna port combination. In some cases, the message includes a compatible port set indicating an antenna port combination that is compatible for concurrent use and thus that two or more antenna ports are available for coincident use. In some cases, the message includes an incompatible port set indicating an antenna port combination that is incompatible for concurrent use. In some cases, the message includes a compatible port set indicating a first set of antenna port combinations that are compatible for concurrent use and an incompatible port set indicating a second set of antenna port combinations that are incompatible for concurrent use. In some cases, compatibility signaling coordinator935may convey the compatibility of a set of antenna port combinations in a bit-map or matrix. In some cases, the message may include an indication of a number of antenna ports available for coincident use—e.g., zero (meaning only one antenna port at a time), two, four, or six, or any other number—which may in some cases function as an indication of whether two or more of antenna ports are available for coincident use.

Uplink/downlink manager940may communicate with a base station105via one or more antenna ports. In some cases, the uplink/downlink manager940may select an antenna port for communication based on compatibility the antenna port. In some cases, the uplink/downlink manager940may receive a scheduling message from the base station indicating an uplink precoder a combination of antenna ports. The uplink/downlink manager940may apply the uplink precoder to the combination of antenna ports.

Hardware monitor945may determine a ratio of transmit chains to physical antennas for an antenna port combination. In some cases, the compatibility identifier930may identify compatibility of an antenna port combination based on the ratio. The hardware monitor945may detect that a number of physical antennas associated with an antenna port combination are co-located on an antenna panel. In such cases, the compatibility identifier930may identify compatibility of an antenna port combination based on the detection. In some cases, the hardware monitor945may detect that the antenna ports in an antenna port combination share a transmit chain. In such cases, the compatibility identifier930may determine that the antenna port combination is incompatible for coincident use based on the detection.

Transmitter920may transmit signals generated by other components of the device. In some examples, the transmitter920may be collocated with a receiver910in a transceiver module. For example, the transmitter920may be an example of aspects of the transceiver1035described with reference toFIG. 10. The transmitter920may utilize a single physical antenna or a set of physical antennas.

FIG. 10shows a diagram of a system1000including a device1005that supports antenna port compatibility signaling in accordance with aspects of the present disclosure. Device1005may be an example of or include the components of wireless device805, wireless device905, or a UE115as described above, e.g., with reference toFIGS. 8 and 9. Device1005may include components for bi-directional voice and data communications including components for transmitting and receiving communications, including communications manager1015, processor1020, memory1025, software1030, transceiver1035, antenna1040, and I/O controller1045. These components may be in electronic communication via one or more buses (e.g., bus1010). Device1005may communicate wirelessly with one or more base stations105(e.g., using one or more antenna ports).

Memory1025may include random access memory (RAM) and read only memory (ROM). The memory1025may store computer-readable, computer-executable software1030including instructions that, when executed, cause the processor to perform various functions described herein. In some cases, the memory1025may 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.

I/O controller1045may manage input and output signals for device1005. I/O controller1045may also manage peripherals not integrated into device1005. In some cases, I/O controller1045may represent a physical connection or port to an external peripheral. In some cases, I/O controller1045may utilize an operating system such as iOS®, ANDROID®, MS-DOS®, MS-WINDOWS®, OS/2®, UNIX®, LINUX®, or another known operating system. In other cases, I/O controller1045may represent or interact with a modem, a keyboard, a mouse, a touchscreen, or a similar device. In some cases, I/O controller1045may be implemented as part of a processor. In some cases, a user may interact with device1005via I/O controller1045or via hardware components controlled by I/O controller1045.

FIG. 11shows a flowchart illustrating a method1100for antenna port compatibility signaling in accordance with aspects of the present disclosure. The operations of method1100may be implemented by a UE115or its components as described herein. For example, the operations of method1100may be performed by a communications manager as described with reference toFIGS. 8 and 9. In some examples, a UE115may execute a set of codes to control the functional elements of the device to perform the functions described below. Additionally or alternatively, the UE115may perform aspects of the functions described below using special-purpose hardware.

At block1105the UE115may identify a plurality of antenna ports associated with the UE115for communication with a base station. The operations of block1105may be performed according to the methods described herein. In certain examples, aspects of the operations of block1105may be performed by an antenna port administrator as described with reference toFIG. 9.

At block1110the UE115may identify the compatibility of at least one antenna port combination of the plurality of antenna ports for coincident use by the UE115. The operations of block1110may be performed according to the methods described herein. In certain examples, aspects of the operations of block1110may be performed by a compatibility identifier as described with reference toFIG. 9.

