Method and apparatus for wireless communication at a communication device

Abstract

Disclosed herein are apparatus, methods, and computer-readable media for facilitating spatial misalignment tracking for OAM beams in millimeter wave and higher frequency bands. An example method for wireless communication at a first communication device includes receiving a first misalignment tracking RS and a second misalignment tracking RS for OAM transmission from a second communication device. The example method may also include determining misalignment based on the first misalignment tracking RS, the second misalignment tracking RS, and using a subset of antenna elements of an antenna array of the first communication device. Additionally, the example method includes adjusting reception of subsequent OAM transmissions from a second communication device at the antenna array of the first communication device.

Description

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims the benefit of U.S. non-provisional patent application serial number 17 / 351,883, filed on June 18, 2021, entitled “SpatialmISALIGNMENT TRACKING FORORBITAL ANGULARmOMENTUM BEAMS INmILLIMETER WAVE AND HIGHER FREQUENCY BANDS,” the entire contents of which are expressly incorporated herein by reference. Technical Field

[0003] The present disclosure relates generally to communication systems and, more particularly, to wireless communications utilizing orbital angular momentum (OAM) beams. Background Art

[0004] Wireless communication systems are widely deployed to provide a variety of telecommunication services such as telephony, video, data, messaging, and broadcast. Typical wireless communication systems may employ multiple access technologies that have the ability to support communications with multiple users by sharing available system resources. Examples of such multiple access technologies include code division multiple access (CDMA) systems, time division multiple access (TDMA) systems, frequency division multiple access (FDMA) systems, orthogonal frequency division multiple access (OFDMA) systems, single carrier frequency division multiple access (SC-FDMA) systems, and time division synchronous code division multiple access (TD-SCDMA) systems.

[0005] These multiple access technologies have been adopted in various telecommunication standards to provide a common protocol that enables different wireless devices to communicate at a city, country, region, and even global level. An example telecommunication standard is 5G New Radio (NR). 5G NR is part of the continuous mobile broadband evolution released by the Third Generation Partnership Project (3GPP) to meet new requirements associated with latency, reliability, security, scalability (e.g., with the Internet of Things (IoT)), and other requirements. 5G NR includes services associated with enhanced mobile broadband (eMBB), massive machine type communication (mMTC), and ultra-reliable low latency communication (URLLC). Some aspects of 5G NR may be based on 4G Long Term Evolution (LTE) standards. There is a need for further improvements in 5GNR technology. These improvements may also be applicable to other multiple access technologies and telecommunication standards that employ these technologies. Summary of the invention

[0006] A simplified summary of one or more aspects is given below to provide a basic understanding of such aspects. This summary is not an extensive overview of all contemplated aspects, and is neither intended to identify key or important elements of all aspects, nor to describe the scope of any or all aspects. Its sole purpose is to present some concepts of one or more aspects in a simplified form as a prelude to a more detailed description that will be presented later.

[0007] In one aspect of the present disclosure, a method for wireless communication at a first communication device is provided. The example method includes receiving a first misalignment tracking reference signal (RS) and a second misalignment tracking RS for orbital angular momentum (OAM) transmission from a second communication device. The example method also includes determining misalignment based on the first misalignment tracking RS, the second misalignment tracking RS, and using a subset of antenna elements of an antenna array of the first communication device. Additionally, the example method includes adjusting reception of subsequent OAM transmissions from a second communication device at the antenna array of the first communication device.

[0008] In another aspect of the present disclosure, an apparatus for wireless communication at a first communication device is provided. The example apparatus includes a unit for receiving a first misalignment tracking RS and a second misalignment tracking RS for OAM transmission from a second communication device. The example apparatus also includes a unit for determining misalignment based on the first misalignment tracking RS, the second misalignment tracking RS, and using a subset of antenna elements of an antenna array of the first communication device. In addition, the example apparatus also includes a unit for adjusting reception of subsequent OAM transmissions from the second communication device at the antenna array of the first communication device.

[0009] In another aspect of the present disclosure, a device is provided, the device comprising a memory and at least one processor coupled to the memory for wireless communication at a first communication device. The at least one processor is configured to receive a first misalignment tracking RS and a second misalignment tracking RS for OAM transmission from a second communication device. The example at least one processor is also configured to determine the misalignment based on the first misalignment tracking RS, the second misalignment tracking RS and using a subset of antenna elements of the antenna array of the first communication device. In addition, the example at least one processor is configured to adjust the reception of subsequent OAM transmissions from the second communication device at the antenna array of the first communication device.

[0010] In another aspect of the present disclosure, a computer-readable storage medium storing a computer executable file is provided for wireless communication at a first wireless device. When the example code is executed, the processor receives a first misalignment tracking RS and a second misalignment tracking RS for OAM transmission from a second communication device. When the example code is executed, the processor is also caused to determine the misalignment based on the first misalignment tracking RS, the second misalignment tracking RS, and using a subset of antenna elements of the antenna array of the first communication device. In addition, when the example code is executed, the processor is also caused to adjust the reception of subsequent OAM transmissions from the second communication device at the antenna array of the first communication device.

[0011] In one aspect of the present disclosure, a method for wirelessly transmitting a reference signal from a second communication device to a first communication device is provided. The example method includes generating a first misalignment tracking RS and a second misalignment tracking RS for OAM transmission. The example method also includes transmitting the first misalignment tracking RS for OAM transmission to the first communication device. In addition, the example method also includes transmitting the second misalignment tracking RS for OAM transmission to the first communication device.

[0012] In another aspect of the present disclosure, an apparatus for wirelessly transmitting a reference signal from a second communication device to a first communication device is provided. The example apparatus includes a unit for generating a first misalignment tracking RS and a second misalignment tracking RS for OAM transmission. The example apparatus also includes a unit for transmitting the first misalignment tracking RS for OAM transmission to the first communication device. In addition, the example apparatus also includes a unit for transmitting the second misalignment tracking RS for OAM transmission to the first communication device.

[0013] In another aspect of the present disclosure, an apparatus is provided, the apparatus comprising a memory and at least one processor coupled to the memory, for a reference signal wirelessly transmitted from a second communication device to a first communication device. The at least one processor is configured to generate a first misalignment tracking RS and a second misalignment tracking RS for OAM transmission. The example at least one processor is also configured to send the first misalignment tracking RS for OAM transmission to the first communication device. Additionally, the example at least one processor is configured to send the second misalignment tracking RS for OAM transmission to the first communication device.

[0014] In another aspect of the present disclosure, a computer-readable storage medium storing a computer executable file is provided for wirelessly sending a reference signal from a second communication device to a first communication device. When the example code is executed, the processor generates a first misalignment tracking RS and a second misalignment tracking RS for OAM transmission. When the example code is executed, the processor also sends the first misalignment tracking RS for OAM transmission to the first communication device. Additionally, when the example code is executed, the processor sends the second misalignment tracking RS for OAM transmission to the first communication device.

[0015] To accomplish the foregoing and related ends, one or more aspects include the features fully described below and particularly pointed out in the claims. The following description and the accompanying drawings set forth in detail certain illustrative features of one or more aspects. However, these features are indicative of only some of the various ways in which the principles of the various aspects may be employed, and this description is intended to include all such aspects and their equivalents. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 is a schematic diagram illustrating an example of a wireless communication system and an access network.

[0017] Figure 2A is a diagram illustrating an example of a first frame according to various aspects of the present disclosure.

[0018] Figure 2B is a diagram illustrating an example of DL channels within a subframe according to various aspects of the present disclosure.

[0019] Figure 2C is a diagram illustrating an example of a second frame according to various aspects of the present disclosure.

[0020] Figure 2D is a diagram illustrating an example of UL channels within a subframe according to various aspects of the present disclosure.

[0021] Figure 3 is a schematic diagram showing an example of a base station and a user equipment (UE) in an access network.

[0022] Figure 4 is a schematic diagram depicting example helical structures and corresponding optical phase and intensity distributions according to various aspects of the present disclosure.

[0023] Figure 5A An example of an OAM transmission including a transmitter according to various aspects of the present disclosure is depicted.

[0024] Figure 5B Depicted are examples of an OAM transmitter in communication with an OAM receiver via OAM transmissions in accordance with various aspects of the present disclosure.

[0025] Fig. 6A is a schematic diagram depicting radiative mode intensity of OAM transmission according to various aspects of the present disclosure.

[0026] Figure 6B Shown is a schematic diagram depicting misalignment between a transmitter and a receiver of OAM transmission in accordance with various aspects of the present disclosure.

[0027] Figure 7 Example implementations of antenna arrays that may be used to transmit and receive OAM transmissions in accordance with various aspects of the present disclosure are shown.

[0028] Figure 8 An example implementation of another antenna array that may be used to transmit and receive OAM transmissions in accordance with various aspects of the present disclosure is shown.

[0029] Fig. 9 Examples of antenna arrays including multiple antenna elements according to various aspects of the present disclosure are shown.

[0030] Fig.10 Examples of antenna arrays including multiple antenna elements according to various aspects of the present disclosure are shown.

[0031] Fig.11 Depicted is a graphical representation of phase measurements for a first helical structure and a second helical structure having an opposite direction of rotation to the first helical structure.

[0032] Fig. 12A An example of an OAM transmitter in communication with an OAM receiver via an OAM transmission at a first time is depicted in accordance with various aspects of the present disclosure.

[0033] Fig. 12B An example of an OAM transmitter in communication with an OAM receiver via an OAM transmission at a second time is depicted in accordance with various aspects of the present disclosure.

[0034] Fig. 12C An example of an OAM transmitter communicating with an OAM receiver via an OAM transmission at a third time is depicted in accordance with various aspects of the present disclosure.

[0035] Fig.13 is an example communication flow between a first communication device and a second communication device according to the teachings disclosed herein.

[0036] Fig.14 is a flow chart of a method of wireless communication at a first communication device according to the teachings disclosed herein.

[0037] Fig.15is a flow chart of a method of wireless communication at a first communication device according to the teachings disclosed herein.

[0038] Fig.16 is a schematic diagram illustrating an example of a hardware implementation of an example apparatus according to the teachings disclosed herein.

[0039] Fig.17 is a flow chart of a method of wireless communication at a second communication device according to the teachings disclosed herein.

[0040] Fig.18 is a flow chart of a method of wireless communication at a second communication device according to the teachings disclosed herein.

[0041] Fig.19 is a schematic diagram illustrating an example of a hardware implementation of an example apparatus according to the teachings disclosed herein. DETAILED DESCRIPTION

[0042] The detailed description set forth below in conjunction with the accompanying drawings is intended as a description of various configurations, and is not intended to represent the only configurations in which the concepts described herein may be practiced. In order to provide a thorough understanding of the various concepts, the detailed description includes specific details. However, it will be apparent to those skilled in the art that these concepts may be practiced without these specific details. In some instances, well-known structures and components are shown in block diagram form in order to avoid obscuring such concepts.

[0043] Several aspects of telecommunication systems will now be presented with reference to various apparatus and methods. These apparatus and methods will be described in the detailed description below and illustrated in the accompanying drawings by various blocks, components, circuits, processes, algorithms, etc. (collectively referred to as "elements"). These elements may be implemented using electronic hardware, computer software, or any combination thereof. Whether such elements are implemented as hardware or software depends on the specific application and the design constraints imposed on the overall system.

[0044] For example, an element, or any part of an element, or any combination of elements, may be implemented as a "processing system" comprising one or more processors. Examples of processors include microprocessors, microcontrollers, graphics processing units (GPUs), central processing units (CPUs), application processors, digital signal processors (DSPs), reduced instruction set computing (RISC) processors, systems on chip (SoCs), baseband processors, field programmable gate arrays (FPGAs), programmable logic devices (PLDs), state machines, gating logic, discrete hardware circuits, and other suitable hardware configured to perform various functions described throughout this disclosure. One or more processors in a processing system may execute software. Whether referred to as software, firmware, middleware, microcode, hardware description language, or other terms, software should be broadly interpreted as meaning instructions, instruction sets, codes, code segments, program codes, programs, subroutines, software components, applications, software applications, software packages, routines, subroutines, objects, executable files, execution threads, processes, functions, etc.

[0045] Accordingly, in one or more example aspects, the functions described may be implemented in hardware, software, or any combination thereof. If implemented in software, the functions may be stored on a computer-readable medium or encoded as one or more instructions or codes. Computer-readable media include computer storage media. Storage media may be any available media that can be accessed by a computer. By way of example and not limitation, such computer-readable media may include random access memory (RAM), read-only memory (ROM), electrically erasable programmable ROM (EEPROM), optical disk storage, magnetic disk storage, other magnetic storage devices, combinations of various types of computer-readable media, or any other media that may be used to store computer executable code in the form of instructions or data structures that can be accessed by a computer.

[0046] Although various aspects and implementations are described in this specification by illustrating some examples, it will be understood by those skilled in the art that additional implementations and use cases can be implemented in many different arrangements and scenarios. The innovation described herein can be implemented across many different platform types, devices, systems, shapes, sizes, and packaging arrangements. For example, each implementation and / or use can be implemented via an integrated chip implementation and other devices based on non-module components (e.g., end-user devices, vehicles, communication devices, computing devices, industrial devices, retail / purchase devices, medical devices, devices implementing artificial intelligence (AI), etc.). Although some examples may be specifically targeted at use cases or applications, or may not be specifically targeted at use cases or applications, a variety of applicability of the described innovations may occur. Implementations can vary in the range of aggregated, distributed, or original equipment manufacturer (OEM) devices or systems from chip-level or modular components to non-modular, non-chip-level implementations and further to one or more aspects of the described innovations. In some actual settings, the device incorporating the various aspects and features described may also include additional components and features for the implementation and practice of the claimed and described aspects. For example, the transmission and reception of wireless signals necessarily include multiple components for analog and digital purposes (e.g., hardware components including antennas, RF chains, power amplifiers, modulators, buffers, processors, interleavers, adders / accumulators, etc.). The innovations described herein are intended to be practiced in a variety of devices, chip-level components, systems, distributed arrangements, aggregated or disaggregated components, end-user devices, etc., having different sizes, shapes, and configurations.

[0047] In wireless communications, a waveform may be applied to electromagnetic waves corresponding to downlink, uplink, and / or sidelink transmissions. Examples of waveforms include cyclic prefix (CP) orthogonal frequency division multiplexing (OFDM) (CP-OFDM) and discrete Fourier transform (DFT) spread OFDM (DFT-s-OFDM) (also known as single carrier frequency division multiple access (SC-FDMA)). Applying CP-OFDM may be beneficial for high throughput scenarios, while applying DFT-s-OFDM may be beneficial for power-constrained scenarios or only when limited to single-stream transmission.

[0048] Another example of a waveform that can be applied to transmission is to send or transmit an electromagnetic wave to carry orbital angular momentum (OAM) associated with the spiral structure of the wavefront around the axis of the beam. For example, the OAM of a beam can correspond to a component of the angular momentum of the beam that is based on the field spatial distribution rather than polarization. In addition to light, radio frequency signals may also have an OAM spiral structure. Radio frequency (RF) signals can be signals for wireless communication, and include beamformed signals, which may be referred to as a "beam" in this article. The spiral structure of the beam can be characterized by a wavefront that is shaped as a spiral with a vortex at the center (e.g., at the axis of the beam).

[0049] The helical structure of the signal can be characterized by a topological charge "m", which corresponds to the amount of rotation the helical structure exhibits in a path that rotates one circle around the center of the receiver. The topological charge m can comprise an integer, and can be positive or negative, depending on the direction in which the helical structure twists around the beam axis. The larger the value of the topological charge m, the faster the phase of the wavefront rotates around the beam axis. The helical structure can also be characterized by the optical phase distribution and intensity distribution corresponding to the topological charge m.

[0050] OAM beams can be used as a transmission scheme for line-of-sight transmission in wireless communication networks. For example, OAM transmission (also called "OAM waveform") can be used for higher frequency bands, such as millimeter wave bands or higher frequency bands (such as FR2, FR4, etc.).

[0051] However, OAM transmissions may also be sensitive to lateral offset misalignment between the transmitter and the receiver. As used herein, the term "misalignment" refers to the difference between the expected reception of an OAM transmission at a receiver and the actual reception at the receiver. For example, as the distance between the transmitter and the receiver increases, the magnitude and direction of the displacement relative to the beam axis of the OAM transmission may have a stronger effect on the reception of the signal. Misalignment may be caused by deviations in the medium through which the OAM transmission passes. In some examples, misalignment may be caused by changes in the physical location of the transmitter and / or receiver. For example, in a data center, a first wireless device may send an OAM transmission to a second wireless device. However, in operation, one or both wireless devices may move due to device operation, floor vibrations, etc.

[0052] Thus, while OAM can improve communications when using higher frequency bands (e.g., FR2, FR4, etc.), OAM transmissions may also be affected by misalignments between the transmitter and the receiver. For example, the transmitter may be located on the ceiling of a data center, and the receiver may be located on top of a server rack in the data center. In some such examples, vibrations of the server rack may cause lateral offset misalignments between the transmitter and the receiver, thereby degrading communication performance, for example, in the data center.

