Formula-based inter-circular precoding weighting for orbital angular momentum (OAM) communication systems

Abstract

Aspects of the present disclosure relate to a formula-based inter-circle precoding weight determination for an orbital angular momentum (OAM) communication system. Some aspects of the present disclosure relate to an apparatus and method for wireless communication, the apparatus including a processor, an antenna element including a first subset and a second subset of the antenna elements, and a memory coupled to the processor, the memory storing instructions that, when executed by the processor, cause the processor to transmit a first reference signal using a first OAM mode via the first subset of the antenna elements, transmit a second reference signal using the first OAM mode via the second subset of the antenna elements, and receive information indicating a subset of antenna elements of the plurality of antenna elements to use to transmit the first OAM mode. Other aspects, embodiments, and features are also claimed and described.

Description

[Technical Field]

[0001]

[0001] The technologies discussed below generally relate to wireless communication systems, and more specifically to the transmission and reception of reference signals. For example, some aspects of the disclosed technologies provide and can enable techniques for calculating precoding weights for orbital angular momentum (OAM) transmission systems. [Background technology]

[0002]

[0002] In wireless communication, information is transmitted via electromagnetic radiation by modulating a carrier signal with one or more information signals. Among the many techniques, many techniques for modulating a carrier signal are used in the art, including various analog and digital modulation techniques such as frequency modulation (FM), amplitude modulation (AM), phase-shift keying (PSK), and quadrature amplitude modulation (QAM). In a typical cellular wireless communication system, many such signals can be multiplexed (e.g., combined) on a suitable carrier or bandwidth to enable simultaneous communication between multiple devices. In this case as well, among the many techniques, many multiplexing and multiple access techniques are used in the art, including frequency-division multiplexing (FDM), time-division multiplexing (TDM), and orthogonal frequency-division multiplexing (OFDM).

[0003]

[0003] As the demand for mobile broadband access continues to grow, research and development is advancing wireless communication technologies not only to meet the growing demand for mobile broadband access, but also to evolve and improve the user experience through mobile communications. [Overview of the project]

[0004]

[0004] The following provides a simplified overview of one or more aspects of the Disclosure in order to provide a basic understanding of such aspects. This overview is not a comprehensive overview of all the features intended for the Disclosure, nor does it identify the main or important elements of all aspects of the Disclosure, nor does it define the scope of any or all aspects of the Disclosure. Its sole purpose is to provide a simplified overview of some concepts of one or more aspects of the Disclosure as an introduction to the more detailed explanations to be presented later.

[0005]

[0005] In one example, a device configured for wireless communication is disclosed. In a more specific example, the device includes a processor and a plurality of antenna elements, including a first subset of antenna elements including at least a first antenna element and a second antenna element, and a second subset of antenna elements including at least a third antenna element and a fourth antenna element, and a memory coupled to the processor, the memory storing instructions, which, when executed by the processor, cause the processor to transmit a first reference signal using a first orbital angular momentum (OAM) mode via the first subset of antenna elements, transmit a second reference signal using the first OAM mode via the second subset of antenna elements, and receive information indicating a subset of antenna elements from a plurality of antenna elements to be used to transmit the first OAM mode.

[0006]

[0006] In another example, another device configured for wireless communication is disclosed. In a more specific example, the device includes a processor and a plurality of antenna elements, including a first subset of antenna elements including at least a first antenna element and a second antenna element, and a second subset of antenna elements including at least a third antenna element and a fourth antenna element, and a memory coupled to the processor, the memory storing instructions, which, when executed by the processor, cause the processor to receive from a transmitter comprising a third subset of antenna elements and a fourth subset of antenna elements an instruction that the third subset of antenna elements should be used to transmit a first reference signal for a first orbital angular momentum (OAM) mode, an instruction that the fourth subset of antenna elements should be used to transmit a second reference signal for a first OAM mode, and information indicating a subset of antenna elements from the plurality of antenna elements used to receive the first reference signal.

