Techniques for estimating misalignment between antenna arrays

Abstract

Methods, systems, and devices for wireless communication are described. A first wireless device may be configured to transmit one or more reference signals to a second wireless device using a first antenna array at the first wireless device and according to a first pre-decoder matrix. The first wireless device may receive a feedback message from the second wireless device based on the one or more reference signals, the feedback message indicating an estimated rotational misalignment, an estimated spatial misalignment, or both between the first antenna array at the first wireless device and a second antenna array at the second wireless device. The first wireless device may then send a message to the second wireless device according to a second pre-decoder matrix that is modified relative to the first pre-decoder matrix based at least in part on the estimated rotational misalignment, the estimated spatial misalignment, or both.

Description

[0001] Cross-references

[0002] This patent application claims the benefit of U.S. patent application No. 18 / 156,690, filed by Park et al. on January 19, 2023, entitled “TECHNIQUES FORESTIMATING MISALIGNMENT BETWEEN ANTENNA ARRAYS,” which is assigned to the assignee of this application and is expressly incorporated herein by reference. Technical Field

[0003] The following relates to wireless communications, including techniques for estimating misalignment between antenna arrays. Background Art

[0004] Wireless communication systems are widely deployed to provide various types of communication content, such as voice, video, packet data, messaging, broadcast, and the like. These systems may be able to support communication with multiple users by sharing available system resources (e.g., time, frequency, and power). Examples of such multiple access systems include fourth generation (4G) systems (such as long term evolution (LTE) systems, advanced LTE (LTE-A) systems, or LTE-A Pro systems) and fifth generation (5G) systems (which may be referred to as new radio (NR) systems). These systems may employ techniques such as code division multiple access (CDMA), time division multiple access (TDMA), frequency division multiple access (FDMA), orthogonal FDMA (OFDMA), or discrete Fourier transform spread orthogonal frequency division multiplexing (DFT-S-OFDM). A wireless multiple access communication system may include one or more base stations, each of which supports wireless communication for communication devices, which may be referred to as user equipment (UE).

[0005] In some wireless communication systems, wireless devices exchange signaling with each other using antenna arrays, which can include many individual antenna elements. For example, a transmitting (Tx) device can use a Tx antenna array to send a signal to a receiving (Rx) device, where the Rx device receives the signal using an Rx antenna array. However, when the Tx antenna array and the Rx antenna array are misaligned, the efficiency and reliability of communication between the antenna arrays can be adversely affected. Summary of the Invention

[0006] The described techniques relate to improved methods, systems, devices, and apparatuses that support techniques for estimating misalignment between antenna arrays. Generally speaking, aspects of the present disclosure relate to techniques for estimating misalignment between a transmit (Tx) antenna array and a receive (Rx) antenna array. Specifically, the techniques described herein can be used to estimate rotational misalignment and / or translational misalignment between antenna arrays, wherein the estimated misalignment can be used to adjust precoding matrices and / or post-processing matrices used for communication between the respective devices.

[0007] A method is described. The method may include transmitting one or more reference signals to a second wireless device using a first antenna array at a first wireless device and based on a first predecoder matrix; receiving a feedback message from the second wireless device based on the one or more reference signals, the feedback message indicating an estimated rotational misalignment, an estimated spatial misalignment, or both between the first antenna array at the first wireless device and a second antenna array at the second wireless device; and transmitting a message to the second wireless device based on a second predecoder matrix, the second predecoder matrix modified relative to the first predecoder matrix based on the estimated rotational misalignment, the estimated spatial misalignment, or both.

[0008] An apparatus is described. The apparatus may include a processor, a memory coupled to the processor, and instructions stored in the memory. The instructions are executable by the processor to cause the apparatus to transmit one or more reference signals to a second wireless device using a first antenna array at a first wireless device and based on a first predecoder matrix; receive a feedback message from the second wireless device based on the one or more reference signals, the feedback message indicating an estimated rotational misalignment, an estimated spatial misalignment, or both, between the first antenna array at the first wireless device and a second antenna array at the second wireless device; and transmit a message to the second wireless device based on a second predecoder matrix, the second predecoder matrix modified relative to the first predecoder matrix based on the estimated rotational misalignment, the estimated spatial misalignment, or both.

[0009] Another apparatus is described. The apparatus may include means for transmitting one or more reference signals to a second wireless device using a first antenna array at a first wireless device and based on a first pre-decoder matrix; means for receiving a feedback message from the second wireless device based on the one or more reference signals, the feedback message indicating an estimated rotational misalignment, an estimated spatial misalignment, or both between the first antenna array at the first wireless device and a second antenna array at the second wireless device; and means for transmitting a message to the second wireless device based on a second pre-decoder matrix, the second pre-decoder matrix modified relative to the first pre-decoder matrix based on the estimated rotational misalignment, the estimated spatial misalignment, or both.

[0010] A non-transitory computer-readable medium storing code is described. The code may include instructions executable by a processor to: transmit one or more reference signals to a second wireless device using a first antenna array at a first wireless device and based on a first pre-decoder matrix; receive a feedback message from the second wireless device based on the one or more reference signals, the feedback message indicating an estimated rotational misalignment, an estimated spatial misalignment, or both between the first antenna array at the first wireless device and a second antenna array at the second wireless device; and transmit a message to the second wireless device based on a second pre-decoder matrix, the second pre-decoder matrix modified relative to the first pre-decoder matrix based on the estimated rotational misalignment, the estimated spatial misalignment, or both.

[0011] Some examples of the methods, apparatus, and non-transitory computer-readable media described herein may also include operations, features, components, or instructions for transmitting one or more reference signals at the same phase across a set of multiple antenna elements of a first antenna array according to a first pre-decoder matrix, wherein the estimated rotational misalignment may be based on transmitting the one or more reference signals at the same phase.

[0012] In some examples of the methods, apparatus, and non-transitory computer-readable media described herein, the estimated rotational misalignment may be estimated relative to one or more axes that may be perpendicular to an additional axis extending from the first antenna array to the second antenna array.

[0013] Some examples of the methods, apparatus, and non-transitory computer-readable media described herein may also include operations, features, components, or instructions for transmitting one or more reference signals with a phase ramp across a set of multiple antenna elements of a first antenna array according to a first pre-decoder matrix, wherein the estimated rotational misalignment may be based on transmitting the one or more reference signals with the phase ramp.

[0014] In some examples of the methods, apparatus, and non-transitory computer-readable media described herein, the estimated rotational misalignment may be estimated relative to an axis extending from the first antenna array to the second antenna array.

[0015] Some examples of the methods, apparatus, and non-transitory computer-readable media described herein may also include operations, features, components, or instructions for transmitting a first subset of reference signals from one or more reference signals via a first subset of antenna elements of a first antenna array, wherein the first subset of reference signals may be transmitted at a first phase; and transmitting a second subset of reference signals from one or more reference signals via a second subset of antenna elements of the first antenna array, wherein the second subset of reference signals may be transmitted at a second phase that may be different from the first phase, wherein the estimated spatial misalignment may be based on transmitting the first subset of reference signals at the first phase and transmitting the second subset of reference signals at the second phase.

[0016] In some examples of the methods, apparatus, and non-transitory computer-readable media described herein, the second phase includes an opposite sign compared to the first phase.

[0017] In some examples of the methods, apparatus, and non-transitory computer-readable media described herein, the estimated spatial misalignment can be estimated relative to one or more axes that can be perpendicular to an additional axis extending from the first antenna array to the second antenna array.

[0018] Some examples of the methods, apparatuses, and non-transitory computer-readable media described herein may also include operations, features, components, or instructions for communicating a control message indicating a reference signal waveform according to which one or more reference signals may be sent.

[0019] Some examples of the methods, apparatus, and non-transitory computer-readable media described herein may also include operations, features, components, or instructions for: receiving one or more additional reference signals from a second wireless device using the first antenna array; and sending a second feedback message to the second wireless device based on the one or more additional reference signals, the second feedback message indicating a second estimated rotational misalignment, a second estimated spatial misalignment, or both, between the first antenna array at the first wireless device, the second antenna array at the second wireless device, wherein the second pre-decoder matrix may be modified relative to the first pre-decoder matrix based on the second estimated rotational misalignment, the second estimated spatial misalignment, or both.

[0020] Some examples of the methods, apparatus, and non-transitory computer-readable media described herein may also include operations, features, components, or instructions for performing measurements on one or more additional reference signals, wherein the second estimated rotational misalignment, the second estimated spatial misalignment, or both may be based on the measurements.

[0021] Some examples of the methods, apparatus, and non-transitory computer-readable media described herein may also include operations, features, components, or instructions for estimating a set of multiple phases along a second axis, a third axis, or both associated with one or more additional reference signals, where the second axis and the third axis may be perpendicular to the first axis, and where the second estimated rotational misalignment may be based on the set of multiple phases.

[0022] Some examples of the methods, apparatus, and non-transitory computer-readable media described herein may also include operations, features, components, or instructions for comparing one or more additional reference signals to the reference signal waveform, wherein the second estimated rotational misalignment, the second estimated spatial misalignment, or both may be based on the comparison.

[0023] Some examples of the methods, apparatus, and non-transitory computer-readable media described herein may also include operations, features, components, or instructions for determining a channel estimation matrix associated with a channel between the first antenna array and the second antenna array based on the estimated rotational misalignment, the estimated spatial misalignment, or both, wherein the second pre-decoder matrix may be modified relative to the first pre-decoder matrix based on the channel estimation matrix.

[0024] In some examples of the methods, apparatus, and non-transitory computer-readable media described herein, the estimated spatial misalignment includes a parallel shift misalignment along one or more axes relative to the first antenna array, the second antenna array, or both.

[0025] A method is described. The method may include receiving one or more reference signals from a first wireless device using a second antenna array at a second wireless device and based on a first post-processing matrix; sending a feedback message to the first wireless device based on the one or more reference signals, the feedback message indicating an estimated rotational misalignment, an estimated spatial misalignment, or both between the second antenna array at the second wireless device and a first antenna array at the first wireless device; and receiving a message from the first wireless device based on a second post-processing matrix, the second post-processing matrix modified relative to the first post-processing matrix based on the estimated rotational misalignment, the estimated spatial misalignment, or both.

[0026] An apparatus is described. The apparatus may include a processor, a memory coupled to the processor, and instructions stored in the memory. The instructions are executable by the processor to cause the apparatus to use a second antenna array at a second wireless device and receive one or more reference signals from a first wireless device based on a first post-processing matrix; send a feedback message to the first wireless device based on the one or more reference signals, the feedback message indicating an estimated rotational misalignment, an estimated spatial misalignment, or both between the second antenna array at the second wireless device and a first antenna array at the first wireless device; and receive a message from the first wireless device based on a second post-processing matrix, the second post-processing matrix modified relative to the first post-processing matrix based on the estimated rotational misalignment, the estimated spatial misalignment, or both.

[0027] Another apparatus is described. The apparatus may include means for receiving one or more reference signals from a first wireless device using a second antenna array at a second wireless device and based on a first post-processing matrix; means for sending a feedback message to the first wireless device based on the one or more reference signals, the feedback message indicating an estimated rotational misalignment, an estimated spatial misalignment, or both between the second antenna array at the second wireless device and a first antenna array at the first wireless device; and means for receiving a message from the first wireless device based on a second post-processing matrix, the second post-processing matrix modified relative to the first post-processing matrix based on the estimated rotational misalignment, the estimated spatial misalignment, or both.

[0028] A non-transitory computer-readable medium storing code is described. The code may include instructions executable by a processor to: receive one or more reference signals from a first wireless device using a second antenna array at a second wireless device and based on a first post-processing matrix; send a feedback message to the first wireless device based on the one or more reference signals, the feedback message indicating an estimated rotational misalignment, an estimated spatial misalignment, or both between the second antenna array at the second wireless device and a first antenna array at the first wireless device; and receive a message from the first wireless device based on a second post-processing matrix, the second post-processing matrix modified relative to the first post-processing matrix based on the estimated rotational misalignment, the estimated spatial misalignment, or both.

[0029] In some examples of the methods, apparatus, and non-transitory computer-readable media described herein, the estimated rotational misalignment may be estimated relative to one or more axes that may be perpendicular to an additional axis extending from the first antenna array to the second antenna array.

[0030] In some examples of the methods, apparatus, and non-transitory computer-readable media described herein, the estimated rotational misalignment may be estimated relative to an axis extending from the first antenna array to the second antenna array.

[0031] In some examples of the methods, apparatus, and non-transitory computer-readable media described herein, the estimated spatial misalignment can be estimated relative to one or more axes that can be perpendicular to an additional axis extending from the first antenna array to the second antenna array.

[0032] Some examples of the methods, apparatuses, and non-transitory computer-readable media described herein may also include operations, features, components, or instructions for communicating a control message indicating a reference signal waveform, wherein one or more reference signals may be communicated according to the reference signal waveform.

[0033] Some examples of the methods, apparatus, and non-transitory computer-readable media described herein may also include operations, features, components, or instructions for: transmitting one or more additional reference signals to the first wireless device using the second antenna array; and receiving a second feedback message from the first wireless device based on the one or more additional reference signals, the second feedback message indicating a second estimated rotational misalignment, a second estimated spatial misalignment, or both, between the first antenna array at the first wireless device, and the second antenna array at the second wireless device, wherein the second post-processing matrix may be modified relative to the first post-processing matrix based on the second estimated rotational misalignment, the second estimated spatial misalignment, or both.

[0034] Some examples of the methods, apparatus, and non-transitory computer-readable media described herein may also include operations, features, components, or instructions for performing measurements on one or more reference signals, wherein the estimated rotational misalignment, the estimated spatial misalignment, or both may be based on the measurements.

[0035] Some examples of the methods, apparatus, and non-transitory computer-readable media described herein may also include operations, features, components, or instructions for estimating a set of multiple phases along a second axis, a third axis, or both associated with one or more reference signals, where the second axis and the third axis may be perpendicular to the first axis, and where the estimated rotational misalignment may be based on the set of multiple phases.

[0036] Some examples of the methods, apparatus, and non-transitory computer-readable media described herein may also include operations, features, components, or instructions for comparing one or more reference signals to a reference signal waveform, wherein the estimated rotational misalignment, the estimated spatial misalignment, or both may be based on the comparison.

[0037] Some examples of the methods, apparatus, and non-transitory computer-readable media described herein may also include operations, features, components, or instructions for determining a channel estimation matrix associated with a channel between the first antenna array and the second antenna array based on an estimated rotational misalignment, an estimated spatial misalignment, or both, wherein the second post-processing matrix may be modified relative to the first post-processing matrix based on the channel estimation matrix.

[0038] In some examples of the methods, apparatus, and non-transitory computer-readable media described herein, the estimated spatial misalignment includes a parallel shift misalignment along one or more axes relative to the first antenna array, the second antenna array, or both. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] Figure 1 An example of a wireless communication system supporting techniques for estimating misalignment between antenna arrays in accordance with one or more aspects of the present disclosure is illustrated.

[0040] Figure 2 An example of a wireless communication system supporting techniques for estimating misalignment between antenna arrays in accordance with one or more aspects of the present disclosure is illustrated.

[0041] Figure 3 Examples of misalignment configurations supporting techniques for estimating misalignment between antenna arrays in accordance with one or more aspects of the present disclosure are illustrated.

[0042] Figure 4 Examples of misalignment configurations supporting techniques for estimating misalignment between antenna arrays in accordance with one or more aspects of the present disclosure are illustrated.

[0043] Figure 5 Examples of misalignment configurations supporting techniques for estimating misalignment between antenna arrays in accordance with one or more aspects of the present disclosure are illustrated.

[0044] Figure 6 Examples of misalignment configurations supporting techniques for estimating misalignment between antenna arrays in accordance with one or more aspects of the present disclosure are illustrated.

[0045] Figure 7 An example of a process flow supporting techniques for estimating misalignment between antenna arrays in accordance with one or more aspects of the present disclosure is illustrated.

[0046] Figure 8 and Figure 9 A block diagram of a device supporting techniques for estimating misalignment between antenna arrays in accordance with one or more aspects of the present disclosure is shown.

[0047] Figure 10A block diagram of a communication manager supporting techniques for estimating misalignment between antenna arrays in accordance with one or more aspects of the present disclosure is shown.

[0048] Figure 11 A diagram is shown of a system including a device supporting techniques for estimating misalignment between antenna arrays in accordance with one or more aspects of the present disclosure.

[0049] Figure 12 and Figure 13 A block diagram of a device supporting techniques for estimating misalignment between antenna arrays in accordance with one or more aspects of the present disclosure is shown.

[0050] Figure 14 A block diagram of a communication manager supporting techniques for estimating misalignment between antenna arrays in accordance with one or more aspects of the present disclosure is shown.

[0051] Figure 15 A diagram is shown of a system including a device supporting techniques for estimating misalignment between antenna arrays in accordance with one or more aspects of the present disclosure.

[0052] Figure 16 and Figure 17 A flow chart illustrating a method supporting techniques for estimating misalignment between antenna arrays in accordance with one or more aspects of the present disclosure is shown. DETAILED DESCRIPTION

[0053] In some wireless communication systems, wireless devices use antenna arrays that can include many individual antenna elements to exchange signaling with each other. For example, a transmitting (Tx) device can use a Tx antenna array to send a signal to a receiving (Rx) device, where the Rx device receives the signal using the Rx antenna array. In such cases, the Rx device can decode the signal by determining the relative phase of the signals received at the corresponding antenna elements of the antenna array. However, the Tx antenna array and the Rx antenna array may be misaligned with each other. Misalignment may occur when one (or both) of the antenna arrays is rotated relative to the X, Y, and / or Z axes, and / or when one of the antenna arrays is laterally shifted relative to each other and / or relative to the direction of propagation of the signal (for example, the center of the antenna array is shifted relative to each other). Such misalignment can cause interference in the phase of the signal received at the Rx device, which may adversely affect the Rx device's ability to receive and decode the received signal.

[0054] Therefore, various aspects of the present disclosure relate to techniques for estimating misalignment between a Tx antenna array and a Rx antenna array. Specifically, various aspects of the present disclosure can be used to estimate rotational misalignment and / or translational misalignment between antenna arrays, where the estimated misalignment can be used to adjust precoding matrices and / or post-processing matrices used for communication between respective devices. For example, wireless devices can use initial precoding matrices and post-processing matrices to exchange reference signals with each other, where the reference signals are sent across respective Tx antenna arrays using different phase configurations to estimate different types of misalignment.

[0055] For example, the first device may use the same phase to send a reference signal across each antenna element of the Tx antenna array to enable the second device to estimate the rotational misalignment in the X / Y direction. By way of another example, the first device may use a phase ramp to send a reference signal in the X direction or the Y direction across the antenna elements of the Tx antenna array to enable the second device to estimate the rotational misalignment in the Z direction. In addition, the first device may use different subsets of the antenna array to send reference signals with opposite signs (e.g., S, -S) to enable the second device to estimate the parallel shift misalignment in the X / Y direction. After estimating the misalignment, the Tx device and the Rx device may selectively modify the precoding matrix and the post-processing matrix to compensate for the estimated misalignment, and may then use the updated matrices to perform wireless communication with each other.

[0056] Aspects of the present disclosure are first described in the context of a wireless communication system. Additional aspects of the present disclosure are described in the context of example misalignment configurations and example process flows. Aspects of the present disclosure are further illustrated and described by and with reference to apparatus diagrams, system diagrams, and flow charts related to techniques for estimating misalignment between antenna arrays.

[0057] Figure 1 An example of a wireless communication system 100 that supports techniques for estimating misalignment between antenna arrays according to one or more aspects of the present disclosure is illustrated. The wireless communication system 100 may include one or more network entities 105, one or more UEs 115, and a core network 130. In some examples, the wireless communication system 100 may be a Long Term Evolution (LTE) network, an Advanced LTE (LTE-A) network, an LTE-A Pro network, a New Radio (NR) network, or a network operating according to other systems and radio technologies, including future systems and radio technologies not explicitly mentioned herein.

[0058] The network entities 105 may be dispersed throughout a geographic area to form the wireless communication system 100 and may include devices that take different forms or have different capabilities. In various examples, the network entities 105 may be referred to as network elements, mobility elements, radio access network (RAN) nodes, or network equipment, among other nomenclature. In some examples, the network entities 105 and the UEs 115 may communicate wirelessly via one or more communication links 125 (e.g., radio frequency (RF) access links). For example, the network entities 105 may support a coverage area 110 (e.g., a geographic coverage area) within which the UEs 115 and the network entities 105 may establish one or more communication links 125. The coverage area 110 may be an example of a geographic area within which the network entities 105 and the UEs 115 may support signal communication according to one or more radio access technologies (RATs).

