Phase pre-compensation for misalignment

Methods, systems, and devices for wireless communications are described. A first device may transmit, from a first antenna of a first antenna array of the first device to a second antenna of a second antenna array of a second device, a first set of reference signals. The first device may transmit, from a first plurality of antennas of the first antenna array to a second plurality of antennas of the second antenna array, a second plurality of reference signals. The first device may receive, from the second device, an indication based at least in part on a linear offset and one or more rotational offsets estimated by the second device associated with the first set of reference signals and the second plurality of reference signals. The first device may communicate with the second device using the first antenna array based on the indication.

TECHNICAL FIELD

The following relates to wireless communications, including determining misalignment conditions between a transmitting antenna array and a receiving antenna array and pre-compensating the antenna arrays based on the misalignment condition.

DESCRIPTION OF THE RELATED TECHNOLOGY

In multiple input, multiple output (MIMO) wireless communication scenarios, devices may communicate using antenna arrays to support relatively higher throughput. In some cases, devices may communicate using orbital angular momentum (OAM) multiplexing. In these environments, it may be beneficial for two antenna arrays to be aligned in order to support orthogonality of related signaling.

SUMMARY

One innovative aspect of the subject matter described in this disclosure can be implemented in a method for wireless communication. A method for wireless communication at a first device is described. The method may include transmitting, from a first antenna of a first antenna array of the first device to a second antenna of a second antenna array of a second device, a first set of reference signals that includes one or more reference signals, transmitting, from a first set of multiple antennas of the first antenna array to a second set of multiple antennas of the second antenna array, a second set of multiple reference signals, receiving, from the second device, an indication based on a linear offset and one or more rotational offsets estimated by the second device associated with the first set of reference signals and the second set of multiple reference signals, and communicating with the second device using the first antenna array based on the indication.

Another innovative aspect of the subject matter described in this disclosure can be implemented in an apparatus for wireless communication. The apparatus may include a processor, memory coupled with the processor, and instructions stored in the memory. The instructions may be executable by the processor to cause the apparatus to transmit, from a first antenna of a first antenna array of the first device to a second antenna of a second antenna array of a second device, a first set of reference signals that includes one or more reference signals, transmit, from a first set of multiple antennas of the first antenna array to a second set of multiple antennas of the second antenna array, a second set of multiple reference signals, receive, from the second device, an indication based on a linear offset and one or more rotational offsets estimated by the second device associated with the first set of reference signals and the second set of multiple reference signals, and communicate with the second device using the first antenna array based on the indication.

Another innovative aspect of the subject matter described in this disclosure can be implemented in an apparatus for wireless communication. The apparatus may include means for transmitting, from a first antenna of a first antenna array of the first device to a second antenna of a second antenna array of a second device, a first set of reference signals that includes one or more reference signals, means for transmitting, from a first set of multiple antennas of the first antenna array to a second set of multiple antennas of the second antenna array, a second set of multiple reference signals, means for receiving, from the second device, an indication based on a linear offset and one or more rotational offsets estimated by the second device associated with the first set of reference signals and the second set of multiple reference signals, and means for communicating with the second device using the first antenna array based on the indication.

Another innovative aspect of the subject matter described in this disclosure can be implemented in a non-transitory computer-readable medium storing code for wireless communication at a first device. The code may include instructions executable by a processor to transmit, from a first antenna of a first antenna array of the first device to a second antenna of a second antenna array of a second device, a first set of reference signals that includes one or more reference signals, transmit, from a first set of multiple antennas of the first antenna array to a second set of multiple antennas of the second antenna array, a second set of multiple reference signals, receive, from the second device, an indication based on a linear offset and one or more rotational offsets estimated by the second device associated with the first set of reference signals and the second set of multiple reference signals, and communicate with the second device using the first antenna array based on the indication.

Another innovative aspect of the subject matter described in this disclosure can be implemented in a method. The method may include receiving, at a first antenna of a first antenna array of the first device from a second antenna of a second antenna array of a second device, a first set of reference signals that includes one or more reference signals, measuring, based on receiving the first set of reference signals, one or more first phases for the first set of reference signals, estimating, based on the one or more first phases for the first set of reference signals, a linear offset between the first antenna array and the second antenna array, receiving, at a first set of multiple antennas of the first antenna array of the first device from a second set of multiple antennas of the second antenna array of the second device, a second set of multiple reference signals, measuring, based on receiving the second set of multiple reference signals, a second set of multiple phases of each of the second set of multiple reference signals, estimating, based on the second set of multiple phases of the second set of multiple reference signals, one or more rotational offsets between the first antenna array and the second antenna array, and transmitting, to the second device, an indication based on the linear offset and the one or more rotational offsets.

Another innovative aspect of the subject matter described in this disclosure can be implemented in an apparatus. The apparatus may include a processor, memory coupled with the processor, and instructions stored in the memory. The instructions may be executable by the processor to cause the apparatus to receive, at a first antenna of a first antenna array of the first device from a second antenna of a second antenna array of a second device, a first set of reference signals that includes one or more reference signals, measuring, base at least in part on receiving the first set of reference signals, one or more first phases for the first set of reference signals, estimating, base at least in part on the one or more first phases for the first set of reference signals, a linear offset between the first antenna array and the second antenna array, receive, at a first set of multiple antennas of the first antenna array of the first device from a second set of multiple antennas of the second antenna array of the second device, a second set of multiple reference signals, measuring, base at least in part on receiving the second set of multiple reference signals, a second set of multiple phases of each of the second set of multiple reference signals, estimating, base at least in part on the second set of multiple phases of the second set of multiple reference signals, one or more rotational offsets between the first antenna array and the second antenna array, and transmit, to the second device, an indication based on the linear offset and the one or more rotational offsets.

Another innovative aspect of the subject matter described in this disclosure can be implemented in an apparatus at a first device. The apparatus may include means for receiving, at a first antenna of a first antenna array of the first device from a second antenna of a second antenna array of a second device, a first set of reference signals that includes one or more reference signals, means for measuring, based on receiving the first set of reference signals, one or more first phases for the first set of reference signals, means for estimating, based on the one or more first phases for the first set of reference signals, a linear offset between the first antenna array and the second antenna array, means for receiving, at a first set of multiple antennas of the first antenna array of the first device from a second set of multiple antennas of the second antenna array of the second device, a second set of multiple reference signals, means for measuring, based on receiving the second set of multiple reference signals, a second set of multiple phases of each of the second set of multiple reference signals, means for estimating, based on the second set of multiple phases of the second set of multiple reference signals, one or more rotational offsets between the first antenna array and the second antenna array, and means for transmitting, to the second device, an indication based on the linear offset and the one or more rotational offsets.

Another innovative aspect of the subject matter described in this disclosure can be implemented in a non-transitory computer-readable medium storing code for wireless communication at a first device is described. The code may include instructions executable by a processor to receive, at a first antenna of a first antenna array of the first device from a second antenna of a second antenna array of a second device, a first set of reference signals that includes one or more reference signals, measuring, base at least in part on receiving the first set of reference signals, one or more first phases for the first set of reference signals, estimating, base at least in part on the one or more first phases for the first set of reference signals, a linear offset between the first antenna array and the second antenna array, receive, at a first set of multiple antennas of the first antenna array of the first device from a second set of multiple antennas of the second antenna array of the second device, a second set of multiple reference signals, measuring, base at least in part on receiving the second set of multiple reference signals, a second set of multiple phases of each of the second set of multiple reference signals, estimating, base at least in part on the second set of multiple phases of the second set of multiple reference signals, one or more rotational offsets between the first antenna array and the second antenna array, and transmit, to the second device, an indication based on the linear offset and the one or more rotational offsets.

DETAILED DESCRIPTION

Various wireless communication schemes, such as line-of-site multiple-input multiple-output (LoS-MIMO), are being considered for advanced wireless communication systems (for example, 6G wireless communication systems) to, for example, support high throughput over short distances. In such environments, two network nodes may communicate using one or more antenna arrays. For example, each of the network nodes may include an orbital angular momentum (OAM) antenna system having multiple antennas arranged in one or more concentric circular antenna arrays, or an antenna system having one or more rectangular antenna arrays. The respective antenna arrays of the two network nodes may be installed such that they are aligned along a first axis (for example, a horizontal axis or a vertical axis) as well as rotationally (for example, such that that respective antenna elements of an antenna array of one network node are aligned with respective antenna elements of an antenna array of the other network node in various rotational axes). It is important that the two antenna arrays are aligned to support wireless communication, such as LoS-MIMO, regardless of the type of antenna arrays implemented, for example, whether OAM arrays or rectangular arrays are used. With any misalignment (for example, axial misalignment or rotational misalignment), between respective antenna arrays of two network nodes, modes in OAM LoS-MIMO between the network nodes may lose orthogonality, which may result in signal loss, among other disadvantages.

Various aspects generally relate to determining two or more misalignment conditions (for example, a linear offset and one or more rotational angle offsets) associated with an antenna array of a receiving device and an antenna array of a transmitting device, and precompensating for these misalignment conditions, such as in a sequential manner. In some aspects, the receiving device may report the misalignment conditions to the transmitter device, which may then use one or more precompensation techniques, such as beamforming. First, the receiving device may estimate a linear offset between an antenna array of the receiving device and an antenna array of the transmitting device based on phase measurements of a first set of reference signals transmitted by the antenna array of the transmitting device and received by an antenna of the antenna array of the receiving device. The receiving device may transmit or otherwise provide an indication of the linear offset to the transmitting device, which may apply precompensation to its antenna array to counter the linear offset. The receiving device may also estimate one or more rotational offsets based on phase measurements of a second set of reference signals transmitted between two or more antennas of the transmitting antenna array and two or more antennas of the receiving antenna array, referred to as “transmit-receive antenna pairs,” which may in some examples be on or relatively near a peripheral edge of the antenna array. The receiving device may then transmit and indication of the one or more rotational offsets to the transmitting device. In some examples, the receiving device may transmit indications of the linear offset and the one or more rotational angles together. In some other examples, the receiving device may transmit the indication of the linear offset first and then subsequently transmit the indication of the rotational offset(s). The transmitting device may then apply further precompensation to its antenna array, for example using beam steering or other mechanisms, as needed, to counter the one or more rotational offsets.