[0007]

[0007] In yet another example, a method for wireless communication is disclosed. In a more detailed example, the method includes transmitting a first reference signal using a first orbital angular momentum (OAM) mode via a first subset of antenna elements from a plurality of antenna elements; transmitting a second reference signal using the first OAM mode via a second subset of antenna elements from a plurality of antenna elements; and receiving information indicating a subset of antenna elements from a plurality of antenna elements to be used to transmit the first OAM mode.

[0008]

[0008] In yet another example, another method of wireless communication is disclosed. In a more specific example, the method includes receiving from a transmitter including a third subset of antenna elements and a fourth subset of antenna elements in a receiving device including a plurality of antenna elements including a first subset of antenna elements and a second subset of antenna elements, an instruction that a third subset of antenna elements should be used to transmit a first reference signal for a first orbital angular momentum (OAM) mode; receiving from the transmitter an instruction that a fourth subset of antenna elements should be used to transmit a second reference signal for a first OAM mode; and transmitting information indicating a subset of antenna elements from the plurality of antenna elements used to receive the first reference signal. [Brief explanation of the drawing]

[0009] [Figure 1]

[0009] This is a schematic diagram of a wireless access network according to some aspects of the present disclosure. [Figure 2]

[0010] This is a schematic diagram of wireless communication between multiple antennas according to some aspects of the present disclosure. [Figure 3]

[0011] This is a block diagram conceptually illustrating an example of a hardware implementation for a transmitting device according to several aspects of this disclosure. [Figure 4]

[0012] This is a block diagram conceptually illustrating an example of a hardware implementation for a receiving device according to several aspects of this disclosure. [Figure 5]

[0013] This diagram shows a schematic representation of wireless communication via a uniform circular array (UCA) configuration that supports the use of orbital angular momentum (OAM) mode for multiplexing communications, according to some aspects of the present disclosure. [Figure 6]

[0014] This is a schematic diagram of a coaxial multicircular OAM configuration supporting secondary index modulation according to several aspects of the present disclosure. [Figure 7]

[0015] A call flow diagram showing an exemplary process for determining the inter - circular precoding weights for an OAM communication system, according to some aspects of the present disclosure. [Figure 8]

[0016] A flowchart showing an exemplary process by which an OAM transmission device determines the inter - circular precoding weights for an OAM communication system, according to some aspects of the present disclosure. [Figure 9]

[0017] A flowchart showing an exemplary process by which an OAM receiving device determines information for a transmission device to determine the inter - circular precoding weights for an OAM communication system, according to some aspects of the present disclosure. [Figure 10]

[0018] A call diagram showing the transmission of reference signal configuration information and the transmission of reference signals for multiple OAM modes using a plurality of equally - spaced circular array circles, according to some aspects of the present disclosure.

DETAILED DESCRIPTION OF THE INVENTION

[0010]

[0019] In some aspects, the present disclosure provides a wireless communication technique that utilizes the orbital angular momentum (OAM) characteristics of electromagnetic (EM) waves to modulate a carrier wave to carry information and / or multiplex information streams on a common wireless resource. Specifically, a co - axial multi - circular equally - spaced circular array (UCA) - based antenna can be utilized to transmit reference signals for multiple OAM modes using a predetermined sequence of resources such that a receiving device can determine the resources to be used for transmitting subsequent reference signals based on the detection of reference signals for a particular mode. Other aspects, embodiments, and features are also described and claimed.

[0011]

[0020] The detailed descriptions below with respect to the attached drawings describe various configurations and are not intended to represent only the configurations in which the concepts described herein can be put into practice. “Modes for Carrying Out the Invention” include specific details intended to provide a complete understanding of the various concepts. However, those skilled in the art will readily understand that these concepts can be put into practice without these specific details. In some cases, this description provides well-known structures and components in the form of block diagrams to avoid obscuring such concepts.