[0059] The UEs 115 may be dispersed throughout the coverage area 110 of the wireless communication system 100, and each UE 115 may be stationary or mobile or both stationary and mobile at different times. The UEs 115 may be devices that take different forms or have different capabilities. Figure 1 Some example UEs 115 are illustrated in FIG. The UEs 115 described herein may be capable of supporting communication with various types of devices such as Figure 1 Other UEs 115 or network entities 105 are shown communicating.

[0060] As described herein, a node of the wireless communication system 100 (which may be referred to as a network node or wireless node) may be a network entity 105 (e.g., any network entity described herein), a UE 115 (e.g., any UE described herein), a network controller, an apparatus, a device, a computing system, one or more components, or another suitable processing entity configured to perform any of the techniques described herein. For example, the node may be a UE 115. As another example, the node may be a network entity 105. As another example, a first node may be configured to communicate with a second node or a third node. In one aspect of this example, the first node may be a UE 115, the second node may be a network entity 105, and the third node may be a UE 115. In another aspect of this example, the first node may be a UE 115, the second node may be a network entity 105, and the third node may be a network entity 105. In other aspects of this example, the first node, the second node, and the third node may be different relative to these examples. Similarly, references to UE 115, network entity 105, apparatus, device, computing system, etc. may include disclosure of UE 115, network entity 105, apparatus, device, computing system, etc. as nodes. For example, a disclosure that UE 115 is configured to receive information from network entity 105 also discloses that the first node is configured to receive information from the second node.

[0061] In some examples, network entities 105 can communicate with core network 130, or with each other, or both. For example, network entities 105 can communicate with core network 130 via one or more backhaul communication links 120 (e.g., according to S1, N2, N3, or other interface protocols). In some examples, network entities 105 can communicate with each other via backhaul communication links 120 (e.g., according to X2, Xn, or other interface protocols), either directly (e.g., directly between network entities 105) or indirectly (e.g., via core network 130). In some examples, network entities 105 can communicate with each other via midhaul communication links 162 (e.g., according to a midhaul interface protocol) or fronthaul communication links 168 (e.g., according to a fronthaul interface protocol), or any combination thereof. Backhaul communication links 120, midhaul communication links 162, or fronthaul communication links 168 can be or include one or more wired links (e.g., electrical links, fiber optic links), one or more wireless links (e.g., radio links, wireless optical links), etc., or various combinations thereof. UE 115 may communicate with core network 130 via communication link 155 .

[0062] One or more of the network entities 105 described herein may include or may be referred to as a base station 140 (e.g., a transceiver base station, a radio base station, an NR base station, an access point, a radio transceiver, a Node B, an eNodeB (eNB), a next-generation Node B, or a gigabit Node B (any of which may be referred to as a gNB), a 5G NB, a next-generation eNB (ng-eNB), a Home Node B, a Home evolved Node B, or other suitable terminology). In some examples, the network entity 105 (e.g., a base station 140) may be implemented in a converged (e.g., monolithic, standalone) base station architecture that may be configured to utilize a protocol stack that is physically or logically integrated within a single network entity 105 (e.g., a single RAN node, such as the base station 140).

[0063] In some examples, the network entity 105 can be implemented in a disaggregated architecture (e.g., a disaggregated base station architecture, a disaggregated RAN architecture) that can be configured to utilize a protocol stack that is physically or logically distributed between two or more network entities 105, such as an integrated access backhaul (IAB) network, an open RAN (O-RAN) (e.g., a network configuration sponsored by the O-RAN Alliance), or a virtualized RAN (vRAN) (e.g., a cloud RAN (C-RAN)). For example, the network entity 105 can include one or more of the following: a central unit (CU) 160, a distributed unit (DU) 165, a radio unit (RU) 170, a RAN intelligent controller (RIC) 175 (e.g., a near real-time RIC (near RT RIC), a non-real-time RIC (non-RT RIC)), a service management and orchestration (SMO) 180 system, or any combination thereof. The RU 170 may also be referred to as a radio head, smart radio head, remote radio head (RRH), remote radio unit (RRU), or transmit receive point (TRP). One or more components of the network entity 105 in the disaggregated RAN architecture may be co-located, or one or more components of the network entity 105 may be located in distributed locations (e.g., separate physical locations). In some examples, one or more network entities 105 of the disaggregated RAN architecture may be implemented as virtual units (e.g., virtual CU (VCU), virtual DU (VDU), virtual RU (VRU)).

[0064] The functional split between CU 160, DU 165, and RU 170 is flexible and can support different functionalities depending on which functions (e.g., network layer functions, protocol layer functions, baseband functions, RF functions, and any combination thereof) are performed at CU 160, DU 165, or RU 170. For example, a functional split of the protocol stack can be employed between CU 160 and DU 165 such that CU 160 can support one or more layers of the protocol stack and DU 165 can support one or more different layers of the protocol stack. In some examples, CU 160 can host higher protocol layer (e.g., Layer 3 (L3), Layer 2 (L2)) functionality and signaling (e.g., Radio Resource Control (RRC), Service Data Adaptation Protocol (SDAP), Packet Data Convergence Protocol (PDCP)). The CU 160 may be connected to one or more DUs 165 or RUs 170, and the one or more DUs 165 or RUs 170 may host lower protocol layers, such as Layer 1 (L1) (e.g., physical (PHY) layer) or L2 (e.g., radio link control (RLC) layer, medium access control (MAC) layer) functionality and signaling, and may each be at least partially controlled by the CU 160. Additionally or alternatively, a functional split of the protocol stack may be employed between the DUs 165 and RUs 170, such that the DUs 165 may support one or more layers of the protocol stack and the RUs 170 may support one or more different layers of the protocol stack. The DUs 165 may support one or more different cells (e.g., via one or more RUs 170). In some cases, the functional split between the CU 160 and the DU 165 or between the DU 165 and the RU 170 may be within the protocol layer (e.g., some functions of the protocol layer may be performed by one of the CU 160, DU 165, or RU 170, while other functions of the protocol layer may be performed by a different one of the CU 160, DU 165, or RU 170). The CU 160 may be further functionally split into CU control plane (CU-CP) and CU user plane (CU-UP) functions. The CU 160 may be connected to one or more DUs 165 via midhaul communication links 162 (e.g., F1, F1-c, F1-u), and the DU 165 may be connected to one or more RUs 170 via fronthaul communication links 168 (e.g., an open fronthaul (FH) interface). In some examples, midhaul communication link 162 or fronthaul communication link 168 may be implemented according to an interface (e.g., a channel) between layers of a protocol stack supported by respective network entities 105 that communicate via such communication links.

[0065] In some wireless communication systems (e.g., wireless communication system 100), the infrastructure and spectrum resources used for radio access may support wireless backhaul link capabilities to supplement wired backhaul connections, thereby providing an IAB network architecture (e.g., to core network 130). In some cases, in an IAB network, one or more network entities 105 (e.g., IAB nodes 104) may be partially controlled by each other. One or more IAB nodes 104 may be referred to as a donor entity or IAB donor. One or more DUs 165 or one or more RUs 170 may be partially controlled by one or more CUs 160 associated with a donor network entity 105 (e.g., donor base station 140). One or more donor network entities 105 (e.g., IAB donors) may communicate with one or more additional network entities 105 (e.g., IAB nodes 104) via supported access and backhaul links (e.g., backhaul communication link 120). The IAB node 104 may include an IAB mobile terminal (IAB-MT) controlled (e.g., scheduled) by the DU 165 of the coupled IAB donor. The IAB-MT may include an independent set of antennas for relaying communications with the UE 115, or may share the same antennas of the IAB node 104 (e.g., of the RU 170) for access via the DU 165 of the IAB node 104 (e.g., referred to as a virtual IAB-MT (vIAB-MT)). In some examples, the IAB node 104 may include a DU 165 that supports communication links with additional entities (e.g., IAB node 104, UE 115) within a relay chain or configuration (e.g., downstream) of the access network. In such cases, one or more components of the decomposed RAN architecture (e.g., one or more IAB nodes 104 or components of the IAB node 104) may be configured to operate according to the techniques described herein.

[0066] For example, an access network (AN) or RAN may include communications between an access node (e.g., an IAB donor), an IAB node 104, and one or more UEs 115. The IAB donor may facilitate connectivity between the core network 130 and the AN (e.g., via a wired or wireless connection to the core network 130). That is, the IAB donor may refer to a RAN node that has a wired or wireless connection to the core network 130. The IAB donor may include a CU 160 and at least one DU 165 (e.g., and RU 170), wherein the CU 160 may communicate with the core network 130 via an interface (e.g., a backhaul link). The IAB donor and the IAB node 104 may communicate via the F1 interface according to a protocol that defines signaling messages (e.g., the F1 AP protocol). Additionally or alternatively, CU 160 may communicate with the core network via an interface (which may be an example of a portion of a backhaul link) and may communicate with other CUs 160 (e.g., CUs 160 associated with alternative IAB donors) via an Xn-C interface (which may be an example of a portion of a backhaul link).

[0067] An IAB node 104 may refer to a RAN node that provides IAB functionality (e.g., access for UE 115, wireless self-backhaul capabilities, etc.). The DU 165 may act as a distributed scheduling node toward child nodes associated with the IAB node 104, and the IAB-MT may act as a scheduled node toward a parent node associated with the IAB node 104. That is, an IAB donor may be referred to as a parent node that communicates with one or more child nodes (e.g., the IAB donor may relay transmissions for UEs through one or more other IAB nodes 104). Additionally or alternatively, depending on the relay chain or configuration of the AN, the IAB node 104 may also be referred to as a parent node or child node of other IAB nodes 104. Thus, the IAB-MT entity of the IAB node 104 may provide a Uu interface for the child IAB node 104 to receive signaling from the parent IAB node 104 , and a DU interface (eg, DU 165 ) may provide a Uu interface for the parent IAB node 104 to signal to the child IAB node 104 or the UE 115 .

[0068] For example, IAB node 104 may be referred to as a parent node supporting communications for child IAB nodes, or as a child node associated with an IAB donor, or both. The IAB donor may include a CU 160 having a wired or wireless connection to the core network 130 (e.g., backhaul communication link 120) and may serve as a parent node for IAB node 104. For example, the DU 165 of the IAB donor may relay transmissions to UE 115 via IAB node 104, or may directly signal the transmissions to UE 115, or both. The CU 160 of the IAB donor may signal the establishment of a communication link to IAB node 104 via the F1 interface, and IAB node 104 may schedule transmissions (e.g., transmissions relayed from the IAB donor to UE 115) via the DU 165. That is, data may be relayed to and from IAB node 104 via signaling via the NR Uu interface of the MT to IAB node 104. Communications with the IAB node 104 may be scheduled by the DU 165 of the IAB donor, and communications with the IAB node 104 may be scheduled by the DU 165 of the IAB node 104 .

[0069] Where the techniques described herein are applied to the context of a disaggregated RAN architecture, one or more components of the disaggregated RAN architecture may be configured to support the techniques described herein for estimating misalignment between antenna arrays. For example, some operations described as being performed by a UE 115 or a network entity 105 (e.g., a base station 140) may additionally or alternatively be performed by one or more components of the disaggregated RAN architecture (e.g., an IAB node 104, a DU 165, a CU 160, a RU 170, a RIC 175, a SMO 180).

[0070] UE 115 may include or may be referred to as a mobile device, a wireless device, a remote device, a handheld device, or a subscriber device, or some other suitable terminology, where "device" may also be referred to as a unit, a station, a terminal, or a client, etc. UE 115 may also include or may be referred to as a personal electronic device, such as a cellular phone, a personal digital assistant (PDA), a tablet computer, a laptop computer, or a personal computer. In some examples, UE 115 may include or may be referred to as a wireless local loop (WLL) station, an Internet of Things (IoT) device, an Internet of Everything (IoE) device, or a machine type communication (MTC) device, etc., which may be implemented in various objects, such as appliances or vehicles, meters, etc.

[0071] The UE 115 described herein may be capable of communicating with various types of devices, such as other UEs 115, which may sometimes act as relays, as well as network entities 105 and network equipment including macro eNBs or gNBs, small cell eNBs or gNBs, or relay base stations, etc. Figure 1 shown.

[0072] The UE 115 and the network entity 105 can wirelessly communicate with each other via one or more communication links 125 (e.g., access links) using resources associated with one or more carriers. The term "carrier" can refer to a collection of RF spectrum resources having a physical layer structure defined for supporting the communication link 125. For example, a carrier used for the communication link 125 can include a portion of an RF spectrum band (e.g., a bandwidth portion (BWP)) that operates according to one or more physical layer channels for a given radio access technology (e.g., LTE, LTE-A, LTE-A Pro, NR). Each physical layer channel can carry acquisition signaling (e.g., synchronization signals, system information), control signaling for coordinating carrier operations, user data, or other signaling. The wireless communication system 100 can support communications with the UE 115 using carrier aggregation or multi-carrier operation. Depending on the carrier aggregation configuration, the UE 115 can be configured with multiple downlink component carriers and one or more uplink component carriers. Carrier aggregation can be used for both frequency division duplex (FDD) and time division duplex (TDD) component carriers. Communication between the network entity 105 and other devices may refer to communication between those devices and any portion (e.g., entity, sub-entity) of the network entity 105. For example, the terms "send," "receive," or "communicate" when referring to the network entity 105 may refer to any portion of the network entity 105 (e.g., base station 140, CU 160, DU 165, RU 170) of the RAN communicating with another device (e.g., directly or via one or more other network entities 105).

[0073] In some examples, such as in a carrier aggregation configuration, a carrier may also have acquisition signaling or control signaling that coordinates the operation of other carriers. A carrier may be associated with a frequency channel (e.g., an Evolved Universal Mobile Telecommunications System Terrestrial Radio Access (E-UTRA) Absolute RF Channel Number (EARFCN)) and may be identified according to a channel raster used for discovery by UE 115. A carrier may operate in a standalone mode, in which case initial acquisition and connection may be performed by a UE 115 via the carrier, or in a non-standalone mode, in which case a different carrier (e.g., of the same or different radio access technology) is used to anchor the connection.

[0074] The communication link 125 shown in the wireless communication system 100 may include downlink transmissions (e.g., forward link transmissions) from the network entity 105 to the UE 115, uplink transmissions (e.g., return link transmissions) from the UE 115 to the network entity 105, or both, as well as other transmission configurations. A carrier may carry downlink communications or uplink communications (e.g., in FDD mode), or may be configured to carry both downlink and uplink communications (e.g., in TDD mode).

[0075] A carrier may be associated with a particular bandwidth of the RF spectrum, and in some examples, the carrier bandwidth may be referred to as the "system bandwidth" of the carrier or wireless communication system 100. For example, the carrier bandwidth may be one of a set of bandwidths of carriers for a particular radio access technology (e.g., 1.4 megahertz (MHz), 3 MHz, 5 MHz, 10 MHz, 15 MHz, 20 MHz, 40 MHz, or 80 MHz). Devices of the wireless communication system 100 (e.g., the network entity 105, the UE 115, or both) may have a hardware configuration that supports communications using a particular carrier bandwidth, or may be configured to support communications using one of the set of carrier bandwidths. In some examples, the wireless communication system 100 may include a network entity 105 or a UE 115 that supports concurrent communications using carriers associated with multiple carrier bandwidths. In some examples, each served UE 115 may be configured to operate using a portion (e.g., a subband, a BWP) or all of the carrier bandwidth.

[0076] The signal waveform transmitted via the carrier may include multiple subcarriers (e.g., using a multicarrier modulation (MCM) technique such as orthogonal frequency division multiplexing (OFDM) or discrete Fourier transform spread OFDM (DFT-S-OFDM)). In a system employing MCM techniques, a resource element may refer to the resource of one symbol period (e.g., the duration of one modulation symbol) and one subcarrier, in which case the symbol period and subcarrier spacing may be inversely related. The number of bits carried by each resource element may depend on the modulation scheme (e.g., the order of the modulation scheme, the coding rate of the modulation scheme, or both), such that a relatively high number of resource elements (e.g., in the transmission duration) and a relatively high order of the modulation scheme may correspond to a relatively high communication rate. Wireless communication resources may refer to a combination of RF spectrum resources, time resources, and spatial resources (e.g., spatial layers or beams), and the use of multiple spatial resources may increase the data rate or data integrity used for communication with UE 115.

[0077] One or more parameter sets for a carrier may be supported, and the parameter set may include subcarrier spacing (Δf) and cyclic prefix. A carrier may be divided into one or more BWPs with the same or different parameter sets. In some examples, a UE 115 may be configured with multiple BWPs. In some examples, a single BWP for a carrier may be active at a given time, and communications by the UE 115 may be constrained to one or more active BWPs.

[0078] The time interval for the network entity 105 or the UE 115 may be expressed as a multiple of a basic time unit, which may be, for example, a sampling period T s =1 / (Δf max ·N f ) seconds, where Δf max It can represent the supported subcarrier spacing, and N f The supported discrete Fourier transform (DFT) size may be indicated. Time intervals of communication resources may be organized according to radio frames, each having a specified duration (e.g., 10 milliseconds (ms)). Each radio frame may be identified by a system frame number (SFN) (e.g., ranging from 0 to 1023).

[0079] Each frame may include a plurality of consecutively numbered subframes or time slots, and each subframe or time slot may have the same duration. In some examples, a frame may be divided (e.g., in the time domain) into subframes, and each subframe may be further divided into a certain number of time slots. Alternatively, each frame may include a variable number of time slots, and the number of time slots may depend on the subcarrier spacing. Each time slot may include a certain number of symbol periods (e.g., depending on the length of the cyclic prefix appended in front of each symbol period). In some wireless communication systems 100, the time slot may be further divided into a plurality of mini-time slots associated with one or more symbols. Excluding the cyclic prefix, each symbol period may be associated with one or more (e.g., N f The duration of a symbol period may depend on the subcarrier spacing or the operating frequency band.

[0080] A subframe, slot, mini-slot, or symbol may be the smallest scheduling unit (e.g., in the time domain) of the wireless communication system 100 and may be referred to as a Transmit Time Interval (TTI). In some examples, the TTI duration (e.g., the number of symbol periods in a TTI) may be variable. Additionally or alternatively, the smallest scheduling unit of the wireless communication system 100 may be dynamically selected (e.g., in a burst of a shortened TTI (sTTI)).

[0081] According to various techniques, physical channels may be multiplexed using carriers for communication. Physical control channels and physical data channels may be multiplexed for signaling over downlink carriers, for example, using one or more of time division multiplexing (TDM), frequency division multiplexing (FDM), or hybrid TDM-FDM techniques. A control region (e.g., a control resource set (CORESET)) of a physical control channel may be defined by a set of symbol periods and may extend across the system bandwidth of a carrier or a subset of the system bandwidth. One or more control regions (e.g., CORESETs) may be configured for a set of UEs 115. For example, one or more of UEs 115 may monitor or search the control region for control information according to one or more search space sets, and each search space set may include one or more control channel candidates in one or more aggregation levels arranged in a cascaded manner. The aggregation level of a control channel candidate may refer to the amount of control channel resources (e.g., control channel elements (CCEs)) associated with coded information for a control information format having a given payload size. The search space sets may include a common search space set configured for transmitting control information to multiple UEs 115 and a UE-specific search space set for transmitting control information to a specific UE 115 .

[0082] In some examples, network entities 105 (e.g., base stations 140, RUs 170) can be mobile and, therefore, provide communication coverage for mobile coverage areas 110. In some examples, different coverage areas 110 associated with different technologies can overlap, but the different coverage areas 110 can be supported by the same network entity 105. In some other examples, overlapping coverage areas 110 associated with different technologies can be supported by different network entities 105. The wireless communication system 100 can include, for example, a heterogeneous network in which different types of network entities 105 provide coverage for various coverage areas 110 using the same or different radio access technologies.