[0053] The various aspects disclosed herein provide a framework for facilitating tracking and correcting spatial (e.g., horizontal and / or vertical) misalignments for wireless communications based on OAM transmission. For example, the various aspects given herein provide for generating and sending a misalignment tracking reference signal (RS) that enables a receiver to detect and / or correct misalignments. Although the term "misalignment tracking reference signal" or "misalignment tracking RS" is used herein, the RS that enables an OAM receiver to detect and / or correct misalignments with a transmitter may also be referred to by other names. An example misalignment tracking RS may include a first misalignment tracking RS and a second misalignment tracking RS, which may be separated in the time domain and / or frequency domain. For example, a first misalignment tracking RS may be sent and received at a first symbol, and a second misalignment tracking RS may be sent and received at a second continuous symbol. In some examples, the misalignment tracking reference signal may be a repeated signal (e.g., a second misalignment tracking RS is a repetition of a first misalignment tracking RS). The first misalignment tracking RS may include a first spiral phase structure, and the second misalignment tracking RS may include a second spiral phase structure, for example, wherein the second spiral phase structure is based on the opposite rotation direction of the first spiral phase structure.

[0054] The receiver may measure a first phase for each of three or more antenna elements based on a first misalignment tracking RS, and may measure a second phase for each of three or more antenna elements based on a second misalignment tracking RS. The receiver may determine an angle relative to the optical center for each antenna element in a subset of antenna elements based on the conjugate of the first phase and the second phase. The receiver may identify the optical center based on the determined angle for each antenna element in the subset of antenna elements and the spatial coordinates for each antenna element in the subset of antenna elements, and for each antenna element in the subset of antenna elements, the misalignment may correspond to a displacement magnitude and direction relative to the optical center. The receiver may then take measures to address the misalignment, such as by selecting a different set of antenna elements for reception and / or physically moving the receiver.

[0055] Various aspects disclosed herein facilitate tracking and correcting misalignment of OAM transmissions. By tracking OAM transmissions, various aspects disclosed herein provide techniques for a receiver to detect misalignment of OAM transmissions. By correcting misalignment of OAM transmissions, various aspects disclosed herein provide techniques for transmitters and receivers to improve communication performance (e.g., by improving reliability).

[0056] Figure 11 is a schematic diagram showing an example of a wireless communication system and access network 100 including a base station 102 / 180 and a UE 104. The wireless communication system and access network 100 may include one or more UEs 104 in communication with the base station 102 or 180. The wireless communication system and access network 100 may include a UE 104 in communication with other UEs 104. The wireless communication system and access network 100 may include an integrated access and backhaul (IAB) network (which includes multiple cells communicating with each other) to provide an access network and a backhaul network for a core network (such as a core network 190 or an evolved packet core (EPC) 160). The core network 190 may be a 5G core network (5GC), such as a core network supporting new radio (NR) communications or another type of core network. The IAB network may include one or more IAB nodes 103. The IAB node may exchange communications with other IAB nodes 103, base stations 102 or 180, and / or UEs 104.

[0057] In some examples, the wireless communication system and access network 100 may adopt an open RAN (O-RAN) to provide standardization of radio interfaces to enable interoperability between component radio devices. For example, in an O-RAN, the RAN can be decomposed into a centralized unit (O-CU), a distributed unit (O-DU), and a radio unit (O-RU). The O-RU is where radio frequency (RF) signals are sent, received, amplified, and / or digitized. The O-RU can be located at, near, or integrated with the antenna. The O-DU and O-CU provide computing capabilities and can facilitate the transmission of digitized radio signals within the network. The O-DU can be physically located at or near the O-RU. The O-CU can be located near the core network.

[0058] The O-DU provides downlink and uplink baseband processing, supplies system synchronization clocks, signal processing, and interfaces with the O-CU. The O-RU provides conversion of downlink baseband signals to RF signals, and conversion of uplink RF signals to baseband signals. The O-RAN may include an open fronthaul (FH) interface between the O-DU and the O-RU.

[0059] In some examples, a wireless communication device may be configured to manage one or more aspects of wireless communication by facilitating misalignment tracking for OAM transmissions 191 . Figure 1A non-limiting example is shown in which the wireless device may be a UE 104 that receives OAM signals from a base station 102 or 180. This example merely illustrates the concept of a receiver configured to detect and / or correct misalignment with an OAM transmitter. Various aspects may be applied to any wireless device that receives wireless communications based on OAM signals. For example, various aspects described in conjunction with UE 104 may be performed by other receivers (e.g., a base station 102 or 180 operating as a receiver, an integrated access and backhaul (IAB) node, etc.). As an example, in Figure 1 In the example, UE 104 may include a misalignment tracking component 198 configured to receive a first misalignment tracking RS and a second misalignment tracking RS for an OAM transmission from a second communication device. The example misalignment tracking component 198 may also be configured to determine the misalignment based on the first misalignment tracking RS, the second misalignment tracking RS, and using a subset of antenna elements of an antenna array of the first communication device. The example misalignment tracking component 198 may also be configured to adjust the reception of subsequent OAM transmissions from the second communication device at the antenna array of the first communication device.

[0060] Still refer to Figure 1 In some examples, a wireless communication device (e.g., base station 102 / 180) may be configured to manage one or more aspects of wireless communication by generating and sending misalignment tracking RS for OAM transmission. As an example, in Figure 1 In the example, the base station 102 / 180 may include an OAM transmission component 199, which is configured to generate a first misalignment tracking RS and a second misalignment tracking RS for OAM transmission. The example OAM transmission component 199 may also be configured to send the first misalignment tracking RS for OAM transmission to the first communication device. Additionally, the example OAM transmission component 199 may be configured to send the second misalignment tracking RS for OAM transmission to the second communication device.

[0061] Although the following description provides an example for 5G NR, the concepts described herein may be applicable to other similar fields, such as LTE, LTE-A, CDMA, GSM, and / or other wireless technologies, where a first communication device receives an OAM transmission from a second communication device. In addition, the following aspects may be applicable to a converged RAN and / or a decomposed RAN (e.g., O-RAN).

[0062] Figure 1An example of a wireless communication system (also referred to as a wireless wide area network (WWAN)) includes a base station 102, a UE 104, an evolved packet core (EPC) 160, and another core network 190 (e.g., a 5G core (5GC)). The base station 102 may include a macro cell (a high-power cellular base station) and / or a small cell (a low-power cellular base station). A macro cell includes a base station. A small cell includes a femto cell, a pico cell, and a micro cell.

[0063] The base station 102 configured for 4G LTE (collectively referred to as the Evolved Universal Mobile Telecommunications System (UMTS) Terrestrial Radio Access Network (E-UTRAN)) can be connected to the EPC 160 via a first backhaul link 132 (e.g., an S1 interface). The base station 102 configured for 5G NR (collectively referred to as the Next Generation RAN (NG-RAN)) can be connected to the core network 190 via a second backhaul link 184. Among other functions, the base station 102 can perform one or more of the following functions: transmission of user data, radio channel encryption and decryption, integrity protection, header compression, mobility control functions (e.g., handover, dual connectivity), inter-cell interference coordination, connection establishment and release, load balancing, distribution of non-access stratum (NAS) messages, NAS node selection, synchronization, radio access network (RAN) sharing, multimedia broadcast multicast service (MBMS), user and equipment tracking, RAN information management (RIM), paging, positioning, and delivery of warning messages. The base stations 102 may communicate with each other directly or indirectly (eg, via the EPC 160 or the core network 190) via a third backhaul link 134 (eg, an X2 interface). The first backhaul link 132, the second backhaul link 184, and the third backhaul link 134 may be wired or wireless.

[0064] Base station 102 can communicate with UE 104 wirelessly. Each base station 102 can provide communication coverage for its own geographic coverage area 110. There may be overlapping geographic coverage areas 110. For example, a small cell 102' can have a coverage area 110' that overlaps with the coverage area 110 of one or more macro base stations 102. A network including both small cells and macro cells can be referred to as a heterogeneous network. A heterogeneous network can also include a home evolved Node B (eNB) (HeNB), which can provide services to a restricted group called a closed subscriber group (CSG). The communication link 120 between base station 102 and UE 104 can include an uplink (UL) (also referred to as a reverse link) transmission from UE 104 to base station 102 and / or a downlink (DL) (also referred to as a forward link) transmission from base station 102 to UE 104. The communication link 120 can use multiple input and multiple output (MIMO) antenna technology, including spatial multiplexing, beamforming and / or transmit diversity. The communication link can be through one or more carriers. Base station 102 / UE 104 may use spectrum with up to Y MHz (e.g., 5, 10, 15, 20, 100, 400, etc. MHz) bandwidth per carrier allocated in carrier aggregation of up to a total of Yx MHz (x component carriers) for transmission in each direction. The carriers may be adjacent to each other or may not be adjacent to each other. The allocation of carriers may be asymmetric with respect to DL and UL (e.g., more or fewer carriers may be allocated for DL ​​than for UL). A component carrier may include a primary component carrier and one or more secondary component carriers. A primary component carrier may be referred to as a primary cell (PCell), and a secondary component carrier may be referred to as a secondary cell (SCell).

[0065] Some UEs 104 may communicate with each other using a device-to-device (D2D) communication link 158. The D2D communication link 158 may use DL / UL WWAN spectrum. The D2D communication link 158 may use one or more sidelink channels, such as a physical sidelink broadcast channel (PSBCH), a physical sidelink discovery channel (PSDCH), a physical sidelink shared channel (PSSCH), and a physical sidelink control channel (PSCCH). The D2D communication may be through a variety of wireless D2D communication systems, such as, for example, WiMedia, Bluetooth, ZigBee, Wi-Fi based on the Institute of Electrical and Electronics Engineers (IEEE) 802.11 standard, LTE, or NR.

[0066] The wireless communication system may further include a Wi-Fi access point (AP) 150 that communicates with a Wi-Fi station (STA) 152 via a communication link 154, such as in a 5 GHz unlicensed spectrum, etc. When communicating in an unlicensed spectrum, the STA 152 / AP 150 may perform a clear channel assessment (CCA) prior to communicating to determine whether a channel is available.

[0067] The small cell 102' may operate in a licensed and / or unlicensed spectrum. When operating in an unlicensed spectrum, the small cell 102' may employ NR and use the same unlicensed spectrum (e.g., 5 GHz, etc.) as used by the Wi-Fi AP 150. The small cell 102' employing NR in the unlicensed spectrum may improve coverage and / or increase capacity of the access network.

[0068] The electromagnetic spectrum is typically subdivided into various categories, bands, channels, etc. based on frequency / wavelength. In 5G NR, two initial operating bands have been identified with the frequency range names FR1 (410mHz-7.125GHz) and FR2 (24.25GHz-52.6GHz). Although a portion of FR1 is greater than 6GHz, FR1 is often (interchangeably) referred to as the "sub-6Ghz" ("below -6GHz") band in various documents and articles. Similar naming issues sometimes arise with respect to FR2, which is often (interchangeably) referred to as the "millimeter wave" band in documents and articles, although it is different from the extremely high frequency (EHF) band (30GHz-300GHz) which is identified as the "millimeter wave" band by the International Telecommunication Union (ITU).

[0069] Frequencies between FR1 and FR2 are generally referred to as mid-band frequencies. Recent 5G NR research has identified the operating bands of these mid-band frequencies as frequency range names FR3 (7.125GHz-24.25GHz). The bands falling within FR3 can inherit FR1 characteristics and / or FR2 characteristics, and therefore the features of FR1 and / or FR2 can be effectively extended to mid-band frequencies. In addition, higher frequency bands are currently being explored to extend 5G NR operations to more than 52.6GHz. For example, three higher operating bands have been identified as frequency range names FR4a or FR4-1 (52.6GHz-71 GHz), FR4 (52.6GHz-114.25GHz) and FR5 (114.25GHz-300GHz). Each of these higher frequency bands falls within the EHF band.

[0070] In view of the above aspects, unless otherwise expressly stated, it should be understood that the term "sub-6GHz" and the like (if used herein) can broadly represent frequencies that can be less than 6GHz, frequencies that can be within FR1, or frequencies that can include mid-band frequencies. In addition, unless otherwise expressly stated, it should be understood that the term "millimeter wave" and the like (if used herein) can broadly represent frequencies that can include mid-band frequencies, frequencies that can be within FR2, FR4, FR4-a or FR4-1 and / or FR5, or frequencies that can be within the EHF band.

[0071] The base station 102, whether a small cell 102' or a large cell (e.g., a macro base station), may include and / or be referred to as an eNB, a gNodeB (gNB), or another type of base station. Some base stations, such as the gNB 180, may operate in the traditional sub-6 GHz spectrum, in millimeter wave frequencies, and / or near millimeter wave frequencies to communicate with the UE 104. When the gNB 180 operates in millimeter wave or near millimeter wave frequencies, the gNB 180 may be referred to as a millimeter wave base station. The millimeter wave base station 180 may utilize beamforming 182 with the UE 104 to compensate for path loss and short range. The base station 180 and the UE 104 may each include multiple antennas, such as antenna elements, antenna panels, and / or antenna arrays, to facilitate beamforming.

[0072] The base station 180 may transmit a beamformed signal in one or more transmit directions 182' to the UE 104. The UE 104 may receive the beamformed signal from the base station 180 in one or more receive directions 182". The UE 104 may also transmit a beamformed signal in one or more transmit directions to the base station 180. The base station 180 may receive the beamformed signal in one or more receive directions from the UE 104. The base station 180 / UE 104 may perform beam training to determine the best receive direction and transmit direction for each of the base station 180 / UE 104. The transmit and receive directions of the base station 180 may be the same or may be different. The transmit and receive directions of the UE 104 may be the same or may be different.

[0073] The EPC 160 may include a mobility management entity (MME) 162, other MMEs 164, a serving gateway 166, a multimedia broadcast multicast service (MBMS) gateway 168, a broadcast multicast service center (BM-SC) 170, and a packet data network (PDN) gateway 172. The MME 162 may communicate with a home subscriber server (HSS) 174. The MME 162 is a control node that handles signaling between the UE 104 and the EPC 160. Typically, the MME 162 provides bearer and connection management. All user Internet Protocol (IP) packets are transmitted through the serving gateway 166, which itself is connected to the PDN gateway 172. The PDN gateway 172 provides UE IP address allocation and other functions. The PDN gateway 172 and the BM-SC 170 are connected to IP services 176. The IP services 176 may include the Internet, an intranet, an IP multimedia subsystem (IMS), a PS streaming service, and / or other IP services. The BM-SC 170 may provide functionality for MBMS user service provisioning and delivery. The BM-SC 170 may serve as an entry point for content provider MBMS transmissions, may be used to authorize and initiate MBMS bearer services within a public land mobile network (PLMN), and may be used to schedule MBMS transmissions. The MBMS Gateway 168 may be used to distribute MBMS services to base stations 102 belonging to a multicast broadcast single frequency network (MBSFN) area of ​​a broadcast specific service, and may be responsible for session management (start / stop) and collecting eMBMS related billing information.

[0074] The core network 190 may include an access and mobility management function (AMF) 192, other AMFs 193, a session management function (SMF) 194, and a user plane function (UPF) 195. The AMF 192 may communicate with a unified data management (UDM) 196. The AMF 192 is a control node that handles signaling between the UE 104 and the core network 190. Typically, the AMF 192 provides QoS flow and session management. All user Internet Protocol (IP) packets are transmitted through the UPF 195. The UPF 195 provides UE IP address allocation and other functions. The UPF 195 is connected to an IP service 197. The IP service 197 may include the Internet, an intranet, an IP multimedia subsystem (IMS), a packet switching (PS) stream (PSS) service, and / or other IP services.

[0075] A base station may include and / or be referred to as a gNB, a Node B, an eNB, an access point, a base transceiver, a radio base station, a radio transceiver, a transceiver function, a basic service set (BSS), an extended service set (ESS), a transmit receive point (TRP), or some other suitable term. The base station 102 provides an access point to the EPC 160 or the core network 190 for the UE 104. Examples of UE 104 include a cellular phone, a smart phone, a session initiation protocol (SIP) phone, a laptop, a personal digital assistant (PDA), a satellite radio unit, a global positioning system, a multimedia device, a video device, a digital audio player (e.g., an MP3 player), a camera, a game console, a tablet computer, a smart device, a wearable device, a transportation vehicle, an electric meter, a gas pump, a large or small kitchen appliance, a healthcare device, an implant, a sensor / actuator, a display, or any other similarly functional device. Some UEs 104 may be referred to as IoT devices (e.g., a parking meter, a gas pump, a toaster, a transportation vehicle, a heart monitor, etc.). UE104 may also be referred to as a station, mobile station, user station, mobile unit, user unit, wireless unit, remote unit, mobile device, wireless device, wireless communication device, remote device, mobile user station, access terminal, mobile terminal, wireless terminal, remote terminal, mobile phone, user agent, mobile client, client, or some other suitable term. In some scenarios, the term UE may also be applied to one or more companion devices, such as companion devices in a device constellation arrangement. One or more of these devices may access a network together and / or individually.