At block1115the UE115may transmit a message to the base station indicating whether two or more antenna ports are available for coincident use based at least in part on the identified compatibility. The operations of block1115may be performed according to the methods described herein. In certain examples, aspects of the operations of block1115may be performed by a compatibility signaling coordinator as described with reference toFIG. 9.

At block1120the UE115may communicate with the base station via at least one of the plurality of antenna ports. The at least one of the plurality of antenna ports may be selected based at least in part on the identified compatibility. The operations of block1120may be performed according to the methods described herein. In certain examples, aspects of the operations of block1120may be performed by a uplink/downlink manager as described with reference toFIG. 9.

FIG. 12shows a flowchart illustrating a method1200for antenna port compatibility signaling in accordance with aspects of the present disclosure. The operations of method1200may be implemented by a UE115or its components as described herein. For example, the operations of method1200may be performed by a communications manager as described with reference toFIGS. 8 and 9. In some examples, a UE115may execute a set of codes to control the functional elements of the device to perform the functions described below. Additionally or alternatively, the UE115may perform aspects of the functions described below using special-purpose hardware.

At block1205the UE115may identify a plurality of antenna ports associated with the UE115for communication with a base station. The operations of block1205may be performed according to the methods described herein. In certain examples, aspects of the operations of block1205may be performed by an antenna port administrator as described with reference toFIG. 9.

At block1210the UE115may identify a compatibility of at least one antenna port combination of the plurality of antenna ports for coincident use by the UE115. The operations of block1210may be performed according to the methods described herein. In certain examples, aspects of the operations of block1210may be performed by a compatibility identifier as described with reference toFIG. 9.

At block1215the UE115may determine a delay constraint between using antenna ports in the at least one antenna port combination. The operations of block1215may be performed according to the methods described herein. In certain examples, aspects of the operations of block1215may be performed by an antenna port administrator as described with reference toFIG. 9.

At block1220the UE115may transmit a message to the base station indicating the compatibility and the delay constraint. The operations of block1220may be performed according to the methods described herein. In certain examples, aspects of the operations of block1220may be performed by a compatibility signaling coordinator as described with reference toFIG. 9.

At block1225the UE115may communicate with the base station via at least one of the plurality of antenna ports. The at least one of the plurality of antenna ports may be selected based at least in part on the indicated compatibility and delay constraint. The operations of block1225may be performed according to the methods described herein. In certain examples, aspects of the operations of block1225may be performed by a uplink/downlink manager as described with reference toFIG. 9.

FIG. 13shows a flowchart illustrating a method1300for antenna port compatibility signaling in accordance with aspects of the present disclosure. The operations of method1300may be implemented by a UE115or its components as described herein. For example, the operations of method1300may be performed by a communications manager as described with reference toFIGS. 8 and 9. In some examples, a UE115may execute a set of codes to control the functional elements of the device to perform the functions described below. Additionally or alternatively, the UE115may perform aspects of the functions described below using special-purpose hardware.

At block1305the UE115may identify a plurality of antenna ports associated with the UE115for communication with a base station. The operations of block1305may be performed according to the methods described herein. In certain examples, aspects of the operations of block1305may be performed by an antenna port administrator as described with reference toFIG. 9.

At block1310the UE115may identify a compatibility of at least one antenna port combination of the plurality of antenna ports for coincident use by the UE. The operations of block1310may be performed according to the methods described herein. In certain examples, aspects of the operations of block1310may be performed by a compatibility identifier as described with reference toFIG. 9.

At block1315the UE115may transmit a message to the base station indicating the compatibility. The operations of block1315may be performed according to the methods described herein. In certain examples, aspects of the operations of block1315may be performed by a compatibility signaling coordinator as described with reference toFIG. 9.

At block1320the UE115may receive a scheduling message from the base station indicating an uplink precoder for the at least one of the plurality of antenna ports for communicating with the base station. The operations of block1320may be performed according to the methods described herein. In certain examples, aspects of the operations of block1320may be performed by a uplink/downlink manager as described with reference toFIG. 9.

At block1325the UE115may apply the uplink precoder to the at least one of the plurality of antenna ports. The operations of block1325may be performed according to the methods described herein. In certain examples, aspects of the operations of block1325may be performed by a uplink/downlink manager as described with reference toFIG. 9.

At block1330the UE115may communicate with the base station via at least one of the plurality of antenna ports. The at least one of the plurality of antenna ports may be selected based at least in part on the indicated compatibility. The operations of block1330may be performed according to the methods described herein. In certain examples, aspects of the operations of block1330may be performed by a uplink/downlink manager as described with reference toFIG. 9.