[0012]

[0021] While this description illustrates aspects and embodiments with several examples, those skilled in the art will understand that additional implementation forms and use cases may arise in many different arrangements and scenarios. The innovations described herein can be implemented across many different platform types, devices, systems, forms, sizes, and packaging arrangements. For example, embodiments and / or applications may arise from integrated chip embodiments and other non-modular component-based devices (e.g., end-user devices, vehicles, communication devices, computing devices, industrial equipment, retail / purchasing devices, medical devices, artificial intelligence (AI)-enabled devices, etc.). Some examples may or may not specifically target use cases or applications, but may result in a wide range of applicability of the innovations described. Implementation forms may range from chip-level or modular components to non-modular, non-chip-level implementation forms, and further, to the range of aggregated, distributed, or OEM devices or systems incorporating one or more aspects of the innovations described. In some practical settings, devices incorporating the embodiments and features described may also necessarily include additional components and features for the implementation and practice of the claims and embodiments described. For example, wireless signal transmission and reception necessarily include several components for analog and digital purposes (hardware components including, for example, antennas, RF chains, power amplifiers, modulators, buffers, processors (one or more), interleavers, adders / analog adders, etc.). It is intended that the innovations described herein can be implemented in various devices, chip-level components, systems, distributed configurations, end-user devices, etc., of various sizes, shapes, and structures.

[0013]

[0022] In communication systems, modulation is the technique of systematically altering a carrier signal so that the transmitted signal contains information. Many techniques for modulating carrier signals are used in this field, including various analog and digital modulation techniques. Modern wireless communication devices often employ quadrature amplitude modulation (QAM), in which a pair of quadrature carrier signals has their amplitudes controlled to represent a desired location in the complex plane (sometimes called the Gaussian plane).

[0014]

[0023] Relatedly, multiplexing and multiple access are techniques that enable simultaneous communication of multiple signals and / or devices on the same channel. For example, the 5G New Radio (NR) specification uses orthogonal frequency division multiplexing (OFDM) with cyclic prefixes (CP) to provide multiple access for uplink transmissions from mobile devices to base stations and multiplexing for downlink transmissions from base stations to mobile devices. In addition, for uplink transmissions, the 5G NR specification provides support for discrete Fourier transform-spread OFDM (DFT-s-OFDM) (also known as single-carrier FDMA (SC-FDMA)) with CP. However, within the scope of this disclosure, multiplexing and multiple access are not limited to the above-described methods. For example, a mobile device may provide uplink multiple access using time division multiple access (TDMA), code division multiple access (CDMA), frequency division multiple access (FDMA), sparse code multiple access (SCMA), resource spread multiple access (RSMA), orbital angular momentum (OAM) multiple access, coaxial polycircular antenna multiple access, and / or other suitable multiple access schemes. Furthermore, a base station may multiplex DL transmissions to the UE using time division multiplexing (TDM), code division multiplexing (CDM), frequency division multiplexing (FDM), orthogonal frequency division multiplexing (OFDM), sparse code multiplexing (SCM), orbital angular momentum (OAM) multiplexing, coaxial polycircular antenna multiplexing, and / or other suitable multiplexing schemes.

[0015] OAM

[0024] EM transmission can be characterized as a wave that carries momentum. In some examples, this momentum may include angular momentum with spin angular momentum (SAM) and orbital angular momentum (OAM) components. In some cases, the SAM of an EM wave may be associated with the polarization of the EM wave. For example, an EM wave may be associated with different polarizations such as left-polarized, right-polarized, and circularly polarized. Thus, the SAM of an EM wave may have multiple (e.g., two) degrees of freedom.