[0076] Figure 2A is a diagram 200 showing an example of a first subframe within a 5G NR frame structure. Figure 2B is a schematic diagram 230 showing an example of DL channels within a 5G NR subframe. Figure 2C is a diagram 250 showing an example of a second subframe within a 5G NR frame structure. Figure 2D 280 is a diagram showing an example of UL channels within a 5G NR subframe. The 5G NR frame structure can be frequency division duplex (FDD) (wherein, for a particular set of subcarriers (carrier system bandwidth), a subframe within a subcarrier set is dedicated to either DL or UL), or can be time division duplex (TDD) (wherein, for a particular set of subcarriers (carrier system bandwidth), a subframe within a subcarrier set is dedicated to both DL and UL). Figure 2A , Figure 2CIn the example provided, the 5G NR frame structure is assumed to be TDD, where subframe 4 is configured with slot format 28 (most of which are DL), where D is DL, U is UL, and F is flexible between DL / UL, and subframe 3 is configured with slot format 1 (all of which are UL). Although subframe 3 and subframe 4 are shown as having slot format 1 and slot format 28, respectively, any particular subframe can be configured using any of the various available slot formats 0-61. Slot format 0 and slot format 1 are full DL and full UL, respectively. Other slot formats 2-slot formats 61 include a mix of DL, UL and flexible symbols. The UE is configured with a slot format (dynamically through DL control information (DCI), or semi-statically / statically through radio resource control (RRC) signaling) through the received slot format indicator (SFI). Note that the following description also applies to the 5G NR frame structure that is TDD.

[0077] Figures 2A-2D A frame structure is shown, and aspects of the present disclosure may be applicable to other wireless communication technologies that may have different frame structures and / or different channels. A frame (10ms) may be divided into 10 equally sized subframes (1ms). Each subframe may include one or more time slots. A subframe may also include a microslot, which may include 7, 4, or 2 symbols. Each time slot may include 14 or 12 symbols, depending on whether the cyclic prefix (CP) is normal or extended. For a normal CP, each time slot may include 14 symbols, and for an extended CP, each time slot may include 12 symbols. The symbol on the DL may be a CP orthogonal frequency division multiplexing (OFDM) (CP-OFDM) symbol. The symbol on the UL may be a CP-OFDM symbol (for high throughput scenarios) or a discrete Fourier transform (DFT) extended OFDM (DFT-s-OFDM) symbol (also referred to as a single carrier frequency division multiple access (SC-FDMA) symbol) (for power-limited scenarios; limited to single-stream transmission). The number of time slots within a subframe is based on the CP and numerology. The digital scheme defines the subcarrier spacing (SCS) and, in effect, the symbol length / duration (which may be equal to 1 / SCS).

[0078]

[0079] For normal CP (14 symbols / slot), different digital schemes μ0 to 4 allow 1, 2, 4, 8, and 16 slots per subframe, respectively. For extended CP, digital scheme 2 allows 4 slots per subframe. Therefore, for normal CP and digital scheme μ, there are 14 symbols / slot and 2 μ timeslots / subframe. The subcarrier spacing can be equal to 2 μ*15kHz, where μ is the digital scheme 0 to 4. As such, digital scheme μ=0 has a subcarrier spacing of 15kHz, and digital scheme μ=4 has a subcarrier spacing of 240kHz. The symbol length / duration is inversely related to the subcarrier spacing. Figures 2A-2D An example of a digital scheme μ=2 with a normal CP of 14 symbols per slot and 4 slots per subframe is provided. The slot duration is 0.25 ms, the subcarrier spacing is 60 kHz, and the symbol duration is about 16.67 μs. Within a frame set, there may be one or more different bandwidth parts (BWPs) of frequency division multiplexing (see Figure 2B ). Each BWP can have a specific number scheme and CP (normal or extended).

[0080] The frame structure can be represented using a resource grid. Each time slot includes a resource block (RB), also called a physical RB (PRB), which extends over 12 consecutive subcarriers. The resource grid is divided into multiple resource elements (REs). The number of bits carried by each RE depends on the modulation scheme.

[0081] like Figure 2A As shown in , some of the REs carry reference (pilot) signals (RS) for the UE. The RS may include a demodulation RS (DM-RS) for channel estimation at the UE (indicated as Rx for one specific configuration, but other DM-RS configurations are possible) and a channel state information reference signal (CSI-RS). The RS may also include a beam measurement RS (BRS), a beam refinement RS (BRRS), and a phase tracking RS (PT-RS).

[0082] Figure 2BExamples of various DL channels within a subframe of a frame are shown. A physical downlink control channel (PDCCH) carries DCI within one or more control channel elements (CCEs) (e.g., 1, 2, 4, 8, or 16 CCEs), each CCE including six RE groups (REGs), each REG including 12 consecutive REs in one OFDM symbol of an RB. A PDCCH within a BWP may be referred to as a control resource set (CORESET). The UE is configured to monitor PDCCH candidates in a PDCCH search space (e.g., a common search space, a UE-specific search space) during a PDCCH monitoring opportunity on a CORESET, wherein the PDCCH candidates have different DCI formats and different aggregation levels. Additional BWPs may be located at larger and / or lower frequencies across the channel bandwidth. A primary synchronization signal (PSS) may be within symbol 2 of a particular subframe of a frame. The PSS is used by UE 104 to determine subframe / symbol timing and physical layer identification. A secondary synchronization signal (SSS) may be within symbol 4 of a particular subframe of a frame. The SSS is used by the UE to determine the physical layer cell identity group number and the radio frame timing. Based on the physical layer identity and the physical layer cell identity group number, the UE can determine the physical cell identifier (PCI). Based on the PCI, the UE can determine the location of the DM-RS. The physical broadcast channel (PBCH) carrying the master information block (MIB) can be logically grouped with the PSS and SSS to form a synchronization signal (SS) / PBCH block (also called SS block (SSB)). The MIB provides the number of RBs in the system bandwidth and the system frame number (SFN). The physical downlink shared channel (PDSCH) carries user data, broadcast system information (such as system information blocks (SIBs)) and paging messages that are not sent via the PBCH.

[0083] like Figure 2C As shown, some of the REs carry DM-RSs for channel estimation performed at the base station (indicated as R for one specific configuration, but other DM-RS configurations are possible). The UE may send DM-RSs for a physical uplink control channel (PUCCH) and DM-RSs for a physical uplink shared channel (PUSCH). The PUSCH DM-RS may be sent in the first one or two symbols of the PUSCH. The PUCCH DM-RS may be sent in different configurations depending on whether a short PUCCH or a long PUCCH is sent and depending on the specific PUCCH format used. The UE may send a sounding reference signal (SRS). The SRS may be sent in the last symbol of a subframe. The SRS may have a comb structure, and the UE may send the SRS in one of the combs. The SRS may be used by the base station for channel quality estimation to enable frequency-dependent scheduling on the UL.

[0084] Figure 2D An example of various UL channels within a subframe of a frame is shown. The PUCCH may be located as indicated in one configuration. The PUCCH carries uplink control information (UCI), such as scheduling requests, channel quality indicator (CQI), precoding matrix indicator (PMI), rank indicator (RI), and hybrid automatic repeat request (HARQ) acknowledgement (ACK) (HARQ-ACK) information (ACK / negative ACK (NACK)) feedback. The PUSCH carries data, and may additionally be used to carry a buffer status report (BSR), a power headroom report (PHR), and / or UCI.

[0085] The various aspects presented herein may be applied by a receiver to receive wireless communications based on OAM signals. In some examples, the receiver may be a UE that receives wireless communications from a base station or another UE. In other examples, the receiver may be a base station, such as receiving an OAM signal from a UE. In other examples, the receiver may be an IAB node, such as receiving an OAM signal from a parent node, a child node, a UE, etc.

[0086] Figure 3 3 is an example of a first wireless device configured to exchange wireless communications with a second wireless device. In the example shown, the first wireless device may include a base station 310, the second wireless device may include a UE 350, and the base station 310 and the UE 350 may communicate in an access network. Figure 3 As shown, the base station 310 includes a transmit processor (TX processor 316), a transceiver 318 including a transmitter 318a and a receiver 318b, an antenna 320, a receive processor (RX processor 370), a channel estimator 374, a controller / processor 375, and a memory 376. The example UE 350 includes an antenna 352, a transceiver 354 (including a transmitter 354a and a receiver 354b), an RX processor 356, a channel estimator 358, a controller / processor 359, a memory 360, and a TX processor 368. The antennas 320 and 352 may correspond to the antenna elements and / or antenna arrays described in connection with columns 5A, 5B, 6A, 6B, 7, 8, 9, 10, 11, 12A, 12B, 12C, and / or 13. In other examples, the base station 310 and / or the UE 350 may include additional or alternative components.

[0087] In the DL, IP packets from the EPC 160 may be provided to the controller / processor 375. The controller / processor 375 implements layer 3 and layer 2 functions. Layer 3 includes a radio resource control (RRC) layer, and layer 2 includes a service data adaptation protocol (SDAP) layer, a packet data convergence protocol (PDCP) layer, a radio link control (RLC) layer, and a medium access control (MAC) layer. The controller / processor 375 provides: RRC layer functions associated with broadcasting of system information (e.g., MIB, SIB), RRC connection control (e.g., RRC connection paging, RRC connection establishment, RRC connection modification, and RRC connection release), mobility between radio access technologies (RATs), and measurement configuration for UE measurement reporting; PDCP layer functions associated with header compression / decompression, security (encryption, decryption, integrity protection, integrity verification), and handover support functions; RLC layer functions associated with transmission of upper layer packet data units (PDUs), error correction through ARQ, concatenation, segmentation and reassembly of RLC service data units (SDUs), re-segmentation of RLC data PDUs, and reordering of RLC data PDUs; and MAC layer functions associated with mapping between logical channels and transport channels, multiplexing of MAC SDUs onto transport blocks (TBs), demultiplexing of MAC SDUs from TBs, scheduling information reporting, error correction through HARQ, priority processing, and logical channel prioritization.

[0088] The TX processor and the RX processor implement layer 1 functions associated with various signal processing functions. Layer 1 (which includes the physical (PHY) layer) may include error detection on the transmission channel, forward error correction (FEC) encoding / decoding of the transmission channel, interleaving, rate matching, mapping to the physical channel, modulation / demodulation of the physical channel, and MIMO antenna processing. The TX processor 316 processes the mapping to the signal constellation diagram based on various modulation schemes (e.g., binary phase shift keying (BPSK), quadrature phase shift keying (QPSK), M-phase shift keying (M-PSK), M-order quadrature amplitude modulation (M-QAM)). Then, the coded and modulated symbols can be divided into parallel streams. Then, each stream can be mapped to an OFDM subcarrier, multiplexed with a reference signal (e.g., pilot) in the time domain and / or frequency domain, and then combined together using an inverse fast Fourier transform (IFFT) to generate a physical channel carrying a time domain OFDM symbol stream. The OFDM stream is precoded in space to generate multiple spatial streams. Channel estimates from a channel estimator 374 may be used to determine coding and modulation schemes, as well as for spatial processing. The channel estimate may be derived from a reference signal and / or channel state feedback sent by the UE 350. Each spatial stream may then be provided to a different antenna 320 via a separate transmitter 318a. Each transmitter 318a may modulate an RF carrier with a corresponding spatial stream for transmission.

[0089] At the UE 350, each receiver 354b receives a signal through its corresponding antenna 352. Each receiver 354b recovers the information modulated onto the RF carrier and provides the information to the RX processor 356. The TX processor 368 and the RX processor 356 implement layer 1 functions associated with various signal processing functions. The RX processor 356 can perform spatial processing on the information to recover any spatial stream to and from the UE 350. If multiple spatial streams are to the UE 350, they can be combined into a single OFDM symbol stream by the RX processor 356. The RX processor 356 then uses a fast Fourier transform (FFT) to convert the OFDM symbol stream from the time domain to the frequency domain. The frequency domain signal includes a separate OFDM symbol stream for each subcarrier of the OFDM signal. The symbols and reference signals on each subcarrier are recovered and demodulated by determining the most likely signal constellation point sent by the base station 310. These soft decisions can be based on the channel estimate calculated by the channel estimator 358. The soft decisions are then decoded and deinterleaved to recover the data and control signals originally sent on the physical channel by base station 310. The data and control signals are then provided to controller / processor 359, which implements layer 3 and layer 2 functions.

[0090] The controller / processor 359 may be associated with a memory 360 that stores program codes and data. The memory 360 may be referred to as a computer readable medium. In the UL, the controller / processor 359 provides demultiplexing, packet reassembly, decryption, header decompression, and control signal processing between transport channels and logical channels to recover IP packets from the EPC 160. The controller / processor 359 is also responsible for error detection using ACK and / or NACK protocols to support HARQ operations.

[0091] Similar to the functions described in conjunction with DL transmissions performed by the base station 310, the controller / processor 359 provides: RRC layer functions associated with system information (e.g., MIB, SIB) acquisition, RRC connection, and measurement reporting; PDCP layer functions associated with header compression / decompression and security (encryption, decryption, integrity protection, integrity verification); RLC layer functions associated with transmission of upper layer PDUs, error correction through ARQ, concatenation, segmentation and reassembly of RLC SDUs, resegmentation of RLC data PDUs, and reordering of RLC data PDUs; and MAC layer functions associated with mapping between logical channels and transport channels, multiplexing of MAC SDUs onto TBs, demultiplexing of MAC SDUs from TBs, scheduling information reporting, error correction through HARQ, priority processing, and logical channel prioritization.

[0092] Channel estimates derived by the channel estimator 358 based on a reference signal or feedback transmitted by the base station 310 may be used by the TX processor 368 to select the appropriate coding and modulation schemes, as well as to facilitate spatial processing. The spatial streams generated by the TX processor 368 may be provided to different antennas 352 via separate transmitters 354 a. Each transmitter 354 a may modulate an RF carrier with a corresponding spatial stream for transmission.

[0093] The UL transmission is processed at the base station 310 in a manner similar to that described in conjunction with the receiver functionality at the UE 350. Each receiver 318b receives a signal through its respective antenna 320. Each receiver 318b recovers information modulated onto an RF carrier and provides the information to the RX processor 370.

[0094] The controller / processor 375 may be associated with a memory 376 that stores program codes and data. The memory 376 may be referred to as a computer readable medium. In the UL, the controller / processor 375 provides demultiplexing between transport channels and logical channels, packet reassembly, decryption, header decompression, control signal processing to recover IP packets from the UE 350. The IP packets from the controller / processor 375 may be provided to the EPC 160. The controller / processor 375 is also responsible for error detection using ACK and / or NACK protocols to support HARQ operations.

[0095] At least one of the TX processor 368, the RX processor 356, and the controller / processor 359 may be configured to perform operations related to Figure 1 Various aspects related to the misalignment tracking component 198.

[0096] At least one of the TX processor 316, the RX processor 370, and the controller / processor 375 may be configured to perform operations related to Figure 1 Various aspects related to the OAM transport component 199.

[0097] An electromagnetic wave may be emitted or sent to carry orbital angular momentum (OAM) associated with a helical structure of a wavefront around the axis of the beam. As an example, the OAM of a beam may correspond to a component of the angular momentum of the beam that is based on the spatial distribution of the field rather than polarization. In addition to light, radio frequency signals may also have an OAM helical structure. RF signals may be signals for wireless communications, and include beamformed signals, which may be referred to as a "beam" herein. The helical structure of a beam may be characterized by a wavefront that is shaped into a helix with a vortex at the center (e.g., at the axis of the beam). A beam may be characterized by an integer number of rotations of the phase of the wavefront around the beam axis. The spatial phase dependence factor of an OAM beam may be represented by the following equation 1.

[0098] Equation 1: Φ(θ) = e imθ

[0099] In Formula 1, the parameter "θ" represents an angular measurement around an axis (e.g., a beam axis). The parameter "m" represents the topological charge, and corresponds to the number of rotations of a helical structure (sometimes called a "helical beam" or "helical wavefront") on a path that rotates one circle around the center of the receiver. The topological charge may include an integer and may be positive or negative, depending on the direction in which the helical structure is twisted. The larger the value of the topological charge m, the faster the phase of the wavefront rotates around the beam axis. For example, for OAM for light, the wavefront rotates around the beam axis. For an example with radio frequency OAM, the beam axis may refer to the axis of the RF signal beam. The parameter "mθ" represents the phase difference obtained during one cycle for the topological charge m.

[0100] Figure 4 4 is a schematic diagram 400 depicting examples of different helical structures 410 and corresponding optical phase distributions 430 and intensity distributions 450. Each helical structure 410 depicts the shape of the helical structure and can be characterized by a topological charge m. Each optical phase distribution 430 depicts a corresponding optical phase distribution in a beam cross section. Each intensity distribution 450 depicts a light intensity distribution in a beam cross section. In some examples, the intensity distribution 450 can be referred to as a "vortex".