Particular aspects of the subject matter described in this disclosure may be implemented to realize one or more of the following potential advantages. The techniques employed by the described communication devices may provide benefits and enhancements to the operation of the communication devices, including supporting orthogonality between transmissions, such as for LoS-MIMO transmissions, which may result in communication efficiencies, among other benefits. For example, operations performed by the described communication devices may provide improvements to LoS-MIMO procedures by precompensating for a loss of orthogonality that may otherwise occur between the devices due to misalignment of one or more antenna arrays of the transmitting device and one or more antenna arrays of the receiving device. In some examples, operations performed by the described communication devices and related precompensation at the transmitting device may also support improvements to power consumption, reliability for communications, spectral efficiency, higher data rates and, in some examples, low latency for communications, among other benefits.

The base stations105may communicate with the core network130, or with one another, or both. For example, the base stations105may interface with the core network130through one or more backhaul links120(for example, via an S1, N2, N3, or other interface). The base stations105may communicate with one another over the backhaul links120(for example, via an X2, Xn, or other interface) either directly (for example, directly between base stations105), or indirectly (for example, via core network130), or both. In some examples, the backhaul links120may be or include one or more wireless links.

The communication links125shown in the wireless communications system100may include uplink transmissions from a UE115to a base station105, or downlink transmissions from a base station105to a UE115. Carriers may carry downlink or uplink communications (for example, in an FDD mode) or may be configured to carry downlink and uplink communications (for example, in a TDD mode).

A subframe, a slot, a mini-slot, or a symbol may be the smallest scheduling unit (for example, in the time domain) of the wireless communications system100and may be referred to as a transmission time interval (TTI). In some examples, the TTI duration (for example, the number of symbol periods in a TTI) may be variable. Additionally or alternatively, the smallest scheduling unit of the wireless communications system100may be dynamically selected (for example, in bursts of shortened TTIs (sTTIs)).

Each base station105may provide communication coverage via one or more cells, for example a macro cell, a small cell, a hot spot, or other types of cells, or any combination thereof. The term “cell” may refer to a logical communication entity used for communication with a base station105(for example, over a carrier) and may be associated with an identifier for distinguishing neighboring cells (for example, a physical cell identifier (PCID), a virtual cell identifier (VCID), or others). In some examples, a cell may also refer to a geographic coverage area110or a portion of a geographic coverage area110(for example, a sector) over which the logical communication entity operates. Such cells may range from smaller areas (for example, a structure, a subset of structure) to larger areas depending on various factors such as the capabilities of the base station105. For example, a cell may be or include a building, a subset of a building, or exterior spaces between or overlapping with geographic coverage areas110, among other examples.

In some examples, transmissions by a device (for example, by a base station105or a UE115) may be performed using multiple beam directions, and the device may use a combination of digital precoding or radio frequency beamforming to generate a combined beam for transmission (for example, from a base station105to a UE115). The UE115may report feedback that indicates precoding weights for one or more beam directions, and the feedback may correspond to a configured number of beams across a system bandwidth or one or more sub-bands. The base station105may transmit a reference signal (for example, a cell-specific reference signal (CRS), a channel state information reference signal (CSI-RS)), which may be precoded or unprecoded. The UE115may provide feedback for beam selection, which may be a precoding matrix indicator (PMI) or codebook-based feedback (for example, a multi-panel type codebook, a linear combination type codebook, a port selection type codebook). Although these techniques are described with reference to signals transmitted in one or more directions by a base station105, a UE115may employ similar techniques for transmitting signals multiple times in different directions (for example, for identifying a beam direction for subsequent transmission or reception by the UE115) or for transmitting a signal in a single direction (for example, for transmitting data to a receiving device).

A receiving device (for example, a UE115) may try multiple receive configurations (for example, directional listening) when receiving various signals from the base station105, such as synchronization signals, reference signals, beam selection signals, or other control signals. For example, a receiving device may try multiple receive directions by receiving via different antenna subarrays, by processing received signals according to different antenna subarrays, by receiving according to different receive beamforming weight sets (for example, different directional listening weight sets) applied to signals received at multiple antenna elements of an antenna array, or by processing received signals according to different receive beamforming weight sets applied to signals received at multiple antenna elements of an antenna array, any of which may be referred to as “listening” according to different receive configurations or receive directions. In some examples, a receiving device may use a single receive configuration to receive along a single beam direction (for example, when receiving a data signal). The single receive configuration may be aligned in a beam direction determined based on listening according to different receive configuration directions (for example, a beam direction determined to have a highest signal strength, highest signal-to-noise ratio (SNR), or otherwise acceptable signal quality based on listening according to multiple beam directions).

A first device (for example, the UE115or the base station105, which may be a receiving device in this example) may receive, at a first antenna of a first antenna array of the first device from a second antenna of a second antenna array of a second device, a first set of reference signals that includes one or more reference signals. The first device may measure, based on receiving the first set of reference signals, one or more first phases for the first set of reference signals. The first device may estimate, based on the one or more first phases for the first set of reference signals, a linear offset between the first antenna array and the second antenna array. The first device may receive, at a first plurality of antennas of the first antenna array of the first device from a second plurality of antennas of the second antenna array of the second device, a second plurality of reference signals. The first device may measure, based on receiving the second plurality of reference signals, a second plurality of phases of each of the second plurality of reference signals. The first device may estimate, based on the second plurality of phases of the second plurality of reference signals, one or more rotational offsets between the first antenna array and the second antenna array. The first device may transmit, to the second device, an indication based on the linear offset and the one or more rotational offsets.

A first device (which may be an example of a UE115or base station105, and may be an example of the second device described in the example above) may transmit, from a first antenna of a first antenna array of the first device to a second antenna of a second antenna array of a second device, a first set of reference signals that includes one or more reference signals. The first device may transmit, from a first plurality of antennas of the first antenna array to a second plurality of antennas of the second antenna array, a second plurality of reference signals. The first device may receive, from the second device, an indication based on a linear offset and one or more rotational offsets estimated by the second device associated with the first set of reference signals and the second plurality of reference signals. The first device may communicate with the first device using the second antenna array based on the indication.

FIGS.2A and2Billustrate an example of an antenna array configuration200that supports phase pre-compensation for misalignment in accordance with aspects of the present disclosure. The antenna array configuration200may implement aspects of or be implemented by the wireless communications system100. The antenna array configuration200may include a second antenna array205associated with a second device and a first antenna array220associated with a first device. In some aspects, the first device or the second device (or both) may be a UE or a base station (or some combination), which may be examples of the corresponding devices described herein.

The techniques described herein may be implemented by the first and second devices to align/compensate for misalignment between the second antenna array205and the first antenna array220. Accordingly, the techniques described herein may be applied for UE-to-UE, base station-to-base station, UE-to-base station, or base station-to-UE antenna array alignment/compensation between the first antenna array220, and the second antenna array205, or both.

As discussed herein, wireless communication systems may be configured to support OAM and other LoS-MIMO schemes to increase throughput over a short distance LoS deployment scenario. These deployment scenarios may include the first device installing, establishing, or otherwise configuring the first antenna array220and the second device installing, establishing, or otherwise configuring the second antenna array205such that each antenna array is coplanar with respect to the other antenna array. That is, each antenna array may include a plurality of antenna elements (for example, antenna elements210of the second antenna array205and antenna elements225of the first antenna array220). Each antenna array may have a circular shape, rectangular shape, oval shape, or square shape, among other examples. The aim if installing such antenna arrays is that the planar face of each antenna array is perfectly coplanar with respect to the planar face of the other antenna array along the Z axis, and are rotated such that each antenna element is aligned with a corresponding antenna element of the other antenna array (for example, antenna pairs) along the X and Y axis (for example, are rotated similarly around the Z axis). This may support Fresnel diffraction, which may be key to the presence of multiple channels supporting the MIMO communications with LoS.

Alignment of the receiving plane to the transmitting plane (for example, alignment of the planar face of the second antenna array205and the first antenna array220) are important aspects for such LoS MIMO schemes, regardless of whether OAM (for example, concentric circles) or rectangular antenna arrays are used. Without such alignment, the modes in OAM and LoS-MIMO lose orthogonality with respect to each other, thus disrupting communications.

Typically, misalignment of the first antenna array220and the second antenna array205is common (at least initially), and therefore an alignment procedure is necessary before the communications sessions are established between the first device and the second device. Misalignment in some scenarios may include a linear offset (for example, linear off-axis) in which the planar face of the antenna arrays are offset along the Z axis, as well as rotational offset(s) in which the planar face of the antenna arrays are rotated around the Z axis or the planar face of one antenna array is tilted or otherwise leans such that it is not parallel to the planar face of the other antenna array. Accordingly, various degrees of freedom be present in the misalignment of the antenna arrays corresponding to the linear axis or the rotational offset(s) or both. If such misalignment is present, the transformation matrix has numerous variables that are tangled together, which makes it difficult to analyze or correct (or both) for the misalignment between the first antenna array220and the second antenna array205.

One example of such misalignment is illustrated in the antenna array configuration200-aofFIG.2A. In this example, the second antenna array205is configured as shown such that the planar face of the second antenna array205is perpendicular to the Z axis and rotated such that the antenna elements210are positioned along the X and Y axis. An ideal placement for the first antenna array220is illustrated in dashed lines as antenna array placement215. That is, antenna array placement215illustrates the ideal alignment of the first antenna array220with respect to the second antenna array205. However, in the example illustrated inFIG.2A, there is misalignment between the first antenna array220and the second antenna array205. More particularly, the misalignment includes the first antenna array220being positioned below the Z axis, and therefore having a corresponding linear offset230. That is, a transmission from a center antenna element225of the first antenna array220may not align with the corresponding center antenna element210of the second antenna array205.

Additionally, the first antenna array220is rotated about the Z axis such that the X and Y axis of the first antenna array220are not aligned with the corresponding X and Y axis of the second antenna array205. Furthermore, the first antenna array220is tilted along the X/Y axis such that the planar face of the second antenna array205is not parallel with the planar face of the first antenna array220. Again, if such misalignment is present, the variables of the transformation matrix are tangled to such a degree that analyzing or otherwise quantifying the misalignment between the second antenna array205and the first antenna array220is extremely difficult, and potentially sometimes prohibitively difficult. For example, it may not be feasible to have a reasonable sized set of codewords to use for pre-compensation due to the high dimensions (for example, due to the numerous degrees of freedom between the antenna array's misalignment). Moreover, physical alignment of the second antenna array205to the first antenna array220may be difficult in some mobility use cases. Finally, in some situations it may be impractical to physically place a lens (or other physical alignment aid) between the second antenna array205and the first antenna array220to aid in alignment.