[0083] Some UEs 115, such as MTC or IoT devices, may be low-cost or low-complexity devices and may provide automated communication between machines (e.g., via machine-to-machine (M2M) communication). M2M communication or MTC may refer to data communication technology that allows devices to communicate with each other or with a network entity 105 (e.g., base station 140) without human intervention. In some examples, M2M communication or MTC may include communication from devices that integrate sensors or meters to measure or acquire information and relay such information to a central server or application that uses the information or presents it to a person interacting with the application. Some UEs 115 may be designed to collect information or implement automated behavior of machines or other equipment. Examples of applications for MTC devices include smart metering, inventory monitoring, water level monitoring, equipment monitoring, healthcare monitoring, wildlife monitoring, weather and geographic event monitoring, queue management and tracking, remote security sensing, physical access control, and transaction-based commercial charging.

[0084] The wireless communication system 100 can be configured to support ultra-reliable communication or low-latency communication or various combinations thereof. For example, the wireless communication system 100 can be configured to support ultra-reliable low-latency communication (URLLC). The UE 115 can be designed to support ultra-reliable or low-latency or critical functions. Ultra-reliable communication can include private or group communications and can be supported by one or more services (such as push-to-talk, video, or data). Support for ultra-reliable, low-latency functions can include prioritization of services, and such services can be used for public safety or general commercial applications. The terms "ultra-reliable," "low latency," and "ultra-reliable low latency" are used interchangeably herein.

[0085] In some examples, a UE 115 can be configured to support communication directly with other UEs 115 via a device-to-device (D2D) communication link 135 (e.g., according to a peer-to-peer (P2P), D2D, or sidelink protocol). In some examples, one or more UEs 115 in a group performing D2D communication can be within a coverage area 110 of a network entity 105 (e.g., a base station 140, a RU 170), which can support aspects of such D2D communication configured by the network entity 105 (e.g., scheduled by the network entity). In some examples, one or more UEs 115 in such a group can be outside the coverage area 110 of the network entity 105 or can otherwise be unable or not configured to receive transmissions from the network entity 105. In some examples, a group of UEs 115 communicating via D2D communication can support a one-to-many (1:M) system, in which each UE 115 transmits to each of the other UEs 115 in the group. In some examples, network entity 105 may facilitate scheduling of resources for D2D communications. In some other examples, D2D communications may be performed between UEs 115 without involving network entity 105.

[0086] In some systems, the D2D communication link 135 can be an example of a communication channel (such as a sidelink communication channel) between vehicles (e.g., UE 115). In some examples, the vehicles can communicate using vehicle-to-everything (V2X) communication, vehicle-to-vehicle (V2V) communication, or some combination thereof. The vehicles can signal information related to traffic conditions, signal scheduling, weather, safety, emergency situations, or any other information related to the V2X system. In some examples, the vehicles in the V2X system can communicate with roadside infrastructure (such as roadside units) or communicate with the network via one or more network nodes (e.g., network entity 105, base station 140, RU 170) using vehicle-to-network (V2N) communication, or both.

[0087] The core network 130 may provide user authentication, access authorization, tracking, Internet Protocol (IP) connectivity, and other access, routing, or mobility functions. The core network 130 may be an evolved packet core (EPC) or a 5G core (5GC), which may include at least one control plane entity (e.g., a mobility management entity (MME), an access and mobility management function (AMF)) for managing access and mobility and at least one user plane entity (e.g., a serving gateway (S-GW), a packet data network (PDN) gateway (P-GW), or a user plane function (UPF)) for routing packets or interconnecting to external networks. The control plane entity may manage non-access stratum (NAS) functions such as mobility, authentication, and bearer management for UEs 115 served by network entities 105 (e.g., base stations 140) associated with the core network 130. User IP packets may be delivered through the user plane entity, which may provide IP address allocation and other functions. The user plane entity may be connected to the IP services 150 of one or more network operators. IP services 150 may include access to the Internet, an intranet, an IP Multimedia Subsystem (IMS), or packet-switched streaming services.

[0088] The wireless communication system 100 can operate using one or more frequency bands that can range from 300 megahertz (MHz) to 300 gigahertz (GHz). Generally speaking, the region from 300 MHz to 3 GHz is referred to as the ultra-high frequency (UHF) region or decimeter band because the wavelengths range from about one decimeter to one meter in length. UHF waves can be blocked or redirected by buildings and environmental features (which can be referred to as clusters), but these waves can penetrate structures sufficiently for a macro cell to provide service to a UE 115 located indoors. Communication using UHF waves can be associated with smaller antennas and a shorter range (e.g., less than 100 kilometers) than communication using the lower frequencies and longer waves in the high frequency (HF) or very high frequency (VHF) portions of the spectrum below 300 MHz.

[0089] The wireless communication system 100 can utilize licensed and unlicensed RF spectrum bands. For example, the wireless communication system 100 can use unlicensed bands (such as the 5 GHz Industrial, Scientific, and Medical (ISM) band) to employ Licensed Assisted Access (LAA), LTE Unlicensed (LTE-U) radio access technology, or NR technology. When operating using unlicensed RF spectrum bands, devices such as the network entity 105 and the UE 115 can employ carrier sensing for conflict detection and avoidance. In some examples, operations using unlicensed bands can be based on carrier aggregation configuration (e.g., LAA) in combination with component carriers operating using licensed bands. Operations using unlicensed spectrum can include downlink transmissions, uplink transmissions, P2P transmissions, or D2D transmissions, among others.

[0090] A network entity 105 (e.g., base station 140, RU 170) or UE 115 may be equipped with multiple antennas that can be used to employ techniques such as transmit diversity, receive diversity, multiple-input, multiple-output (MIMO) communications, or beamforming. The antennas of the network entity 105 or UE 115 may be located within one or more antenna arrays or antenna panels, which may support MIMO operations or transmit or receive beamforming. For example, one or more base station antennas or antenna arrays may be co-located at an antenna assembly, such as an antenna tower. In some examples, the antennas or antenna arrays associated with the network entity 105 may be located at different geographical locations. The network entity 105 may include an antenna array having a set of multiple rows and columns of antenna ports that the network entity 105 can use to support beamforming for communications with the UE 115. Similarly, the UE 115 may include one or more antenna arrays that may support various MIMO or beamforming operations. Additionally or alternatively, the antenna panels may support RF beamforming for signals transmitted via the antenna ports.

[0091] The network entity 105 or the UE 115 may use MIMO communication to exploit multipath signal propagation and improve spectral efficiency by sending or receiving multiple signals via different spatial layers. Such a technique may be referred to as spatial multiplexing. The multiple signals may be sent, for example, by a transmitting device via different antennas or different combinations of antennas. Similarly, the multiple signals may be received by a receiving device via different antennas or different combinations of antennas. Each of the multiple signals may be referred to as a separate spatial stream and may carry information associated with the same data stream (e.g., the same codeword) or different data streams (e.g., different codewords). Different spatial layers may be associated with different antenna ports for channel measurement and reporting. MIMO techniques include single-user MIMO (SU-MIMO), in which multiple spatial layers are transmitted to the same receiving device, and multi-user MIMO (MU-MIMO), in which multiple spatial layers are transmitted to multiple devices.

[0092] Beamforming (which may also be referred to as spatial filtering, directional transmission, or directional reception) is a signal processing technique that can be used at a transmitting device or a receiving device (e.g., a network entity 105, a UE 115) to shape or steer an antenna beam (e.g., a transmit beam, a receive beam) along a spatial path between the transmitting device and the receiving device. Beamforming can be achieved by combining signals communicated via antenna elements of an antenna array so that some signals propagating along a particular orientation relative to the antenna array experience constructive interference, while other signals experience destructive interference. Adjustments to signals communicated via antenna elements can include the transmitting device or the receiving device applying an amplitude offset, a phase offset, or both to signals carried via antenna elements associated with the device. The adjustments associated with each of these antenna elements can be defined by a set of beamforming weights associated with a particular orientation (e.g., relative to the antenna array of the transmitting device or the receiving device or relative to some other orientation).

[0093] The network entity 105 or the UE 115 may use beam sweeping techniques as part of a beamforming operation. For example, the network entity 105 (e.g., base station 140, RU 170) may use multiple antennas or antenna arrays (e.g., antenna panels) to perform beamforming operations for directional communication with the UE 115. Some signals (e.g., synchronization signals, reference signals, beam selection signals, or other control signals) may be transmitted multiple times by the network entity 105 along different directions. For example, the network entity 105 may transmit signals according to different sets of beamforming weights associated with different transmit directions. Transmissions along different beam directions may be used to identify (e.g., by a transmitting device, such as the network entity 105, or by a receiving device, such as the UE 115) the beam direction for later transmission or reception by the network entity 105.

[0094] Some signals, such as data signals associated with a particular receiving device, may be transmitted by a transmitting device (e.g., transmitting network entity 105, transmitting UE 115) along a single beam direction (e.g., a direction associated with a receiving device (e.g., receiving network entity 105 or receiving UE 115)). In some examples, a beam direction associated with transmission along a single beam direction may be determined based on signals transmitted along one or more beam directions. For example, UE 115 may receive one or more of the signals transmitted by network entity 105 along different directions and may report to network entity 105 an indication of the signal received by UE 115 with the highest signal quality or other acceptable signal quality.

[0095] In some examples, transmission by a device (e.g., by network entity 105 or UE 115) may be performed using multiple beam directions, and the device may use a combination of digital precoding or beamforming to generate a combined beam for transmission (e.g., from network entity 105 to UE 115). UE 115 may report feedback indicating precoding weights for one or more beam directions, and the feedback may correspond to a configured set of beams across the system bandwidth or one or more subbands. Network entity 105 may transmit reference signals (e.g., cell-specific reference signals (CRS), channel state information reference signals (CSI-RS)), which may or may not be precoded. UE 115 may provide feedback for beam selection, which may be a precoding matrix indicator (PMI) or codebook-based feedback (e.g., a multi-panel codebook, a linear combination codebook, a port-selective codebook). Although these techniques are described with reference to signals sent along one or more directions by a network entity 105 (e.g., base station 140, RU 170), UE 115 may use similar techniques to send signals multiple times along different directions (e.g., to identify a beam direction for subsequent transmission or reception by UE 115), or to send signals along a single direction (e.g., to send data to a receiving device).

[0096] A receiving device (e.g., UE 115) may perform reception operations according to multiple reception configurations (e.g., directional listening) when receiving various signals (such as synchronization signals, reference signals, beam selection signals, or other control signals) from a receiving device (e.g., network entity 105). For example, the receiving device may perform reception according to multiple reception directions by receiving via different antenna subarrays, processing received signals according to different antenna subarrays, receiving according to different receive beamforming weight sets applied to signals received at multiple antenna elements of an antenna array (e.g., different directional listening weight sets), or 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 reception configurations or reception directions. In some examples, the receiving device may use a single reception configuration to receive along a single beam direction (e.g., when receiving a data signal). A single receive configuration may be aligned along a beam direction determined based on listening according to different receive configuration directions (e.g., a beam direction determined to have the highest signal strength, highest signal-to-noise ratio (SNR), or other acceptable signal quality based on listening according to multiple beam directions).

[0097] The wireless communication system 100 may be a packet-based network operating according to a layered protocol stack. In the user plane, communications at the bearer or PDCP layer may be IP-based. The RLC layer may perform packet segmentation and reassembly for communication via logical channels. The MAC layer may perform priority handling and multiplexing of logical channels into transport channels. The MAC layer may also support retransmission using error detection, error correction, or both to improve link efficiency. In the control plane, the RRC layer may provide for the establishment, configuration, and maintenance of RRC connections between the UE 115 and the network entity 105 or core network 130 for radio bearers supporting user plane data. The PHY layer may map transport channels to physical channels.

[0098] UE 115 and network entity 105 may support retransmission of data to increase the likelihood of successful data reception. Hybrid Automatic Repeat Request (HARQ) feedback is a technique for increasing the likelihood of correctly receiving data via a communication link (e.g., communication link 125, D2D communication link 135). HARQ may include a combination of error detection (e.g., using a cyclic redundancy check (CRC)), forward error correction (FEC), and retransmission (e.g., automatic repeat request (ARQ)). HARQ may improve throughput at the MAC layer under poor radio conditions (e.g., low signal-to-noise ratio conditions). In some examples, a device may support same-slot HARQ feedback, in which case the device may provide HARQ feedback in a particular time slot for data received via previous symbols in that time slot. In some other examples, the device may provide HARQ feedback in subsequent time slots or based on some other time interval.

[0099] In some implementations, wireless devices (e.g., UE 115, network entity 105, IAB node, etc.) of the wireless communication system 100 may support techniques for estimating misalignment between a Tx antenna array and an Rx antenna array. Specifically, aspects of the present disclosure may be used to estimate rotational misalignment and / or translational misalignment between antenna arrays, wherein the estimated misalignment may be used to adjust a precoding matrix and / or a post-processing matrix used for communication between the respective devices. For example, the wireless devices may use an initial precoding matrix and a post-processing matrix to exchange reference signals with each other, wherein the reference signals are sent across the respective Tx antenna arrays using different phase configurations to estimate different types of misalignment.

[0100] For example, a first device (e.g., UE 115, network entity 105, IAB node, etc.) may transmit a reference signal to a second device (e.g., another UE 115, network entity 105, IAB node, etc.) using the same phase across each antenna element of the Tx antenna array to enable the second device to estimate rotational misalignment in the X / Y direction. By way of another example, the first device may transmit a reference signal in the X or Y direction across the antenna elements of the Tx antenna array using a phase ramp to enable the second device to estimate rotational misalignment in the Z direction. In addition, the first device may transmit a reference signal with opposite signs (e.g., S, -S) using different subsets of the antenna array to enable the second device to estimate parallel shift misalignment in the X / Y direction. After estimating the misalignment, the Tx device and the Rx device may selectively modify the precoding matrix and the post-processing matrix to compensate for the estimated misalignment, and may then use the updated matrices to perform wireless communication with each other.

[0101] The techniques described herein may enable wireless devices to estimate misalignments between antenna arrays and compensate for such misalignments to improve the efficiency and reliability of wireless communications. Specifically, the techniques described herein may enable wireless devices to exchange reference signals (e.g., OAM waveforms) with each other using a defined phase configuration (e.g., a common phase, a phase ramp, etc.) that enables other corresponding devices to estimate rotational misalignment and / or translational shift misalignment. By enabling wireless devices to estimate misalignment, the corresponding devices may be able to update pre-decoding matrices and post-processing matrices used to send and receive signals between the devices. Therefore, the techniques described herein may improve the efficiency and reliability of wireless communications exchanged between devices, thereby reducing the number / ratio of retransmissions and resulting in improved resource utilization and reduced power consumption.

[0102] Figure 2 An example of a wireless communication system 200 that supports techniques for estimating misalignment between antenna arrays according to one or more aspects of the present disclosure is illustrated. In some examples, aspects of the wireless communication system 200 may implement or be implemented by aspects of the wireless communication system 100. Specifically, the wireless communication system 200 may support techniques for estimating and compensating for misalignment between antenna arrays, as previously described herein.

[0103] The wireless communication system 200 includes a first wireless device 205-a and a second wireless device 205-b, which can be examples of wireless devices as described herein. For example, in some cases, the first wireless device 205-a can include the network entity 105, and the second wireless device 205-b can include the UE 115. By way of another example, both the wireless devices 205-a and 205-b can include the UE 115, an IAB node, etc.

[0104] In some aspects, the first wireless device 205-a and the second wireless device 205-b can communicate with each other using a communication link 210, which can be an example of an NR or LTE link, a side link (e.g., a PC5 link), etc. between the respective devices. In some cases, the communication link 210 can include an example of an access link (e.g., a Uu link), which can include a bidirectional link that enables both uplink and downlink communication. For example, the second wireless device 205-b can use the communication link 210 to send uplink signals, such as uplink control signals or uplink data signals, to one or more components of the first wireless device 205-a, and one or more components of the first wireless device 205-a can use the communication link 210 to send downlink signals, such as downlink control signals or downlink data signals, to the second wireless device 205-b.

[0105] The first wireless device 205-a and the second wireless device 205-b can communicate with each other using a first antenna array 215-a and a second antenna array 215-b, respectively. Each of the respective antenna arrays 215 may include a set of antenna elements that can be used to send and / or receive communications. For example, Figure 2 As shown, the first antenna array 215 - a may include a 4×4 antenna array (eg, 16 antenna elements), and the second antenna array 215 - b may include a 6×3 antenna array (eg, 18 antenna elements).

[0106] In some cases, the first antenna array 215-a may be referred to as a Tx antenna array, and the second antenna array 215-b may be referred to as an Rx antenna array. However, it should be noted herein that, as described herein, the terms Tx and Rx may generally be used to refer to the relative directions of communication between devices. Thus, both wireless devices 205-a and 205-b and both antenna arrays 215-a and 215-b may be configured to transmit signals to each other, receive signals from one respective device, or both.

[0107] like Figure 3 As shown, the antenna arrays 215-a, 215-b can be illustrated relative to each other using an X-axis, a Y-axis, and a Z-axis. Specifically, the antenna arrays 215-a, 215-b can be illustrated in the X / Y plane, where the Z-axis extends from one antenna array 215 to the other antenna array (e.g., the Z-axis passes through the center of each antenna array 215). In this regard, signals exchanged between the wireless devices 205 can propagate along (or parallel to) the Z-axis. When the antenna arrays are perfectly aligned (e.g., there is no rotational misalignment or translational misalignment between the devices), the distance 220 between the first wireless device 205-a and the second wireless device 205-b can be measured along the Z-axis as the distance between the centers of the respective antenna arrays 215.

[0108] As previously noted herein, several types of misalignment may occur between the first antenna array 215-a and the second antenna array 215-b, which may adversely affect the performance of communications exchanged between the respective devices. Two main types of misalignment may include rotational misalignment and translational shift misalignment (e.g., parallel shift misalignment). Rotational misalignment may occur when one or both antenna arrays in the antenna array 215 are rotated relative to the X-axis, Y-axis, and / or Z-axis. Rotational misalignment relative to the Z-axis may be referred to as parallel rotation, where rotational misalignment relative to the X-axis and Y-axis may be referred to as vertical rotation. In contrast, shift misalignment may occur when the centers of one (or both) antenna arrays in the antenna array 215 are displaced relative to each other. For example, shift misalignment may occur when the first antenna array 215-a is displaced laterally relative to the X-axis (e.g., a shift in the X coordinate), relative to the Y-axis (e.g., a shift in the Y coordinate), or both.

[0109] Both rotational misalignment and translational shift misalignment may result in interference in the phase of a signal received by a respective wireless device 205, which may adversely affect the ability of the respective wireless device 205 to receive and decode a signal transmitted by another respective device.

[0110] Thus, aspects of the present disclosure relate to techniques that enable wireless devices 205 to estimate and compensate for misalignment between respective antenna arrays 215. Specifically, aspects of the present disclosure may support techniques that enable wireless devices 205 to estimate rotational misalignment and / or translational misalignment between respective antenna arrays 215, wherein the estimated misalignment may be used to adjust precoding matrices and / or post-processing matrices used for communications between respective wireless devices 205.

[0111] For example, see Figure 2 In the wireless communication system 200 illustrated in FIG, a first wireless device 205-a and a second wireless device can communicate (e.g., send, receive) control messages (e.g., RRC, DCI, MAC-CE) to / from each other, where the control messages indicate a reference signal waveform associated with a reference signal 225 (e.g., OAM reference signal 225) that can be communicated between the respective devices.

[0112] The first wireless device 205-a may transmit one or more reference signals 225 (e.g., OAM reference signals 225) to the second wireless device 205-b. For example, the first wireless device 205-a may transmit the one or more reference signals 225 to the second wireless device 205-b based on a first pre-decoder matrix. Similarly, the second wireless device 205-b may receive the reference signals 225 using (e.g., based on) a first post-processing matrix. In some cases, the reference signals 225 may be transmitted at 715 based on a reference signal waveform communicated / negotiated between the devices.

[0113] In some aspects, the first wireless device 205-a may transmit multiple different reference signals 225 according to different configurations to enable the second wireless device 205-b to measure different types of misalignments, such as rotational misalignment in the X direction, Y direction and / or Z direction, shift misalignment, or any combination thereof.

[0114] For example, to enable the second wireless device 205-b to measure rotational misalignment in the X / Y direction, the first wireless device 205-a may transmit a reference signal 225 with the same phase across the set of antenna elements of the first antenna array 215-a at the first wireless device 205-a and according to the first pre-decoder matrix. Figure 3 Techniques for estimating rotational misalignment in the X / Y directions are further shown and described.