[0101] For example, the first helical structure 412 ("m=+1") is characterized by one phase rotation around the beam axis 402 and in a first direction. The first optical phase distribution 432 corresponding to the first helical structure 412 indicates one period. That is, if the receiving element is placed perpendicular to the beam axis 402, the phase measured at the receiving element indicates that the first helical structure 412 is in the shape of a single helical surface and completes one period (e.g., 0 to 2π) of phase rotation around the beam axis 402. The first intensity distribution 452 corresponding to the first helical structure 412 indicates the luminous intensity for the first helical structure 412 measured at the receiving element. Due to the twisted nature of the first helical structure 412, the light waves at the beam axis 402 cancel each other. When projected onto a plane (e.g., the receiving element is placed perpendicular to the beam axis 402), the intensity distribution (or "optical vortex") appears as a ring of light with a dark vortex core at the center. The dark vortex core (also called a "singularity") corresponds to a low-intensity area.

[0102] Figure 4 Examples include a second helical structure 414 ("m = -1"), which is also characterized by a phase rotation around the beam axis 402. Figure 4 As shown, the second spiral structure 414 is based on a rotation direction opposite to the first spiral structure 412. For example, the first optical phase distribution 432 indicates a clockwise rotation of the first spiral structure 412, and the second optical phase distribution 434 corresponding to the second spiral structure 414 indicates a counterclockwise rotation of the second spiral structure 414. The second intensity distribution 454 corresponding to the second spiral structure 414 indicates an intensity distribution similar to the first intensity distribution 452.

[0103] Figure 4Examples also include a third helical structure 416 ("m=0"), which is characterized by zero rotation about the beam axis 402. That is, the third helical structure 416 indicates that the corresponding beam is not helical. Therefore, the wavefront associated with the third helical structure 416 is depicted as multiple unconnected surfaces, such as a series of parallel planes. Since there is no "twist" or phase rotation associated with the third helical structure 416, the third optical phase distribution 436 corresponding to the third helical structure 416 indicates the same phase. In addition, since there is no twist in the phase rotation associated with the third helical structure 416, the corresponding third intensity distribution 456 does not depict a singularity at the center because the light waves associated with the third helical structure 416 do not cancel each other.

[0104] Figure 4 Examples also include a fourth helical structure 418 ("m = +2") and a fifth helical structure 420 ("m = -2"). The fourth helical structure 418 and the fifth helical structure 420 are characterized by rotating two circles around the beam axis 402. Figure 4 As shown, the fifth helical structure 420 is based on a rotation direction opposite to that of the fourth helical structure 418. The fourth optical phase distribution 438 corresponding to the fourth helical structure 418 indicates that the fourth helical structure 418 is shaped as a double helical surface and completes two cycles (e.g., two completions of 0 to 2π or 4π) of phase rotation around the beam axis 402. In addition, the singularity at the fourth intensity distribution 458 corresponding to the fourth helical structure 418 is larger than, for example, the first intensity distribution 452 because the additional "twist" associated with the fourth helical structure 418 provides additional beams to cancel each other, resulting in an increased low-intensity region.

[0105] The fifth optical phase distribution 440 corresponding to the fifth spiral structure 420 indicates that the fifth spiral structure 420 is based on a rotation direction opposite to the fourth spiral structure 418. For example, the fourth optical phase distribution 438 indicates two clockwise rotations of the fourth spiral structure 418, and the fifth optical phase distribution 440 indicates two counterclockwise rotations of the fifth spiral structure 420. The fifth intensity distribution 460 corresponding to the fifth spiral structure 420 indicates an intensity distribution similar to the fourth intensity distribution 458.

[0106] Figure 4 Examples of the invention also include a sixth helical structure 422 ("m = +3") and a seventh helical structure 424 ("m = -3"). The sixth helical structure 422 and the seventh helical structure 424 are characterized by three rotations around the beam axis 402. Figure 4As shown, the seventh helical structure 424 is based on a rotation direction opposite to the sixth helical structure 422. The sixth optical phase distribution 442 corresponding to the sixth helical structure 422 indicates that the sixth helical structure 422 is shaped as a triple helical surface and completes three cycles (e.g., three completions of 0 to 2π or 6π) of phase rotation around the beam axis 402. In addition, the singularity at the sixth intensity distribution 462 corresponding to the sixth helical structure 422 is larger than, for example, the first intensity distribution 452 because the additional "twist" associated with the sixth helical structure 422 provides additional beams to cancel each other, resulting in an increased low-intensity region.

[0107] The seventh optical phase distribution 444 corresponding to the seventh spiral structure 424 indicates that the seventh spiral structure 424 is based on a rotation direction opposite to the sixth spiral structure 422. For example, the sixth optical phase distribution 442 indicates three clockwise rotations of the sixth spiral structure 422, and the seventh optical phase distribution 444 indicates three counterclockwise rotations of the seventh spiral structure 424. The seventh intensity distribution 464 corresponding to the seventh spiral structure 424 indicates an intensity distribution similar to the sixth intensity distribution 462.

[0108] OAM beams can be used as a signal for wireless communication networks such as Figure 1 The invention provides a transmission scheme for line-of-sight transmission in the access network 100 of the present invention. For example, OAM transmission (also referred to as "OAM waveform") can be used in higher frequency bands, such as millimeter wave bands or higher frequency bands (such as FR2, FR4, etc.). When the mIMO technology is adopted, each topological charge of the OAM transmission can correspond to an orthogonal carrier.

[0109] The spiral structure used for wireless communication can be generated using various techniques. For example, Figure 5A An example 500 of an OAM transmission 503 transmitted by an OAM transmitter 502 and received by an OAM receiver 506 is described. In some examples, the OAM transmitter 502 may include a component configured to generate a helical structure having a specific topological charge. In some examples, an optical element such as a lens may be employed to generate the desired helical structure. For example, the lens may be positioned and configured so that the beam output by the OAM transmitter 502 is shaped to have a specific topological charge (e.g., m=+1, m=-1, etc.). In other examples, a lens may not be used.

[0110] An antenna array at a receiver, such as OAM receiver 506, may receive OAM transmission 503 output by OAM transmitter 502. OAM transmission 503 may include a beam axis 504, such as an axis of a beamformed signal. Figure 5ADepicted is a vortex 510 that may correspond to the intensity distribution of the OAM transmission 503. The vortex 510 includes a singularity 512 (eg, a central singularity) associated with a region of low intensity.

[0111] An antenna array at a receiver may include a collection of connected antenna elements. The antenna elements operate as an interface between radio waves and a transmitter and / or receiver. The antenna elements of an antenna array may operate as a single antenna to send and / or receive transmissions. Thus, an antenna may correspond to an antenna element and / or an antenna array, and an antenna array may correspond to a collection of connected antenna elements, such as a combination of Figure 6B , 7 , 8, 9 and / or 10. The OAM transmission 503 can be received at multiple antenna elements (e.g., a first antenna element 520 ("antenna 1") and a second antenna element 522 ("antenna 2")) at the OAM receiver 506. In some examples, the first antenna element 520 and the second antenna element 522 can be part of the same antenna array. In some examples, the first antenna element 520 can be part of a first antenna array, and the second antenna element 522 can be part of a second antenna array that is different from the first antenna array. For example, the first antenna array can be associated with a first transmit receive point (TRP), and the second antenna array can be associated with a second TRP.

[0112] The OAM receiver 506 can compare the detected phases around the singularity 512 to determine the topological charge associated with the OAM transmission 503. For example, the OAM receiver 506 can measure the phase at the first antenna element 520 and the phase of the second antenna element 522 relative to the singularity 512 to determine the topological charge associated with the OAM transmission 503. In some examples, the number of antenna elements at which the measurement is made can be based on the topological charge. For example, the receiver can use a number of antenna elements based on the following formula 2.

[0113] Equation 2: Number of elements ≥ 2|m|+1

[0114] In Equation 2, the number of elements is determined to be at least one more than twice the absolute value of the topological charge. For example, to detect a topological charge of m=+1 or m=-1, the receiver may employ at least three antenna elements to measure the phase. However, in some examples, the number of elements may depend on the configuration of the elements at the OAM receiver 506.

[0115] In some examples, reception of OAM transmissions may be sensitive to lateral offset misalignment between the transmitter and the receiver. For example, as the distance between the transmitter and the receiver increases, the magnitude and direction of the displacement relative to the beam axis of the OAM transmission may have an increasing effect on the accurate reception of the OAM transmission. The misalignment may be caused by deviations in the medium through which the OAM transmission passes. In some examples, the misalignment may be caused by a change in the physical location of the transmitter and / or receiver. For example, in a data center, a first wireless device (e.g., a server rack) may send an OAM transmission to a second wireless device. However, in operation, one or both wireless devices may move due to, for example, operation of the wireless devices, such as floor vibrations, and the like.

[0116] Figure 5B 5 is a diagram 550 showing OAM transmitter 502 communicating with OAM receiver 506. Figure 5B , the OAM transmitter 502 may send a beamformed signal in one or more directions 552a, 552b, 552c, 552d, 552e, 552f, 552g, 552h to the OAM receiver 506. The OAM receiver 506 may receive the beamformed signal from the OAM transmitter 502 in one or more receive directions 554a, 554b, 554c, 554d. The OAM receiver 506 may also send a beamformed signal to the OAM transmitter 502 in one or more of the directions 554a, 554b, 554c, 554d. The OAM transmitter 502 may receive the beamformed signal from the OAM receiver 506 in one or more of the receive directions 552a, 552b, 552c, 552d, 552e, 552f, 552g, 552h. The OAM transmitter 502 / OAM receiver 506 may perform beam training to determine the best receive direction and transmit direction for each of the OAM transmitter 502 / OAM receiver 506. The transmit and receive directions for the OAM transmitter 502 may or may not be the same. The transmit and receive directions for the UE receiver 506 may or may not be the same.

[0117] A beam pair link (BPL) refers to a transmit beam and a receive beam pair. For example, a first BPL may include a transmit direction 552c and a receive direction 554b pair, and a second BPL may include a transmit direction 554c and a receive direction 552g pair.

[0118] exist Figure 5A and 5BIn the example of, the OAM transmitter 502 may be implemented by a base station (e.g., base station 102 / 180, base station 310), UE 350, and / or an IAB device (e.g., a distributed unit (DU) node of an IAB device and / or a mobile terminal (MT) node of an IAB device). Various aspects of the OAM receiver 506 may be implemented by a UE (e.g., UE 104), a base station 310, a UE 350, and / or an IAB device (e.g., a distributed unit (DU) node of an IAB device and / or a mobile terminal (MT) node of an IAB device).

[0119] Fig. 6A 600 is a graph depicting the intensity of the radiation mode of OAM transmission as presented herein. Figure 4 As described, OAM transmission may include a radiating ring having a helical phase for a particular OAM order m. Fig. 6A As shown in Figure 600, OAM transmission and radiating rings can generate a conical beam. The divergence angle can depend on m (e.g., beam order), the radiating ring diameter, and the wavelength. The radiation pattern intensity can follow a Bessel function of the first kind. The energy J for different values ​​of m is m (x) Basically no overlap.

[0120] Figure 6B A graph 650 depicting misalignment between a transmitter and a receiver of an OAM transmission is shown. In the example shown, the transmitter sends the OAM transmission using eight transmitter antenna elements (shown as eight solid circles in the center of graph 650). The receiver receives the OAM transmission at positions corresponding to eight receiver antenna elements of the antenna array (shown as eight circles near the center of graph 650).

[0121] Various aspects disclosed herein provide a framework that facilitates tracking and correcting spatial (e.g., horizontal and / or vertical) misalignments for wireless communications based on OAM transmissions. For example, various aspects presented herein provide for the generation and transmission of a misalignment tracking reference signal (RS), which allows a receiver to detect misalignments and / or correct misalignments in order to more accurately receive OAM transmissions. Detection and correction of deviations can enable transmitters and receivers to improve alignment, and thereby improve reception of OAM transmissions. An example misalignment tracking RS may include a first misalignment tracking RS and a second misalignment tracking RS, which may be separated in the time domain and / or frequency domain. For example, a first misalignment tracking RS may be sent and received at a first symbol, and a second misalignment tracking RS may be sent and received at a second continuous symbol. In some examples, the misalignment tracking reference signal may be a repetitive signal. The first misalignment tracking RS may include a first spiral phase structure (e.g., a topological charge of m=1), and the second misalignment tracking RS may include a second spiral phase structure, for example, wherein the second spiral phase structure is based on a rotation direction opposite to the first spiral phase structure (e.g., wherein the topological charge is m=-1).

[0122] The misalignment tracking RS may be a new reference signal that allows for detection of misalignments relative to OAM transmissions. For example, the RS may be different from existing reference signals, such as CSI-RS, DM-RS, BRS, PT-RS, and / or SSB, that enable a receiving device to determine information about channel quality, timing, and / or power estimates associated with a transmission. However, due to the nature of OAM transmissions, reference signals such as CSI-RS, DM-RS, BRS, PT-RS, SSB, etc. may not provide information that allows a receiving device to determine a receiver misalignment. For example, the misalignment tracking RS disclosed herein may facilitate determination of horizontal and / or vertical misalignments associated with OAM transmissions. The disclosed misalignment tracking RS may also facilitate estimation of a rotational mismatch between an antenna array at a transmitter and an antenna array at a receiver.

[0123] Figure 7 and Figure 8 An example implementation of an antenna array that can be used to send and receive OAM transmissions is shown. Figure 7 and 8 In the illustrated example, the corresponding antenna array includes multiple antenna elements. The antenna elements of the corresponding antenna array can be connected and operated as a single antenna to receive and / or transmit transmissions. Figure 7 In the example shown in , the antenna array 700 includes eight antenna elements arranged in a circle. Figure 8 In the illustrated example, the antenna array 800 includes a plurality of antenna elements 802, subsets of which may be activated for transmitting and receiving OAM transmissions. Figure 8In the illustrated example, the antenna array 800 includes eight activated antenna elements 804 (in Figure 8 ), and the remaining antenna elements in the plurality of antenna elements 802 are deactivated antenna elements 806. It will be appreciated that activating a subset of the antenna elements of the antenna array 800 rather than all of the antenna elements of the antenna array 800 may be beneficial in saving power.

[0124] Although Figure 7 and 8 The examples in show a circular pattern of activated antenna elements, but other examples may employ additional or alternative patterns to receive and transmit OAM transmissions. Furthermore, additional or alternative examples may include different numbers of activated antenna elements.

[0125] Fig. 9 An example of an antenna array 900 is shown that includes a plurality of antenna elements 902. In the example shown, the antenna array 900 includes a subset of activated antenna elements 904 and a subset of deactivated antenna elements 906. Figure 7 and Figure 8 Similar to the example of , the antenna elements 902 of the antenna array 900 can be connected and used as a single antenna to receive and / or send transmissions. Fig. 9 As shown, antenna array 900 includes eight example activated antenna elements 904 arranged in a circular pattern.

[0126] As mentioned above, OAM transmissions can be sensitive to spatial misalignments between the transmitter and the receiver. Fig. 9 , the spatial misalignment between the transmitter and the receiver may be such that the OAM transmission will be received at the antenna element 908 corresponding to the received misaligned OAM beam.

[0127] Various aspects disclosed herein facilitate a transmitting device to periodically transmit a misalignment tracking reference signal that is received by a receiving device. The receiving device may use the misalignment tracking reference signal to scan across a receiver antenna element to find any misalignment between a transmitter and a receiver. In some examples, the misalignment tracking reference signal may have one or more repetitions to increase the chances of the receiving device scanning the receiver antenna element. The misalignment tracking reference signal enables the receiving device to estimate horizontal and / or vertical misalignment. The misalignment tracking reference signal disclosed herein may also enable the receiving device to estimate any rotational mismatch between the receiver and the transmitter.

[0128] Reference again Fig. 9In some examples, the receiving device may determine the position of the antenna element 908 corresponding to the received misaligned OAM beam. The receiving device may use the determined position to measure the horizontal and / or vertical misalignment between the transmitter and the receiver. The receiving device may also determine any rotational mismatch between the receiver and the transmitter. Based on the determined misalignment, the receiving device may adjust the reception of subsequent OAM transmissions. For example, the receiving device may determine to activate the antenna element 908 corresponding to the received misaligned OAM beam. In some examples, the receiving device may mechanically move the antenna array 900 so that the activated antenna element 904 is aligned with the transmitter to correct the misalignment. In some examples, the receiver may mechanically move the antenna array 900 and activate a second subset of antenna elements to correct the misalignment between the transmitter and the receiver.

[0129] Fig.10 An example antenna array 1000 including a plurality of antenna elements 1002 is shown. Fig.10 The example of includes seven activated antenna elements 1004 and antenna elements at positions 1008 corresponding to misaligned OAM beams received due to spatial misalignment between the transmitter and the receiver. For simplicity, Fig.10 The example does not include deactivated antenna elements in antenna array 1000 that are not located at positions corresponding to the spatial misalignment. Figure 7 , 8 Similar to the example of FIG. 9 , the antenna elements 1004 , 1008 of the antenna array 1000 may be connected and used as a single antenna to receive and / or transmit transmissions.

[0130] exist Fig.10 , the first activated antenna element 1004a (antenna element "k") is a first distance 1012 ("R_k") from the optical center 1010. The first misaligned antenna element 1008a is located at a second distance 1014 ("R'_k") from the optical center 1010. The difference between the first distance 1012 and the second distance 1014 can be characterized as a displacement in the x-direction ("Δx") and a displacement in the y-direction ("Δy").