Accordingly, aspects of the described techniques provide for a sequential method to find and apply accurate phase pre-compensation at the transmitting device (for example, the second device in this example) to compensate for the linear axis offset as well as the rotational offset(s) between the second antenna array205and the first antenna array220. Broadly, the linear axis offset (for example, the off-axis offset) is initially estimated based on phase measurements at the center antenna arrays along the X and Y axis using a reference signal transmitted from the second device. After the linear offset has been estimated and compensated for, the rotational offsets are then estimated and compensated for using multiple reference signals transmitted from the peripheral antenna elements210of the second antenna array205. For example, the rotational offset(s) are estimated based on phase measurements among the antenna element pairs along the X and Y axis using reference signals transmitted from the corresponding antenna array antenna elements. Accordingly, the phase terms from the rotational offsets are no longer tangled with the linear offset, which supports sequentially estimating and correcting for the linear offset or rotational offset(s) (or both).FIGS.2A and2Billustrate examples of the linear offset estimation/pre-compensation aspects of the described techniques, withFIGS.3A and3Billustrating examples of the rotational offset(s) estimation/pre-compensation aspects of the described techniques.

Accordingly, this may include the second device transmitting a first set of reference signals (for example, one or more reference signals). Broadly, the first set of reference signals may be transmitted from a central or center antenna element210of the second antenna array205of the second device. The first set of reference signals may be transmitted to a corresponding central or center antenna element225of the first antenna array220of the first device (for example, the corresponding antenna pair). The first device may receive the first set of reference signals at the first antenna element225of the first antenna array220transmitted from the second device. Accordingly, the first device may measure a first phase of each reference signal in the first set of reference signals (e.g., one or more first phases). Based on the first phase(s) measured by the first device, the first device may then estimate the linear offset between the first antenna array220and the second antenna array205. For example, the first device may determine the difference between the distance between the first antenna element225and the second antenna element225and the distance between other antenna elements210and the second antenna element225along the linear axis that is perpendicular to the plane (for example, the planar face) of the second antenna array205. More particularly, the first device may not directly determine the distance between the respective antenna elements, but the first device may estimate the difference in the distances based on the phase measurements in order to determine the linear offsets. The first device may evaluate (for example, compare) a physical distance between the center of the first antenna array220and the center of the second antenna array225along the linear axis to determine or otherwise estimate or calculate the linear offset. That is, the distance may correspond to the horizontal distance along the horizontal axis and a vertical distance along a vertical axis. The horizontal axis and the vertical axis (for example, the X and Y planes, respectively) may be perpendicular to the plane of the second antenna array205.

In some aspects, rectangular coordinates may be used for the algorithms, although the results may be easy applicable to OAM and Polar coordinates. The coordinates for the receive plane (for example, for the first antenna array220) may have their origin at (X0,Y0, Z0) and (−γ, −β, −α) with respect to the X-, Y-, and Z-axis. The coordinates for the transmit plane (for example, for the second antenna array205) may be at a rotational offset of (γ,β, α) with respect to the Z-, Y-, and X-axis, respectively.

With respect to coordinate transform (for example, with respect to the rotation matrix), a point with receive plane coordinates of (x′, y′, z′) has its coordinates in the transmit plane as according to Equation (1) below:

In a direction solution approach to estimating/compensating for the misalignment, the coordinates X0, Y0, Z0, γ,β, α leave six unknown variables to solve for, which may be difficult to solve for given the degree of freedom between the antenna arrays.

However, the techniques described herein provide an iterative approach to solve for these variables, to pre-compensate for the misalignment between the first antenna array220and the second antenna array205. This may include making the transmit plane (for example, the second antenna array205) appear as (x″,y″, z″) to the receive plane (for example, the first antenna array220).

As discussed herein, this may include the first device measuring a first phase of each reference signal on the first set of reference signals. This may include projecting the origin of the receive plane to the transmit plane along the Z axis (for example, corresponding to the linear offset230). Estimating the linear offset230may include the first device measuring (for example, based on the first phase distance) the distance between the first antenna and the second antenna along the linear axis that is perpendicular to the plane of the second antenna array205. For example, this may include the distance between the receive plane (0,0,0) and the transmit plane (kx, dx,0,0)—distance between the receive plane (0,0,0) and the receive plane (0,0,0).

In some aspects, the distance between the receive plane (0,0,0) (for example, the center of the first antenna array220) and the transmit plane (kx, dx,0,0)—the distance between the receive plane (0,0,0,) and the transmit plane (0,0,0) may be as according to Equation (2) below:

And the distance between the receive plane (0,0,0) and the transmit plane (ky, dy,0,0)—the distance between the receive plane (0,0,0) and the transmit plane (0,0,0) may be as according to Equation (3) below:

The receive plane (0,0,0) may be the same as (X0, Y0, Z0) in the transmit plane coordinates. With dxand dyknown, the given observations at multiple kxand ky, x0, Y0, and z0can be solved (for example, using linear regression). To remove phase ambiguity (for example, based on2n), this may include using dense frequency sampling by the reference signal, or may use extra units close to the origin (for example, additional centrally located antenna elements), or both, for phase de-ambiguity because multiple modes may use Equation (4) below:

The multiple transmit units (for example, antenna elements) used for the phase measurements may not have to be equally spaced along the two axis (for example, as long as their respective locations are known to the receive device, such as the second device in this example). As discussed, reference signals may be used for the transmitting units (for example, the antenna elements) to support the phase measurements (for example, measurement of the first phase), with each unit being along the two axis (for example, the X and Y axis).

In one alternative, the linear offset may be estimated according to the distance between the receive plane (0,0,0) and the transmit plane (kxdx, 0,0)—the distance between the receive plane (0,0,0) and the transmit plane(−kxdx, 0,0) being according to Equation (5) below:

The distance between the receive plane (0,0,0) and the transmit plane (0, kydy, 0)—the distance between receive plane (0,0,0) and transmit plane (0, −kydy, 0) being as according to Equation (6) below:

x0z0⁢and⁢y0z0
can be soived. The variable z0by itself may or may not be used for alignment. This alternative also uses reference signals for the transmit units (for example, the antenna elements) used for phase measurements (for example, two units at the far end of each of the two axis).

To remove any ambiguity in the phase measurements, the total phase of reference signals (for example, the first set or second plurality of reference signals or both) from (x, y, 0) at sub-carrier f1 may be as according to Equation (7) below:

The total phase of reference signal from (−x, y, 0) at sub-carrier f1 may be as according to Equations (8) and (9) below:

φ1(f2)-φ2(f2)+(m1,f2-m2,f2)⁢(2⁢π)=2⁢π⁢f2c⁢(d(x,y)-d(-x,y))
and φ1(f1), φ2(f1), φ1(f2), φ2(f2) may be observable by channel estimation based on the reference signal(s), but the unknown integer multiple of (2π) is also to be resolved.

If multiple of (2π) remains in [φ1(f1)−φ2(f1)]−[φ1(f2)−φ2(f2)], namely, (m1, f1−m2, f1)≠(m1, f2−m2, f2), we may have

❘"\[LeftBracketingBar]"2⁢πc⁢(f1-f2)⁢(d(x,y)-d(-x,y))❘"\[RightBracketingBar]"≥2⁢π,
this implies

In a typical use environment of passive MIMO, reference signals are placed densely in the frequency domain. |f1−f2| may be on the order of sub-carrier spacing, or physical resource block size, among other examples. So it may be assumed that |f1−f2|˜102kHz, then the corresponding ambiguity length |(d(x,y)−d(−x,y))|˜103m, which is sufficient to remove the phase ambiguity. Accordingly, this may include reference signal samples in the frequency domain with a density of the order of 102kHz, and receiver using multiple sub-carriers in the reference signal to remove phase ambiguity. It may be assumed that phase ambiguity is removed in the estimated differential distance such as |d(x,y)−d(−x,y))|, although d(x,y)and d(−x,y)themselves may still have some degree of ambiguity. Accordingly, the first set of reference signals may be transmitted at a first frequency and the second plurality of reference signals may be transmitted at a second frequency that is within a frequency threshold of the first frequency.

Accordingly, the first device may determine the phase accuracy for the linear offset or the rotational offset(s) (or both) and adjust the first antenna array220or the second antenna array205(or both) accordingly.

In some aspects, the first device may transmit or otherwise convey an indication that the linear offset to the second device. The indication may be transmitted along with an indication of the rotational offsets (discussed with reference toFIGS.3A and3B) or may be provided initially such that the second device may adjust communication metric(s) to compensate for the linear offset before measuring and compensating for the rotational offset(s).

Referring next to antenna array configuration200-bofFIG.2B, the second device in this example may adjust or otherwise modify various metric(s) used for communications between the first antenna array220and the second antenna array205. The alignment procedure may be based on the second device receiving the indication (for example, feedback) from the first device indicating the calculated offset of x0 and y0, and z0. The second device may apply, for (kxdx, kydy), an extra phase of the following, in effect steering the beam235toward the origin of the receive plane as according to Equation (10) below:

Accordingly, adjusting the metric(s) used for communications between the first antenna array220and the second antenna array may include the second device applying various beam steering, beamforming, or other techniques in order to steer beam235from the center of the second antenna array205to the first antenna array220. In some aspects, the second device may adjust a first subset of the metric(s) based on the indication before transmitting a second plurality of reference signals used for rotational offset estimation and measurement.

FIGS.3A and3Billustrate an example of an antenna array configuration300that supports phase pre-compensation for misalignment in accordance with aspects of the present disclosure. The antenna array configuration300may implement aspects of or be implemented by the wireless communications system100or aspects of the antenna array configuration200(or both). The antenna array configuration300may include a second antenna array305associated with a second device and a first antenna array320associated with a first device. In some aspects, the first device or the second device (or both) may be a UE or a base station (or some combination), which may be examples of the corresponding devices described herein.

Broadly, the antenna array configuration300continues the discussion of the antenna array configuration200. That is, the discussion of antenna array configuration200included the second device transmitting or otherwise conveying a first set of reference signal(s) to a first antenna of the first antenna array320and from the second antenna of the second antenna array305. The first device receives the first set of reference signal(s) and measures a first phase of each reference signal (e.g., one or more first phases for the first set of reference signals) and the first set of reference signal(s). Based on the first phase, the first device may estimate the linear offset between a first antenna array320and the second antenna array305. The first device may transmit or otherwise provide an indication of the linear offset to the second device, which then adjust various metric(s) (for example, such as beam steering, beamforming, weighting factors) associated with communications between the first antenna array320and the second antenna array305. As discussed herein, in some examples first device may transmit or otherwise provide the indication of the linear offset (for example, the actual linear offset or the first phase or both) before measuring and estimating for rotational offset(s) between the first antenna array320and the second antenna array305. In other examples, the indication of the linear offset may be provided with the indication of the rotational offset(s). Antenna array configuration300provides an example in which the indication of the linear offset has been provided to the second device, which has adjusted the metric(s) to compensate for the linear offset prior to transmitting reference signals used for measuring and estimating the rotational offset(s).