[0016]

[0025] In some cases, the OAM of an EM wave may be associated with the field spatial distribution of the EM wave, which may take the form of a helical or torsional wavefront shape. For example, an EM wave or optical beam may be a helical mode, sometimes called an OAM mode, such a helical mode may be characterized by a wavefront shaped as a helix with an optical vortex in the center (e.g., along the beam axis), and each helical mode may be associated with a different helical waveform structure. A helical mode (e.g., an OAM mode) may be defined by or referred to as a mode index l, where the sign of the mode index l corresponds to the "palmistry" (e.g., left or right) of one or more helices, and the magnitude of the mode index l (e.g., |l|) corresponds to the amount of different, interleaved helices in the EM wave.

[0017]

[0026] For example, in the case of an EM wave associated with an OAM mode index of l=0, the EM wave is not a helix, and the waveform of the EM wave is multiple cross-sections (for example, the EM wave is a series of parallel planes). In the case of an EM wave associated with an OAM mode index of l=+1, the EM wave may propagate clockwise (for example, the EM wave may form a right-handed helix rotating clockwise around the beam axis), and the wavefront of the EM wave may be formed as a single helical surface with a step length equal to the wavelength λ of the EM wave. Similarly, the phase delay over one revolution of the EM wave may be equal to 2π. Similarly, in the case of an OAM mode index of l=-1, the EM wave may propagate counterclockwise (for example, the EM wave may form a left-handed helix rotating counterclockwise around the beam axis), and the wavefront of the EM wave may again be formed as a single helical surface with a step length equal to the wavelength λ of the EM wave. Similarly, the phase delay over one revolution of the EM wave may be equal to -2π.

[0018]

[0027] As a further example, for an OAM mode index of l = ±2, the EM wave can propagate either clockwise (when l = +2) or counterclockwise (when l = -2), and the wavefront of the EM wave may contain two distinct but interleaved helical surfaces. In such an example, the step length of each helical surface may be equal to λ / 2. Similarly, the phase delay over one revolution of the EM wave may be equal to ±4π. In general, the EM wave of mode l can propagate either clockwise or counterclockwise (depending on the sign of l), and may contain l distinct but interleaved helical surfaces, each with a step length equal to π / |l|. Similarly, the phase delay over one revolution of the EM wave may be equal to 2lπ. In some cases, the EM wave may be extended infinitely to provide a theoretically infinite number of degrees of freedom for the OAM of the EM wave (e.g., l ∈ Z, where Z is an unbounded set of integers). Therefore, the OAM of an EM wave can be associated with an infinite number of degrees of freedom.

[0019] OAM modulation

[0028] In some examples, the OAM mode index l of an EM wave may correspond to, or in some cases function as (for example, may be defined as) an additional dimension for signal or channel multiplexing. For example, each OAM mode or OAM state (which may be infinite) may function like (or equally like) a communication channel, such as a subchannel. In other words, an OAM mode or OAM state may correspond to a communication channel, and vice versa. For example, a transmitting or receiving device may communicate separate signals using EM waves with different OAM modes or OAM states, similar to how a transmitting or receiving device may communicate separate signals over different communication channels. In some embodiments, such use of OAM modes or OAM states of an EM wave to carry different signals is sometimes referred to as the use of an OAM beam.

[0020]

[0029] In addition, in some examples, EM waves having different OAM modes (e.g., OAM states) can be mutually orthogonal to each other (for example, in the Hilbert sense, where the sequence can be infinite by space containing an infinite set of axes and there is always another coordinate direction to which the next element of the sequence can travel). Similarly, in the Hilbert sense, orthogonal OAM modes or OAM states can correspond to orthogonal communication channels (e.g., orthogonal sequences transmitted over a communication channel), and a wireless communication system employing the use of OAM beams based on a potentially infinite number of OAM modes or OAM states can logically achieve infinite capability. Here, due to the mutual orthogonality between OAM modes, the waveform of one OAM mode cannot generally be received by an aperture of a receiver configured for a different OAM mode. Logically, an infinite number of OAM states or OAM modes can be twisted together for multiplexing, maintaining orthogonality between signals carried by different OAM modes (e.g., index l), while the capability of the OAM link can approach infinity. However, in reality, due to non-ideal factors (e.g., Tx / Rx axis direction and / or positional errors, propagation divergence, etc.), crosstalk may exist between OAM modes in the receiver, and therefore, a reduced number of simultaneous OAM modes may be implemented between wireless devices. In some cases, the transmitting device may generate such an OAM beam using an equally spaced circular array (UCA) configuration, as discussed with reference to Figures 6 and 7.