[0115] By way of another example, to enable the second wireless device 205-b to measure rotational misalignment in the Z direction, the first wireless device 205-a may transmit a reference signal 225 across a set of antenna elements of the first antenna array 215-a at the first wireless device 205-a and with a phase ramp according to a first pre-decoder matrix. Figure 4 and Figure 5 Techniques for estimating rotational misalignment in the Z direction are further shown and described.

[0116] By way of another example, to enable the second wireless device 205-b to measure the parallel shift misalignment, the first wireless device 205-a may transmit a first subset of reference signals 225 at a first phase using a first subset of antenna elements of the first antenna array 215-a, and may transmit a second subset of reference signals 225 at a second phase different from the first phase using a second subset of antenna elements of the first antenna array 215-a. For example, the first wireless device 205-a may transmit the first subset of reference signals 225 at a first phase S(t), and may transmit the second subset of reference signals 225 at a second phase -S(t) associated with an opposite sign (e.g., ±S(t)). Figure 6Techniques for estimating spatial misalignment (eg, parallel / lateral shift misalignment) are further shown and described.

[0117] In some aspects, the second wireless device 205-b may perform measurements on the reference signal 225. For example, the second wireless device 205-b may perform measurements to estimate the phase of the reference signal 225 received at corresponding antenna elements of the second antenna array 215-b (e.g., estimate the phase of the reference signal 225 along the X direction, the Y direction, and the Z direction). Additionally or alternatively, the second wireless device 205-b may perform other types of measurements, such as RSSI, RSRP, RSRQ, SNR, SINR, etc.

[0118] In some implementations, the second wireless device 205-b can compare the received reference signal 225 with the reference signal waveform. In some cases, comparing the reference signal 225 (e.g., the phase of the received reference signal 225) with the reference signal waveform can enable the second wireless device 205-b to estimate misalignment between the antenna arrays 215 of the respective devices.

[0119] The second wireless device 205-b may estimate one or more misalignments (e.g., estimated rotational misalignment, estimated spatial misalignment, etc.) between the respective devices' antenna arrays 215. The second wireless device 205-b may estimate the one or more misalignments based on receiving a reference signal 225, performing measurements on the reference signal, comparing the reference signal 225 to a reference signal waveform, or any combination thereof.

[0120] For example, the second wireless device 205-b may be configured to estimate the rotational misalignment relative to the X / Y axis if the first wireless device 205-a transmits the reference signal 225 with the same phase, such as Figure 3 In such cases, the estimated rotational misalignment may be estimated relative to one or more axes perpendicular to additional axes extending from the first antenna array 215-a of the first wireless device 205-a to the second antenna array 215-b of the second wireless device 205-b.

[0121] By way of another example, the second wireless device 205-b may be configured to estimate the rotational misalignment about the Z axis when the first wireless device 205-a transmits the reference signal 225 with a phase ramp, such as by using the reference signal 225 as the reference signal. Figure 4 Additionally or alternatively, the second wireless device 205-b may be configured to estimate the rotational misalignment relative to the Z axis when the first wireless device 205-a transmits a subset of the reference signals 225 with different (e.g., opposite) phases, such as by shifting the reference signals 225 to the Z axis. Figure 5In such cases, the estimated rotational misalignment may be estimated relative to a Z-axis extending from the Tx antenna array 215 - a to the Rx antenna array 215 - b .

[0122] By way of another example, the second wireless device 205-b can be configured to estimate the spatial misalignment (e.g., parallel / lateral shift misalignment) axis when the first wireless device 205-a transmits a subset of the reference signals 225 with different (e.g., opposite) phases, such as by using the reference signals 225 as the first wireless device 205-a. Figure 6 In such cases, the estimated spatial misalignment may be estimated relative to an X / Y axis that is perpendicular to a Z axis extending from the first antenna array 215 - a to the second antenna array 215 - b .

[0123] The second wireless device 205-b may send a feedback message 230 to the first wireless device 205-a, wherein the feedback message 230 indicates one or more misalignments (e.g., estimated rotational misalignment, estimated spatial misalignment, or both) between the first antenna array 215-a at the first wireless device 205-a and the second antenna array 215-b at the second wireless device 205-b.

[0124] In some aspects, the first wireless device 205-a, the second wireless device 205-b, or both may determine a channel estimation matrix associated with a channel between the first antenna array 215-a and the second antenna array 215-b. In some aspects, the devices may determine the channel estimation matrix based on the estimated misalignment indicated via the feedback message 230.

[0125] In some aspects, the first wireless device 205-a may determine a new precoding matrix to be used for transmitting a signal to the second wireless device 205-b. In other words, the first wireless device 205-a may update / modify the first precoding matrix used to transmit the reference signal 225 to generate a second precoding matrix. Specifically, the first wireless device 205-a may update / modify the first precoding matrix based on the estimated rotational misalignment, estimated spatial misalignment (e.g., parallel / lateral shift misalignment) indicated via the feedback message 230.

[0126] Similarly, the second wireless device 205-b may determine a new post-processing matrix to be used for receiving signals from the first wireless device 205-a. In other words, the second wireless device 205-b may update / modify the first post-processing matrix used to receive the reference signal 225 to generate a second post-processing matrix. Specifically, the second wireless device 205-b may update / modify the first post-processing matrix based on the estimated rotational misalignment and the estimated spatial misalignment (e.g., parallel / lateral shift misalignment) indicated via the feedback message 230.

[0127] Subsequently, the first wireless device 205-a can use (e.g., based on) the second pre-decoder matrix to send a message 230 (e.g., a data message, a reference signal, etc.) to the second wireless device 205-b. Similarly, the second wireless device 205-b can use (e.g., based on) the second post-processing matrix to receive the message 230 from the first wireless device 205-a.

[0128] In some implementations, the steps / operations for estimating misalignment and modifying the pre-coding / post-processing matrices can be repeated multiple times to reduce the misalignment between the antenna arrays 215 and, therefore, improve the efficiency and reliability of communications exchanged between the devices. In some cases, the process for estimating misalignment can occur a predefined number of times within a predetermined time interval / duration, and / or until the estimated misalignment is sufficiently small (e.g., less than a certain threshold).

[0129] While the wireless communication system 200 is shown and described in the context of the first wireless device 205-a being a "Tx device" and the second wireless device 205-b being an "Rx device," this is for illustrative purposes only and should not be considered limiting of the present disclosure. For example, in some cases, the second wireless device 205-b can transmit a reference signal 225 to the first wireless device 205-a, and the first wireless device 205-a can perform measurements on the received reference signal 225, compare the reference signal 225 with a reference signal waveform, estimate a misalignment between the antenna arrays 215, and transmit a feedback message 230 indicating the estimated misalignment to the second wireless device 205-b. In such cases, the second wireless device 205-b can update a precoding matrix, and the first wireless device 205-a can update a post-processing matrix, as described herein.

[0130] The techniques described herein can enable wireless devices 205 to estimate misalignment between antenna arrays and compensate for such misalignment to improve the efficiency and reliability of wireless communications. Specifically, the techniques described herein can enable wireless devices 205 to exchange reference signals 225 (e.g., OAM waveforms) with each other using a defined phase configuration (e.g., a common phase, a phase ramp, etc.) that enables other corresponding devices to estimate rotational misalignment and / or translational shift misalignment. By enabling wireless devices 205 to estimate misalignment, the corresponding devices can be able to update pre-decoding matrices and post-processing matrices used to send and receive signals between the devices. Thus, the techniques described herein can improve the efficiency and reliability of wireless communications exchanged between wireless devices 205, thereby reducing the number / ratio of retransmissions and resulting in improved resource utilization and reduced power consumption.

[0131] Figure 3An example of a misalignment configuration 300 supporting techniques for estimating misalignment between antenna arrays according to one or more aspects of the present disclosure is illustrated. In some examples, aspects of the misalignment configuration 300 can implement or be implemented by aspects of the wireless communication system 100, the wireless communication system 200, or both. Specifically, the misalignment configuration 300 illustrates techniques that can be used between devices to estimate rotational misalignment between a Tx antenna array and an Rx antenna array relative to the X-axis and the Y-axis, as described herein.

[0132] To measure or estimate the rotation of the OAM waveform on the X and / or Y axis, the Tx device may transmit the same pilot signal for both the X rotation misalignment estimation and the Y rotation misalignment estimation. For example, the Tx device may use a mode 0 OAM waveform as a pilot signal, where each antenna element in the Tx antenna array is configured to transmit the same OAM signal / waveform. For example, Figure 3 As shown, the Tx device can use a Tx antenna array 305 to transmit a pilot signal (eg, a reference signal), wherein each corresponding antenna element of the Tx antenna array transmits the pilot / reference signal with a common waveform (such as S(t)) and with the same phase.

[0133] In such cases, the linear phase slope of the OAM waveform received at the Rx device can be correlated with (e.g., used to estimate) the amount of rotation about the X and Y axes. In other words, the phase slope of the OAM waveform at the Rx device can be used to measure the amount of rotational misalignment between the Tx and Rx antenna arrays.

[0134] The rotation sequence (eg, rotational misalignment) with respect to the Z-axis, Y-axis, and X-axis can be represented via a rotation matrix, which is illustrated in Equation 1 and Equation 2 below:

[0135]

[0136] The three matrices in Equation 1 represent the yaw, pitch, and roll rotations relative to the Z, Y, and X axes, respectively.

[0137] The linear phase ramps on the Y-axis and X-axis can be expressed by the following equations 3 and 4:

[0138] -2πh*sin(θ y ) (3)

[0139] 2πh*cos(θ y )*sin(θ x ) (4)

[0140] Wherein Formula 3 represents the slope on the Y-axis, and Formula 4 represents the slope on the X-axis.

[0141] Using Equations 1–4 above, the Rx device can estimate the average phase rotation relative to the X and Y axes based on the slope of the estimated phase ramp. Specifically, the Rx device can calculate the phase rotation between two adjacent samples of the received OAM waveform along the X and Y axes and average them across the X and Y axes. After the estimation, the Rx device can apply phase compensation to the adjacent samples.

[0142] For example, Figure 3 The phase diagram 310-a shown in exemplifies the received phase of the reference signal transmitted by the Tx antenna array 305 and received by the Rx device when there is no rotational misalignment between the Tx antenna array and the Rx antenna array with respect to the X-axis and the Y-axis. In contrast, Figure 3 The phase diagram 310-b shown in FIG3 illustrates the received phase of the reference signal transmitted by the Tx antenna array 305 and received by the Rx device when there is a rotational misalignment between the Tx antenna array and the Rx antenna array with respect to the X-axis and the Y-axis. Therefore, the Rx device can be configured to estimate the rotational misalignment by calculating the phase rotation between adjacent samples of the OAM waveform illustrated in the phase diagram 310-b.

[0143] An example estimation and compensation algorithm for estimating rotational misalignment about the X-axis is illustrated below in Equations 5 and 6:

[0144]

[0145] [e -j2πΔ / 2 e j2πΔ / 2 ] (6)

[0146] Wherein Δ=h*sin(θ), and wherein Equation 5 illustrates the phase difference between the Rx antennas, and wherein Equation 6 illustrates where compensation for phase shifts may be applied at the Rx antenna elements.

[0147] In the context of compensating for rotational misalignment in the X and Y directions (e.g., vertical X / Y rotation), the corresponding devices (e.g., Tx device, Rx device) can be configured to send OAM signals to each other so that the Tx device and the Rx device can each estimate the rotational misalignment between the corresponding antenna arrays and share the estimated rotational misalignment information with each other. Based on the estimated rotational misalignment information, a channel estimation matrix associated with the channel between the corresponding devices (e.g., between the corresponding antenna arrays) can be updated at both the Tx device and the Rx device. In addition, the Tx device can be configured to update the pre-decoder matrix (V) and the Rx device can be configured to update the post-processing matrix (U) based on the updated channel estimation matrix and / or the rotational misalignment estimated by the corresponding device.

[0148] For general cases (e.g., non-far-field context), the Tx device can estimate θ and θ according to the following equations 7 and 8: To construct the rotation matrix And the Rx device can estimate according to the following formulas 9 and 10 and To construct the rotation matrix

[0149]

[0150] in represents the unit vector in the X / Y plane on which the Tx antenna array 305 rotates, and represents the rotation angle of the Tx antenna array 305 Similarly, denotes a unit vector in the X / Y plane on which the Rx antenna array rotates, and θ denotes a rotation angle of the Rx antenna array (θ∈[0 2π]).

[0151] Subsequently, the Tx device and the Rx device may be configured to inform each other about the estimated misalignment at each of the respective devices. In other words, the Tx device may indicate to the Rx device (e.g., estimated rotational misalignment at the Tx device), and the Rx device may indicate to the Tx device (e.g., estimated rotational misalignment at the Rx device). Using the estimated rotational misalignment information at the respective devices, the Tx device, the Rx device, or both may update the channel matrix (H) according to the following equations 11 and 12:

[0152]

[0153] For i = 1, 2, ..., M and j = 1, 2, ..., N, where is the distance vector between the Tx antenna array and the Rx antenna array when the centers of the antenna arrays are perfectly aligned (e.g., no misalignment), is when the center of the antenna array is perfectly aligned th The position vector of the Tx antenna element from the center of the Tx antenna array, and is when the center of the antenna array is perfectly aligned th The position vector of the Rx antenna element from the center of the Rx antenna array. The device can then perform singular value decomposition (SVD) to retrieve a new pre-coding matrix (V New ) and the new post-processing matrix (U New ).

[0154] In some aspects, the estimated rotational misalignment can be simplified in the context of a far-field scenario. In a far-field scenario, the Tx device and the Rx device can each estimate the rotational misalignment between the respective antenna arrays. However, in the context of a far-field scenario, the devices may not exchange estimated rotational misalignment information with each other. Instead, the respective devices can locally update the channel estimation matrix and the pre-decoding / post-processing matrix. For example, the Tx device can locally update the pre-decoder matrix (V) based on its own estimated rotational misalignment information, and the Rx device can locally update the post-processing matrix (U) based on its own estimated rotational misalignment information.

[0155] For example, in the context of a far-field scenario, the Tx device can locally estimate the rotation parameters according to Equations 13 and 14 and To construct the rotation matrix And the Rx device can locally estimate the rotation parameters θ and θ according to the following formulas 15 and 16

[0156]

[0157] in represents the unit vector in the X / Y plane on which the Tx antenna array 305 rotates, and represents the rotation angle of the Tx antenna array 305

[0158] After exchanging reference / pilot signals, locally estimated rotation misalignment, and updating the channel matrix, the Tx device and the Rx device may respectively update the pre-decoder matrix and the post-processing matrix for communication between the respective devices. For example, the Tx device may update the pre-decoder matrix (V New ), and the Rx device can update the post-processing matrix (U) according to Equation 18:

[0159]

[0160] Figure 4 An example of a misalignment configuration 400 supporting techniques for estimating misalignment between antenna arrays according to one or more aspects of the present disclosure is illustrated. In some examples, aspects of the misalignment configuration 400 may implement or be implemented by aspects of the wireless communication system 100, the wireless communication system 200, the misalignment configuration 300, or any combination thereof. Specifically, the misalignment configuration 400 illustrates techniques that can be used between devices to estimate rotational misalignment between a Tx antenna array and an Rx antenna array about a Z-axis, as described herein.

[0161] To measure or estimate the rotation of the OAM waveform on the Z axis, the Tx device may transmit a reference / pilot signal with a phase ramp on the X axis and / or Y axis. For example, the Tx device may use a mode 0 OAM waveform as a pilot signal, where the pilot signal is transmitted with a phase ramp in the interval [-ππ] with respect to the X axis. For example, Figure 4 As shown, the Tx device can use the Tx antenna array 405 to transmit the same pilot signal (e.g., reference signal) at 1000λ, where the pilot / reference signal is transmitted by each corresponding antenna element of the Tx antenna array according to the corresponding phase (e.g., S(t)e -jπ / 2 、S(t)e -j0 、S(t)e jπ / 2 、S(t)e jπ ) is sent with the phase ramp illustrated.

[0162] In some aspects, the Rx device may be configured to estimate the amount of rotational misalignment relative to the Z axis based on the slope of the plane at the phase transition of the received pilot signal. Specifically, the Rx device may be configured to calculate the phase slope ratio (e.g., the tilt of the edge) of the received pilot signal relative to the X axis and the Y axis. For example, the Rx device may be configured to calculate the average phase slope on the X axis (e.g., slope-x) and the average phase slope on the Y axis (e.g., slope-y), and may be configured to calculate the estimated rotational misalignment between the antenna arrays relative to the Z axis using the following formula 19:

[0163]

[0164] In some aspects, the phase diagram 410 - a illustrates the received phase (Tx(4×4), h ) of the reference signal transmitted by the Tx antenna array 405 and received by the Rx device when there is no rotational misalignment on the Z axis. Tx =λ,r=1000λ,θ z =0). In contrast, phase diagram 410-b illustrates the received phase (Tx(4×4), h) of the reference signal transmitted by the Tx antenna array 405 and received by the Rx device when there is a certain amount of rotational misalignment on the Z axis. Tx =λ,r=1000λ,θ z =20).

[0165] Additionally or alternatively, Figure 5 The technique shown is used to estimate rotational misalignment about the Z axis.

[0166] Figure 5An example of a misalignment configuration 500 supporting techniques for estimating misalignment between antenna arrays according to one or more aspects of the present disclosure is illustrated. In some examples, aspects of the misalignment configuration 500 may implement or be implemented by aspects of the wireless communication system 100, the wireless communication system 200, the misalignment configuration 300, the misalignment configuration 400, or any combination thereof. Specifically, the misalignment configuration 500 illustrates techniques that can be used between devices to estimate rotational misalignment between a Tx antenna array and an Rx antenna array about a Z-axis, as described herein.

[0167] To measure or estimate the rotation of the OAM waveform on the Z axis, the Tx device can use a subset of antenna elements to transmit reference / pilot signals with opposite signs along the X or Y axis. Figure 5 As shown, the Tx device can use the Tx antenna array 505 to transmit a pilot signal (eg, a reference signal), wherein a first subset of antenna elements are configured to transmit a pilot signal with a first sign (eg, S(t)ej π ) transmits a pilot / reference signal, and wherein a second subset of antenna elements is configured to transmit a pilot / reference signal with a second sign opposite to the first sign (e.g., S(t)e jπ ) to transmit a pilot / reference signal. In this regard, the Tx antenna array 505 may be divided along the X-axis (or Y-axis).

[0168] In such cases, the Rx device can be configured to estimate the amount of rotational misalignment relative to the Z axis based on the slope of the plane at the phase transition of the received pilot signal. Specifically, the Rx device can be configured to project the phase transition plane onto the X / Y plane and fit a line (e.g., the slope of the phase transition) to calculate the rotational misalignment on the Z axis. In some aspects, the phase diagram 510 illustrates the received phase (Tx (8×8, 16×16), h) of the reference signal transmitted by the Tx antenna array 505 and received by the Rx device when there is a certain amount of rotational misalignment on the Z axis. Tx =λ,r=1000λ,θ z =20).

[0169] Figure 6 An example of a misalignment configuration 600 supporting techniques for estimating misalignment between antenna arrays according to one or more aspects of the present disclosure is illustrated. In some examples, aspects of the misalignment configuration 600 can implement or be implemented by aspects of the wireless communication system 100, the wireless communication system 200, the misalignment configurations 300, 400, 500, or any combination thereof. Specifically, the misalignment configuration 600 illustrates techniques that can be used between devices to estimate shift misalignment (e.g., parallel shift misalignment) between a Tx antenna array and an Rx antenna array, as described herein.

[0170] To measure the shift misalignment, the Tx antenna array can be used to transmit reference / pilot signals using opposite phases (e.g., up-modulation and down-modulation). For example, to estimate the parallel shift misalignment on the Y axis, the upper and lower portions of the Tx antenna array 605-a can be used to transmit reference signals with opposite phases. Figure 6 As shown, to estimate the shift misalignment on the Y-axis, the Tx device can use the Tx antenna array 605-a to send a pilot signal (e.g., a reference signal), wherein a first subset of antenna elements within the upper portion of the Tx antenna array 605-a is configured to send the pilot / reference signal with a first sign (e.g., S(t)), and wherein a second subset of antenna elements within the lower portion of the Tx antenna array 605-a is configured to send the pilot / reference signal with a second sign opposite to the first sign (e.g., -S(t)).