With reference to antenna array configuration300-aofFIG.3A, as previously discussed orientation between the first antenna array320and the second antenna array305may be misaligned along the linear access (for example, along the Z access corresponding to the linear offset) as well as including one or more rotational offsets (e.g., rotational angle offsets). The rotational offsets may correspond to the first antenna array320being rotated about the Z axis such that the antenna elements pairs are not aligned. For example, antenna element310-aof the second antenna array305may be misaligned with respect to the corresponding antenna elements325-aof the first antenna array320. Similarly, antenna elements310-bmay be misaligned with reference to antenna element325-b, antenna element310-cmay be misaligned with reference to antenna elements325-c, and antenna elements310-dmay be misaligned with reference to antenna elements325-d. Such misalignment may also be based on the planer face of the first antenna array320being non-planar with respect to the planer face of the second antenna array305. That is, the first antenna array320may be positioned in a manner inconsistent with the antenna array placement315.

Aspects are described herein for determining the rotational offsets in terms of rotational angle offsets (for example, rotational angles along one or more axis at the first antenna array320relative to the second antenna array305). As described herein, various types of coordinate systems may be used to estimate the offsets, including the rotational offsets. As such, the rotational offsets may be represented as an angle (for example, in degrees) or in another type of rotational measurement representation.

Turning to the antenna array configuration300-bofFIG.3B, aspects of the described techniques may also include the second device transmitting a second plurality of reference signals to a first plurality of antennas of the first antenna array320and from a second plurality of antennas of the second antenna array305. For example, a reference signal may be transmitted from antenna element310-ato antenna element325-a, another reference signal may be transmitted from antenna element310-bto antenna element325-b, another reference signal may be transmitted from antenna element310-cto antenna element325-c, and another reference signal may be transmitted from antenna element310-dto antenna elements325-d. Accordingly, the first plurality of antennas in this example may be located at noncentral locations of the first antenna array, such as along the peripheral edge of each antenna array.

The first device may receive the second plurality reference signals and measure a corresponding second plurality of phases corresponding to the second probably reference signals. That is, the first device may measure the phase of the reference signal transmitted from antenna element310-ato antenna element325-a, and so forth. Based on the second plurality of phases, the first device may estimate the rotational offset(s) (e.g., angle(s)) between the first antenna array320and the second antenna array305. In some aspects, estimating the rotational offset(s) may be based on adjusting for the linear offset. That is, the second device may apply the adjustments to the metric(s) if transmitting the second set of reference signals in order to eliminate or otherwise pre-compensate for the linear offset misalignment.

Accordingly, with the origin of the receive plain coordinate on the transmitting plane Z axis adjusted for, only the rotational offsets RLF to be determined. This may be illustrated as according to Equation (11) below:

An intuitive approach to this may be, if β=0 and γ=0, the following four distances may be considered equal: distance [receive plane (d′x, 0,0) and transmit plane (dx, 0,0)], distance [receive plane (−d′x, 0,0) and transmit plane (−dx, 0,0)], distance [receive plane (0, d′y, 0) and transmit plane (0, dy, 0)], and distance [receive plane (0, −d′y, 0) and transmit plane (0, −dy, 0)].

Rotational offset compensation if symmetric transmit plane and receive plane channel reciprocity may be based on the correlation between the antenna elements of the antenna arrays. For example, if there are the same number of transmit plane and receive plane units (for example, antenna elements), and each unit in the transmit plane (x,y,0) is paired with a corresponding receive plane unit (x′,y′,z′), then the following may be calculated: the distance between (x,y,z) and (x′,y′,z′)—the distance between (0,0,0) (transmit plane) and (0,0,0)(receive plane). The distance/phase difference can be fed back by the first device; or if channel reciprocity is assumed, this can be estimated directly by the second device by transmissions from the first device. However, other scenarios may not have either symmetry or reciprocity.

In this situation, the distance [receive plane (d′x, 0,0) and transmit plane

(0,dy,0)]=[(cos⁢α⁢sin⁢β⁢sin⁢γ-sin⁢αcosγ)⁢dy′]2+[(sin⁢α⁢sin⁢β⁢sin⁢γ+cos⁢α⁢cos⁢γ)⁢dy′-dy]2+(cos⁢β⁢sin⁢γ⁢dy′+z0)2≈z0+[(cos⁢α⁢sin⁢β⁢sin⁢γ-sin⁢α⁢cos⁢γ)⁢dy′]2+[(sin⁢α⁢sin⁢β⁢sin⁢γ+cos⁢α⁢cos⁢γ)⁢dy′-dy]2+(cos⁢β⁢sin⁢γ⁢dy′)2+2⁢cos⁢β⁢sin⁢γ⁢dy′⁢z02⁢z0,
and the distance[receive plane (0, −d′y, 0) and transmit plane

(0,-dy,0)]}≈2⁢cos⁢β⁢sin⁢γ⁢dy′⁢z0z0≈2⁢dy′⁢cos⁢β⁢sin⁢γ∝cos⁢β⁢sin⁢γ.
The asymmetry between β and γ may come from the 3D rotation matrix in which (α,β, γ) with respect to the z-,y- and x-axis of the transmit plane coordinates, in that order. Accordingly, β,γ can be solved; then α can be solved by any one or multiple of the four distances above. Again, reference signals (for example, the second plurality of reference signals) are needed for the transmit plane units (for example, the antenna elements310of the second antenna array305) may be used for phase measurements, wherein the units are at the four corners or peripheral edges of the transmit plane or both.

Accordingly, the first device may measure the second plurality of phases and transmit or otherwise convey an indication of the rotational offset(s) (for example, the rotational offset(s) or the second plurality of phases or both) to the second device. The second device may adjust or otherwise modify metric(s) used for communications between the first antenna array320and the second antenna array305based on the indication.

In some aspects, this may be as according to Equation (12) below:

For each transmitter at (x,y,0) in the transmit plane: this may include finding the corresponding (x″,y″,z″) at the rotated transmit plane according to the formula, in which the matrix inverse can be found in closed form by reversing the rotation angles. The propagation path length may be found using: sign(z″)√{square root over ((x−x″)2+(y−y″)2+z″2)}. Pre-compensating a phase may be equal to

In multiple steps discussed herein there is evaluation evaluate (for example, comparison) of distance, in which the evaluation of distance may be implemented by evaluation of the measured phase(s). The phase may have a periodicity of 2π, but it may be assumed that such ambiguity has been removed based on the techniques discussed herein.

As also discussed herein, the accuracy of the phase measurements (which are used to estimate the distance between each antenna element) is important for accuracy. This may include assuming the received signal at one receive plane from the transmit plane, after coherent integration in time, is in the form y=Aejθ+z, in which A is the signal amplitude and z (z=zr+jzi) is noise with zrand zias the real and imaginary parts, respectively, and a total variance σ2. In some aspects, y=Real(y)+jImag(y)=Acos(θ)+jAsin(θ)+zr+jziand

θˆ=Phase⁢(y)=arctan⁡(y)=arctan⁡(A⁢sin⁡(θ)+ziA⁢cos⁡(θ)+zr).
At high SINR, it can be assumed:

At a high SINR, E[{circumflex over (θ)}]≅θ,

Var[θˆ]≅12⁢S⁢N⁢R[1+tan⁡(θ)2].
The var [{circumflex over (θ)}] may be small if tan(θ)→∞, but this does not pose any practical problem because the singularity of tan(θ) at θ=π/2 and θ=3π/2 can be mitigated. To evaluate (for example, compare) two phases at two receive plane units, the phase difference which can be accurately estimate is around

1S⁢N⁢R.
The phase difference could be small due to the very nature of par-axial approximation. Then the coherent integration may be used to boost SNR. No array gain is possible because no beamforming is used at this stage. Phase noise may be mitigated, or non-coherent integration can be used to further increase the phase difference evaluation (for example, comparison).

Accordingly, the first or second devices (or both) may determine the noise level for the channel between the first antenna array320and the second antenna array305, which may determine the phase accuracy for the measurements, at least to some degree.

Moreover, there may be a timing aspect with respect to the described techniques. For example, the phase noise may hamper any phase evaluation (for example, comparison) of the same receive plane unit across time. Therefore, aspects of the described techniques maintain such comparison within the “coherence time” due to phase noise. An alternative is to avoid phase evaluation across time: evaluation across time can be replaced by evaluation across two receive units at the same time. If the phase ambiguity is an issue, then the evaluation (for example, comparison) may be made at two receive plane units that are close enough to each other for phase-deambiguity to work (for example, dense phase sampling). Phase noise may still have an impact on limiting the coherent integration time. Accordingly, the first device may evaluate the two or more phases measured for the first or second sets (or both) of reference signals based on the reference signals being communicated within a time threshold (for example, the coherence time).

FIG.4shows a block diagram of a device405that supports phase pre-compensation for misalignment in accordance with aspects of the present disclosure. The device405may be an example of aspects of a UE115or a base station105as described herein. The device405may include a receiver410, a transmitter415, and a communications manager420. The device405can be implemented, at least in part, by one or both of a modem and a processor. Each of these components may be in communication with one another (for example, via one or more buses).

The transmitter415may provide a means for transmitting signals generated by other components of the device405. For example, the transmitter415may transmit information such as packets, user data, control information, or any combination thereof associated with various information channels (for example, control channels, data channels, information channels related to phase pre-compensation for misalignment). In some examples, the transmitter415may be co-located with a receiver410in a transceiver component. The transmitter415may utilize a single antenna or a set of multiple antennas.

The communications manager420, the receiver410, the transmitter415, or various combinations thereof or various components thereof may be examples of means for performing various aspects of phase pre-compensation for misalignment as described herein. For example, the communications manager420, the receiver410, the transmitter415, or various combinations or components thereof may support a method for performing one or more of the functions described herein.

In some examples, the communications manager420, the receiver410, the transmitter415, or various combinations or components thereof may be implemented in hardware (for example, in communications management circuitry). The hardware may include a processor, a digital signal processor (DSP), an application-specific integrated circuit (ASIC), a field-programmable gate array (FPGA) or other programmable logic device, a discrete gate or transistor logic, discrete hardware components, or any combination thereof configured as or otherwise supporting a means for performing the functions described in the present disclosure. In some examples, a processor and memory coupled with the processor may be configured to perform one or more of the functions described herein (for example, by executing, by the processor, instructions stored in the memory).