[0131] The various aspects disclosed herein enable a receiving device to determine displacements Δx and Δy based on received misalignment tracking reference signals. For example, a receiving device may receive a first misalignment tracking reference signal including a first spiral phase structure, and receive a second misalignment tracking reference signal including a second spiral phase structure. The receiving device may measure the phases of at least three non-collinear elements (e.g., elements that are not on a straight line) for the first misalignment tracking reference signal and the second misalignment tracking reference signal. However, it will be appreciated that the number of elements for which the phases are measured for the first misalignment tracking reference signal and the second misalignment tracking reference signal may be determined based on the topological charge m of the first misalignment tracking reference signal and the second misalignment tracking reference signal, as described in conjunction with Equation 2 (above). Based on the measured phase, the receiving device may determine the position of the optical center. The receiving device may then determine the misalignment using known spatial coordinates for the antenna elements and the optical center. The various aspects disclosed herein may adjust the reception of subsequent OAM transmissions based on the misalignment.

[0132] Fig. 12A Depicted is an example 1200 of an OAM transmitter 1202 communicating with an OAM receiver 1206 via an OAM transmission at a first time, as presented herein. Fig. 12B Depicted is an example 1250 of an OAM transmitter 1202 communicating with an OAM receiver 1206 via an OAM transmission at a second time, as presented herein. Fig. 12C An example 1260 of an OAM transmitter 1202 communicating with an OAM receiver 1206 via an OAM transmission at a third time is depicted, as presented herein. Aspects disclosed herein facilitate tracking and correcting misalignments of OAM transmissions. By tracking OAM transmissions, aspects disclosed herein provide techniques for a receiver to detect misalignments of OAM transmissions. By correcting misalignments of OAM transmissions, aspects disclosed herein provide techniques for transmitters and receivers to improve communication performance (e.g., by improving reliability).

[0133] Aspects of the OAM transmitter 1202 and / or the OAM receiver 1206 may be implemented by Figure 1 UE 104, Figure 3 UE 350, Figure 1 Base station 102 / 180 and / or Figure 3 In some examples, at least one of the OAM transmitter 1202 or the OAM receiver 1206 may include an IAB node. For example, the OAM transmitter 1202 may be an IAB node, and the OAM receiver 1206 may be a parent node, a child node, a UE, a base station, etc.

[0134] exist Fig. 12A , 12BIn the example of 12C and 12D, OAM transmitter 1202 includes antenna array 1204. Antenna array 1204 may include one or more antenna elements. In some examples, antenna array 1204 may include one or more sets of antenna elements. For example, antenna array 1204 may include a first set of antenna elements and a second set of antenna elements. In such an example, the first set of antenna elements may include a first TRP, and the first set of antenna elements may include a second TRP.

[0135] Similar to the OAM transmitter 1202, Fig. 12A , 12B The OAM receiver 1206 of 12C includes an antenna array 1208. The antenna array 1208 may include one or more antenna elements. Fig. 12A and 12B As shown in , the antenna array 1208 includes a first antenna element 1208a, a second antenna element 1208b, and a third antenna element 1208c. Fig. 12A and 12B In the example of FIG. 1 , the antenna elements 1208a, 1208b, and 1208c of the antenna array 1208 are non-collinear elements (eg, antenna elements that are not located in a line). Fig. 12C As shown in , the antenna array 1208 includes a fourth antenna element 1208d, a fifth antenna element 1208e, and a sixth antenna element 1208f. Fig. 12C In the example of , antenna elements 1208d, 1208e, 1208f of antenna array 1208 are non-collinear elements. Similar to OAM transmitter 1202, antenna array 1208 may include one or more sets of antenna elements. For example, antenna array 1208 may include a first set of antenna elements (e.g., first antenna element 1208a, second antenna element 1208b, and third antenna element 1208c) and a second set of antenna elements (e.g., fourth antenna element 1208d, fifth antenna element 1208e, and sixth antenna element 1208f). In various examples, the first set of antenna elements may include a first TRP, and the second set of antenna elements may include a second TRP. In other examples, the first set of antenna elements and the second set of antenna elements may be subsets of different antenna elements of the same antenna array or the same TRP.

[0136] Various aspects disclosed herein provide a framework that facilitates tracking and correcting spatial (e.g., horizontal and / or vertical) misalignments for wireless communications based on OAM transmissions. For example, various aspects presented herein provide an OAM transmitter 1202 to generate and transmit a reference signal that enables an OAM receiver 1206 to detect and / or correct misalignments with the OAM transmitter 1202. As used herein, such a reference signal may be referred to as a "misalignment tracking reference signal" or "misalignment tracking RS," although other names may also be used.

[0137] like Fig. 12A As shown, the OAM transmitter 1202 transmits a first RS 1210 and a second RS 1212. The first RS 1210 and the second RS 1212 may be separated in the time domain and / or the frequency domain. For example, Fig. 12A An example time slot 1230 including a plurality of symbols is included. Fig. 12A As shown, time slot 1230 includes at least a first symbol 1232, a second symbol 1234, and a third symbol 1236. In some examples, the first RS 1210 can transmit and receive at the first symbol 1232, and the second RS 1212 can transmit and receive at the second consecutive symbol (e.g., the second symbol 1234). In some examples, the first RS 1210 can transmit and receive at the first symbol 1232, and the second RS 1212 can transmit and receive at the second consecutive symbol (e.g., the third symbol 1234). In some examples, the second RS 1212 can be a repetition of the first RS 1210. In some examples, the first RS 1210 can include a first spiral phase structure, and the second RS 1212 can include a second spiral phase structure. For example, as described above in conjunction with Fig.11 As described, the second spiral phase structure may be based on a rotation direction opposite to the first spiral phase structure.

[0138] In some examples, to facilitate tracking and correction of spatial (e.g., horizontal and / or vertical) misalignment of wireless communications based on OAM transmission, the OAM receiver 1206 can measure the phase of the antenna element based on the received reference signal. For example, the OAM receiver 1206 can measure the first phase for each antenna element 1208a, 1208b, 1208c based on the first RS1210. The OAM receiver 1206 can also measure the second phase for each antenna element 1208a, 1208b and 1208c based on the second RS1212. For each antenna element in the antenna elements 1208a, 1208b, 1208c, the OAM receiver 1206 can determine the angle relative to the optical center. In some examples, the OAM receiver 1206 can determine the angle based on the conjugate of the first phase and the second phase at each antenna element. For example, the OAM receiver 1206 can determine the first angle based on the conjugate of the measured first phase at the first antenna element 1208a and the second phase measured at the first antenna element 1208a. In a similar manner, the OAM receiver 1206 may determine a second angle for the second antenna element 1208b and a third angle for the third antenna element 1208c. The OAM receiver 1206 may determine an optical center based on the determined angles for each of the antenna elements 1208a, 1208b, 1208c and the corresponding spatial coordinates for each of the antenna elements 1208a, 1208b, 1208c. For each of the antenna elements 1208a, 1208b, and 1208c, the misalignment may correspond to a displacement magnitude and direction relative to the optical center.

[0139] The OAM receiver 1206 may then take steps to correct the misalignment. In some examples, the OAM receiver 1206 may physically move the antenna array 1208. For example, Fig. 12B An example 1250 is depicted of the OAM transmitter 1202 communicating with the OAM receiver 1206 via an OAM transmission at a second time. Fig. 12A and 12B In the illustrated example, the OAM receiver 1206 includes a motor 1220 that can be configured to adjust the antenna array 1208. For example, the motor 1220 can rotate the antenna array 1208 and / or the OAM receiver 120 to adjust the angle between the OAM transmitter 1202 and the OAM receiver 1206. Fig. 12B As shown, OAM transmitter 1202 may send OAM transmission 1252, which may be received by OAM receiver 1206. OAM receiver 1206 may receive OAM transmission 1252 at antenna elements 1208a, 1208b, and 1208c. However, at a second time (eg, Fig. 12B), the spatial positioning of at least one of the antenna elements 1208a, 1208b, 1208c relative to the antenna elements 1208a, 1208b, 1208c at a first time (as shown in Fig. 12A 1206). That is, although the OAM receiver 1206 may receive the OAM transmission 1252 using the same antenna element at the first time and the second time, the spatial positioning of the antenna elements 1208a, 1208b, 1208c at the second time may correct the misalignment between the OAM transmitter 1202 and the OAM receiver 1206 as determined by the OAM receiver 1206. Therefore, correction of the misalignment may improve the communication performance between the OAM transmitter 1202 and the OAM receiver 1206 by, for example, improving reliability.

[0140] In some examples, the OAM receiver 1206 may select different sets of antenna elements for reception. For example, Fig. 12C An example 1260 is depicted of the OAM transmitter 1202 communicating with the OAM receiver 1206 via an OAM transmission at a third time. Fig. 12C As shown, the OAM transmitter 1202 can send an OAM transmission 1262, which is received by the OAM receiver 1206. The OAM receiver 1206 can receive the OAM transmission 1252 at antenna elements 1208a, 1208e, and 1208f. In some examples, the reception of the OAM transmission 1262 at antenna elements 1208d, 1208e, 1208f can correct for misalignment between the OAM transmitter 1202 and the OAM receiver 1206. That is, receiving the OAM transmission 1262 using different antenna elements can correct for misalignment between the OAM transmitter 1202 and the OAM receiver 1206 as determined by the OAM receiver 1206. Therefore, correction of the misalignment can improve the communication performance between the OAM transmitter 1202 and the OAM receiver 1206 by, for example, improving reliability.

[0141] In some examples, such as combining Fig. 12B As described above, the OAM receiver 1206 can mechanically move the antenna array so that the activated antenna elements are aligned with the OAM transmitter 1202 to correct the misalignment and receive the OAM transmission. Fig. 12C As described, the OAM receiver 1206 may activate a second subset of antenna elements corresponding to the misalignment to receive the OAM transmission. In some examples, the OAM receiver 1206 may mechanically move the antenna array and activate a second subset of antenna elements to correct the misalignment between the OAM transmitter 1202 and the OAM receiver 1206 to receive the OAM transmission.

[0142] Fig.13An example communication flow 1300 is shown between a first communication device 1302 and a second communication device 1304. In the example shown, the communication flow 1300 facilitates the first communication device 1302 to track misalignment of OAM transmissions.

[0143] Although in Fig.13 It is not shown in the example, but it can be understood that in additional or alternative examples, the first communication device 1302 and / or the second communication device 1304 can communicate with one or more other communication devices.

[0144] Aspects of the communication devices 1302, 1304 may be provided by Figure 1 UE 104, Figure 3 UE 350, Figure 1 Base station 102 / 180 and / or Figure 3 310 is implemented. For example, in some examples, the communication between the first communication device 1302 and the second communication device 1304 may include a downlink transmission. In some such examples, the first communication device 1302 may include a UE, and the second communication device 1304 may include a base station. In some examples, the communication between the first communication device 1302 and the second communication device 1304 may include an uplink transmission. In some such examples, the second communication device 1304 may include a UE, and the first communication device 1302 may include a base station. In some examples, the communication between the first communication device 1302 and the second communication device 1304 may include a sidelink transmission. In some such examples, the first communication device 1302 may include a first sidelink device, and the second communication device 1304 may include a second sidelink device (for example, both the first communication device 1302 and the second communication device 1304 may be UEs). In some examples, at least one of the first communication device 1302 or the second communication device 1304 may include an IAB node. For example, other communication devices may be parent nodes, child nodes, UEs, base stations, etc.

[0145] exist Fig.13 In the illustrated example of , the second communication device 1304 generates a misalignment tracking reference signal at 1320. For example, the second communication device 1304 can generate a first misalignment tracking RS 1330 and a second misalignment tracking RS 1332. The first misalignment tracking RS 1330 can include a first spiral phase structure, and the second misalignment tracking RS 1332 can include a second spiral phase structure. In some examples, the second spiral phase structure is based on a rotation direction opposite to the first spiral phase structure. For example, the first misalignment tracking RS 1330 can include Figure 4 The first spiral structure 412, and the second misalignment tracking RS1332 may include Figure 4The second spiral structure 414. In some examples, the first misalignment tracking RS 1330 may be based on a topological charge of m=1, and the second misalignment tracking RS 1332 may be based on a topological charge of m=-1.

[0146] The second communication device 1304 sends a first misalignment tracking RS 1330 received by the first communication device 1302. The second communication device 1304 also sends a second misalignment tracking RS 1332 received by the first communication device 1302. In some examples, the first misalignment tracking RS 1330 and the second misalignment tracking RS 1332 can be separated in at least one of the time domain and the frequency domain. For example, the second communication device 1304 can send (and the first communication device 1302 can receive) the first misalignment tracking RS 1330 at the first symbol. The second communication device 1304 can send (and the first communication device 1302 can receive) the second misalignment tracking RS 1332 at the second continuous symbol.

[0147] In some examples, the second communication device 1304 may send one or more repetitions of the misalignment tracking reference signal. For example, the second communication device 1304 may send a first misalignment tracking RS repetition 1334 received by the first communication device 1302. The second communication device 1304 may send a second misalignment tracking RS repetition 1336 received by the first communication device 1302.

[0148] The example first communications device 1302 determines misalignment using a misalignment tracking reference signal at 1340. For example, the first communications device 1302 may use the misalignment tracking RS 1330, 1332 and / or the misalignment tracking RS repetitions 1334, 1336 to determine displacements Δx and Δy between an activated antenna element and an antenna element at a location corresponding to a received misaligned OAM beam.

[0149] In the example shown, the first communication device 1302 measures the first phase for the element based on the first misalignment tracking RS1330 at 1342. The first communication device 1302 selects a subset of activated antenna elements based on the first misalignment tracking RS1330 to measure the first phase. For example, the first communication device 1302 can select at least three non-collinear antenna elements in the activated antenna elements to measure the first phase. The first communication device 1302 can select at least three non-collinear elements to measure the first phase based on the topological charge m of the first misalignment tracking RS1330. For example, based on Formula 2 (above), the first communication device 1302 can use at least three non-collinear antenna elements to determine the misalignment of the misalignment tracking reference signal with topological charge m=1 or topological charge m=-1. However, in other examples, the number of elements may depend on the configuration of the antenna elements at the receiver. For example, the first communication device 1302 may have the ability to use one antenna element, two antenna elements, or multiple antenna elements to determine the misalignment for the misalignment tracking reference signal. In some examples, the level of accuracy regarding the determined misalignment can depend on the number of antenna elements selected for which the first phase is measured. In some examples, the first communication device 1302 can apply Equation 3 below to measure the first phase for each antenna element in the subset of selected antenna elements based on the first misalignment tracking RS 1330.

[0150] Equation 3: Ψ m＝1 =e iα e iθ

[0151] In Formula 3, parameter "α" represents aspects such as distance and / or other implementation aspects. Fig.11 A graphical representation 1100 of Equation 3 is depicted at 1110 .

[0152] In the example shown, the first communication device 1302 measures a second phase for the element based on the second misalignment tracking RS 1330 at 1344. The first communication device 1302 uses the selected activated antenna element to measure the second phase based on the second misalignment tracking RS 1332. In some examples, the first communication device 1302 can apply Equation 4 below to measure the second phase for each antenna element in the subset of selected antenna elements based on the second misalignment tracking RS 1332.

[0153] Equation 4: Ψ m＝-1 =e iα e -iθ

[0154] In Equation 4, parameter "α" represents aspects such as distance and / or other implementation aspects. Fig.11 A graphical representation of Formula 4 is depicted at 1120 .

[0155] It can be understood that for a topological charge of m=1 (e.g., as shown in Equation 3) and for a topological charge of m=-1 (e.g., as shown in Equation 4), the first term "e iα " may be the same. In some examples, to remove the first term from the calculation, "e iα ", the first communication device 1302 may set the phase (Ψ) of m=1 for each antenna element in the selected subset of antenna elements m＝1 )) and the phase of m = -1 Phase conjugation is a transformation that propagates in opposite directions but has the same amplitude and phase. Therefore, by multiplying the beam by the conjugate of the beam, the first term "e" in Equation 3 and Equation 4 is iα " cancel each other out, so that the first term can be removed. For example, the first communications device 1302 can apply the following equation 5 to obtain the value "2θ".

[0156] Equation 5:

[0157] Fig.11 A graphical representation of Equation 5 is depicted at 1130 in FIG.

[0158] The first communication device 1302 may use the measured phase to triangulate the location of the optical center at 1346. For example, for each selected body in the antenna element, the first communication device may know the spatial coordinates (x, y) and phase "θ" of the antenna element. For example, for antenna element k, the first communication device 1302 may use the spatial coordinates of antenna element k (e.g., a(x, y)) and phase "θ". k ,y k )). The first communications device may then apply Equation 6 to each antenna element in the selected subset of antenna elements to triangulate the location of the center.

[0159] Equation 6:

[0160] In Formula 6, the term "θ k " represents the phase of antenna element k, and the term "y k " represents the y spatial coordinate of antenna element k, and the term "x k " denotes the x spatial coordinate of antenna element k, the term "Δy" denotes the displacement in the y direction between the transmitter and the receiver, and the term "Δx" denotes the y spatial coordinate of antenna element k.