[0171] Similarly, to estimate the parallel shift misalignment on the X-axis, the left and right portions of the Tx antenna array 605-b may be used to transmit reference signals in opposite phases. Figure 6 As shown, to estimate the shift misalignment on the X-axis, the Tx device can use the Tx antenna array 605-b to send a pilot signal (e.g., a reference signal), wherein a first subset of antenna elements on a first lateral side of the Tx antenna array 605-a is configured to send the pilot / reference signal with a first sign (e.g., S(t)), and wherein a second subset of antenna elements on a second lateral side of the Tx antenna array 605-a is configured to send the pilot / reference signal with a second sign opposite to the first sign (e.g., -S(t)).

[0172] In some aspects, the Rx device may be configured to estimate shift misalignment (e.g., parallel shift misalignment, lateral shift misalignment on the X / Y axis) by determining / estimating where the phase jump occurs. Shift misalignment on the Y and X axes may be estimated separately (e.g., using different sets of reference / pilot signals transmitted by the Tx antenna array 605-a and the Tx antenna array 605-b, respectively).

[0173] In the absence of shift misalignment, the phase jump may occur in the middle of the Rx antenna array. For example, phase diagram 610-a illustrates the received phases 615-a, 615-b of the reference signal transmitted by the Tx antenna array 605-a and received by the Rx device when there is no shift misalignment. In contrast, in the presence of some degree of shift misalignment, the phase jump of the reference / pilot signal received at the Rx device may be shifted relative to the center of the Rx antenna array. For example, phase diagram 610-b illustrates the received phases 615-c, 615-d of the reference signal transmitted by the Tx antenna array 605-a and received by the Rx device when there is some shift misalignment and rotational misalignment on the Z axis. In some aspects, the resolution used to estimate the misalignment can be based on the distance (h) between the antenna elements.

[0174] In some aspects, to estimate the shift misalignment, the Rx device may be configured to take the inner product between the phase of the received reference / pilot signal (e.g., the received OAM waveform) and the expected / expected phase for each hypothesis, where the peak value indicates the fractional shift. For example, a first hypothesis (hypothesis 1) may be determined by taking the inner product between a known reference signal waveform and a waveform received at the Rx device (e.g., the inner product between the Tx signal and the Rx signal). A second hypothesis (hypothesis 2) may be determined by taking the inner product between the known reference signal waveform and a received waveform with a shift (e.g., λ, λ, where λ is the wavelength of the known waveform). Furthermore, a third hypothesis (hypothesis 3) may be determined by taking the inner product between the known reference signal waveform and a received waveform with a shift (e.g., 1 / 2*λ, λ). To find the estimated shift misalignment (in both the X and Y directions), the Rx device may be configured to identify the hypothesis with the largest inner product (e.g., the largest inner product may be identified as the best estimate of the X / Y shift misalignment).

[0175] After calculating the shift misalignment, the respective devices may be configured to calculate or update a precoding matrix and a post-processing matrix to be used for communication between the respective devices, as illustrated in the following Equations 20 and 21:

[0176]

[0177] in represents the parallel shift vector in three-dimensional (3D) space (e.g., the estimated shift misalignment), d is the distance between the Tx antenna array and the Rx antenna array (when perfectly aligned), and Indicates the jth th Tx antenna element and the i-th thIn this regard, the Tx device and the Rx device may report the locally calculated shift misalignment to each other, and the respective devices may update the precoding matrix V based on the shift misalignment calculated at the respective devices. ij new And the post-processing matrix U ij new .

[0178] In some implementations, the shift misalignment between the Tx antenna array and the Rx antenna array can be characterized in terms of rotational misalignment. That is, in some implementations, the Tx device, the Rx device, or both can be configured to estimate the shift misalignment (e.g., parallel shift misalignment) and convert the shift misalignment into an X / Y rotational misalignment (or vice versa). For example, the respective devices can send reference / pilot signals to each other, locally calculate the shift misalignment, and convert the shift misalignment into an estimated rotational misalignment with respect to the X / Y axis. In such cases, the respective devices may be able to compensate for the estimated rotational misalignment by calculating a new channel estimation matrix, a pre-coding matrix, and / or a post-processing matrix, and thereby compensate for the estimated shift misalignment.

[0179] Figure 7 An example of a process flow 700 supporting techniques for estimating misalignment between antenna arrays according to one or more aspects of the present disclosure is illustrated. In some examples, aspects of the process flow 700 can implement or be implemented by aspects of the wireless communication system 100, the wireless communication system 200, the misalignment configurations 300-600, or any combination thereof. Specifically, the process flow 700 illustrates techniques for estimating and compensating for misalignment between antenna arrays, as described with reference to FIG. Figure 1 – Figure 6 described, and other aspects.

[0180] The process flow 700 includes a first wireless device 705-a and a second wireless device 705-b, which may be examples of wireless devices as described herein. Figure 7 The illustrated first wireless device 705-a and the second wireless device 705-b may each include: Figure 2 Illustrated are examples of a first wireless device 205-a and a second wireless device 205-b. In this regard, the respective wireless device 705 may include any type of wireless device including, but not limited to, a network entity 105, a UE 115, an IAB node, and the like.

[0181] In some examples, the operations illustrated in process flow 700 may be performed by hardware (e.g., including circuits, processing blocks, logic components, and other components), code executed by a processor (e.g., software), or any combination thereof. The following alternative examples may be implemented in which some steps are performed in a different order than described or not performed at all. In some cases, the steps may include additional features not mentioned below, or other steps may be added.

[0182] At 710, the first wireless device 705-a and the second wireless device can communicate (e.g., send, receive) a control message (e.g., RRC, DCI, MAC-CE) to / from each other, where the control message indicates a reference signal waveform associated with a reference signal (e.g., an OAM reference signal) that can be communicated between the respective devices.

[0183] At 715, the first wireless device 705-a may transmit one or more reference signals (e.g., OAM reference signals) to the second wireless device 705-b. For example, the first wireless device 705-a may transmit the one or more reference signals to the second wireless device 705-b based on the first pre-decoder matrix. Similarly, the second wireless device 705-b may receive the reference signals using (e.g., based on) the first post-processing matrix. In some cases, the reference signals may be transmitted at 715 based on the reference signal waveform indicated via the control message at 710.

[0184] As previously described herein, devices may exchange reference signals with one another so that each respective device can locally estimate misalignment between antenna arrays at the respective device. However, for simplicity, process flow 700 illustrates an example in which a first wireless device 705-a transmits a reference signal to a second wireless device 705-b. In this regard, in some cases, the first wireless device 705-a may transmit a reference signal to the second wireless device 705-b to enable the second wireless device 705-b to estimate antenna array misalignment, and the second wireless device 705-b may transmit a reference signal to the first wireless device 705-a to enable the first wireless device 705-a to estimate antenna array misalignment.

[0185] In some aspects, the first wireless device 705-a may transmit multiple different reference signals according to different configurations to enable the second wireless device 705-b to measure different types of misalignments, such as rotational misalignment in the X direction, Y direction and / or Z direction, shift misalignment, or any combination thereof.

[0186] For example, to enable the second wireless device 705-b to measure rotational misalignment in the X / Y direction, the first wireless device 705-a may transmit a reference signal with the same phase across a set of antenna elements of a first antenna array at the first wireless device 705-a and according to a first pre-decoder matrix, such as Figure 3 By way of another example, to enable the second wireless device 705-b to measure rotational misalignment in the Z direction, the first wireless device 705-a may transmit a reference signal across a set of antenna elements of a first antenna array at the first wireless device 705-a and with a phase ramp according to a first pre-decoder matrix, as shown in FIG. Figure 4 shown.

[0187] By way of another example, to enable the second wireless device 705-b to measure the parallel shift misalignment, the first wireless device 705-a may transmit a first subset of reference signals at a first phase using a first subset of antenna elements of a first antenna array, and may transmit a second subset of reference signals at a second phase different from the first phase using a second subset of antenna elements of the first antenna array. Figure 6 As shown, the first wireless device 705-a may transmit a first subset of reference signals at a first phase S(t) and may transmit a second subset of reference signals at a second phase -S(t) associated with an opposite sign (e.g., ±S(t)). Furthermore, as described herein, and as Figure 5 As illustrated, sending a subset of reference signals with different phases (eg, opposite signs) may also enable the second wireless device 705 - b to estimate rotational misalignment with respect to the Z axis.

[0188] At 720, the second wireless device 705-b may perform measurements on the reference signal received at 715. For example, the second wireless device 705-b may perform measurements to estimate the phase of the reference signal received at the corresponding antenna elements of the antenna array (e.g., estimate the phase of the reference signal along the X direction, the Y direction, and the Z direction). Additionally or alternatively, the second wireless device 705-b may perform other types of measurements, such as RSSI, RSRP, RSRQ, SNR, SINR, etc.

[0189] At 725, the second wireless device 705-b may compare the received reference signal with the reference signal waveform received at 710. In some cases, comparing the reference signal (e.g., the phase of the received reference signal) with the reference signal waveform may enable the second wireless device 705-b to estimate misalignment between the antenna arrays of the respective devices. In this regard, the second wireless device 705-b may compare the reference signal with the reference signal waveform based on the control message at 710, receiving the reference signal at 715, performing measurements at 720, or any combination thereof.

[0190] At 730, the second wireless device 705-b may estimate one or more misalignments (e.g., estimated rotational misalignment, estimated spatial misalignment, etc.) between the antenna arrays of the respective devices. The second wireless device 705-b may estimate the one or more misalignments at 730 based on the control message at 710, receiving the reference signal at 715, performing measurements at 720, comparing the reference signal to a reference signal waveform at 725, or any combination thereof.

[0191] For example, the second wireless device 705-b may be configured to estimate the rotational misalignment about the X / Y axis if the first wireless device 705-a transmits a reference signal with the same phase, such as Figure 3 In such cases, the estimated rotational misalignment may be estimated relative to one or more axes that are perpendicular to additional axes extending from the first antenna array of the first wireless device 705 - a to the second antenna array of the second wireless device 705 - b .

[0192] By way of another example, the second wireless device 705-b may be configured to receive a reference signal when the first wireless device 705-a transmits the reference signal with a phase ramp (e.g., Figure 4 ) and / or in the case where the first wireless device 705-a sends a subset of reference signals with different (e.g., opposite) phases (e.g., Figure 5 ) estimates the rotational misalignment relative to the Z axis. In such cases, the estimated rotational misalignment may be estimated relative to an axis extending from the Tx antenna array of the first wireless device 705-a to the Rx antenna array of the second wireless device 705-b.

[0193] By way of another example, the second wireless device 705-b may be configured to estimate a spatial misalignment (e.g., parallel / lateral shift misalignment) axis if the first wireless device 705-a transmits a subset of reference signals with different (e.g., opposite) phases, such as Figure 6 In such cases, the estimated spatial misalignment may be estimated relative to one or more axes that are perpendicular to additional axes extending from the first antenna array of the first wireless device 705 - a to the second antenna array of the second wireless device 705 - b .

[0194] At 735, the second wireless device 705-b may send a feedback message to the first wireless device 705-a, wherein the feedback message indicates one or more misalignments (e.g., estimated rotational misalignment, estimated spatial misalignment, or both) between the first antenna array at the first wireless device 705-a and the second antenna array at the second wireless device 705-b. In this regard, the second wireless device 705-b may send the feedback message at 730 based on the control message at 710, receiving the reference signal at 715, performing the measurement at 720, comparing the reference signal to the reference signal waveform at 725, estimating the misalignment at 730, or any combination thereof.

[0195] At 740, the first wireless device 705-a, the second wireless device 705-b, or both may determine a channel estimation matrix associated with a channel between the first antenna array of the first wireless device 705-a and the second antenna array of the second wireless device 705-b. In some aspects, the devices may determine the channel estimation matrix based on the estimated misalignment indicated via the feedback message at 735. In this regard, the wireless device 705 may determine the channel estimation matrix at 740 based on the control message at 710, receiving the reference signal at 715, performing measurements at 720, comparing the reference signal to a reference signal waveform at 725, estimating the misalignment at 730, communicating the feedback message at 735, or any combination thereof.

[0196] At 745, the first wireless device 705-a may determine a new precoding matrix to be used for transmitting a signal to the second wireless device 705-b. In other words, the first wireless device 705-a may update / modify the first precoding matrix used to transmit the reference signal at 715 to generate a second precoding matrix. Specifically, the first wireless device 705-a may update / modify the first precoding matrix based on the estimated rotational misalignment, estimated spatial misalignment (e.g., parallel / lateral shift misalignment) indicated via the feedback message at 735.

[0197] In this regard, the first wireless device 705-a may modify / update the precoding matrix at 745 based on the control message at 710, the transmission of the reference signal at 715, the reception of the feedback message at 735, the determination of the channel estimation matrix at 740, or any combination thereof. For example, in some cases, the first wireless device 705-a may modify the first precoding matrix based on the channel estimation matrix determined at 740 to generate a second (modified) precoding matrix.

[0198] At 750, the second wireless device 705-b may determine a new post-processing matrix to be used for receiving signals from the first wireless device 705-a. In other words, the second wireless device 705-b may update / modify the first post-processing matrix used to receive the reference signal at 715 to generate a second post-processing matrix. Specifically, the second wireless device 705-b may update / modify the first post-processing matrix based on the estimated rotational misalignment, estimated spatial misalignment (e.g., parallel / lateral shift misalignment) indicated via the feedback message at 735.

[0199] In this regard, the second wireless device 705-b may modify / update the post-processing matrix at 750 based on the control message at 710, receiving the reference signal at 715, performing measurements at 720, comparing the reference signal to the reference signal waveform at 725, estimating the misalignment at 730, sending the feedback message at 735, determining the channel estimation matrix at 740, or any combination thereof. For example, in some cases, the second wireless device 705-b may modify the first post-processing matrix based on the channel estimation matrix determined at 740 to generate a second (modified) post-processing matrix.

[0200] At 755, the first wireless device 705-a may transmit a message (e.g., a data message, a reference signal, etc.) to the second wireless device 705-b using (e.g., based on) the second pre-decoder matrix determined at 745. Similarly, the second wireless device 705-b may receive a message from the first wireless device 705-a using (e.g., based on) the second post-processing matrix determined at 750.

[0201] In some implementations, the steps / operations shown in process flow 700 can be repeated multiple times to iteratively estimate the misalignment between antenna arrays and update the pre-coding matrix and post-processing matrix used for communication between the corresponding devices. In some cases, the process for estimating the misalignment can occur a predefined number of times within a predetermined time interval / duration and / or until the estimated misalignment is sufficiently small (e.g., less than a threshold).

[0202] Although the process flow 700 is shown and described in the context of the first wireless device 705-a being a "Tx device" and the second wireless device 705-b being a "Rx device", this is for illustration purposes only and should not be considered a limitation of the present disclosure. Specifically, in some implementations, Figure 7The process flow 700 illustrated in FIG. 7 can be reversed to enable the first wireless device 705-a to estimate the misalignment between the antenna arrays. In such a case, the second wireless device 705-b can send a reference signal to the first wireless device 705-a (e.g., step 715), and the first wireless device 705-a can perform measurements (e.g., step 720), compare the reference signal (e.g., step 725), estimate the misalignment (e.g., step 730), and send a feedback message indicating the estimated misalignment (e.g., step 740). In such a case, the second wireless device 705-b can update the precoding matrix (e.g., step 745), and the first wireless device 705-a can update the post-processing matrix (e.g., step 750), as described herein.

[0203] The techniques described herein can enable wireless devices 705 to estimate misalignments between antenna arrays and compensate for such misalignments to improve the efficiency and reliability of wireless communications. Specifically, the techniques described herein can enable wireless devices 705 to exchange reference signals (e.g., OAM waveforms) with each other using a defined phase configuration (e.g., a common phase, a phase ramp, etc.) that enables other corresponding devices to estimate rotational misalignment and / or translational shift misalignment. By enabling wireless devices 705 to estimate misalignment, the corresponding devices can update pre-decoding matrices and post-processing matrices used to send and receive signals between the devices. Therefore, the techniques described herein can improve the efficiency and reliability of wireless communications exchanged between wireless devices 705, thereby reducing the number / ratio of retransmissions and resulting in improved resource utilization and reduced power consumption.

[0204] Figure 8 A block diagram 800 is shown of a device 805 that supports techniques for estimating misalignment between antenna arrays in accordance with one or more aspects of the present disclosure. The device 805 may be an example of aspects of the network entity 105 as described herein. The device 805 may include a receiver 810, a transmitter 815, and a communication manager 820. The device 805 may also include a processor. Each of these components may communicate with each other (e.g., via one or more buses).

[0205] Receiver 810 may provide means for obtaining (e.g., receiving, determining, identifying) information associated with various channels (e.g., control channels, data channels, information channels, channels associated with a protocol stack), such as user data, control information, or any combination thereof (e.g., I / Q samples, symbols, packets, protocol data units, service data units). The information may be passed to other components of device 805. In some examples, receiver 810 may support obtaining information by receiving signals via one or more antennas. Additionally or alternatively, receiver 810 may support obtaining information by receiving signals via one or more wired (e.g., electrical, optical) interfaces, wireless interfaces, or any combination thereof.

[0206] The transmitter 815 may provide means for outputting (e.g., transmitting, providing, conveying, transmitting) information generated by other components of the device 805. For example, the transmitter 815 may output information associated with various channels (e.g., control channels, data channels, information channels, channels associated with a protocol stack), such as user data, control information, or any combination thereof (e.g., I / Q samples, symbols, packets, protocol data units, service data units). In some examples, the transmitter 815 may support outputting information by transmitting signals via one or more antennas. Additionally or alternatively, the transmitter 815 may support outputting information by transmitting signals via one or more wired (e.g., electrical, optical) interfaces, wireless interfaces, or any combination thereof. In some examples, the transmitter 815 and the receiver 810 may be co-located in a transceiver, which may include a modem or be coupled to a modem.

[0207] The communication manager 820, the receiver 810, the transmitter 815, or various combinations thereof, or various components thereof, may be examples of means for performing various aspects of the techniques for estimating misalignment between antenna arrays as described herein. For example, the communication manager 820, the receiver 810, the transmitter 815, or various combinations thereof, or components thereof, may support methods for performing one or more of the functions described herein.

[0208] In some examples, the communication manager 820, the receiver 810, the transmitter 815, or various combinations or components thereof can be implemented in hardware (e.g., in a communication management circuit). The hardware can include a processor, a DSP, a CPU, an ASIC, an FPGA or other programmable logic device, a microcontroller, discrete gate or transistor logic components, discrete hardware components, or any combination thereof configured as or otherwise supporting components for performing the functions described in this disclosure. In some examples, a processor and a memory coupled to the processor can be configured to perform one or more of the functions described herein (e.g., by executing instructions stored in the memory by the processor).

[0209] Additionally or alternatively, in some examples, the communication manager 820, receiver 810, transmitter 815, or various combinations or components thereof may be implemented in code executed by a processor (e.g., as communication management software or firmware). If implemented in code executed by a processor, the functionality of the communication manager 820, receiver 810, transmitter 815, or various combinations or components thereof may be performed by a general-purpose processor (e.g., configured as or otherwise supporting means for performing the functions described in this disclosure), a DSP, a CPU, an ASIC, an FPGA, a microcontroller, or any combination of these or other programmable logic devices.

[0210] In some examples, the communication manager 820 can be configured to perform various operations (e.g., receive, obtain, monitor, output, transmit) using or otherwise cooperating with the receiver 810, the transmitter 815, or both. For example, the communication manager 820 can receive information from the receiver 810, transmit information to the transmitter 815, or be integrated with the receiver 810, the transmitter 815, or both to obtain information, output information, or perform various other operations as described herein.

[0211] For example, the communication manager 820 may be configured to or otherwise support means for transmitting one or more reference signals to a second wireless device using a first antenna array at a first wireless device and in accordance with a first pre-decoder matrix. The communication manager 820 may be configured to or otherwise support means for receiving a feedback message from the second wireless device based on the one or more reference signals, the feedback message indicating an estimated rotational misalignment, an estimated spatial misalignment, or both between the first antenna array at the first wireless device and a second antenna array at the second wireless device. The communication manager 820 may be configured to or otherwise support means for transmitting a message to the second wireless device in accordance with a second pre-decoder matrix that is modified relative to the first pre-decoder matrix based on the estimated rotational misalignment, the estimated spatial misalignment, or both.