In some examples, the communications manager420may be configured to perform various operations (for example, receiving, monitoring, transmitting) using or otherwise in cooperation with the receiver410, the transmitter415, or both. For example, the communications manager420may receive information from the receiver410, send information to the transmitter415, or be integrated in combination with the receiver410, the transmitter415, or both to receive information, transmit information, or perform various other operations as described herein.

The communications manager420may support wireless communication at a device in accordance with examples as disclosed herein. For example, the communications manager420may be configured as or otherwise support a means for transmitting, from a first antenna of a first antenna array of the first device to a second antenna of a second antenna array of a second device, a first set of reference signals that includes one or more reference signals. The communications manager420may be configured as or otherwise support a means for transmitting, from a first set of multiple antennas of the first antenna array to a second set of multiple antennas of the second antenna array, a second set of multiple reference signals. The communications manager420may be configured as or otherwise support a means for receiving, from the second device, an indication based on a linear offset and one or more rotational offsets estimated by the second device associated with the first set of reference signals and the second set of multiple reference signals. The communications manager420may be configured as or otherwise support a means for communicating with the second device using the first antenna array is based on the indication.

Additionally or alternatively, the communications manager420may support wireless communication at a first device in accordance with examples as disclosed herein. For example, the communications manager420may be configured as or otherwise support a means for receiving, at a first antenna of a first antenna array of the first device from a second antenna of a second antenna array of a second device, a first set of reference signals that includes one or more reference signals. The communications manager420may be configured as or otherwise support a means for measuring, basing at least in part on receiving the first set of reference signals, one or more first phases for the first set of reference signals. The communications manager420may be configured as or otherwise support a means for estimating, basing at least in part on the one or more first phases for the first set of reference signals, a linear offset between the first antenna array and the second antenna array. The communications manager420may be configured as or otherwise support a means for receiving, at a first set of multiple antennas of the first antenna array of the first device from a second set of multiple antennas of the second antenna array of the second device, a second set of multiple reference signals. The communications manager420may be configured as or otherwise support a means for measuring, basing at least in part on receiving the second set of multiple reference signals, a second set of multiple phases of each of the second set of multiple reference signals. The communications manager420may be configured as or otherwise support a means for estimating, basing at least in part on the second set of multiple phases of the second set of multiple reference signals, one or more rotational offsets between the first antenna array and the second antenna array. The communications manager420may be configured as or otherwise support a means for transmitting, to the second device, an indication based on the linear offset and the one or more rotational offsets.

By including or configuring the communications manager420in accordance with examples as described herein, the device405(for example, a processor controlling or otherwise coupled to the receiver410, the transmitter415, the communications manager420, or a combination thereof) may support techniques for an iterative approach to isolate and compensate for linear offset and rotation angle offsets associated with misalignment between planar antenna arrays comprising multiple antenna elements.

FIG.5shows a block diagram of a device505that supports phase pre-compensation for misalignment in accordance with aspects of the present disclosure. The device505may be an example of aspects of a device405, a UE115, or a base station105as described herein. The device505may include a receiver510, a transmitter515, and a communications manager520. The device505can be implemented, at least in part, by one or both of a modem and a processor. Each of these components may be in communication with one another (for example, via one or more buses).

The receiver510may provide a means for receiving information such as packets, user data, control information, or any combination thereof associated with various information channels (for example, control channels, data channels, information channels related to phase pre-compensation for misalignment). Information may be passed on to other components of the device505. The receiver510may utilize a single antenna or a set of multiple antennas.

The transmitter515may provide a means for transmitting signals generated by other components of the device505. For example, the transmitter515may transmit information such as packets, user data, control information, or any combination thereof associated with various information channels (for example, control channels, data channels, information channels related to phase pre-compensation for misalignment). In some examples, the transmitter515may be co-located with a receiver510in a transceiver component. The transmitter515may utilize a single antenna or a set of multiple antennas.

The device505, or various components thereof, may be an example of means for performing various aspects of phase pre-compensation for misalignment as described herein. For example, the communications manager520may include a linear axis manager525, a rotational offset manager530, an offset indication manager535, a compensation manager540, or any combination thereof. The communications manager520may be an example of aspects of a communications manager420as described herein. In some examples, the communications manager520, or various components thereof, may be configured to perform various operations (for example, receiving, monitoring, transmitting) using or otherwise in cooperation with the receiver510, the transmitter515, or both. For example, the communications manager520may receive information from the receiver510, send information to the transmitter515, or be integrated in combination with the receiver510, the transmitter515, or both to receive information, transmit information, or perform various other operations as described herein.

The communications manager520may support wireless communication at a device in accordance with examples as disclosed herein. The linear axis manager525may be configured as or otherwise support a means for transmitting, from a first antenna of a first antenna array of the first device to a second antenna of a second antenna array of a second device, a first set of reference signals that includes one or more reference signals. The rotational offset manager530may be configured as or otherwise support a means for transmitting, from a first set of multiple antennas of the first antenna array to a second set of multiple antennas of the second antenna array, a second set of multiple reference signals. The offset indication manager535may be configured as or otherwise support a means for receiving, from the second device, an indication based on a linear offset and one or more rotational offsets estimated by the second device associated with the first set of reference signals and the second set of multiple reference signals. The compensation manager540may be configured as or otherwise support a means for communicating with the second device using the second antenna array is based on the indication.

Additionally or alternatively, the communications manager520may support wireless communication at a first device in accordance with examples as disclosed herein. The linear axis manager525may be configured as or otherwise support a means for receiving, at a first antenna of a first antenna array of the first device from a second antenna of a second antenna array of a second device, a first set of reference signals that includes one or more reference signals. The linear axis manager525may be configured as or otherwise support a means for measuring, based on receiving the first set of reference signals, one or more first phases for the first set of reference signals. The linear axis manager525may be configured as or otherwise support a means for estimating, based on the one or more first phases for the first set of reference signals, a linear offset between the first antenna array and the second antenna array. The rotational offset manager530may be configured as or otherwise support a means for receiving, at a first set of multiple antennas of the first antenna array of the first device from a second set of multiple antennas of the second antenna array of the second device, a second set of multiple reference signals. The rotational offset manager530may be configured as or otherwise support a means for measuring, based on receiving the second set of multiple reference signals, a second set of multiple phases of each of the second set of multiple reference signals. The rotational offset manager530may be configured as or otherwise support a means for estimating, based on the second set of multiple phases of the second set of multiple reference signals, one or more rotational offsets between the first antenna array and the second antenna array. The rotational offset manager530may be configured as or otherwise support a means for transmitting, to the second device, an indication based on the linear offset and the one or more rotational offsets.

FIG.6shows a block diagram of a communications manager620that supports phase pre-compensation for misalignment in accordance with aspects of the present disclosure. The communications manager620may be an example of aspects of a communications manager420, a communications manager520, or both, as described herein. The communications manager620, or various components thereof, may be an example of means for performing various aspects of phase pre-compensation for misalignment as described herein. For example, the communications manager620may include a linear axis manager625, a rotational offset manager630, an offset indication manager635, a compensation manager640, a linear axis offset manager645, an offset frequency manager650, a timing manager655, a linear axis adjustment manager660, a linear axis offset indication manager665, a rotational angle offset manager670, a phase accuracy manager675, an offset adjustment manager680, or any combination thereof. Each of these components may communicate, directly or indirectly, with one another (for example, via one or more buses).

The communications manager620may support wireless communication at a first device in accordance with examples as disclosed herein. The linear axis manager625may be configured as or otherwise support a means for transmitting, from a first antenna of a first antenna array of the first device to a second antenna of a second antenna array of the second device, a first set of reference signals that includes one or more reference signals. The rotational offset manager630may be configured as or otherwise support a means for transmitting, from a first set of multiple antennas of the first antenna array to a second set of multiple antennas of the second antenna array, a second set of multiple reference signals. The offset indication manager635may be configured as or otherwise support a means for receiving, from the second device, an indication based on a linear offset and one or more rotational offsets estimated by the second device associated with the first set of reference signals and the second set of multiple reference signals. The compensation manager640may be configured as or otherwise support a means for communicating with the second device using the first antenna array based on indication.

In some examples, the linear axis offset manager645may be configured as or otherwise support a means for adjusting one or more metrics for communications between the first antenna array and the second antenna array based on the indication, wherein the communicating with the second device using the first antenna array is based at least in part on adjusting the one or more metrics.

In some examples, the linear axis offset manager645may be configured as or otherwise support a means for receiving the indication based on the linear offset before transmitting the second set of multiple reference signals, where transmitting the second set of multiple reference signals is based on the indication.

In some examples, the linear axis offset manager645may be configured as or otherwise support a means for adjusting, before transmitting the second set of multiple reference signals, a first subset of one or more metrics based the indication.

In some examples, the offset frequency manager650may be configured as or otherwise support a means for transmitting the first set of reference signals at a first frequency. In some examples, the offset frequency manager650may be configured as or otherwise support a means for transmitting the second set of multiple reference signals at a second frequency, the first frequency within a frequency threshold of the second frequency.

In some examples, the indication includes information associated with one or more first phases for the first set of reference signals measured by the second device, the linear offset, a second set of multiple phases of the second set of multiple reference signals measured by the second device, the one or more rotational offsets, or any combination thereof.

In some examples, the timing manager655may be configured as or otherwise support a means for transmitting the first set of reference signals and the second set of multiple reference signals within a time threshold, where each of the linear offset and the one or more rotational offsets is based on the time threshold. In some examples, the first antenna is located at a central location of the first antenna array and the first set of multiple antennas are located at a non-central location of the first antenna array.

Additionally or alternatively, the communications manager620may support wireless communication at a first device in accordance with examples as disclosed herein. In some examples, the linear axis manager625may be configured as or otherwise support a means for receiving, at a first antenna of a first antenna array of the first device from a second antenna of a second antenna array of a second device, a first set of reference signals that includes one or more reference signals. In some examples, the linear axis manager625may be configured as or otherwise support a means for measuring, based on receiving the first set of reference signals, one or more first phases for the first set of reference signals. In some examples, the linear axis manager625may be configured as or otherwise support a means for estimating, based on the one or more first phases for the first set of reference signals, a linear offset between the first antenna array and the second antenna array. In some examples, the rotational offset manager630may be configured as or otherwise support a means for receiving, at a first set of multiple antennas of the first antenna array of the first device from a second set of multiple antennas of the second antenna array of the second device, a second set of multiple reference signals. In some examples, the rotational offset manager630may be configured as or otherwise support a means for measuring, based on receiving the second set of multiple reference signals, a second set of multiple phases of each of the second set of multiple reference signals. In some examples, the rotational offset manager630may be configured as or otherwise support a means for estimating, based on the second set of multiple phases of the second set of multiple reference signals, one or more rotational offsets between the first antenna array and the second antenna array. In some examples, the rotational offset manager630may be configured as or otherwise support a means for transmitting, to the second device, an indication based on the linear offset and the one or more rotational offsets.