[0161] It can be understood that for each antenna element k, the phase θ of the antenna element k , y space coordinate y k and the x-space coordinate xk is known. Therefore, there are two unknown quantities Δx, Δy left. However, it can be understood that the unknown quantities Δx, Δy are not based on the antenna element k. Therefore, by applying equation 6 to at least three non-colinear antenna elements, the first communication device 1302 can determine the misalignment between the transmitter and the receiver based on the displacement Δx, Δy. That is, the first communication device 1302 can solve the difference caused by the 4π phase rotation by utilizing (or applying) equation 6 to each antenna element in the subset of selected antenna elements.

[0162] At 1350, the first communications device 1302 adjusts reception of subsequent OAM transmissions based on the misalignment. For example, the second communications device 1304 can send an OAM transmission 1360 that is received by the first communications device 1302. In some examples, Fig. 12C As described in the example of , the first communications device 1302 can activate a second subset of antenna elements corresponding to the misalignment to receive the OAM transmission 1360. In some examples, such as in conjunction with Fig. 12B As described in the example of , the first communications device 1302 can mechanically move the antenna array so that the activated antenna elements are aligned with the second communications device 1304 to correct the misalignment and receive the OAM transmission 1360. In some examples, the first communications device 1302 can mechanically move the antenna array and activate a second subset of antenna elements to correct the misalignment between the second communications device 1304 and the first communications device 1302 and receive the OAM transmission 1360.

[0163] In some examples, the first communication device 1302 may adjust the reception of subsequent OAM transmissions based on a determination that the misalignment is less than a certain amount. For example, when the misalignment is less than a threshold amount, the first communication device 1302 may adjust the reception of subsequent OAM transmissions based on the misalignment. However, in one example, when the misalignment is greater than the threshold amount, the first communication device 1302 may forgo making adjustments to facilitate the reception of subsequent OAM transmissions.

[0164] In some examples, the level of accuracy regarding the determined misalignment can depend on the number of antenna elements selected for which the first phase is measured. For example, for misalignment tracking RS 1330, 1332 including topological charge m=1 or topological charge m=-1, when the subset of antenna elements includes at least three antenna elements, the first communication device 1302 can associate a first level of the determined misalignment accuracy, and when the subset of antenna elements includes less than three antenna elements, a second level of the determined misalignment accuracy can be associated. In some examples, the first communication device 1302 can adjust the reception of the OAM transmission 1360 based on the determined level of misalignment accuracy at 1350. For example, for the first level of the determined misalignment accuracy, the first communication device 1302 can activate the second subset of antenna elements corresponding to the misalignment to receive the OAM transmission 1360. For example, for the second level of the determined misalignment accuracy, the first communication device 1302 can activate the third subset of antenna elements corresponding to the misalignment to receive the OAM transmission 1360. In some examples, the third subset of antenna elements may include antenna elements in the second subset of antenna elements and one or more additional antenna elements. For example, for each antenna element in the second subset of antenna elements, the first communication device 1302 may select one or more surrounding antenna elements to improve alignment for receiving subsequent OAM transmissions (e.g., OAM transmission 1360). That is, in this example, because using less than three antenna elements may result in a reduced level of accuracy in the determined misalignment, the first communication device 1302 may increase the number of activated antenna elements to facilitate improved reception of subsequent OAM transmissions (e.g., OAM transmission 1360).

[0165] Although the above examples provide a first level and a second level of determined misalignment accuracy, other examples may employ additional or alternative numbers of levels. For example, based on the above examples in which the misalignment tracking RS 1330, 1332 include a topological charge m=1 or a topological charge m=-1, when the subset of antenna elements includes less than three antenna elements, the first communication device 1302 may be associated with a first level of determined misalignment accuracy; when the subset of antenna elements includes three antenna elements, a second level of determined misalignment accuracy may be associated; when the subset of antenna elements includes more than three antenna elements, a third level of determined misalignment accuracy may be associated. In some such examples, the adjustments made by the first communication device 1302 at 1350 to receive the OAM transmission 1360 may depend on the determined level of misalignment accuracy.

[0166] Fig.14 1400 is a flowchart of a method of wireless communication. The method may be performed by a first communication device (eg, UE 104, UE 350, first communication device 1302 and / or Fig.16The method may facilitate tracking and correcting misalignment of OAM transmissions.

[0167] In some examples, the communication between the first communication device and the second communication device may include a downlink transmission. In some such examples, the first communication device may include a UE, and the second communication device may include a base station. In some examples, the communication between the first communication device and the second communication device may include an uplink transmission. In some such examples, the second communication device may include a UE, and the first communication device may include a base station. In some examples, the communication between the first communication device and the second communication device may include a sidelink transmission. In some such examples, the first communication device may include a first sidelink device, and the second communication device may include a second sidelink device. In some examples, at least one of the first communication device or the second communication device may include an IAB node.

[0168] At 1402, a first communication device receives a first misalignment tracking reference signal and a second misalignment tracking RS for OAM transmission from a second communication device, such as in combination with Fig.13 The first misalignment tracking RS1330 and the second misalignment tracking RS1332 are described. For example, 1402 can be composed of Fig.16 The misalignment tracking RS component 1640 of the apparatus 1602 is executed. In some examples, the first communication device may receive a first misalignment tracking RS at a first symbol, and may receive a second misalignment tracking RS at a second consecutive symbol.

[0169] In some examples, the first misalignment tracking RS includes a first spiral phase structure, and the second misalignment tracking RS includes a second spiral phase structure. In some examples, the second spiral phase structure can be based on a rotation direction opposite to the first spiral phase structure. For example, the first misalignment tracking RS can be based on a topological charge of m=1, and the second misalignment tracking RS can be based on a topological charge of m=-1. In some examples, the first misalignment tracking RS and the second misalignment tracking RS can be separated in at least one of a time domain and a frequency domain.

[0170] At 1404, the first communications device determines misalignment based on the first misalignment tracking RS, the second misalignment tracking RS, and using a subset of antenna elements of the antenna array of the first communications device, such as in combination with Fig.13 For example, 1404 may be composed of Fig.16The misalignment determination component 1642 of the apparatus 1602 is executed. In some examples, the subset of antenna elements of the antenna array may include at least three non-collinear antenna elements. However, it will be appreciated that the number of antenna elements of the subset of antenna elements of the antenna array may be based on the configuration of the antenna elements at the receiver. Additionally or alternatively, in some examples, the first communication device may determine the number of antenna elements to be included in the subset of antenna elements of the antenna array based on Equation 2 (above).

[0171] In some examples, the first communications device may determine the misalignment based on measurements associated with the misalignment tracking RS and a subset of antenna elements of the first communications device.

[0172] At 1406, if combined Fig.13 In 1350, the first communication device adjusts reception of subsequent OAM transmissions from the second communication device at the antenna array of the first communication device. For example, 1406 may be performed by Fig.16 The adjustment component 1644 of the device 1602 is executed.

[0173] In some examples, the first communications device may adjust reception to correct the misalignment based on the misalignment being less than a certain amount (e.g., within a threshold amount). In some examples, if the misalignment is greater than a certain amount (e.g., greater than a threshold amount), the first communications device may forgo adjusting reception of subsequent OAM transmissions to correct the misalignment.

[0174] In some examples, the first communications device may adjust reception of subsequent OAM by activating a second set of antenna elements of the antenna array based on the misalignment, such as in conjunction with Fig. 12C 1260 and / or Fig.13 of 1350.

[0175] In some examples, the first communication device can adjust the reception of subsequent OAM by mechanically moving the antenna array relative to the second communication device, such as in conjunction with Fig. 12B 1250 and / or Fig.13 of 1350.

[0176] Fig.15 1500 is a flowchart of a method of wireless communication. The method may be performed by a first communication device (eg, UE 104, UE 350, first communication device 1302 and / or Fig.16 The method may facilitate tracking and correcting misalignment of OAM transmissions.

[0177] In some examples, the communication between the first communication device and the second communication device may include a downlink transmission. In some such examples, the first communication device may include a UE, and the second communication device may include a base station. In some examples, the communication between the first communication device and the second communication device may include an uplink transmission. In some such examples, the second communication device may include a UE, and the first communication device may include a base station. In some examples, the communication between the first communication device and the second communication device may include a sidelink transmission. In some such examples, the first communication device may include a first sidelink device, and the second communication device may include a second sidelink device. In some examples, at least one of the first communication device or the second communication device may include an IAB node.

[0178] At 1502, a first communication device receives a first misalignment tracking reference signal and a second misalignment tracking RS for OAM transmission from a second communication device, such as in combination with Fig.13 The first misalignment tracking RS1330 and the second misalignment tracking RS1332 are described. For example, 1502 can be composed of Fig.16 The misalignment tracking RS component 1640 of the apparatus 1602 is executed. In some examples, the first communication device may receive a first misalignment tracking RS at a first symbol, and may receive a second misalignment tracking RS at a second consecutive symbol.

[0179] In some examples, the first misalignment tracking RS includes a first spiral phase structure, and the second misalignment tracking RS includes a second spiral phase structure. In some examples, the second spiral phase structure can be based on a rotation direction opposite to the first spiral phase structure. For example, the first misalignment tracking RS can be based on a topological charge of m=1, and the second misalignment tracking RS can be based on a topological charge of m=-1. In some examples, the first misalignment tracking RS and the second misalignment tracking RS can be separated in at least one of a time domain and a frequency domain.

[0180] At 1504, the first communications device may receive a repetition of the first misalignment tracking RS and the second misalignment tracking RS from the second communications device, such as in conjunction with Fig.13 The first misalignment tracking RS repetition 1334 and the second misalignment tracking RS repetition 1336 are described in FIG. For example, 1504 may be composed of Fig.16 The repetition component 1646 of the apparatus 1602 is executed. In some such examples, the first communications device may use repetition to determine the misalignment (e.g., at 1506).

[0181] At 1506, the first communications device determines misalignment based on the first misalignment tracking RS, the second misalignment tracking RS, and using a subset of antenna elements of the antenna array of the first communications device, such as in combination with Fig.13For example, 1506 may be composed of Fig.16 The misalignment determination component 1642 of the apparatus 1602 is executed. In some examples, the subset of antenna elements of the antenna array may include at least three non-collinear antenna elements. However, it will be appreciated that the number of antenna elements of the subset of antenna elements of the antenna array may be based on the configuration of the antenna elements at the receiver. Additionally or alternatively, in some examples, the first communication device may determine the number of antenna elements to be included in the subset of antenna elements of the antenna array based on Equation 2 (above).

[0182] In some examples, the first communications device may determine the misalignment based on measurements associated with the misalignment tracking RS and a subset of antenna elements of the first communications device. For example, at 1508, the first communications device may measure a first phase for each antenna element in the subset of antenna elements based on the first misalignment tracking RS, such as in combination with Fig.13 For example, 1508 can be composed of Fig.16 The phase measurement component 1648 of the apparatus 1602 is executed. In some examples, the first communications device can apply Equation 3 above to measure a first phase for each antenna element in the subset of antenna elements based on the first misalignment tracking RS.

[0183] At 1510, the first communications device may measure a second phase for each antenna element in the subset of antenna elements based on a second misalignment tracking RS, such as in combination with Fig.13 For example, 1510 may be composed of Fig.16 The phase measurement component 1648 of the apparatus 1602 is executed. In some examples, the first communications device can apply Equation 4 above to measure a second phase for each antenna element in the subset of antenna elements based on the second misalignment tracking RS.

[0184] At 1512, the first communications device may determine, for each antenna element in the subset of antenna elements, an angle relative to the optical center based on the conjugate of the first phase and the second phase, such as in combination with Fig.13 For example, 1512 can be made of Fig.16 The angle determination component 1650 of the apparatus 1602 is executed. In some examples, the first communications device can apply Equation 5 above to determine the angle relative to the optical center for each antenna element in the subset of antenna elements.

[0185] At 1514, the first communications device may identify an optical center based on the determined angle for each antenna element in the subset of antenna elements and the spatial coordinates for each antenna element in the subset of antenna elements, such as in combination with Fig.13 For example, 1514 can be made of Fig.16 The optical center component 1652 of the apparatus 1602 is performed. In some examples, for each antenna element in the subset of antenna elements, the misalignment can correspond to a displacement magnitude and direction relative to the optical center. In some examples, the first communication device can apply Equation 6 above to identify the optical center based on the determined angle for each antenna element in the subset of antenna elements and the spatial coordinates for each antenna element in the subset of antenna elements.

[0186] At 1516, if combined Fig.13 In 1350, the first communication device adjusts reception of subsequent OAM transmissions from the second communication device at the antenna array of the first communication device. For example, 1516 may be performed by Fig.16 The adjustment component 1644 of the device 1602 is executed.

[0187] In some examples, the first communications device may adjust reception of subsequent OAM by activating a second set of antenna elements of the antenna array based on the misalignment at 1518, such as in conjunction with Fig. 12C 1260 and / or Fig.13 For example, 1518 can be made of Fig.16 The activation component 1654 of the device 1602 is executed.

[0188] In some examples, the first communications device may adjust reception of subsequent OAM by mechanically moving the antenna array relative to the second communications device at 1520, such as in conjunction with Fig. 12B 1250 and / or Fig.13 For example, 1520 may be composed of Fig.16 The mechanical movement component 1656 of the device 1602 is executed.

[0189] Fig.16 is shown for a device configured to perform a combination Fig.14Schematic diagram 1600 of an example of a hardware implementation of an apparatus 1602 of the various aspects described in and / or 15. The apparatus may be referred to as a receiving device or a receiver, but may have the ability to send and receive. In some examples, the apparatus 1602 may be a UE. In other examples, the apparatus 1602 may be a base station. In other examples, the apparatus 1602 may be an IAB node. The apparatus 1602 may include a cellular baseband processor 1604 (also referred to as a modem) coupled to a cellular radio frequency transceiver 1622. In some aspects, the apparatus 1602 may also include one or more subscriber identity modules (SIM) cards 1620, an application processor 1606 coupled to a secure digital (SD) card 1608 and a screen 1610, a Bluetooth module 1612, a wireless local area network (WLAN) module 1614, a global positioning system (GPS) module 1616, or a power supply 1618. The cellular baseband processor 1604 communicates with the UE 104, the base station 102 / 180 and / or the IAB node 1660 through the cellular RF transceiver 1622. The cellular baseband processor 1604 may include a computer-readable medium / memory. The computer-readable medium / memory may be non-temporary. The cellular baseband processor 1604 is responsible for general processing, including executing software stored on a computer-readable medium / memory. The software, when executed by the cellular baseband processor 1604, enables the cellular baseband processor 1604 to perform the various functions described above. The computer-readable medium / memory may also be used to store data manipulated by the cellular baseband processor 1604 when executing the software. The cellular baseband processor 1604 also includes a receiving component 1630, a communication manager 1632, and a sending component 1634. The communication manager 1632 includes one or more of the components shown. The components within the communication manager 1632 may be stored in a computer-readable medium / memory and / or configured as hardware within the cellular baseband processor 1604. The cellular baseband processor 1604 may be a component of the UE 350 and may include the memory 360 and / or at least one of the TX processor 368, the RX processor 356, and the controller / processor 359. In one configuration, the device 1602 may be a modem chip and include only the cellular baseband processor 1604, while in another configuration, the device 1602 may be the entire UE (e.g., see Figure 3 UE350) and includes additional modules of device 1602.

[0190] The communication manager 1632 includes a misalignment tracking RS component 1640 configured to receive a first misalignment tracking reference signal and a second misalignment tracking RS for OAM transmission from a second communication device, for example, as combined with Fig.14 1402 and / or Fig.15 As stated in 1502.

[0191] The communication manager 1632 also includes a misalignment determination component 1642 configured to determine the misalignment based on the first misalignment tracking RS, the second misalignment tracking RS, and using a subset of antenna elements of the antenna array of the first communication device, for example, as combined with Fig.14 1404 and / or Fig.15 As stated in 1506.

[0192] The communication manager 1632 also includes an adjustment component 1644 configured to adjust the reception of subsequent OAM transmissions from the second communication device at the antenna array of the first communication device, for example, as combined with Fig.14 1406 and / or Fig.15 As stated in 1516.

[0193] The communication manager 1632 also includes a repeating component 1646 configured to receive a repeat of the first misalignment tracking RS and the second misalignment tracking RS from the second communication device, for example, as combined with Fig.15 As stated in 1504.

[0194] The communication manager 1632 also includes a phase measurement component 1648 that is configured to measure a first phase for each antenna element in the subset of antenna elements based on the first misalignment tracking RS, for example, as combined with Fig.15 1508, and / or based on the second misalignment tracking RS to measure a second phase for each antenna element in the subset of antenna elements, for example, as combined with Fig.15 As stated in 1510.

[0195] The communication manager 1632 also includes an angle determination component 1650 configured to determine an angle relative to the optical center for each antenna element in the subset of antenna elements based on a conjugate of the first phase and the second phase, for example, as combined with Fig.15 As stated in 1512.