[0212] By including or configuring the communication manager 820 according to the examples described herein, the device 805 (e.g., a processor controlling or otherwise coupled to the receiver 810, the transmitter 815, the communication manager 820, or a combination thereof) can support techniques that enable wireless devices to estimate misalignment between antenna arrays and compensate for such misalignment to improve the efficiency and reliability of wireless communications. Specifically, the techniques described herein can enable wireless devices to exchange reference signals (e.g., OAM waveforms) with each other using a defined phase configuration (e.g., a common phase, a phase ramp, etc.) that enables other corresponding devices to estimate rotational misalignment and / or translational shift misalignment. By enabling wireless devices to estimate misalignment, the corresponding devices can update pre-coding matrices and post-processing matrices used to transmit and receive signals between the devices. Thus, the techniques described herein can improve the efficiency and reliability of wireless communications exchanged between devices, thereby reducing the number / ratio of retransmissions and resulting in improved resource utilization and reduced power consumption.

[0213] Figure 9 A block diagram 900 is shown of a device 905 that supports techniques for estimating misalignment between antenna arrays in accordance with one or more aspects of the present disclosure. The device 905 may be an example of aspects of the device 805 or the network entity 105 as described herein. The device 905 may include a receiver 910, a transmitter 915, and a communication manager 920. The device 905 may also include a processor. Each of these components may communicate with each other (e.g., via one or more buses).

[0214] Receiver 910 may provide means for obtaining (e.g., receiving, determining, identifying) information associated with various channels (e.g., control channels, data channels, information channels, channels associated with a protocol stack), such as user data, control information, or any combination thereof (e.g., I / Q samples, symbols, packets, protocol data units, service data units). The information may be passed to other components of device 905. In some examples, receiver 910 may support obtaining information by receiving signals via one or more antennas. Additionally or alternatively, receiver 910 may support obtaining information by receiving signals via one or more wired (e.g., electrical, optical) interfaces, wireless interfaces, or any combination thereof.

[0215] The transmitter 915 may provide means for outputting (e.g., transmitting, providing, conveying, transmitting) information generated by other components of the device 905. For example, the transmitter 915 may output information associated with various channels (e.g., control channels, data channels, information channels, channels associated with a protocol stack), such as user data, control information, or any combination thereof (e.g., I / Q samples, symbols, packets, protocol data units, service data units). In some examples, the transmitter 915 may support outputting information by transmitting signals via one or more antennas. Additionally or alternatively, the transmitter 915 may support outputting information by transmitting signals via one or more wired (e.g., electrical, optical) interfaces, wireless interfaces, or any combination thereof. In some examples, the transmitter 915 and the receiver 910 may be co-located in a transceiver, which may include a modem or be coupled to a modem.

[0216] Device 905 or its various components may be examples of means for performing various aspects of the techniques for estimating misalignment between antenna arrays as described herein. For example, communication manager 920 may include reference signal transmission manager 925, feedback message reception manager 930, message transmission manager 935, or any combination thereof. Communication manager 920 may be an example of aspects of communication manager 820 as described herein. In some examples, communication manager 920 or its various components may be configured to perform various operations (e.g., receive, obtain, monitor, output, transmit) using or otherwise coordinating with receiver 910, transmitter 915, or both. For example, communication manager 920 may receive information from receiver 910, transmit information to transmitter 915, or be integrated with receiver 910, transmitter 915, or both to obtain information, output information, or perform various other operations as described herein.

[0217] The reference signal transmission manager 925 may be configured to or otherwise support means for transmitting one or more reference signals to a second wireless device using a first antenna array at a first wireless device and in accordance with a first pre-decoder matrix. The feedback message reception manager 930 may be configured to or otherwise support means for receiving a feedback message from the second wireless device based on the one or more reference signals, the feedback message indicating an estimated rotational misalignment, an estimated spatial misalignment, or both, between the first antenna array at the first wireless device and a second antenna array at the second wireless device. The message transmission manager 935 may be configured to or otherwise support means for transmitting a message to the second wireless device in accordance with a second pre-decoder matrix modified relative to the first pre-decoder matrix based on the estimated rotational misalignment, the estimated spatial misalignment, or both.

[0218] Figure 10 Block diagram 1000 illustrates a communication manager 1020 that supports techniques for estimating misalignment between antenna arrays in accordance with one or more aspects of the present disclosure. Communication manager 1020 may be an example of communication manager 820, communication manager 920, or aspects of both, as described herein. Communication manager 1020 or its various components may be examples of means for performing various aspects of the techniques for estimating misalignment between antenna arrays as described herein. For example, communication manager 1020 may include a reference signal transmission manager 1025, a feedback message reception manager 1030, a message transmission manager 1035, a control message communication manager 1040, a reference signal reception manager 1045, a feedback message transmission manager 1050, a channel estimation matrix manager 1055, a phase estimation manager 1060, or any combination thereof. Each of these components may communicate directly or indirectly with each other (e.g., via one or more buses), which communication may include communication within a protocol layer of a protocol stack, communication associated with a logical channel of a protocol stack (e.g., between protocol layers of a protocol stack, within a device, component, or virtualized component associated with the network entity 105, between devices, components, or virtualized components associated with the network entity 105), or any combination thereof.

[0219] The reference signal transmission manager 1025 may be configured to or otherwise support means for transmitting one or more reference signals to a second wireless device using a first antenna array at a first wireless device and in accordance with a first pre-decoder matrix. The feedback message reception manager 1030 may be configured to or otherwise support means for receiving a feedback message from the second wireless device based on the one or more reference signals, the feedback message indicating an estimated rotational misalignment, an estimated spatial misalignment, or both, between the first antenna array at the first wireless device and a second antenna array at the second wireless device. The message transmission manager 1035 may be configured to or otherwise support means for transmitting a message to the second wireless device in accordance with a second pre-decoder matrix modified relative to the first pre-decoder matrix based on the estimated rotational misalignment, the estimated spatial misalignment, or both.

[0220] In some examples, reference signal transmission manager 1025 can be configured to or otherwise support means for transmitting one or more reference signals at the same phase across a set of multiple antenna elements of a first antenna array according to a first pre-decoder matrix, wherein the estimated rotational misalignment is based on transmitting the one or more reference signals at the same phase. In some examples, the estimated rotational misalignment is estimated relative to one or more axes perpendicular to an additional axis extending from the first antenna array to the second antenna array.

[0221] In some examples, the reference signal transmission manager 1025 can be configured to or otherwise support means for transmitting one or more reference signals with a phase ramp across a set of multiple antenna elements of a first antenna array according to a first pre-decoder matrix, wherein the estimated rotational misalignment is based on transmitting the one or more reference signals with the phase ramp. In some examples, the estimated rotational misalignment is estimated relative to an axis extending from the first antenna array to the second antenna array.

[0222] In some examples, the reference signal transmission manager 1025 can be configured to or otherwise support means for transmitting a first subset of reference signals of the one or more reference signals via a first subset of antenna elements of the first antenna array, wherein the first subset of reference signals is transmitted at a first phase. In some examples, the reference signal transmission manager 1025 can be configured to or otherwise support means for transmitting a second subset of reference signals of the one or more reference signals via a second subset of antenna elements of the first antenna array, wherein the second subset of reference signals is transmitted at a second phase different from the first phase, wherein the estimated spatial misalignment is based on transmitting the first subset of reference signals at the first phase and transmitting the second subset of reference signals at the second phase.

[0223] In some examples, the second phase comprises an opposite sign compared to the first phase.In some examples, the estimated spatial misalignment is estimated relative to one or more axes perpendicular to an additional axis extending from the first antenna array to the second antenna array.

[0224] In some examples, control message communication manager 1040 may be configured or otherwise support components for communicating a control message indicating a reference signal waveform according to which one or more reference signals are transmitted.

[0225] In some examples, the reference signal reception manager 1045 can be configured to or otherwise support means for receiving one or more additional reference signals from the second wireless device using the first antenna array. In some examples, the feedback message transmission manager 1050 can be configured to or otherwise support means for transmitting a second feedback message to the second wireless device based on the one or more additional reference signals, the second feedback message indicating a second estimated rotational misalignment, a second estimated spatial misalignment, or both, between the first antenna array at the first wireless device and the second antenna array at the second wireless device, wherein the second precoder matrix is modified relative to the first precoder matrix based on the second estimated rotational misalignment, the second estimated spatial misalignment, or both.

[0226] In some examples, reference signal reception manager 1045 can be configured or otherwise support components for performing measurements on one or more additional reference signals, where the second estimated rotational misalignment, the second estimated spatial misalignment, or both are based on the measurements.

[0227] In some examples, the phase estimation manager 1060 can be configured to or otherwise support components for estimating a set of multiple phases along a second axis, a third axis, or both associated with one or more additional reference signals, where the second axis and the third axis are perpendicular to the first axis, and where the second estimated rotational misalignment is based on the set of multiple phases.

[0228] In some examples, the reference signal reception manager 1045 can be configured or otherwise support components for comparing one or more additional reference signals to the reference signal waveform, wherein the second estimated rotational misalignment, the second estimated spatial misalignment, or both are based on the comparison.

[0229] In some examples, the channel estimation matrix manager 1055 can be configured to or otherwise support components for determining a channel estimation matrix associated with a channel between a first antenna array and a second antenna array based on an estimated rotational misalignment, an estimated spatial misalignment, or both, wherein the second pre-decoder matrix is modified relative to the first pre-decoder matrix based on the channel estimation matrix. In some examples, the estimated spatial misalignment includes a parallel shift misalignment along one or more axes relative to the first antenna array, the second antenna array, or both.

[0230] Figure 11 A diagram of a system 1100 including a device 1105 supporting techniques for estimating misalignment between antenna arrays according to one or more aspects of the present disclosure is shown. The device 1105 may be an example of, or include a component of, a device 805, a device 905, or a network entity 105 as described herein. The device 1105 may communicate with one or more network entities 105, one or more UEs 115, or any combination thereof, which may include communication via one or more wired interfaces, via one or more wireless interfaces, or any combination thereof. The device 1105 may include components that support output and receipt of communications, such as a communication manager 1120, a transceiver 1110, an antenna 1115, a memory 1125, code 1130, and a processor 1135. These components may be in electronic communication or otherwise coupled (e.g., operatively, communicatively, functionally, electronically, electrically) via one or more buses (e.g., bus 1140).

[0231] The transceiver 1110 may support bidirectional communication via a wired link, a wireless link, or both as described herein. In some examples, the transceiver 1110 may include a wired transceiver and may communicate bidirectionally with another wired transceiver. Additionally or alternatively, in some examples, the transceiver 1110 may include a wireless transceiver and may communicate bidirectionally with another wireless transceiver. In some examples, the device 1105 may include one or more antennas 1115, which may be capable of transmitting or receiving wireless transmissions (e.g., concurrently). The transceiver 1110 may also include a modem for: modulating a signal; providing the modulated signal for transmission (e.g., via one or more antennas 1115, via a wired transmitter); receiving the modulated signal (e.g., from one or more antennas 1115, from a wired receiver); and demodulating the signal. In some implementations, the transceiver 1110 may include one or more interfaces, such as one or more interfaces coupled to one or more antennas 1115 configured to support various receive or obtain operations, or one or more interfaces coupled to one or more antennas 1115 configured to support various transmit or output operations, or a combination thereof. In some implementations, the transceiver 1110 may include or be configured to be coupled to one or more processors or memory components operable to perform or support operations based on received or obtained information or signals, or to generate information or other signals for transmission or other output, or any combination thereof. In some implementations, the transceiver 1110, or the transceiver 1110 and one or more antennas 1115, or the transceiver 1110 and one or more antennas 1115 and one or more processors or memory components (e.g., processor 1135 or memory 1125 or both) may be included in a chip or chip assembly installed in the device 1105. In some examples, the transceiver may be operable to support communications via one or more communication links (eg, communication link 125 , backhaul communication link 120 , midhaul communication link 162 , fronthaul communication link 168 ).

[0232] Memory 1125 may include RAM and ROM. Memory 1125 may store computer-readable, computer-executable code 1130 including instructions that, when executed by processor 1135, cause device 1105 to perform the various functions described herein. Code 1130 may be stored in a non-transitory computer-readable medium such as system memory or another type of memory. In some cases, code 1130 may not be directly executable by processor 1135, but (e.g., when compiled and executed) may cause a computer to perform the functions described herein. In some cases, memory 1125 may include a BIOS, etc., which may control basic hardware or software operations, such as interaction with peripheral components or devices.

[0233] The processor 1135 may include an intelligent hardware device (e.g., a general-purpose processor, a DSP, an ASIC, a CPU, an FPGA, a microcontroller, a programmable logic device, a discrete gate or transistor logic component, a discrete hardware component, or any combination thereof). In some cases, the processor 1135 may be configured to operate a memory array using a memory controller. In some other cases, the memory controller may be integrated into the processor 1135. The processor 1135 may be configured to execute computer-readable instructions stored in a memory (e.g., memory 1125) to cause the device 1105 to perform various functions (e.g., functions or tasks supporting techniques for estimating misalignment between antenna arrays). For example, the device 1105 or a component of the device 1105 may include a processor 1135 and a memory 1125 coupled to the processor 1135, the processor 1135 and the memory 1125 being configured to perform the various functions described herein. The processor 1135 may be an example of a cloud computing platform (e.g., one or more physical nodes and supporting software (such as an operating system, virtual machine, or container instance)) that can host functionality (e.g., by executing code 1130) to perform the functions of the device 1105. The processor 1135 may be any one or more suitable processors capable of executing scripts or instructions of one or more software programs stored in the device 1105 (such as in the memory 1125). In some implementations, the processor 1135 may be a component of a processing system. A processing system may generally refer to a system or series of machines or components that receives inputs and processes those inputs to produce a set of outputs (which may be passed to, for example, other systems or components of the device 1105). For example, the processing system of the device 1105 may refer to a system that includes various other components or subcomponents of the device 1105, such as the processor 1135, or the transceiver 1110, or the communication manager 1120, or other components or combinations of components of the device 1105. The processing system of device 1105 can interface with other components of device 1105 and can process information (such as input or signals) received from other components or output information to other components. For example, a chip or modem of device 1105 may include a processing system and one or more interfaces for outputting information or for obtaining information, or both. The one or more interfaces may be implemented as or otherwise include a first interface configured to output information and a second interface configured to obtain information, or the same interface configured to output information and obtain information, among other specific implementations. In some specific implementations, the one or more interfaces may refer to an interface between the processing system of the chip or modem and a transmitter, so that device 1105 can transmit information output from the chip or modem.Additionally or alternatively, in some implementations, one or more interfaces may refer to an interface between a processing system of a chip or modem and a receiver, such that the device 1105 can obtain information or signal input and pass the information to the processing system. A person skilled in the art will readily recognize that a first interface can also obtain information or signal input, and a second interface can also output information or signal output.

[0234] In some examples, bus 1140 may support communications for protocol layers (e.g., within a protocol layer) of a protocol stack. In some examples, bus 1140 may support communications associated with logical channels of a protocol stack (e.g., between protocol layers of a protocol stack), which may include communications performed within components of device 1105 or between different components of device 1105 that may be co-located or located in different locations (e.g., where device 1105 may refer to a system in which one or more of communication manager 1120, transceiver 1110, memory 1125, code 1130, and processor 1135 may be located in one of the different components or divided between the different components).

[0235] In some examples, communication manager 1120 can manage aspects of communications with core network 130 (e.g., via one or more wired or wireless backhaul links). For example, communication manager 1120 can manage the transfer of data communications for client devices, such as one or more UEs 115. In some examples, communication manager 1120 can manage communications with other network entities 105 and can include a controller or scheduler for controlling communications with UEs 115 in coordination with other network entities 105. In some examples, communication manager 1120 can support an X2 interface within LTE / LTE-A wireless communication network technology to provide communications between network entities 105.

[0236] For example, the communication manager 1120 may be configured to or otherwise support means for transmitting one or more reference signals to a second wireless device using a first antenna array at a first wireless device and based on a first pre-decoder matrix. The communication manager 1120 may be configured to or otherwise support means for receiving a feedback message from the second wireless device based on the one or more reference signals, the feedback message indicating an estimated rotational misalignment, an estimated spatial misalignment, or both between the first antenna array at the first wireless device and a second antenna array at the second wireless device. The communication manager 1120 may be configured to or otherwise support means for transmitting a message to the second wireless device based on a second pre-decoder matrix that is modified relative to the first pre-decoder matrix based on the estimated rotational misalignment, the estimated spatial misalignment, or both.

[0237] By including or configuring the communication manager 1120 according to the examples described herein, the device 1105 can support techniques that enable wireless devices to estimate misalignment between antenna arrays and compensate for such misalignment to improve the efficiency and reliability of wireless communications. Specifically, the techniques described herein can enable wireless devices to exchange reference signals (e.g., OAM waveforms) with each other using a defined phase configuration (e.g., a common phase, a phase ramp, etc.) that enables other corresponding devices to estimate rotational misalignment and / or translational shift misalignment. By enabling wireless devices to estimate misalignment, the corresponding devices can be able to update pre-decoding matrices and post-processing matrices used to send and receive signals between the devices. Thus, the techniques described herein can improve the efficiency and reliability of wireless communications exchanged between devices, thereby reducing the number / ratio of retransmissions and resulting in improved resource utilization and reduced power consumption.

[0238] In some examples, the communication manager 1120 can be configured to perform various operations (e.g., receive, obtain, monitor, output, transmit) using or otherwise cooperating with the transceiver 1110, one or more antennas 1115 (e.g., where applicable), or any combination thereof. Although the communication manager 1120 is illustrated as a separate component, in some examples, one or more functions described with reference to the communication manager 1120 may be supported or performed by the transceiver 1110, the processor 1135, the memory 1125, the code 1130, or any combination thereof. For example, the code 1130 may include instructions executable by the processor 1135 to cause the device 1105 to perform various aspects of the techniques for estimating misalignment between antenna arrays as described herein, or the processor 1135 and the memory 1125 may be otherwise configured to perform or support such operations.

[0239] Figure 12 A block diagram 1200 is shown of a device 1205 supporting techniques for estimating misalignment between antenna arrays according to one or more aspects of the present disclosure. The device 1205 may be an example of aspects of the UE 115 as described herein. The device 1205 may include a receiver 1210, a transmitter 1215, and a communication manager 1220. The device 1205 may also include a processor. Each of these components may communicate with each other (e.g., via one or more buses).

[0240] Receiver 1210 may provide means for receiving information such as packets associated with various information channels (e.g., control channels, data channels, information channels related to techniques for estimating misalignment between antenna arrays), user data, control information, or any combination thereof. The information may be passed to other components of device 1205. Receiver 1210 may utilize a single antenna or a collection of multiple antennas.

[0241] The transmitter 1215 may provide means for transmitting signals generated by other components of the device 1205. For example, the transmitter 1215 may transmit information such as packets associated with various information channels (e.g., control channels, data channels, information channels related to techniques for estimating misalignment between antenna arrays), user data, control information, or any combination thereof. In some examples, the transmitter 1215 may be co-located with the receiver 1210 in a transceiver module. The transmitter 1215 may utilize a single antenna or a collection of multiple antennas.

[0242] The communication manager 1220, the receiver 1210, the transmitter 1215, or various combinations thereof, or various components thereof, may be examples of means for performing various aspects of the techniques for estimating misalignment between antenna arrays as described herein. For example, the communication manager 1220, the receiver 1210, the transmitter 1215, or various combinations thereof, or components thereof, may support methods for performing one or more of the functions described herein.

[0243] In some examples, the communication manager 1220, the receiver 1210, the transmitter 1215, or various combinations or components thereof can be implemented in hardware (e.g., in a communication management circuit). The hardware may include a processor, a digital signal processor (DSP), a central processing unit (CPU), an application specific integrated circuit (ASIC), a field programmable gate array (FPGA) or other programmable logic device, a microcontroller, discrete gate or transistor logic components, discrete hardware components, or any combination thereof configured as or otherwise supporting components for performing the functions described in this disclosure. In some examples, the processor and a memory coupled to the processor can be configured to perform one or more of the functions described herein (e.g., by executing instructions stored in the memory by the processor).

[0244] Additionally or alternatively, in some examples, the communication manager 1220, the receiver 1210, the transmitter 1215, or various combinations or components thereof may be implemented in code executed by a processor (e.g., as communication management software or firmware). If implemented in code executed by a processor, the functionality of the communication manager 1220, the receiver 1210, the transmitter 1215, or various combinations or components thereof may be performed by a general-purpose processor (e.g., configured as or otherwise supporting means for performing the functions described in this disclosure), a DSP, a CPU, an ASIC, an FPGA, a microcontroller, or any combination of these or other programmable logic devices.