In some examples, the linear axis adjustment manager660may be configured as or otherwise support a means for adjusting, before receiving the second set of multiple reference signals, a first subset of one or more metrics associated with communications between the first antenna array and the second antenna array based on the linear offset.

In some examples, the linear axis offset indication manager665may be configured as or otherwise support a means for transmitting, before receiving the second set of multiple reference signals, the indication of the linear offset.

In some examples, to support estimating the linear offset, the linear axis offset manager645may be configured as or otherwise support a means for measuring, based at least in part on the one or more first phases, a difference between a first linear distance between the first antenna and the second antenna and a second linear distance between the first antenna of the first antenna array and a third antenna of the second antenna array, wherein estimating the linear offset is based at least in part on the difference. In some examples, to support estimating the linear offset, the linear axis offset manager645may be configured as or otherwise support a means for comparing the distance to a physical distance between a center of the first antenna array and a center of the second antenna array. In some examples, the first linear distance and the second linear distance identifies a horizontal distance along a horizontal axis and a vertical distance along a vertical axis, the horizontal axis being perpendicular to the plane of the second antenna array and the vertical axis being along a vertical plane of the second antenna array.

In some examples, the linear axis offset manager645may be configured as or otherwise support a means for receiving the first set of reference signals at a first frequency. In some examples, the linear axis offset manager645may be configured as or otherwise support a means for receiving the second set of multiple reference signals at a second frequency, the first frequency within a frequency threshold of the second frequency.

In some examples, to support estimating the one or more rotational offsets, the rotational angle offset manager670may be configured as or otherwise support a means for estimating the one or more rotational offsets based on adjusting the position of the first antenna array for the linear offset.

In some examples, the phase accuracy manager675may be configured as or otherwise support a means for determining a phase accuracy associated with the first phase, the second set of multiple phases, or both, where the adjusting is based on the phase accuracy.

In some examples, the phase accuracy manager675may be configured as or otherwise support a means for determining a noise level for a channel between the first antenna array and the second antenna array, where the phase accuracy is based on the noise level for the channel.

In some examples, the indication includes information associated with the one or more first phases for the first set of reference signals, the linear offset, the second set of multiple phases for the second set of multiple reference signals, the one or more rotational offsets, or any combination thereof.

In some examples, the offset adjustment manager680may be configured as or otherwise support a means for adjusting one or more metrics for communications between the first antenna array and the second antenna array based on the linear offset and the one or more rotational offsets, wherein the communicating with the second device using the first antenna array is based at least in part on adjusting the one or more metrics.

In some examples, the timing manager655may be configured as or otherwise support a means for comparing two or more of phases measured for the first set of reference signals, the second set of multiple of reference signals, or both, based on first set of reference signals, the second set of multiple reference signals, or both, being received within a time threshold, where estimating the linear offset, the one or more rotational offsets, or both are based on the two or more of phases.

In some examples, the first antenna is located at a central location of the first antenna array and the first set of multiple antennas are located at a non-central location of the first antenna array.

FIG.7shows a diagram of a system including a device705that supports phase pre-compensation for misalignment in accordance with aspects of the present disclosure. The device705may be an example of or include the components of a device405, a device505, or a UE115as described herein. The device705may communicate wirelessly with one or more base stations105, UEs115, or any combination thereof. The device705may include components for bi-directional voice and data communications including components for transmitting and receiving communications, such as a communications manager720, an input/output (I/O) controller710, a transceiver715, an antenna725, a memory730, code735, and a processor740. These components may be in electronic communication or otherwise coupled (for example, operatively, communicatively, functionally, electronically, electrically) via one or more buses (for example, a bus745).

The I/O controller710may manage input and output signals for the device705. The I/O controller710may also manage peripherals not integrated into the device705. In some examples, the I/O controller710may represent a physical connection or port to an external peripheral. In some examples, the I/O controller710may utilize an operating system such as iOS®, ANDROID®, MS-DOS®, MS-WINDOWS®, OS/2®, UNIX®, LINUX®, or another known operating system. Additionally or alternatively, the I/O controller710may represent or interact with a modem, a keyboard, a mouse, a touchscreen, or a similar device. In some examples, the I/O controller710may be implemented as part of a processor, such as the processor740. In some examples, a user may interact with the device705via the I/O controller710or via hardware components controlled by the I/O controller710.

In some examples, the device705may include a single antenna725. However, in some other cases, the device705may have more than one antenna725, which may be capable of concurrently transmitting or receiving multiple wireless transmissions. The transceiver715may communicate bi-directionally, via the one or more antennas725, wired, or wireless links as described herein. For example, the transceiver715may represent a wireless transceiver and may communicate bi-directionally with another wireless transceiver. The transceiver715may also include a modem to modulate the packets, to provide the modulated packets to one or more antennas725for transmission, and to demodulate packets received from the one or more antennas725. The transceiver715, or the transceiver715and one or more antennas725, may be an example of a transmitter415, a transmitter515, a receiver410, a receiver510, or any combination thereof or component thereof, as described herein.

The memory730may include random access memory (RAM) and read-only memory (ROM). The memory730may store computer-readable, computer-executable code735including instructions that, when executed by the processor740, cause the device705to perform various functions described herein. The code735may be stored in a non-transitory computer-readable medium such as system memory or another type of memory. In some examples, the code735may not be directly executable by the processor740but may cause a computer (for example, when compiled and executed) to perform functions described herein. In some examples, the memory730may contain, among other things, a basic I/O system (BIOS) which may control basic hardware or software operation such as the interaction with peripheral components or devices.

The processor740may include an intelligent hardware device (for example, a general-purpose processor, a DSP, a 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 examples, the processor740may be configured to operate a memory array using a memory controller. In some other cases, a memory controller may be integrated into the processor740. The processor740may be configured to execute computer-readable instructions stored in a memory (for example, the memory730) to cause the device705to perform various functions (for example, functions or tasks supporting phase pre-compensation for misalignment). For example, the device705or a component of the device705may include a processor740and memory730coupled to the processor740, the processor740and memory730configured to perform various functions described herein.

The communications manager720may support wireless communication at a first device in accordance with examples as disclosed herein. For example, the communications manager720may be configured as or otherwise support a means for transmitting, from a first antenna of a first antenna array of the first device to a second antenna of a second antenna array of a second device, a first set of reference signals that includes one or more reference signals. The communications manager720may be configured as or otherwise support a means for transmitting, from a first set of multiple antennas of the first antenna array to a second set of multiple antennas of the second antenna array, a second set of multiple reference signals. The communications manager720may be configured as or otherwise support a means for receiving, from the second device, an indication based on a linear offset and one or more rotational offsets estimated by the second device associated with the first set of reference signals and the second set of multiple reference signals. The communications manager720may be configured as or otherwise support a means for communicating with the second device using the first antenna array based on the indication.

Additionally or alternatively, the communications manager720may support wireless communication at a first device in accordance with examples as disclosed herein. For example, the communications manager720may be configured as or otherwise support a means for receiving, at a first antenna of a first antenna array of the first device from a second antenna of a second antenna array of a second device, a first set of reference signals that includes one or more reference signals. The communications manager720may be configured as or otherwise support a means for measuring, basing at least in part on receiving the first set of reference signals, one or more first phases for the first set of reference signals. The communications manager720may be configured as or otherwise support a means for estimating, basing at least in part on the one or more first phases for the first set of reference signals, a linear offset between the first antenna array and the second antenna array. The communications manager720may be configured as or otherwise support a means for receiving, at a first set of multiple antennas of the first antenna array of the first device from a second set of multiple antennas of the second antenna array of the second device, a second set of multiple reference signals. The communications manager720may be configured as or otherwise support a means for measuring, basing at least in part on receiving the second set of multiple reference signals, a second set of multiple phases of each of the second set of multiple reference signals. The communications manager720may be configured as or otherwise support a means for estimating, basing at least in part on the second set of multiple phases of the second set of multiple reference signals, one or more rotational offsets between the first antenna array and the second antenna array. The communications manager720may be configured as or otherwise support a means for transmitting, to the second device, an indication based on the linear offset and the one or more rotational offsets.

By including or configuring the communications manager720in accordance with examples as described herein, the device705may support techniques for an iterative approach to isolate and compensate for linear offset and rotation offset offsets associated with misalignment between planar antenna arrays comprising multiple antenna elements.

In some examples, the communications manager720may be configured to perform various operations (for example, receiving, monitoring, transmitting) using or otherwise in cooperation with the transceiver715, the one or more antennas725, or any combination thereof. Although the communications manager720is illustrated as a separate component, in some examples, one or more functions described with reference to the communications manager720may be supported by or performed by the processor740, the memory730, the code735, or any combination thereof. For example, the code735may include instructions executable by the processor740to cause the device705to perform various aspects of phase pre-compensation for misalignment as described herein, or the processor740and the memory730may be otherwise configured to perform or support such operations.

FIG.8shows a diagram of a system including a device805that supports phase pre-compensation for misalignment in accordance with aspects of the present disclosure. The device805may be an example of or include the components of a device405, a device505, or a base station105as described herein. The device805may communicate wirelessly with one or more base stations105, UEs115, or any combination thereof. The device805may include components for bi-directional voice and data communications including components for transmitting and receiving communications, such as a communications manager820, a network communications manager810, a transceiver815, an antenna825, a memory830, code835, a processor840, and an inter-station communications manager845. These components may be in electronic communication or otherwise coupled (for example, operatively, communicatively, functionally, electronically, electrically) via one or more buses (for example, a bus850).

In some examples, the device805may include a single antenna825. However, in some other cases the device805may have more than one antenna825, which may be capable of concurrently transmitting or receiving multiple wireless transmissions. The transceiver815may communicate bi-directionally, via the one or more antennas825, wired, or wireless links as described herein. For example, the transceiver815may represent a wireless transceiver and may communicate bi-directionally with another wireless transceiver. The transceiver815may also include a modem to modulate the packets, to provide the modulated packets to one or more antennas825for transmission, and to demodulate packets received from the one or more antennas825. The transceiver815, or the transceiver815and one or more antennas825, may be an example of a transmitter415, a transmitter515, a receiver410, a receiver510, or any combination thereof or component thereof, as described herein.