[0196] The communication manager 1632 also includes an optical center component 1652 that is configured to identify an optical center based on the determined angle for each antenna element in the subset of antenna elements and the spatial coordinates for each antenna element in the subset of antenna elements, for example, as combined with Fig.15 As stated in 1514.

[0197] The communication manager 1632 also includes an activation component 1654 configured to activate a second subset of antenna elements of the antenna array based on the misalignment, for example, as combined with Fig.15 As stated in 1518.

[0198] The communication manager 1632 also includes a mechanical movement component 1656 that is configured to mechanically move the antenna array relative to the second communication device, for example, as combined with Fig.15 As described in 1520.

[0199] The apparatus may include executing Fig.14 and / or additional components to each of the blocks of the algorithm in the flowchart of 15. Thus, Fig.14 Each block in the flowchart of 15 and / or 15 may be executed by a component, and the apparatus may include one or more of these components. These components may be one or more hardware components specifically configured to execute the stated process / algorithm, implemented by a processor configured to execute the stated process / algorithm, stored in a computer-readable medium to be implemented by a processor, or some combination thereof.

[0200] In one configuration, the apparatus 1602, and in particular the cellular baseband processor 1604, includes means for receiving a first misalignment tracking RS and a second misalignment tracking RS for an OAM transmission from a second communication device. The example apparatus 1602 may also include means for determining misalignment based on the first misalignment tracking RS, the second misalignment tracking RS, and using a subset of antenna elements of an antenna array of the first communication device. The example apparatus 1602 also includes means for adjusting reception of subsequent OAM transmissions from the second communication device at the antenna array of the first communication device.

[0201] In another configuration, the example apparatus 1602 further includes means for receiving a repetition of the first misalignment tracking RS and the second misalignment tracking RS from the second communications device, wherein the first communications device uses the repetition to determine the misalignment.

[0202] In another configuration, the example apparatus 1602 further includes means for receiving a first misalignment tracking RS at a first symbol and receiving a second misalignment tracking RS at a second consecutive symbol.

[0203] In another configuration, the apparatus 1602 further includes means for measuring a first phase for each antenna element in the subset of antenna elements based on the first misalignment tracking RS. The example apparatus 1602 further includes means for measuring a second phase for each antenna element in the subset of antenna elements based on the second misalignment tracking RS. The example apparatus 1602 further includes means for determining an angle relative to the optical center for each antenna element in the subset of antenna elements based on a conjugate of the first phase and the second phase.

[0204] In another configuration, the example apparatus 1602 further includes a unit for identifying an optical center based on a determined angle for each antenna element in a subset of antenna elements and a spatial coordinate for each antenna element in the subset of antenna elements, and wherein, for each antenna element in the subset of antenna elements, the misalignment corresponds to a magnitude and direction of a displacement relative to the optical center.

[0205] In another configuration, the example apparatus 1602 further includes means for activating a second subset of antenna elements in the antenna array based on the misalignment.

[0206] In another configuration, the example apparatus 1602 further includes means for mechanically moving the antenna array relative to the second communications device.

[0207] These means may be one or more of the components of the apparatus 1602 configured to perform the functions recited by the means. As described above, the apparatus 1602 may include the TX processor 368, the RX processor 356, and the controller / processor 359. Thus, in one configuration, the means may be the TX processor 368, the RX processor 356, and the controller / processor 359 configured to perform the functions recited by the means.

[0208] Fig.17 1700 is a flowchart of a method of wireless communication. The method may be performed by a second communication device (eg, base station 102 / 104, base station 350, second communication device 1304 and / or Fig.19 The method may facilitate a first communication device receiving an OAM transmission from a second communication device to track and correct misalignment of the OAM transmission.

[0209] In some examples, the communication between the first communication device and the second communication device may include a downlink transmission. In some such examples, the first communication device may include a UE, and the second communication device may include a base station. In some examples, the communication between the first communication device and the second communication device may include an uplink transmission. In some such examples, the second communication device may include a UE, and the first communication device may include a base station. In some examples, the communication between the first communication device and the second communication device may include a sidelink transmission. In some such examples, the first communication device may include a first sidelink device, and the second communication device may include a second sidelink device. In some examples, at least one of the first communication device or the second communication device may include an IAB node.

[0210] At 1702, the second communication device generates a first misalignment tracking RS and a second misalignment tracking RS for OAM transmission, such as in combination with Fig.13For example, 1702 may be composed of Fig.19 The generating component 1940 of the device 1902 is executed.

[0211] In some examples, the first misalignment tracking RS includes a first spiral phase structure, and the second misalignment tracking RS includes a second spiral phase structure. In some examples, the second spiral phase structure can be based on a rotation direction opposite to the first spiral phase structure. For example, the first misalignment tracking RS can be based on a topological charge of m=1, and the second misalignment tracking RS can be based on a topological charge of m=-1. In some examples, the first misalignment tracking RS and the second misalignment tracking RS can be separated in at least one of a time domain and a frequency domain.

[0212] At 1704, the second communication device sends a first misalignment tracking RS for OAM transmission to the first communication device, such as in combination with Fig.13 The first misalignment tracking RS1330 is described. For example, 1704 can be composed of Fig.19 The misalignment tracking RS component 1942 of the device 1902 is performed.

[0213] At 1706, the second communication device sends a second misalignment tracking RS for OAM transmission to the first communication device, such as in combination with Fig.13 The second misalignment tracking RS1332. For example, 1706 can be made Fig.19 The misalignment tracking RS component 1942 of the device 1902 is performed.

[0214] In some examples, the first misalignment tracking RS and the second misalignment tracking RS may be separated in at least one of a time domain and a frequency domain. In some examples, the second communication device may send the first misalignment tracking RS at a first symbol and send the second misalignment tracking RS at a second consecutive symbol.

[0215] Fig.18 1800 is a flowchart of a method of wireless communication. The method may be performed by a second communication device (eg, base station 102 / 104, base station 350, second communication device 1304 and / or Fig.19 The method may facilitate a first communication device receiving an OAM transmission from a second communication device to track and correct misalignment of the OAM transmission.

[0216] In some examples, the communication between the first communication device and the second communication device may include a downlink transmission. In some such examples, the first communication device may include a UE, and the second communication device may include a base station. In some examples, the communication between the first communication device and the second communication device may include an uplink transmission. In some such examples, the second communication device may include a UE, and the first communication device may include a base station. In some examples, the communication between the first communication device and the second communication device may include a sidelink transmission. In some such examples, the first communication device may include a first sidelink device, and the second communication device may include a second sidelink device. In some examples, at least one of the first communication device or the second communication device may include an IAB node.

[0217] At 1802, the second communication device generates a first misalignment tracking RS and a second misalignment tracking RS for OAM transmission, such as in combination with Fig.13 For example, 1802 can be composed of Fig.19 The generating component 1940 of the device 1902 is executed.

[0218] In some examples, the first misalignment tracking RS includes a first spiral phase structure, and the second misalignment tracking RS includes a second spiral phase structure. In some examples, the second spiral phase structure can be based on a rotation direction opposite to the first spiral phase structure. For example, the first misalignment tracking RS can be based on a topological charge of m=1, and the second misalignment tracking RS can be based on a topological charge of m=-1. In some examples, the first misalignment tracking RS and the second misalignment tracking RS can be separated in at least one of a time domain and a frequency domain.

[0219] At 1804, the second communication device sends a first misalignment tracking RS for OAM transmission to the first communication device, such as in combination with Fig.13 The first misalignment tracking RS1330 is described. For example, 1804 can be made Fig.19 The misalignment tracking RS component 1942 of the device 1902 is performed.

[0220] At 1806, the second communication device sends a second misalignment tracking RS for OAM transmission to the first communication device, such as in combination with Fig.13 The second misalignment tracking RS1332. For example, 1806 can be made Fig.19 The misalignment tracking RS component 1942 of the device 1902 is performed.

[0221] In some examples, the first misalignment tracking RS and the second misalignment tracking RS may be separated in at least one of a time domain and a frequency domain. In some examples, the second communication device may send the first misalignment tracking RS at a first symbol and send the second misalignment tracking RS at a second consecutive symbol.

[0222] At 1808, the second communication device may send one or more repetitions of the first misalignment tracking RS and the second misalignment tracking RS to the first communication device, such as in combination with Fig.13 The first misalignment tracking RS repetition 1334 and the second misalignment tracking RS repetition 1336 are described in FIG. For example, 1808 may be composed of Fig.19 The repeating component 1944 of the device 1902 is executed.

[0223] Fig.19 is shown for a device configured to perform a combination Fig.17 Schematic diagram 1900 of an example of a hardware implementation of an apparatus 1902 of the various aspects described in and / or 18. The apparatus may be referred to as a transmitting device or a transmitter, but may have the ability to transmit and receive. In some examples, the apparatus 1902 may be a base station. In other examples, the apparatus 1902 may be an IAB node. In other examples, the apparatus 1902 may be a UE. The apparatus 1902 may include a baseband unit 1904. The baseband unit 1904 may communicate with the UE 104 and / or the IAB node 1960 via a cellular RF transceiver 1922. The baseband unit 1904 may include a computer-readable medium / memory. The baseband unit 1904 is responsible for general processing, including executing software stored on a computer-readable medium / memory. When the software is executed by the baseband unit 1904, the baseband unit 1904 performs the various functions described above. The computer-readable medium / memory may also be used to store data manipulated by the baseband unit 1904 when executing the software. The baseband unit 1904 also includes a receiving component 1930, a communication manager 1932, and a transmitting component 1934. The communication manager 1932 includes one or more of the components shown. The components within the communication manager 1932 may be stored in a computer-readable medium / memory and / or configured as hardware within the baseband unit 1904. The baseband unit 1904 may be a component of the base station 310 and may include at least one of the memory 376 and / or the TX processor 316, the RX processor 370, and the controller / processor 375.

[0224] The communication manager 1932 includes a generating component 1940 configured to generate a first misalignment tracking RS and a second misalignment tracking RS for OAM transmission, for example, as combined with Fig.17 1702 and / or Fig.18 As stated in 1802.

[0225] The communication manager 1932 also includes a misalignment tracking RS component 1942, which is configured to send a first misalignment tracking RS for OAM transmission to the first communication device, for example, as combined with Fig.17 1704 and / or Fig.18 1804. The example misalignment tracking RS component 1942 may also be configured to send a second misalignment tracking RS for OAM transmission to the first communication device, for example, Fig.17 1706 and / or Fig.18 Described in 1806.

[0226] The communication manager 1932 also includes a repeating component 1944 configured to send one or more repetitions of the first misalignment tracking RS and the second misalignment tracking RS to the first communication device, for example, as combined with Fig.18 As described in 1808.

[0227] The apparatus may include executing Fig.17 and / or additional components to each of the blocks of the algorithm in the flowchart of 18. Thus, Fig.17 Each block in the flowchart of 18 and / or 18 may be executed by a component, and the apparatus may include one or more of these components. These components may be one or more hardware components specifically configured to execute the stated process / algorithm, implemented by a processor configured to execute the stated process / algorithm, stored in a computer-readable medium to be implemented by a processor, or some combination thereof.

[0228] In one configuration, the apparatus 1902, and in particular the baseband unit 1904, includes means for generating a first misalignment tracking RS and a second misalignment tracking RS for OAM transmission. The example apparatus 1902 also includes means for sending the first misalignment tracking RS for OAM transmission to the first communication device. The example apparatus 1902 also includes means for sending the second misalignment tracking RS for OAM transmission to the first communication device.

[0229] In another configuration, the example apparatus 1902 further includes means for transmitting one or more repetitions of the first misalignment tracking RS and the second misalignment tracking RS to the first communications device.

[0230] In another configuration, the example apparatus 1902 further includes means for transmitting a first misalignment tracking RS at a first symbol and transmitting a second misalignment tracking RS at a second consecutive symbol.

[0231] These means may be one or more of the components of the apparatus 1902 configured to perform the functions recited by the means. As described above, the apparatus 1902 may include the TX processor 316, the RX processor 370, and the controller / processor 375. Thus, in one configuration, the means may be the TX processor 316, the RX processor 370, and the controller / processor 375 configured to perform the functions recited by the means.

[0232] Various aspects disclosed herein facilitate tracking and correcting misalignment of OAM transmissions. By tracking OAM transmissions, various aspects disclosed herein provide techniques for a receiver to detect misalignment of OAM transmissions. By correcting misalignment of OAM transmissions, various aspects disclosed herein provide techniques for transmitters and receivers to improve communication performance (e.g., by improving reliability).

[0233] It should be understood that the specific order or hierarchy of the blocks in the disclosed process / flowchart is an illustration of an exemplary manner. Based on design preferences, it should be understood that the specific order or hierarchy of the blocks in the process / flowchart can be rearranged. Further, some blocks can be combined or omitted. The attached method claims provide the elements of each block in a sample order and are not meant to be limited to the specific order or hierarchy provided.

[0234] The above description is provided to enable any person skilled in the art to practice the various aspects described herein. Various modifications to these aspects will be apparent to those skilled in the art, and the general principles defined herein may be applied to other aspects. Therefore, the claims are not intended to be limited to the various aspects shown herein, but are to be given the full scope consistent with the textual claims, wherein, unless explicitly stated so, reference to an element in the singular is not intended to mean "one and only one", but to mean "one or more". Terms such as "if", "when ..." and "while ..." should be interpreted as "under the conditions of ...", rather than meaning a direct temporal relationship or reaction. That is, these phrases (e.g., "when ...") do not mean immediate action in response to the occurrence of an action or during the occurrence of the action, but only mean that if the condition is met, the action will occur, but no specific or immediate time constraint is required for the occurrence of the action. The word "exemplary" is used herein to mean "used as an example, instance, or illustration." Any aspect described herein as "exemplary" is not necessarily to be construed as preferred or advantageous over other aspects. Unless otherwise specifically stated, the term "some" refers to one or more. Combinations such as "at least one of A, B, or C," "one or more of A, B, or C," "at least one of A, B and C," "one or more of A, B, and C," and "A, B, C, or any combination thereof" include any combination of A, B, or C, and may include multiple A, multiple B, or multiple C. Specifically, phrases such as "at least one of A, B, or C," "A, B, or Combinations such as "one or more of A, B, and C," "at least one of A, B, and C," "one or more of A, B, and C," and "A, B, C, or any combination thereof" may be A only, B only, C only, A and B, A and C, B and C, or A and B and C, wherein any such combination may include one or more members of A, B, or C. All structural and functional equivalents of the various aspects of the elements described throughout the present disclosure that are known or later known to one of ordinary skill in the art are expressly incorporated into the present disclosure by reference and are intended to be included in the claims. In addition, nothing disclosed herein is intended to be dedicated to the public, regardless of whether such disclosure is expressly recited in the claims. Words such as "module," "mechanism," "element," and "device" are not substitutes for the word "unit." As such, no claim element is to be interpreted as a functional module unless the element is expressly recited using the phrase "unit for..."

[0235] The following aspects are merely illustrative and may be combined with other aspects or teachings described herein, but are not limited thereto.

[0236] Aspect 1 is a method for performing wireless communication at a first communication device, comprising: receiving a first misalignment tracking RS and a second misalignment tracking RS for OAM transmission from a second communication device; determining misalignment based on the first misalignment tracking RS, the second misalignment tracking RS and using a subset of antenna elements of an antenna array of the first communication device; and adjusting reception of subsequent OAM transmissions from the second communication device at the antenna array of the first communication device.

[0237] Aspect 2 is the method of aspect 1, further comprising: the first misalignment tracking RS comprises a first spiral phase structure, and the second misalignment tracking RS comprises a second spiral phase structure.

[0238] Aspect 3 is the method of any one of Aspect 1 or Aspect 2, further comprising: the second spiral phase structure is based on a rotation direction opposite to that of the first spiral phase structure.

[0239] Aspect 4 is the method of any one of aspects 1 to 3, further comprising: the first misalignment tracking RS is based on a topological charge of m=1, and the second misalignment tracking RS is based on a topological charge of m=-1.

[0240] Aspect 5 is the method of any one of aspects 1 to 4, further comprising: the subset of the antenna elements of the antenna array includes at least three non-colinear antenna elements.

[0241] Aspect 6 is the method of any one of aspects 1 to 5, further comprising: receiving a repetition of the first misalignment tracking RS and the second misalignment tracking RS from the second communication device, wherein the first communication device determines the misalignment using the repetition.

[0242] Aspect 7 is the method of any one of aspects 1 to 6, further comprising: the first misalignment tracking RS and the second misalignment tracking RS are separated in at least one of a time domain and a frequency domain.

[0243] Aspect 8 is the method of any one of aspects 1 to 7, further comprising: the first communication device receiving the first misalignment tracking RS at a first symbol, and receiving the second misalignment tracking RS at a second consecutive symbol.

[0244] Aspect 9 is a method of any one of Aspects 1 to 8, further including: determining the misalignment includes: measuring a first phase for each antenna element in a subset of the antenna elements based on the first misalignment tracking RS; measuring a second phase for each antenna element in the subset of the antenna elements based on the second misalignment tracking RS; and determining an angle relative to the optical center for each antenna element in the subset of the antenna elements based on the conjugate of the first phase and the second phase.