[0245] In some examples, communication manager 1220 can be configured to perform various operations (e.g., receive, obtain, monitor, output, transmit) using or otherwise cooperating with receiver 1210, transmitter 1215, or both. For example, communication manager 1220 can receive information from receiver 1210, transmit information to transmitter 1215, or be integrated with receiver 1210, transmitter 1215, or both to obtain information, output information, or perform various other operations as described herein.

[0246] For example, the communication manager 1220 may be configured to or otherwise support means for receiving one or more reference signals from the first wireless device using a second antenna array at the second wireless device and based on a first post-processing matrix. The communication manager 1220 may be configured to or otherwise support means for sending a feedback message to the first wireless device based on the one or more reference signals, the feedback message indicating an estimated rotational misalignment, an estimated spatial misalignment, or both between the second antenna array at the second wireless device and the first antenna array at the first wireless device. The communication manager 1220 may be configured to or otherwise support means for receiving a message from the first wireless device based on a second post-processing matrix that is modified relative to the first post-processing matrix based on the estimated rotational misalignment, the estimated spatial misalignment, or both.

[0247] By including or configuring the communication manager 1220 according to the examples described herein, the device 1205 (e.g., a processor controlling or otherwise coupled to the receiver 1210, the transmitter 1215, the communication manager 1220, or a combination thereof) can support techniques that enable wireless devices to estimate misalignment between antenna arrays and compensate for such misalignment to improve the efficiency and reliability of wireless communications. Specifically, the techniques described herein can enable wireless devices to exchange reference signals (e.g., OAM waveforms) with each other using a defined phase configuration (e.g., a common phase, a phase ramp, etc.) that enables other corresponding devices to estimate rotational misalignment and / or translational shift misalignment. By enabling wireless devices to estimate misalignment, the corresponding devices can update pre-coding matrices and post-processing matrices used to transmit and receive signals between the devices. Thus, the techniques described herein can improve the efficiency and reliability of wireless communications exchanged between devices, thereby reducing the number / ratio of retransmissions and resulting in improved resource utilization and reduced power consumption.

[0248] Figure 13A block diagram 1300 is shown of a device 1305 supporting techniques for estimating misalignment between antenna arrays in accordance with one or more aspects of the present disclosure. The device 1305 may be an example of aspects of the device 1205 or UE 115 as described herein. The device 1305 may include a receiver 1310, a transmitter 1315, and a communication manager 1320. The device 1305 may also include a processor. Each of these components may communicate with each other (e.g., via one or more buses).

[0249] Receiver 1310 may provide means for receiving information such as packets associated with various information channels (e.g., control channels, data channels, information channels related to techniques for estimating misalignment between antenna arrays), user data, control information, or any combination thereof. The information may be passed to other components of device 1305. Receiver 1310 may utilize a single antenna or a collection of multiple antennas.

[0250] The transmitter 1315 may provide means for transmitting signals generated by other components of the device 1305. For example, the transmitter 1315 may transmit information such as packets associated with various information channels (e.g., control channels, data channels, information channels related to techniques for estimating misalignment between antenna arrays), user data, control information, or any combination thereof. In some examples, the transmitter 1315 may be co-located with the receiver 1310 in a transceiver module. The transmitter 1315 may utilize a single antenna or a collection of multiple antennas.

[0251] Device 1305 or its various components may be examples of means for performing various aspects of the techniques for estimating misalignment between antenna arrays as described herein. For example, communication manager 1320 may include reference signal reception manager 1325, feedback message transmission manager 1330, message reception manager 1335, or any combination thereof. Communication manager 1320 may be an example of aspects of communication manager 1220 as described herein. In some examples, communication manager 1320 or its various components may be configured to perform various operations (e.g., receive, obtain, monitor, output, transmit) using or otherwise coordinating with receiver 1310, transmitter 1315, or both. For example, communication manager 1320 may receive information from receiver 1310, transmit information to transmitter 1315, or be integrated in conjunction with receiver 1310, transmitter 1315, or both to obtain information, output information, or perform various other operations as described herein.

[0252] The reference signal reception manager 1325 may be configured to or otherwise support means for receiving one or more reference signals from the first wireless device using a second antenna array at the second wireless device and according to a first post-processing matrix. The feedback message transmission manager 1330 may be configured to or otherwise support means for transmitting a feedback message to the first wireless device based on the one or more reference signals, the feedback message indicating an estimated rotational misalignment, an estimated spatial misalignment, or both between the second antenna array at the second wireless device and the first antenna array at the first wireless device. The message reception manager 1335 may be configured to or otherwise support means for receiving a message from the first wireless device according to a second post-processing matrix, the second post-processing matrix modified relative to the first post-processing matrix based on the estimated rotational misalignment, the estimated spatial misalignment, or both.

[0253] Figure 14 Block diagram 1400 of a communication manager 1420 supporting techniques for estimating misalignment between antenna arrays according to one or more aspects of the present disclosure is shown. Communication manager 1420 may be an example of aspects of communication manager 1220, communication manager 1320, or both, as described herein. Communication manager 1420 or its various components may be examples of means for performing various aspects of the techniques for estimating misalignment between antenna arrays as described herein. For example, communication manager 1420 may include a reference signal reception manager 1425, a feedback message transmission manager 1430, a message reception manager 1435, a control message communication manager 1440, a reference signal transmission manager 1445, a feedback message reception manager 1450, a phase estimation manager 1455, a channel estimation matrix manager 1460, or any combination thereof. Each of these components may communicate directly or indirectly with one another (e.g., via one or more buses).

[0254] The reference signal reception manager 1425 may be configured to or otherwise support means for receiving one or more reference signals from the first wireless device using a second antenna array at the second wireless device and according to a first post-processing matrix. The feedback message transmission manager 1430 may be configured to or otherwise support means for transmitting a feedback message to the first wireless device based on the one or more reference signals, the feedback message indicating an estimated rotational misalignment, an estimated spatial misalignment, or both between the second antenna array at the second wireless device and the first antenna array at the first wireless device. The message reception manager 1435 may be configured to or otherwise support means for receiving a message from the first wireless device according to a second post-processing matrix, the second post-processing matrix modified relative to the first post-processing matrix based on the estimated rotational misalignment, the estimated spatial misalignment, or both.

[0255] In some examples, the estimated rotational misalignment is estimated relative to one or more axes perpendicular to an additional axis extending from the first antenna array to the second antenna array. In some examples, the estimated rotational misalignment is estimated relative to an axis extending from the first antenna array to the second antenna array. In some examples, the estimated spatial misalignment is estimated relative to one or more axes perpendicular to the additional axis extending from the first antenna array to the second antenna array.

[0256] In some examples, control message communication manager 1440 may be configured or otherwise support components for communicating a control message indicative of a reference signal waveform according to which one or more reference signals are communicated.

[0257] In some examples, the reference signal transmission manager 1445 can be configured to or otherwise support means for transmitting one or more additional reference signals to the first wireless device using the second antenna array. In some examples, the feedback message reception manager 1450 can be configured to or otherwise support means for receiving a second feedback message from the first wireless device based on the one or more additional reference signals, the second feedback message indicating a second estimated rotational misalignment, a second estimated spatial misalignment, or both between the first antenna array at the first wireless device and the second antenna array at the second wireless device, wherein the second post-processing matrix is modified relative to the first post-processing matrix based on the second estimated rotational misalignment, the second estimated spatial misalignment, or both.

[0258] In some examples, reference signal reception manager 1425 may be configured or otherwise support components for performing measurements on one or more reference signals, where the estimated rotational misalignment, the estimated spatial misalignment, or both are based on the measurements.

[0259] In some examples, the phase estimation manager 1455 can be configured to or otherwise support components for estimating a set of multiple phases along a second axis, a third axis, or both associated with one or more reference signals, where the second axis and the third axis are perpendicular to the first axis, and where the estimated rotational misalignment is based on the set of multiple phases.

[0260] In some examples, the reference signal reception manager 1425 can be configured or otherwise support components for comparing one or more reference signals to a reference signal waveform, where the estimated rotational misalignment, the estimated spatial misalignment, or both are based on the comparison.

[0261] In some examples, channel estimation matrix manager 1460 can be configured to or otherwise support components for determining a channel estimation matrix associated with a channel between a first antenna array and a second antenna array based on an estimated rotational misalignment, an estimated spatial misalignment, or both, wherein the second post-processing matrix is modified relative to the first post-processing matrix based on the channel estimation matrix. In some examples, the estimated spatial misalignment includes a parallel shift misalignment along one or more axes relative to the first antenna array, the second antenna array, or both.

[0262] Figure 15 A diagram of a system 1500 including a device 1505 supporting techniques for estimating misalignment between antenna arrays according to one or more aspects of the present disclosure is shown. Device 1505 may be an example of, or include components of, device 1205, device 1305, or UE 115 as described herein. Device 1505 may communicate (e.g., wirelessly) with one or more network entities 105, one or more UEs 115, or any combination thereof. Device 1505 may include components for two-way voice and data communications, including components for sending and receiving communications, such as a communications manager 1520, an input / output (I / O) controller 1510, a transceiver 1515, an antenna 1525, a memory 1530, code 1535, and a processor 1540. These components may be in electronic communication or otherwise coupled (e.g., operatively, communicatively, functionally, electronically, electrically) via one or more buses (e.g., bus 1545).

[0263] I / O controller 1510 can manage input and output signals for device 1505. I / O controller 1510 can also manage peripheral devices that are not integrated into device 1505. In some cases, I / O controller 1510 can represent a physical connection or port to an external peripheral device. In some cases, I / O controller 1510 can utilize an operating system such as or another known operating system. Additionally or alternatively, I / O controller 1510 may represent or interact with a modem, keyboard, mouse, touch screen, or similar device. In some cases, I / O controller 1510 may be implemented as part of a processor (such as processor 1540). In some cases, a user may interact with device 1505 via I / O controller 1510 or via hardware components controlled by I / O controller 1510.

[0264] In some cases, device 1505 may include a single antenna 1525. However, in some other cases, device 1505 may have more than one antenna 1525, which may be capable of concurrently transmitting or receiving multiple wireless transmissions. Transceiver 1515 may communicate bidirectionally via one or more antennas 1525, wired, or wireless links, as described herein. For example, transceiver 1515 may represent a wireless transceiver and may communicate bidirectionally with another wireless transceiver. Transceiver 1515 may also include a modem for modulating packets; providing the modulated packets to one or more antennas 1525 for transmission; and demodulating packets received from one or more antennas 1525. Transceiver 1515, or transceiver 1515 and one or more antennas 1525, may be examples of transmitter 1215, transmitter 1315, receiver 1210, receiver 1310, or any combination thereof, or components thereof, as described herein.

[0265] Memory 1530 may include random access memory (RAM) and read-only memory (ROM). Memory 1530 may store computer-readable, computer-executable code 1535 including instructions that, when executed by processor 1540, cause device 1505 to perform the various functions described herein. Code 1535 may be stored in a non-transitory computer-readable medium such as system memory or another type of memory. In some cases, code 1535 may not be directly executable by processor 1540, but (e.g., when compiled and executed) may cause a computer to perform the functions described herein. In some cases, memory 1530 may also contain, among other things, a basic I / O system (BIOS) that may control basic hardware or software operations, such as interaction with peripheral components or devices.

[0266] The processor 1540 may include an intelligent hardware device (e.g., 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 cases, the processor 1540 may be configured to operate a memory array using a memory controller. In some other cases, the memory controller may be integrated into the processor 1540. The processor 1540 may be configured to execute computer-readable instructions stored in a memory (e.g., memory 1530) to cause the device 1505 to perform various functions (e.g., functions or tasks supporting techniques for estimating misalignment between antenna arrays). For example, the device 1505 or a component of the device 1505 may include a processor 1540 and a memory 1530 coupled to or coupled to the processor 1540, the processor 1540 and the memory 1530 being configured to perform the various functions described herein.

[0267] For example, the communication manager 1520 may be configured to or otherwise support means for receiving one or more reference signals from the first wireless device using a second antenna array at the second wireless device and based on a first post-processing matrix. The communication manager 1520 may be configured to or otherwise support means for sending a feedback message to the first wireless device based on the one or more reference signals, the feedback message indicating an estimated rotational misalignment, an estimated spatial misalignment, or both between the second antenna array at the second wireless device and the first antenna array at the first wireless device. The communication manager 1520 may be configured to or otherwise support means for receiving a message from the first wireless device based on a second post-processing matrix that is modified relative to the first post-processing matrix based on the estimated rotational misalignment, the estimated spatial misalignment, or both.

[0268] By including or configuring the communication manager 1520 according to the examples described herein, the device 1505 can support techniques that enable wireless devices to estimate misalignment between antenna arrays and compensate for such misalignment to improve the efficiency and reliability of wireless communications. Specifically, the techniques described herein can enable wireless devices to exchange reference signals (e.g., OAM waveforms) with each other using a defined phase configuration (e.g., a common phase, a phase ramp, etc.) that enables other corresponding devices to estimate rotational misalignment and / or translational shift misalignment. By enabling wireless devices to estimate misalignment, the corresponding devices can be able to update pre-decoding matrices and post-processing matrices used to send and receive signals between the devices. Thus, the techniques described herein can improve the efficiency and reliability of wireless communications exchanged between devices, thereby reducing the number / ratio of retransmissions and resulting in improved resource utilization and reduced power consumption.

[0269] In some examples, the communication manager 1520 can be configured to perform various operations (e.g., receive, monitor, transmit) using or otherwise coordinating with the transceiver 1515, one or more antennas 1525, or any combination thereof. Although the communication manager 1520 is illustrated as a separate component, in some examples, one or more functions described with reference to the communication manager 1520 can be supported or performed by the processor 1540, the memory 1530, the code 1535, or any combination thereof. For example, the code 1535 can include instructions executable by the processor 1540 to cause the device 1505 to perform various aspects of the techniques for estimating misalignment between antenna arrays as described herein, or the processor 1540 and the memory 1530 can be otherwise configured to perform or support such operations.

[0270] Figure 16 A flow chart illustrating a method 1600 for supporting techniques for estimating misalignment between antenna arrays according to one or more aspects of the present disclosure is shown. The operations of the method 1600 may be implemented by a network entity or component thereof as described herein. For example, the operations of the method 1600 may be implemented by a network entity or component thereof as described herein. Figures 1 to 11 The network entity described herein performs. In some examples, the network entity may execute an instruction set to control the functional elements of the network entity to perform the described functions. Additionally or alternatively, the network entity may use dedicated hardware to perform various aspects of the described functions.

[0271] At 1605, the method may include transmitting one or more reference signals to a second wireless device using a first antenna array at the first wireless device and according to a first pre-decoder matrix. The operations of 1605 may be performed according to examples as disclosed herein. In some examples, aspects of the operations of 1605 may be performed by reference to Figure 10 The described reference signal transmission manager 1025 is performed.

[0272] At 1610, the method may include receiving a feedback message from a second wireless device based on one or more reference signals, the feedback message indicating an estimated rotational misalignment, an estimated spatial misalignment, or both between a first antenna array at the first wireless device and a second antenna array at the second wireless device. The operations of 1610 may be performed according to examples as disclosed herein. In some examples, aspects of the operations of 1610 may be performed by a second wireless device as described in reference to Figure 10 The described feedback message receiving manager 1030 is executed.

[0273] At 1615, the method may include sending a message to the second wireless device according to a second pre-decoder matrix that is modified relative to the first pre-decoder matrix based on the estimated rotational misalignment, the estimated spatial misalignment, or both. The operations of 1615 may be performed according to examples as disclosed herein. In some examples, aspects of the operations of 1615 may be performed as described with reference to Figure 10 The described message sending manager 1035 is executed.

[0274] Figure 17 A flow chart illustrating a method 1700 for supporting techniques for estimating misalignment between antenna arrays according to one or more aspects of the present disclosure is shown. The operations of the method 1700 may be implemented by a UE or components thereof as described herein. For example, the operations of the method 1700 may be implemented by a UE or components thereof as described herein. Figures 1 to 7 and Figures 12 to 15 The described functions may be performed by the UE 115. In some examples, the UE may execute an instruction set to control the functional elements of the UE to perform the described functions. Additionally or alternatively, the UE may use dedicated hardware to perform various aspects of the described functions.

[0275] At 1705, the method may include receiving one or more reference signals from the first wireless device using a second antenna array at the second wireless device and according to the first post-processing matrix. The operations of 1705 may be performed according to examples as disclosed herein. In some examples, aspects of the operations of 1705 may be performed by reference to Figure 14 The described reference signal reception manager 1425 is executed.

[0276] At 1710, the method may include sending a feedback message to the first wireless device based on one or more reference signals, the feedback message indicating an estimated rotational misalignment, an estimated spatial misalignment, or both between a second antenna array at the second wireless device and a first antenna array at the first wireless device. The operations of 1710 may be performed according to examples as disclosed herein. In some examples, aspects of the operations of 1710 may be performed by reference to Figure 14 The described feedback message sending manager 1430 is executed.

[0277] At 1715, the method may include receiving a message from the first wireless device according to a second post-processing matrix that is modified relative to the first post-processing matrix based on an estimated rotational misalignment, an estimated spatial misalignment, or both. The operations of 1715 may be performed according to examples as disclosed herein. In some examples, aspects of the operations of 1715 may be performed as described with reference to Figure 14 The message receiving manager 1435 described is executed.

[0278] The following provides an overview of various aspects of the disclosure:

[0279] Aspect 1: A method for wireless communication at a first wireless device, the method comprising: sending one or more reference signals to a second wireless device using a first antenna array at the first wireless device and based on a first predecoder matrix; receiving a feedback message from the second wireless device based at least in part on the one or more reference signals, the feedback message indicating an estimated rotational misalignment, an estimated spatial misalignment, or both between the first antenna array at the first wireless device and a second antenna array at the second wireless device; and sending a message to the second wireless device based on a second predecoder matrix, the second predecoder matrix being modified relative to the first predecoder matrix based at least in part on the estimated rotational misalignment, the estimated spatial misalignment, or both.

[0280] Aspect 2: The method according to Aspect 1 further includes: sending the one or more reference signals at the same phase across multiple antenna elements of the first antenna array according to the first pre-decoder matrix, wherein the estimated rotational misalignment is at least partially based on sending the one or more reference signals at the same phase.

[0281] Aspect 3: The method of aspect 2, wherein the estimated rotational misalignment is estimated relative to one or more axes perpendicular to an additional axis extending from the first antenna array to the second antenna array.

[0282] Aspect 4: The method according to any one of Aspects 1 to 3 further includes: sending the one or more reference signals with a phase ramp across multiple antenna elements of the first antenna array according to the first pre-decoder matrix, wherein the estimated rotational misalignment is at least partially based on sending the one or more reference signals with the phase ramp.

[0283] Aspect 5: The method of aspect 4, wherein the estimated rotational misalignment is estimated relative to an axis extending from the first antenna array to the second antenna array.

[0284] Aspect 6: The method according to any one of Aspects 1 to 5 further includes: sending a first subset of reference signals of the one or more reference signals via a first subset of antenna elements of the first antenna array, wherein the first subset of reference signals is sent at a first phase; and sending a second subset of reference signals of the one or more reference signals via a second subset of antenna elements of the first antenna array, wherein the second subset of reference signals is sent at a second phase different from the first phase, wherein the estimated spatial misalignment is at least partially based on sending the first subset of reference signals at the first phase and sending the second subset of reference signals at the second phase.

[0285] Aspect 7: The method according to aspect 6, wherein the second phase comprises an opposite sign compared to the first phase.

[0286] Aspect 8: The method according to any one of aspects 6 to 7, wherein the estimated spatial misalignment is estimated relative to one or more axes perpendicular to an additional axis extending from the first antenna array to the second antenna array.

[0287] Aspect 9: The method according to any one of aspects 1 to 8, further comprising: communicating a control message indicating a reference signal waveform according to which one or more reference signals are sent.

[0288] Aspect 10: The method according to any one of Aspects 1 to 9 further includes: receiving one or more additional reference signals from the second wireless device using the first antenna array; and sending a second feedback message to the second wireless device based at least in part on the one or more additional reference signals, the second feedback message indicating a second estimated rotational misalignment, a second estimated spatial misalignment, or both between the first antenna array at the first wireless device and the second antenna array at the second wireless device, wherein the second pre-decoder matrix is modified relative to the first pre-decoder matrix based at least in part on the second estimated rotational misalignment, the second estimated spatial misalignment, or both.