The memory830may include RAM and ROM. The memory830may store computer-readable, computer-executable code835including instructions that, when executed by the processor840, cause the device805to perform various functions described herein. The code835may be stored in a non-transitory computer-readable medium such as system memory or another type of memory. In some examples, the code835may not be directly executable by the processor840but may cause a computer (for example, when compiled and executed) to perform functions described herein. In some examples, the memory830may contain, among other things, a BIOS which may control basic hardware or software operation such as the interaction with peripheral components or devices.

The processor840may include an intelligent hardware device (for example, a general-purpose processor, a DSP, a 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 examples, the processor840may be configured to operate a memory array using a memory controller. In some other cases, a memory controller may be integrated into the processor840. The processor840may be configured to execute computer-readable instructions stored in a memory (for example, the memory830) to cause the device805to perform various functions (for example, functions or tasks supporting phase pre-compensation for misalignment). For example, the device805or a component of the device805may include a processor840and memory830coupled to the processor840, the processor840and memory830configured to perform various functions described herein.

The inter-station communications manager845may manage communications with other base stations105and may include a controller or scheduler for controlling communications with UEs115in cooperation with other base stations105. For example, the inter-station communications manager845may coordinate scheduling for transmissions to UEs115for various interference mitigation techniques such as beamforming or joint transmission. In some examples, the inter-station communications manager845may provide an X2 interface within an LTE/LTE-A wireless communications network technology to provide communication between base stations105.

The communications manager820may support wireless communication at a first device in accordance with examples as disclosed herein. For example, the communications manager820may be configured as or otherwise support a means for transmitting, from a first antenna of a first antenna array of the first device to a second antenna of a second antenna array of a second device, a first set of reference signals that includes one or more reference signals. The communications manager820may be configured as or otherwise support a means for transmitting, from a first set of multiple antennas of the first antenna array to a second set of multiple antennas of the second antenna array, a second set of multiple reference signals. The communications manager820may be configured as or otherwise support a means for receiving, from the second device, an indication based on a linear offset and one or more rotational offsets estimated by the second device associated with the first set of reference signals and the second set of multiple reference signals. The communications manager820may be configured as or otherwise support a means for communicating with the second device using the first antenna array is based on the indication.

Additionally or alternatively, the communications manager820may support wireless communication at a first device in accordance with examples as disclosed herein. For example, the communications manager820may be configured as or otherwise support a means for receiving, at a first antenna of a first antenna array of the first device from a second antenna of a second antenna array of a second device, a first set of reference signals that includes one or more reference signals. The communications manager820may be configured as or otherwise support a means for measuring, basing at least in part on receiving the first set of reference signals, one or more first phases for the first set of reference signals. The communications manager820may be configured as or otherwise support a means for estimating, basing at least in part on the one or more first phases for the first set of reference signals, a linear offset between the first antenna array and the second antenna array. The communications manager820may be configured as or otherwise support a means for receiving, at a first set of multiple antennas of the first antenna array of the first device from a second set of multiple antennas of the second antenna array of the second device, a second set of multiple reference signals. The communications manager820may be configured as or otherwise support a means for measuring, basing at least in part on receiving the second set of multiple reference signals, a second set of multiple phases of each of the second set of multiple reference signals. The communications manager820may be configured as or otherwise support a means for estimating, basing at least in part on the second set of multiple phases of the second set of multiple reference signals, one or more rotational offsets between the first antenna array and the second antenna array. The communications manager820may be configured as or otherwise support a means for transmitting, to the second device, an indication based on the linear offset and the one or more rotational offsets.

By including or configuring the communications manager820in accordance with examples as described herein, the device805may support techniques for an iterative approach to isolate and compensate for linear offset and rotation offset offsets associated with misalignment between planar antenna arrays comprising multiple antenna elements.

FIG.9shows a flowchart illustrating a method900that supports phase pre-compensation for misalignment in accordance with aspects of the present disclosure. The operations of the method900may be implemented by a UE or a base station or its components as described herein. For example, the operations of the method900may be performed by a UE115or a base station105as described with reference toFIGS.1-8. In some examples, a UE or a base station may execute a set of instructions to control the functional elements of the UE or the base station to perform the described functions. Additionally or alternatively, the UE or the base station may perform aspects of the described functions using special-purpose hardware.

At905, the method may include transmitting, from a first antenna of a first antenna array of the first device to a second antenna of a second antenna array of a second device, a first set of reference signals that includes one or more reference signals. The operations of905may be performed in accordance with examples as disclosed herein. In some examples, aspects of the operations of905may be performed by a linear axis manager625as described with reference toFIG.6.

At910, the method may include transmitting, from a first set of multiple antennas of the first antenna array to a second set of multiple antennas of the second antenna array, a second set of multiple reference signals. The operations of910may be performed in accordance with examples as disclosed herein. In some examples, aspects of the operations of910may be performed by a rotational offset manager630as described with reference toFIG.6.

At915, the method may include receiving, from the second device, an indication based on a linear offset and one or more rotational offsets estimated by the second device associated with the first set of reference signals and the second set of multiple reference signals. The operations of915may be performed in accordance with examples as disclosed herein. In some examples, aspects of the operations of915may be performed by an offset indication manager635as described with reference toFIG.6.

At920, the method may include communicating with the second device using the first antenna array is based on the indication. The operations of925may be performed in accordance with examples as disclosed herein. In some examples, aspects of the operations of925may be performed by a compensation manager640as described with reference toFIG.6.

FIG.10shows a flowchart illustrating a method1000that supports phase pre-compensation for misalignment in accordance with aspects of the present disclosure. The operations of the method1000may be implemented by a UE or a base station or its components as described herein. For example, the operations of the method1000may be performed by a UE115or a base station105as described with reference toFIGS.1-8. In some examples, a UE or a base station may execute a set of instructions to control the functional elements of the UE or the base station to perform the described functions. Additionally or alternatively, the UE or the base station may perform aspects of the described functions using special-purpose hardware.

At1005, the method may include transmitting, from a first antenna of a first antenna array of the first device to a second antenna of a second antenna array of a second device, a first set of reference signals that includes one or more reference signals. The operations of1005may be performed in accordance with examples as disclosed herein. In some examples, aspects of the operations of1005may be performed by a linear axis manager625as described with reference toFIG.6.

At1010, the method may include receiving an indication based on a linear offset before transmitting a second set of multiple reference signals, where transmitting the second set of multiple reference signals is based on the indication. The operations of1010may be performed in accordance with examples as disclosed herein. In some examples, aspects of the operations of1010may be performed by a linear axis offset manager645as described with reference toFIG.6.

At1015, the method may include transmitting, from a first set of multiple antennas of the first antenna array to a second set of multiple antennas of the second antenna array, a second set of multiple reference signals. The operations of1015may be performed in accordance with examples as disclosed herein. In some examples, aspects of the operations of1015may be performed by a rotational offset manager630as described with reference toFIG.6.

At1020, the method may include receiving, from the second device, an indication based on the linear offset and one or more rotational offsets estimated by the second device associated with the first set of reference signals and the second set of multiple reference signals. The operations of1020may be performed in accordance with examples as disclosed herein. In some examples, aspects of the operations of1020may be performed by an offset indication manager635as described with reference toFIG.6.

At1025, the method may include communicating with the second device using the first antenna array based on the indication. The operations of1030may be performed in accordance with examples as disclosed herein. In some examples, aspects of the operations of1030may be performed by a compensation manager640as described with reference toFIG.6.

FIG.11shows a flowchart illustrating a method1100that supports phase pre-compensation for misalignment in accordance with aspects of the present disclosure. The operations of the method1100may be implemented by a UE or a base station or its components as described herein. For example, the operations of the method1100may be performed by a UE115or a base station105as described with reference toFIGS.1-8. In some examples, a UE or a base station may execute a set of instructions to control the functional elements of the UE or the base station to perform the described functions. Additionally or alternatively, the UE or the base station may perform aspects of the described functions using special-purpose hardware.

At1105, the method may include receiving, at a first antenna of a first antenna array of the first device from a second antenna of a second antenna array of a second device, a first set of reference signals that includes one or more reference signals. The operations of1105may be performed in accordance with examples as disclosed herein. In some examples, aspects of the operations of1105may be performed by a linear axis manager625as described with reference toFIG.6.

At1110, the method may include measuring, based on receiving the first set of reference signals, one or more first phases for the first set of reference signals. The operations of1110may be performed in accordance with examples as disclosed herein. In some examples, aspects of the operations of1110may be performed by a linear axis manager625as described with reference toFIG.6.

At1115, the method may include estimating, based on the one or more first phases for the first set of reference signals, a linear offset between the first antenna array and the second antenna array. The operations of1115may be performed in accordance with examples as disclosed herein. In some examples, aspects of the operations of1115may be performed by a linear axis manager625as described with reference toFIG.6.

At1120, the method may include receiving, at a first set of multiple antennas of the first antenna array of the first device from a second set of multiple antennas of the second antenna array of the second device, a second set of multiple reference signals. The operations of1120may be performed in accordance with examples as disclosed herein. In some examples, aspects of the operations of1120may be performed by a rotational offset manager630as described with reference toFIG.6.

At1125, the method may include measuring, based on receiving the second set of multiple reference signals, a second set of multiple phases of each of the second set of multiple reference signals. The operations of1125may be performed in accordance with examples as disclosed herein. In some examples, aspects of the operations of1125may be performed by a rotational offset manager630as described with reference toFIG.6.

At1130, the method may include estimating, based on the second set of multiple phases of the second set of multiple reference signals, one or more rotational offsets between the first antenna array and the second antenna array. The operations of1130may be performed in accordance with examples as disclosed herein. In some examples, aspects of the operations of1130may be performed by a rotational offset manager630as described with reference toFIG.6.

At1135, the method may include transmitting, to the second device, an indication based on the linear offset and the one or more rotational offsets. The operations of1135may be performed in accordance with examples as disclosed herein. In some examples, aspects of the operations of1135may be performed by a rotational offset manager630as described with reference toFIG.6.

FIG.12shows a flowchart illustrating a method1200that supports phase pre-compensation for misalignment in accordance with aspects of the present disclosure. The operations of the method1200may be implemented by a UE or a base station or its components as described herein. For example, the operations of the method1200may be performed by a UE115or a base station105as described with reference toFIGS.1-8. In some examples, a UE or a base station may execute a set of instructions to control the functional elements of the UE or the base station to perform the described functions. Additionally or alternatively, the UE or the base station may perform aspects of the described functions using special-purpose hardware.

At1205, the method may include receiving, at a first antenna of a first antenna array of the first device from a second antenna of a second antenna array of a second device, a first set of reference signals that includes one or more reference signals. The operations of1205may be performed in accordance with examples as disclosed herein. In some examples, aspects of the operations of1205may be performed by a linear axis manager625as described with reference toFIG.6.