[0245] Aspect 10 is a method of any one of Aspects 1 to 9, further comprising: identifying the optical center based on a determined angle for each antenna element in a subset of the antenna elements and a spatial coordinate for each antenna element in the subset of the antenna elements, wherein for each antenna element in the subset of the antenna elements, the misalignment corresponds to a displacement magnitude and direction relative to the optical center.

[0246] Aspect 11 is the method of any one of aspects 1 to 10, further comprising: adjusting reception of the subsequent OAM transmission further comprises: activating a second subset of antenna elements of the antenna array based on the misalignment.

[0247] Aspect 12 is the method of any one of aspects 1 to 11, further comprising: adjusting the reception of the subsequent OAM transmission further comprises: mechanically moving the antenna array relative to the second communication.

[0248] Aspect 13 is the method of any one of Aspects 1 to 12, further comprising: the first communication device comprises a user equipment, and the second communication device comprises a base station.

[0249] Aspect 14 is the method of any one of Aspects 1 to 12, further comprising: the first communication device comprises a user equipment, and the first communication device comprises a base station.

[0250] Aspect 15 is the method of any one of Aspects 1 to 12, further comprising: the first communication device comprises a first sidelink device, and the second communication device comprises a second sidelink device.

[0251] Aspect 16 is the method of any one of aspects 1 to 12, further comprising: at least one of the first communication device or the second communication device comprises an IAB node.

[0252] Aspect 17 is the method of any one of Aspects 1 to 16, further comprising: the first misalignment tracking RS comprises a first spiral phase structure and is based on a topological charge of m=1; and the second misalignment tracking RS comprises a second spiral phase structure and is based on a topological charge of m=-1.

[0253] Aspect 18 is the method of any one of aspects 1 to 17, further comprising a transceiver.

[0254] Aspect 19 is an apparatus for wireless communication, comprising a memory and at least one processor coupled to the memory, wherein the memory and the at least one processor are configured to implement the method of any one of aspects 1 to 18.

[0255] Aspect 20 is an apparatus for wireless communication, comprising means for implementing the method of any one of aspects 1 to 18.

[0256] Aspect 21 is a non-transitory computer-readable storage medium storing computer-executable code, wherein the code, when executed, causes a processor to implement the method of any one of aspects 1 to 18.

[0257] Aspect 22 is a method for wirelessly sending a reference signal from a second communication device to a first communication device, comprising: generating a first misalignment tracking RS and a second misalignment tracking RS for OAM transmission; sending the first misalignment tracking RS for the OAM transmission to the first communication device; and sending the second misalignment tracking RS for the OAM transmission to the first communication device.

[0258] Aspect 23 is the method of Aspect 22, further comprising: the first misalignment tracking RS comprises a first spiral phase structure, and the second misalignment tracking RS comprises a second spiral phase structure.

[0259] Aspect 24 is the method of any one of Aspect 22 or Aspect 23, further comprising: the second spiral phase structure is based on a rotation direction opposite to that of the first spiral phase structure.

[0260] Aspect 25 is the method of any one of aspects 22 to 24, further comprising: the first misalignment tracking RS is based on a topological charge of m=1, and the second misalignment tracking RS is based on a topological charge of m=-1.

[0261] Aspect 26 is the method of any one of aspects 22 to 25, further comprising: sending one or more repetitions of the first misalignment tracking RS and the second misalignment tracking RS to the first communication device.

[0262] Aspect 27 is the method of any one of Aspects 22 to 26, further comprising: the first misalignment tracking RS and the second misalignment tracking RS are separated in at least one of a time domain and a frequency domain.

[0263] Aspect 28 is the method of any one of aspects 22 to 27, further comprising: the second communication device sending the first misalignment tracking RS at a first symbol, and sending the second misalignment tracking RS at a second consecutive symbol.

[0264] Aspect 29 is the method of any one of Aspects 22 to 28, further comprising: the second communication device comprises a base station, and the first communication device comprises a user equipment.

[0265] Aspect 30 is the method of any one of aspects 22 to 28, further comprising: the first communication device comprises a base station, and the second communication device comprises a user equipment.

[0266] Aspect 31 is the method of any one of aspects 22 to 28, further comprising: the first communication device comprises a first sidelink device, and the second communication device comprises a second sidelink device.

[0267] Aspect 32 is the method of any one of aspects 22 to 28, further comprising: at least one of the first communication device or the second communication device comprises an IAB node.

[0268] Aspect 33 is the method of any one of Aspects 22 to 32, further comprising: the first misalignment tracking RS comprises a first spiral phase structure and is based on a topological charge of m=1; and the second misalignment tracking RS comprises a second spiral phase structure and is based on a topological charge of m=-1.

[0269] Aspect 34 is the method of any one of aspects 22 to 32, further comprising a transceiver.

[0270] Aspect 35 is an apparatus for wireless communication, comprising a memory and at least one processor coupled to the memory, wherein the memory and the at least one processor are configured to implement the method of any one of aspects 22 to 34.

[0271] Aspect 36 is an apparatus for wireless communication, comprising means for implementing the method of any one of aspects 22 to 34.

[0272] Aspect 37 is a non-transitory computer-readable storage medium storing computer-executable code, wherein the code, when executed, causes a processor to implement the method as described in any one of aspects 22 to 34.

[0273] Aspect 38 is a method for performing wireless communications at a receiving device, comprising: receiving a first misalignment tracking RS and a second misalignment tracking RS for OAM transmission from a transmitting device; determining misalignment based on the first misalignment tracking RS, the second misalignment tracking RS and using a subset of antenna elements of an antenna array of the receiving device; and adjusting reception of subsequent OAM transmissions from the transmitting device at the antenna array of the receiving device.

[0274] Aspect 39 is an apparatus for wireless communication, comprising a memory and at least one processor coupled to the memory, wherein the memory and the at least one processor are configured to implement the method as in aspect 38.

[0275] Aspect 40 is an apparatus for wireless communication, comprising means for implementing the method as in aspect 38.

[0276] Aspect 41 is a non-transitory computer-readable storage medium storing computer executable code, wherein the code, when executed by a processor, causes the processor to implement the method as in aspect 38.

[0277] Aspect 42 is a method for wirelessly sending a reference signal from a transmitting device to a receiving device, comprising: generating a first misalignment tracking RS and a second misalignment tracking RS for OAM transmission; sending the first misalignment tracking RS for the OAM transmission to the receiving device; and sending the second misalignment tracking RS for the OAM transmission to the receiving device.

[0278] Aspect 43 is an apparatus for wireless communication, comprising a memory and at least one processor coupled to the memory, wherein the memory and the at least one processor are configured to implement the method as in aspect 42.

[0279] Aspect 44 is an apparatus for wireless communication, comprising means for implementing the method as in aspect 42.

[0280] Aspect 45 is a non-transitory computer-readable storage medium storing computer-executable code, wherein the code, when executed by a processor, causes the processor to implement the method as in aspect 42.

Claims

1. An apparatus for performing wireless communication at a first communication device, comprising: one or more memories; as well as one or more processors coupled to the one or more memories, the one or more processors configured to cause the first communication device to: receiving a first misalignment tracking reference signal (RS) and a second misalignment tracking RS for orbital angular momentum (OAM) transmission from a second communication device; determining misalignment based on the first misalignment tracking RS, the second misalignment tracking RS and using a subset of antenna elements of an antenna array of the first communication device; as well as Reception of a subsequent OAM transmission from the second communication device is adjusted at the antenna array of the first communication device.

2. The device according to claim 1, wherein: The first misalignment tracking RS includes a first spiral phase structure, and the second misalignment tracking RS includes a second spiral phase structure.

3. The device according to claim 2, wherein: The second spiral phase structure is based on a rotation direction opposite to the first spiral phase structure.

4. The device according to claim 2, wherein: The first misalignment tracking RS is based on a first topological charge of m=1, and the second misalignment tracking RS is based on a second topological charge of m=-1.

5. The device according to claim 1, wherein: The subset of antenna elements of the antenna array includes at least three non-collinear antenna elements.

6. The device according to claim 1, wherein: The at least one processor is further configured to: receiving a repetition of the first misalignment tracking RS and the second misalignment tracking RS from the second communication device, and The repetitions are used to determine the misalignment.

7. The device according to claim 1, wherein: The first misalignment tracking RS and the second misalignment tracking RS are separated in at least one of a time domain and a frequency domain.

8. The device according to claim 1, wherein: The at least one processor is configured to: receiving the first misalignment tracking RS at a first symbol, and The second misalignment tracking RS is received at a second symbol consecutive to the first symbol.

9. The device according to claim 1, wherein: To determine the misalignment, the at least one processor is configured to: measuring a first phase for each antenna element in the subset of antenna elements based on the first misalignment tracking RS; measuring a second phase for each antenna element in the subset of antenna elements based on the second misalignment tracking RS; as well as Based on a conjugate of the first phase and the second phase, an angle relative to an optical center is determined for each antenna element in the subset of antenna elements.

10. The device according to claim 9, wherein: The at least one processor is further configured to: identifying the optical center based on the angle for each antenna element in the subset of antenna elements and spatial coordinates for each antenna element in the subset of antenna elements, Therein, for each antenna element in the subset of antenna elements the misalignment corresponds to a displacement magnitude and direction relative to the optical center.

11. The device according to claim 1, wherein: To adjust the reception of the subsequent OAM transmission, the at least one processor is further configured to: A second subset of the antenna elements of the antenna array is activated based on the misalignment.

12. The device according to claim 1, wherein: To adjust the reception of the subsequent OAM transmission, the at least one processor is further configured to: The antenna array is mechanically moved relative to the second communications device.

13. The device according to claim 1, wherein: The first communication device comprises a user equipment and the second communication device comprises a base station, or the second communication device comprises the user equipment and the first communication device comprises the base station.

14. The device according to claim 1, wherein: The first communication device includes a first sidelink device, and the second communication device includes a second sidelink device.

15. The device according to claim 1, wherein: At least one of the first communication device or the second communication device comprises an integrated access and backhaul (IAB) node.

16. The apparatus according to claim 1, further comprising: A transceiver is coupled to the at least one processor.

17. A method for wireless communication at a first communication device, comprising: receiving a first misalignment tracking reference signal (RS) and a second misalignment tracking RS for orbital angular momentum (OAM) transmission from a second communication device; determining misalignment based on the first misalignment tracking RS, the second misalignment tracking RS and using a subset of antenna elements of an antenna array of the first communication device; as well as Reception of a subsequent OAM transmission from the second communication device is adjusted at the antenna array of the first communication device.

18. The method according to claim 17, wherein: The first misalignment tracking RS includes a first spiral phase structure, and the second misalignment tracking RS includes a second spiral phase structure.

19. The method according to claim 17, further comprising: receiving a repetition of the first misalignment tracking RS and the second misalignment tracking RS from the second communication device, and The repetitions are used to determine the misalignment.

20. The method of claim 17, further comprising: receiving the first misalignment tracking RS at a first symbol, and The second misalignment tracking RS is received at a second symbol consecutive to the first symbol.

21. The method according to claim 17, wherein: Determining the misalignment further comprises: measuring a first phase for each antenna element in the subset of antenna elements based on the first misalignment tracking RS; measuring a second phase for each antenna element in the subset of antenna elements based on the second misalignment tracking RS; and Based on a conjugate of the first phase and the second phase, an angle relative to an optical center is determined for each antenna element in the subset of antenna elements.

22. The method according to claim 17, wherein: Adjusting the reception of the subsequent OAM transmission further includes: A second subset of the antenna elements of the antenna array is activated based on the misalignment to adjust the reception.

23. The method according to claim 17, wherein: Adjusting the reception of the subsequent OAM transmission further includes: The antenna array is mechanically moved relative to the second communications device.

24. An apparatus for wirelessly communicating with a first communication device at a second communication device, comprising: Memory; as well as at least one processor coupled to the memory, the at least one processor configured to: generating a first misalignment tracking reference signal (RS) and a second misalignment tracking RS for orbital angular momentum (OAM) transmission; sending the first misalignment tracking RS for the OAM transmission to the first communication device at a first symbol; as well as The second misalignment tracking RS for the OAM transmission is transmitted to the first communication device at a second symbol consecutive to the first symbol.

25. The device according to claim 24, wherein: The first misalignment tracking RS includes a first spiral phase structure, and the second misalignment tracking RS includes a second spiral phase structure.

26. The device according to claim 25, wherein The second spiral phase structure is based on a rotation direction opposite to the first spiral phase structure.

27. The device according to claim 25, wherein: The first misalignment tracking RS is based on a first topological charge of m=1, and the second misalignment tracking RS is based on a second topological charge of m=-1.

28. The device according to claim 24, wherein: The at least one processor is further configured to: One or more repetitions of the first misalignment tracking RS and the second misalignment tracking RS are sent to the first communication device.

29. The device according to claim 24, wherein: The first misalignment tracking RS and the second misalignment tracking RS are separated in at least one of a time domain and a frequency domain.

30. The device according to claim 24, wherein: The second communication device includes a base station and the first communication device includes a user equipment, or the first communication device includes the base station and the second communication device includes the user equipment.

31. The device according to claim 24, wherein: The first communication device includes a first sidelink device, and the second communication device includes a second sidelink device.

32. The apparatus of claim 24, wherein: At least one of the first communication device or the second communication device comprises an integrated access and backhaul (IAB) node.

33. The apparatus of claim 24, further comprising: A transceiver is coupled to the at least one processor.

34. A method for wirelessly transmitting a reference signal from a second communication device to a first communication device, comprising: generating a first misalignment tracking reference signal (RS) and a second misalignment tracking RS for orbital angular momentum (OAM) transmission; sending the first misalignment tracking RS for the OAM transmission to the first communication device at a first symbol; as well as The second misalignment tracking RS for the OAM transmission is transmitted to the first communication device at a second symbol consecutive to the first symbol.

35. The method of claim 34, wherein: The first misalignment tracking RS includes a first spiral phase structure, and the second misalignment tracking RS includes a second spiral phase structure.

36. The method of claim 34, further comprising: One or more repetitions of the first misalignment tracking RS and the second misalignment tracking RS are sent to the first communication device.

37. A non-transitory computer-readable storage medium comprising computer executable code at a first communication device, the computer executable code, when executed, causing a processor to perform the following operations: receiving a first misalignment tracking reference signal (RS) and a second misalignment tracking RS for orbital angular momentum (OAM) transmission from a second communication device; determining misalignment based on the first misalignment tracking RS, the second misalignment tracking RS and using a subset of antenna elements of an antenna array of the first communication device; as well as Reception of a subsequent OAM transmission from the second communication device is adjusted at the antenna array of the first communication device.

38. The non-transitory computer-readable storage medium of claim 37, wherein: The first misalignment tracking RS includes a first spiral phase structure, and the second misalignment tracking RS includes a second spiral phase structure.

39. The non-transitory computer-readable storage medium of claim 37, wherein: When the computer executable code is executed, the processor is further caused to perform the following operations: receiving a repetition of the first misalignment tracking RS and the second misalignment tracking RS from the second communication device, and The repetitions are used to determine the misalignment.

40. The non-transitory computer-readable storage medium of claim 37, wherein: When the computer executable code is executed, the processor is further caused to perform the following operations: receiving the first misalignment tracking RS at a first symbol, and The second misalignment tracking RS is received at a second symbol consecutive to the first symbol.

41. The non-transitory computer-readable storage medium of claim 37, wherein: When the computer executable code is executed, the processor is further caused to perform the following operations: measuring a first phase for each antenna element in the subset of antenna elements based on the first misalignment tracking RS; measuring a second phase for each antenna element in the subset of antenna elements based on the second misalignment tracking RS; as well as Based on a conjugate of the first phase and the second phase, an angle relative to an optical center is determined for each antenna element in the subset of antenna elements.

42. The non-transitory computer-readable storage medium of claim 37, wherein: When the computer executable code is executed, the processor is further caused to perform the following operations: A second subset of the antenna elements of the antenna array is activated based on the misalignment to adjust the reception.

43. The non-transitory computer-readable storage medium of claim 37, wherein: When the computer executable code is executed, the processor is further caused to perform the following operations: The antenna array is mechanically moved relative to the second communications device.

44. A non-transitory computer-readable storage medium comprising computer-executable code for wirelessly communicating with a first communication device at a second communication device, the computer-executable code, when executed, causing a processor to perform the following operations: generating a first misalignment tracking reference signal (RS) and a second misalignment tracking RS for orbital angular momentum (OAM) transmission; transmitting the first misalignment tracking RS for the OAM transmission to the first communication device at a first symbol; and The second misalignment tracking RS for the OAM transmission is transmitted to the first communication device at a second symbol consecutive to the first symbol.

45. The non-transitory computer-readable storage medium of claim 44, wherein: The first misalignment tracking RS includes a first spiral phase structure, and the second misalignment tracking RS includes a second spiral phase structure.

46. ​​The non-transitory computer-readable storage medium of claim 44, wherein: When the computer executable code is executed, the processor is further caused to perform the following operations: One or more repetitions of the first misalignment tracking RS and the second misalignment tracking RS are sent to the first communication device.

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