[0289] Aspect 11: The method according to aspect 10, further comprising: performing measurements on the one or more additional reference signals, wherein the second estimated rotational misalignment, the second estimated spatial misalignment, or both are based at least in part on the measurements.

[0290] Aspect 12: A method according to any one of Aspects 10 to 11, wherein a first axis extends from the first antenna array to the second antenna array, and the method further comprises: estimating multiple phases along a second axis, a third axis, or both associated with the one or more additional reference signals, wherein the second axis and the third axis are perpendicular to the first axis, and wherein the second estimated rotational misalignment is based at least in part on the multiple phases.

[0291] Aspect 13: The method according to any one of Aspects 10 to 12 further includes: comparing the one or more additional reference signals with a reference signal waveform, wherein the second estimated rotational misalignment, the second estimated spatial misalignment, or both are at least partially based on the comparison.

[0292] Aspect 14: The method according to any one of Aspects 1 to 13 also includes: determining a channel estimation matrix associated with a channel between the first antenna array and the second antenna array based at least in part on the estimated rotational misalignment, the estimated spatial misalignment, or both, wherein the second pre-decoder matrix is modified relative to the first pre-decoder matrix based at least in part on the channel estimation matrix.

[0293] Aspect 15: The method according to any one of aspects 1 to 14, wherein the estimated spatial misalignment comprises a parallel shift misalignment along one or more axes relative to the first antenna array, the second antenna array, or both.

[0294] Aspect 16: A method for wireless communication at a second wireless device, the method comprising: receiving one or more reference signals from a first wireless device using a second antenna array at the second wireless device and based on a first post-processing matrix; sending a feedback message to the first wireless device based at least in part on the one or more reference signals, the feedback message indicating an estimated rotational misalignment, an estimated spatial misalignment, or both between the second antenna array at the second wireless device and the first antenna array at the first wireless device; and receiving a message from the first wireless device based on a second post-processing matrix, the second post-processing matrix being modified relative to the first post-processing matrix based at least in part on the estimated rotational misalignment, the estimated spatial misalignment, or both.

[0295] Aspect 17: The method of aspect 16, wherein the estimated rotational misalignment is estimated relative to one or more axes perpendicular to an additional axis extending from the first antenna array to the second antenna array.

[0296] Aspect 18: The method according to any one of aspects 16 to 17, wherein the estimated rotational misalignment is estimated relative to an axis extending from the first antenna array to the second antenna array.

[0297] Aspect 19: The method according to any one of aspects 16 to 18, wherein the estimated spatial misalignment is estimated relative to one or more axes perpendicular to an additional axis extending from the first antenna array to the second antenna array.

[0298] Aspect 20: The method according to any one of aspects 16 to 19, further comprising: communicating a control message indicative of a reference signal waveform according to which one or more reference signals are communicated.

[0299] Aspect 21: The method according to any one of Aspects 16 to 20 further includes: sending one or more additional reference signals to the first wireless device using the second antenna array; and receiving a second feedback message from the first wireless device based at least in part on the one or more additional reference signals, the second feedback message indicating a second estimated rotational misalignment, a second estimated spatial misalignment, or both between the first antenna array at the first wireless device and the second antenna array at the second wireless device, wherein the second post-processing matrix is modified relative to the first post-processing matrix based at least in part on the second estimated rotational misalignment, the second estimated spatial misalignment, or both.

[0300] Aspect 22: The method according to any one of aspects 16 to 21, further comprising: performing measurements on the one or more reference signals, wherein the estimated rotational misalignment, the estimated spatial misalignment, or both are based at least in part on the measurements.

[0301] Aspect 23: A method according to any one of Aspects 16 to 22, wherein a first axis extends from the first antenna array to the second antenna array, and the method further comprises: estimating multiple phases along a second axis, a third axis, or both associated with the one or more reference signals, wherein the second axis and the third axis are perpendicular to the first axis, and wherein the estimated rotational misalignment is based at least in part on the multiple phases.

[0302] Aspect 24: The method according to any one of Aspects 16 to 23 further includes: comparing the one or more reference signals with a reference signal waveform, wherein the estimated rotational misalignment, the estimated spatial misalignment, or both are based at least in part on the comparison.

[0303] Aspect 25: The method according to any one of Aspects 16 to 24 further includes: determining a channel estimation matrix associated with a channel between the first antenna array and the second antenna array based at least in part on the estimated rotational misalignment, the estimated spatial misalignment, or both, wherein the second post-processing matrix is modified relative to the first post-processing matrix based at least in part on the channel estimation matrix.

[0304] Aspect 26: The method according to any one of aspects 16 to 25, wherein the estimated spatial misalignment comprises a parallel shift misalignment along one or more axes relative to the first antenna array, the second antenna array, or both.

[0305] Aspect 27: An apparatus comprising: a processor; a memory coupled to the processor; and instructions stored in the memory and executable by the processor to cause the apparatus to perform a method according to any one of aspects 1 to 15.

[0306] Aspect 28: An apparatus comprising: at least one component for performing the method according to any one of aspects 1 to 15.

[0307] Aspect 29: A non-transitory computer-readable medium storing code comprising instructions executable by a processor to perform the method according to any one of aspects 1 to 15.

[0308] Aspect 30: An apparatus comprising: a processor; a memory coupled to the processor; and instructions stored in the memory and executable by the processor to cause the apparatus to perform a method according to any one of aspects 16 to 26.

[0309] Aspect 31: An apparatus comprising: at least one component for performing the method according to any one of aspects 16 to 26.

[0310] Aspect 32: A non-transitory computer-readable medium storing code comprising instructions executable by a processor to perform the method according to any one of aspects 16 to 26.

[0311] It should be noted that the methods described herein describe possible implementations, and that the operations and steps may be rearranged or otherwise modified and that other implementations are possible. Furthermore, aspects of two or more of these methods may be combined.

[0312] Although aspects of LTE, LTE-A, LTE-A Pro, or NR systems may be described for example purposes, and the terminology of LTE, LTE-A, LTE-A Pro, or NR may be used throughout much of the description, the techniques described herein may also be applicable to networks other than LTE, LTE-A, LTE-A Pro, or NR networks. For example, the techniques described may be applicable to various other wireless communication systems, such as Ultra Mobile Broadband (UMB), Institute of Electrical and Electronics Engineers (IEEE) 802.11 (Wi-Fi), IEEE 802.16 (WiMAX), IEEE 802.20, Flash-OFDM, and other systems and radio technologies not explicitly mentioned herein.

[0313] The information and signals described herein may be represented using any of a variety of different technologies and techniques. For example, data, instructions, commands, information, signals, bits, symbols, and chips referred to throughout the description may be represented by voltages, currents, electromagnetic waves, magnetic fields or particles, optical fields or particles, or any combination thereof.

[0314] The various illustrative blocks and components described in conjunction with the disclosure herein may be implemented or executed using a general purpose processor, a DSP, an ASIC, a CPU, an FPGA or other programmable logic device, discrete gate or transistor logic components, discrete hardware components, or any combination thereof designed to perform the functions described herein. A general purpose processor may be a microprocessor, but in the alternative, the processor may be any processor, controller, microcontroller, or state machine. A processor may also be implemented as a combination of computing devices (e.g., a combination of a DSP and a microprocessor, a plurality of microprocessors, one or more microprocessors in conjunction with a DSP core, or any other such configuration).

[0315] The functions described herein may be implemented using hardware, software executed by a processor, firmware, or any combination thereof. When implemented using software executed by a processor, the functions may be stored as one or more instructions or codes of a computer-readable medium or sent using one or more instructions or codes of a computer-readable medium. Other examples and specific implementations are within the scope of this disclosure and the appended claims. For example, due to the nature of software, the functions described herein may be implemented using software executed by a processor, hardware, firmware, hard wiring, or a combination of any of these. Features that implement the functions may also be physically located at different locations, including being distributed so that parts of the functions are implemented at different physical locations.

[0316] Computer-readable medium includes both non-transient computer storage media and communication media, and it includes any medium that promotes a computer program to be transferred from one location to another location.Non-transient storage medium can be any available medium that can be accessed by a general or special-purpose computer.By way of example and not limitation, non-transient computer-readable medium can include RAM, ROM, electrically erasable programmable ROM (EEPROM), flash memory, compact disc (CD) ROM or other optical disc storage, disk storage or other magnetic storage device or can be used for carrying or storing desired program code components and any other non-transient medium that can be accessed by a general or special-purpose computer or a general or special-purpose processor in the form of an instruction or data structure.Moreover, any connection is appropriately referred to as computer-readable medium.For example, if software is sent from a website, server or other remote source using coaxial cable, fiber optic cable, twisted pair, digital subscriber line (DSL) or wireless technologies such as infrared, radio and microwave, then coaxial cable, fiber optic cable, twisted pair, DSL or wireless technologies such as infrared, radio and microwave are included in the definition of computer-readable medium. As used herein, disk and optical disc include CD, laser disc, optical disc, digital versatile disc (DVD), floppy disk and Blu-ray disc. Magnetic disk can reproduce data magnetically, and optical disc can reproduce data optically using lasers. Combinations of the above are also included within the scope of computer-readable media.

[0317] As used herein, including in the claims, "or" used in a list of items (e.g., a list of items followed by a phrase such as "at least one of" or "one or more of") indicates an inclusive list, so that, for example, a list of at least one of A, B, or C means A or B or C or AB or AC or BC or ABC (i.e., A and B and C). Moreover, as used herein, the phrase "based on" should not be interpreted as a reference to a closed set of conditions. For example, an example step described as "based on condition A" can be based on both condition A and condition B without departing from the scope of this disclosure. In other words, as used herein, the phrase "based on" should be interpreted in the same manner as the phrase "based at least in part on."

[0318] The term "determining" encompasses a variety of actions, and thus, "determining" may include calculating, computing, processing, deriving, investigating, looking up (such as via looking up in a table, database, or other data structure), ascertaining, and the like. Furthermore, "determining" may include receiving (e.g., receiving information), accessing (e.g., accessing data stored in a memory), etc. Furthermore, "determining" may include parsing, retrieving, selecting, choosing, establishing, and other such similar actions.

[0319] In the drawings, similar components or features may have the same reference number. In addition, various components of the same type may be distinguished by following the reference number with a dash and a second reference number to distinguish between similar components. If only the first reference number is used in the specification, the description applies to any of the similar components having the same first reference number, regardless of the second or subsequent reference numbers.

[0320] The description set forth herein in conjunction with the accompanying drawings describes example configurations and does not represent all examples that may be implemented or within the scope of the claims. The term "example" as used herein means "serving as an example, instance, or illustration," rather than "preferred" or "having advantages over other examples." The detailed description includes specific details to provide an understanding of the described techniques. However, these techniques may be practiced without these specific details. In some cases, known structures and devices are shown in block diagram form to avoid obscuring the concepts of the described examples.

[0321] The description herein is provided to enable one of ordinary skill in the art to make or use the present disclosure. Various modifications to the present disclosure will be apparent to those of ordinary skill in the art, and the general principles defined herein may be applied to other variations without departing from the scope of the present disclosure. Thus, the present disclosure is not limited to the examples and designs described herein, but should be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. An apparatus for wireless communication at a first wireless device, the apparatus comprising: processor; a memory coupled to the processor; and instructions stored in the memory and executable by the processor to cause the apparatus to: transmitting one or more reference signals to a second wireless device using a first antenna array at the first wireless device and according to a first precoder matrix; receiving a feedback message from the second wireless device based at least in part on the one or more reference signals, the feedback message indicating an estimated rotational misalignment, an estimated spatial misalignment, or both, between the first antenna array at the first wireless device and a second antenna array at the second wireless device; as well as A message is sent to the second wireless device according to a second precoder matrix that is modified relative to the first precoder matrix based at least in part on the estimated rotational misalignment, the estimated spatial misalignment, or both.

2. The apparatus of claim 1 , wherein the instructions are further executable by the processor to cause the apparatus to: The one or more reference signals are sent with a same phase across multiple antenna elements of the first antenna array according to the first precoder matrix, wherein the estimated rotational misalignment is based at least in part on sending the one or more reference signals with the same phase. 3 . The apparatus of claim 2 , wherein the estimated rotational misalignment is estimated relative to one or more axes perpendicular to an additional axis extending from the first antenna array to the second antenna array.

4. The apparatus of claim 1 , wherein the instructions are further executable by the processor to cause the apparatus to: The one or more reference signals are transmitted with a phase ramp across multiple antenna elements of the first antenna array according to the first precoder matrix, wherein the estimated rotational misalignment is based at least in part on transmitting the one or more reference signals with the phase ramp. The apparatus of claim 4 , wherein the estimated rotational misalignment is estimated relative to an axis extending from the first antenna array to the second antenna array.

6. The apparatus of claim 1 , wherein the instructions are further executable by the processor to cause the apparatus to: transmitting a first subset of the one or more reference signals via a first subset of antenna elements of the first antenna array, wherein the first subset of reference signals is transmitted with a first phase; and a second subset of reference signals of the one or more reference signals being transmitted via a second subset of antenna elements of the first antenna array, wherein the second subset of reference signals is transmitted at a second phase different from the first phase, and wherein the estimated spatial misalignment is based at least in part on transmitting the first subset of reference signals at the first phase and transmitting the second subset of reference signals at the second phase. The apparatus of claim 6 , wherein the second phase comprises an opposite sign compared to the first phase.

8. The apparatus of claim 6, wherein the estimated spatial misalignment is estimated relative to one or more axes perpendicular to an additional axis extending from the first antenna array to the second antenna array.

9. The apparatus of claim 1 , wherein the instructions are further executable by the processor to cause the apparatus to: A control message is communicated that indicates a reference signal waveform according to which one or more reference signals are sent.

10. The apparatus of claim 1 , wherein the instructions are further executable by the processor to cause the apparatus to: receiving one or more additional reference signals from the second wireless device using the first antenna array; and and sending a second feedback message to the second wireless device based at least in part on the one or more additional reference signals, the second feedback message indicating a second estimated rotational misalignment, a second estimated spatial misalignment, or both, between the first antenna array at the first wireless device and the second antenna array at the second wireless device, wherein the second precoder matrix is modified relative to the first precoder matrix based at least in part on the second estimated rotational misalignment, the second estimated spatial misalignment, or both.

11. The apparatus of claim 10, wherein the instructions are further executable by the processor to cause the apparatus to: Measurements are performed on the one or more additional reference signals, wherein the second estimated rotational misalignment, the second estimated spatial misalignment, or both are based at least in part on the measurements.

12. The apparatus of claim 10, wherein a first axis extends from the first antenna array to the second antenna array, wherein the instructions are further executable by the processor to cause the apparatus to: A plurality of phases along a second axis, a third axis, or both associated with the one or more additional reference signals are estimated, wherein the second axis and the third axis are perpendicular to the first axis, and wherein the second estimated rotational misalignment is based at least in part on the plurality of phases.

13. The apparatus of claim 10, wherein the instructions are further executable by the processor to cause the apparatus to: The one or more additional reference signals are compared to a reference signal waveform, wherein the second estimated rotational misalignment, the second estimated spatial misalignment, or both are based at least in part on the comparison.

14. The apparatus of claim 1 , wherein the instructions are further executable by the processor to cause the apparatus to: A channel estimation matrix associated with a channel between the first antenna array and the second antenna array is determined based at least in part on the estimated rotational misalignment, the estimated spatial misalignment, or both, wherein the second precoder matrix is modified relative to the first precoder matrix based at least in part on the channel estimation matrix.

15. The apparatus of claim 1, wherein the estimated spatial misalignment comprises a parallel shift misalignment along one or more axes relative to the first antenna array, the second antenna array, or both.

16. An apparatus for wireless communication at a second wireless device, the apparatus comprising: processor; a memory coupled to the processor; and instructions stored in the memory and executable by the processor to cause the apparatus to: receiving one or more reference signals from the first wireless device using a second antenna array at the second wireless device and according to a first post-processing matrix; sending a feedback message to the first wireless device based at least in part on the one or more reference signals, the feedback message indicating an estimated rotational misalignment, an estimated spatial misalignment, or both, between the second antenna array at the second wireless device and the first antenna array at the first wireless device; as well as A message is received from the first wireless device according to a second post-processing matrix that is modified relative to the first post-processing matrix based at least in part on the estimated rotational misalignment, the estimated spatial misalignment, or both.

17. The apparatus of claim 16, wherein the estimated rotational misalignment is estimated relative to one or more axes perpendicular to an additional axis extending from the first antenna array to the second antenna array.

18. The apparatus of claim 16, wherein the estimated rotational misalignment is estimated relative to an axis extending from the first antenna array to the second antenna array.

19. The apparatus of claim 16, wherein the estimated spatial misalignment is estimated relative to one or more axes perpendicular to an additional axis extending from the first antenna array to the second antenna array.

20. The apparatus of claim 16, wherein the instructions are further executable by the processor to cause the apparatus to: A control message is communicated that indicates a reference signal waveform according to which one or more reference signals are communicated.

21. The apparatus of claim 16, wherein the instructions are further executable by the processor to cause the apparatus to: transmitting one or more additional reference signals to the first wireless device using the second antenna array; and and receiving a second feedback message from the first wireless device based at least in part on the one or more additional reference signals, the second feedback message indicating a second estimated rotational misalignment, a second estimated spatial misalignment, or both, between the first antenna array at the first wireless device and the second antenna array at the second wireless device, wherein the second post-processing matrix is modified relative to the first post-processing matrix based at least in part on the second estimated rotational misalignment, the second estimated spatial misalignment, or both.

22. The apparatus of claim 16, wherein the instructions are further executable by the processor to cause the apparatus to: Measurements are performed on the one or more reference signals, wherein the estimated rotational misalignment, the estimated spatial misalignment, or both are based at least in part on the measurements.

23. The apparatus of claim 16, wherein a first axis extends from the first antenna array to the second antenna array, wherein the instructions are further executable by the processor to cause the apparatus to: A plurality of phases along a second axis, a third axis, or both associated with the one or more reference signals are estimated, wherein the second axis and the third axis are perpendicular to the first axis, and wherein the estimated rotational misalignment is based at least in part on the plurality of phases.

24. The apparatus of claim 16, wherein the instructions are further executable by the processor to cause the apparatus to: The one or more reference signals are compared to a reference signal waveform, wherein the estimated rotational misalignment, the estimated spatial misalignment, or both are based at least in part on the comparison.

25. The apparatus of claim 16, wherein the instructions are further executable by the processor to cause the apparatus to: A channel estimation matrix associated with a channel between the first antenna array and the second antenna array is determined based at least in part on the estimated rotational misalignment, the estimated spatial misalignment, or both, wherein the second post-processing matrix is modified relative to the first post-processing matrix based at least in part on the channel estimation matrix.

26. The apparatus of claim 16, wherein the estimated spatial misalignment comprises a parallel shift misalignment along one or more axes relative to the first antenna array, the second antenna array, or both.

27. A method for wireless communication at a first wireless device, the method comprising: transmitting one or more reference signals to a second wireless device using a first antenna array at the first wireless device and according to a first precoder matrix; receiving a feedback message from the second wireless device based at least in part on the one or more reference signals, the feedback message indicating an estimated rotational misalignment, an estimated spatial misalignment, or both, between the first antenna array at the first wireless device and a second antenna array at the second wireless device; as well as A message is sent to the second wireless device according to a second precoder matrix that is modified relative to the first precoder matrix based at least in part on the estimated rotational misalignment, the estimated spatial misalignment, or both.

28. The method according to claim 27, further comprising: The one or more reference signals are sent with a same phase across multiple antenna elements of the first antenna array according to the first precoder matrix, wherein the estimated rotational misalignment is based at least in part on sending the one or more reference signals with the same phase.

29. A method for wireless communication at a second wireless device, the method comprising: receiving one or more reference signals from the first wireless device using a second antenna array at the second wireless device and according to a first post-processing matrix; sending a feedback message to the first wireless device based at least in part on the one or more reference signals, the feedback message indicating an estimated rotational misalignment, an estimated spatial misalignment, or both, between the second antenna array at the second wireless device and the first antenna array at the first wireless device; as well as A message is received from the first wireless device according to a second post-processing matrix that is modified relative to the first post-processing matrix based at least in part on the estimated rotational misalignment, the estimated spatial misalignment, or both.

30. The method of claim 29, wherein the estimated rotational misalignment is estimated relative to one or more axes perpendicular to an additional axis extending from the first antenna array to the second antenna array.

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