At1210, the method may include measuring, based on receiving the first set of reference signals, one or more first phases for the first set of reference signals. The operations of1210may be performed in accordance with examples as disclosed herein. In some examples, aspects of the operations of1210may be performed by a linear axis manager625as described with reference toFIG.6.

At1215, the method may include estimating, based on the one or more first phases for the first set of reference signals, a linear offset between the first antenna array and the second antenna array. The operations of1215may be performed in accordance with examples as disclosed herein. In some examples, aspects of the operations of1215may be performed by a linear axis manager625as described with reference toFIG.6.

At1220, the method may include adjusting, before receiving the second set of multiple reference signals, a first subset of one or more metrics associated with communications between the first antenna array and the second antenna array based on the linear offset. The operations of1220may be performed in accordance with examples as disclosed herein. In some examples, aspects of the operations of1220may be performed by a linear axis adjustment manager660as described with reference toFIG.6.

At1225, the method may include receiving, at a first set of multiple antennas of the first antenna array of the first device from a second set of multiple antennas of the second antenna array of the second device, a second set of multiple reference signals. The operations of1225may be performed in accordance with examples as disclosed herein. In some examples, aspects of the operations of1225may be performed by a rotational offset manager630as described with reference toFIG.6.

At1230, the method may include measuring, based on receiving the second set of multiple reference signals, a second set of multiple phases of each of the second set of multiple reference signals. The operations of1230may be performed in accordance with examples as disclosed herein. In some examples, aspects of the operations of1230may be performed by a rotational offset manager630as described with reference toFIG.6.

At1235, the method may include estimating, based on the second set of multiple phases of the second set of multiple reference signals, one or more rotational offsets between the first antenna array and the second antenna array. The operations of1235may be performed in accordance with examples as disclosed herein. In some examples, aspects of the operations of1235may be performed by a rotational offset manager630as described with reference toFIG.6.

At1240, the method may include transmitting, to the second device, an indication based on the linear offset and the one or more rotational offsets. The operations of1240may be performed in accordance with examples as disclosed herein. In some examples, aspects of the operations of1240may be performed by a rotational offset manager630as described with reference toFIG.6.

FIG.13shows a flowchart illustrating a method1300that supports phase pre-compensation for misalignment in accordance with aspects of the present disclosure. The operations of the method1300may be implemented by a UE or a base station or its components as described herein. For example, the operations of the method1300may be performed by a UE115or a base station105as described with reference toFIGS.1through8. In some examples, a UE or a base station may execute a set of instructions to control the functional elements of the UE or the base station to perform the described functions. Additionally or alternatively, the UE or the base station may perform aspects of the described functions using special-purpose hardware.

At1305, the method may include receiving, at a first antenna of a first antenna array of the first device from a second antenna of a second antenna array of a second device, a first set of reference signals that includes one or more reference signals. The operations of1305may be performed in accordance with examples as disclosed herein. In some examples, aspects of the operations of1305may be performed by a linear axis manager625as described with reference toFIG.6.

At1310, the method may include measuring, based on receiving the first set of reference signals, one or more first phases for the first set of reference signals. The operations of1310may be performed in accordance with examples as disclosed herein. In some examples, aspects of the operations of1310may be performed by a linear axis manager625as described with reference toFIG.6.

At1315, the method may include estimating, based on the one or more first phases for the first set of reference signals, a linear offset between the first antenna array and the second antenna array. The operations of1315may be performed in accordance with examples as disclosed herein. In some examples, aspects of the operations of1315may be performed by a linear axis manager625as described with reference toFIG.6.

At1320, the method may include transmitting, before receiving the second set of multiple reference signals, the indication of the linear offset. The operations of1320may be performed in accordance with examples as disclosed herein. In some examples, aspects of the operations of1320may be performed by a linear axis offset indication manager665as described with reference toFIG.6.

At1325, the method may include receiving, at a first set of multiple antennas of the first antenna array of the first device from a second set of multiple antennas of the second antenna array of the second device, a second set of multiple reference signals. The operations of1325may be performed in accordance with examples as disclosed herein. In some examples, aspects of the operations of1325may be performed by a rotational offset manager630as described with reference toFIG.6.

At1330, the method may include measuring, based on receiving the second set of multiple reference signals, a second set of multiple phases of each of the second set of multiple reference signals. The operations of1330may be performed in accordance with examples as disclosed herein. In some examples, aspects of the operations of1330may be performed by a rotational offset manager630as described with reference toFIG.6.

At1335, the method may include estimating, based on the second set of multiple phases of the second set of multiple reference signals, one or more rotational offsets between the first antenna array and the second antenna array. The operations of1335may be performed in accordance with examples as disclosed herein. In some examples, aspects of the operations of1335may be performed by a rotational offset manager630as described with reference toFIG.6.

At1340, the method may include transmitting, to the second device, an indication based on the linear offset and the one or more rotational offsets. The operations of1340may be performed in accordance with examples as disclosed herein. In some examples, aspects of the operations of1340may be performed by a rotational offset manager630as described with reference toFIG.6.

Aspect 1: A method for wireless communication at a first device, comprising: transmitting, from a first antenna of a first antenna array of the first device to a second antenna of a second antenna array of a second device, a first set of reference signals that includes one or more reference signals; transmitting, from a first plurality of antennas of the first antenna array to a second plurality of antennas of the second antenna array, a second plurality of reference signals; receiving, from the second device, an indication based at least in part on a linear offset and one or more rotational offsets estimated by the second device associated with the first set of reference signals and the second plurality of reference signals; and communicating with the second device using the first antenna array based at least in part on the indication.

Aspect 2: The method of aspect 1, further comprising: adjusting one or more metrics for communications between the first antenna array and the second antenna array based at least in part on the indication, wherein the communicating with the second device using the first antenna array is based at least in part on adjusting the one or more metrics.

Aspect 3: The method of any of aspects 1 through 2, further comprising receiving the indication based at least in part on the linear offset before transmitting the second plurality of reference signals, wherein transmitting the second plurality of reference signals is based at least in part on the indication.

Aspect 4: The method of aspect 3, further comprising adjusting, before transmitting the second plurality of reference signals, a first subset of one or more metrics based at least in part on the indication.

Aspect 5: The method of any of aspects 1 through 4, wherein the first set of reference signals are transmitted at a first frequency that is within a frequency threshold of a second frequency used for transmitting the second plurality of reference signals.

Aspect 6: The method of any of aspects 1 through 5, wherein the indication comprises information associated with one or more first phases for the first set of reference signals measured by the second device, the linear offset, a second plurality of phases for the second plurality of reference signals measured by the second device, the one or more rotational offsets, or any combination thereof.

Aspect 7: The method of any of aspects 1 through 6, wherein the first antenna is located at a central location of the first antenna array and the first plurality of antennas are located at a non-central location of the first antenna array.

Aspect 8: A method for wireless communication at a first device, comprising: receiving, at a first antenna of a first antenna array of the first device from a second antenna of a second antenna array of a second device, a first set of reference signals that includes one or more reference signals; measuring, based at least in part on receiving the first set of reference signals, one or more first phases for the first set of reference signals; estimating, based at least in part on the one or more first phases for the first set of reference signals, a linear offset between the first antenna array and the second antenna array; receiving, at a first plurality of antennas of the first antenna array of the first device from a second plurality of antennas of the second antenna array of the second device, a second plurality of reference signals; measuring, based at least in part on receiving the second plurality of reference signals, a second plurality of phases of each of the second plurality of reference signals; estimating, based at least in part on the second plurality of phases of the second plurality of reference signals, one or more rotational offsets between the first antenna array and the second antenna array; and transmitting, to the second device, an indication based at least in part on the linear offset and the one or more rotational offsets.

Aspect 9: The method of aspect 8, further comprising adjusting, before receiving the second plurality of reference signals, a first subset of one or more metrics associated with communications between the first antenna array and the second antenna array based on the linear offset.

Aspect 10: The method of any of aspects 8 through 9, further comprising transmitting, before receiving the second plurality of reference signals, the indication of the linear offset.

Aspect 11: The method of any of aspects 8 through 10, wherein estimating the linear offset comprises: measuring, based at least in part on the one or more first phases, a difference between a first linear distance between the first antenna and the second antenna and a second linear distance between the first antenna of the first antenna array and a third antenna of the second antenna array, wherein estimating the linear offset is based at least in part on the difference.

Aspect 12: The method of aspect 11, wherein the first linear distance and the second linear distance identifies a horizontal distance along a horizontal axis and a vertical distance along a vertical axis, the horizontal axis being perpendicular to the plane of the second antenna array and the vertical axis being along a vertical plane of the second antenna array.

Aspect 13: The method of any of aspects 11 through 12, wherein the first set of reference signals are transmitted at a first frequency that is within a frequency threshold of a second frequency used for transmitting the second plurality of reference signals.

Aspect 14: The method of any of aspects 8 through 13, wherein estimating the one or more rotational offsets comprises: estimating the one or more rotational offsets based at least in part on adjusting the position of the first antenna array for the linear offset.

Aspect 15: The method of any of aspects 8 through 14, further comprising determining a phase accuracy associated with the one or more first phases, the second plurality of phases, or both, wherein the adjusting is based at least in part on the phase accuracy.

Aspect 16: The method of aspect 15, further comprising determining a noise level for a channel between the first antenna array and the second antenna array, wherein the phase accuracy is based at least in part on the noise level for the channel.

Aspect 17: The method of any of aspects 8 through 16, wherein the indication comprises information associated with the one or more first phases for the first set of reference signals, the linear offset, the second plurality of phases for the second plurality of reference signals, the one or more rotational offsets, or any combination thereof.

Aspect 18: The method of any of aspects 8 through 17, further comprising adjusting one or more metrics for communications between the first antenna array and the second antenna array based at least in part on the linear offset and the one or more rotational offsets.

Aspect 19: The method of any of aspects 8 through 18, wherein the first antenna is located at a central location of the first antenna array and the first plurality of antennas are located at a non-central location of the first antenna array.

Aspect 20: The method of any of aspects 8 through 19, wherein each antenna of the first plurality of antennas are positioned at a location of the first antenna array that corresponds to each antenna of the second plurality of antennas of the second antenna array.

Aspect 22: An apparatus for wireless communication at a first device, comprising at least one means for performing a method of any of aspects 1 through 7.

Aspect 25: An apparatus for wireless communication at a first device, comprising at least one means for performing a method of any of aspects 8 through 20.

Aspect 26: A non-transitory computer-readable medium storing code for wireless communication at a first device, the code comprising instructions executable by a processor to perform a method of any of aspects 8 through 20.