[0021] Wireless communication system

[0030] The following disclosures present a variety of concepts that can be implemented across a wide range of telecommunications systems, network architectures, and communication standards. Figure 1 shows an example of a radio access network (RAN) 100 operating within a wireless communication system that supports one-dimensional and / or two-dimensional index modulation in relation to coaxial multicircular OAM transmission. The wireless communication system 100 may enable a UE 106 to communicate data with an external data network 110, such as the Internet (but is not limited to the Internet).

[0022]

[0031] RAN100 can implement one or more of any suitable wireless communication technologies to provide wireless access to one or more UEs. For example, RAN100 can be used in the third-generation partnership project (3G), often referred to as 5G. rd It may operate in accordance with the Generation Partnership Project (3GPP) New Radio (NR) specifications. As another example, RAN100 may operate under a hybrid of the 5G NR standard and the Evolved Universal Terrestrial Radio Access Network (eUTRAN) standard, often referred to as LTE. 3GPP calls this hybrid RAN Next Generation RAN or NG-RAN. Of course, RAN100 can operate in accordance with any suitable 6G or other technology, and many other examples may be available within the scope of this disclosure.

[0023]

[0032] In Figure 1, two base stations 110 and 112 are shown within cells 102 and 104, and a third base station 114 is shown controlling a remote radio head (RRH) 116 within cell 106. That is, a base station may have an integrated antenna or may be connected to an antenna or RRH by a feeder cable. Broadly speaking, a base station is a network element in the RAN responsible for transmitting and receiving radio signals within one or more cells to or from the UE. In different technologies, standards, or contexts, a base station may be referred to by those skilled in the art in various ways, such as a base transceiver station (BTS), radio base station, radio transceiver, transceiver function, basic service set (BSS), extended service set (ESS), access point (AP), node B (NB), eNode B (eNB), gNode B (gNB), or any other preferred technology.

[0024]

[0033] The geographic area covered by RAN100 can be divided into cellular areas (cells) that can be uniquely identified by user equipment (UE) based on identification information broadcast from a single access point or base station. Figure 1 shows macrocells 102, 104, and 106, and a small cell 108, each of which may contain one or more sectors (not shown). A sector is a sub-area of ​​a cell. All sectors within a single cell are serviced by the same base station. A radio link within a sector can be identified by a single logical identification information belonging to that sector. In a cell divided into sectors, multiple sectors within a cell may be formed by groups of antennas, each with an antenna responsible for communication with the UE within a portion of the cell.

[0025]

[0034] In the example shown, cells 102, 104, and 126 may be referred to as macrocells because base stations 110, 112, and 114 support cells with larger sizes. Furthermore, base station 118 is shown within a small cell 108 (e.g., microcell, picocell, femtocell, home base station, home node B, home enode B, etc.) which may overlap with one or more macrocells. In this example, cell 108 may be referred to as a small cell because base station 118 supports cells with relatively smaller sizes. Cell size determination can be carried out according to system design and component constraints.

[0026]

[0035] It should be understood that RAN100 may include any number of wireless base stations and cells. Furthermore, relay nodes may be deployed to expand the size or coverage area of ​​a given cell. Base stations 110, 112, 114, and 118 provide wireless access points for any number of mobile devices to the core network.

[0027]

[0036] RAN100 supports wireless communication for multiple mobile devices. Mobile devices are sometimes referred to as user equipment (UE) in 3GPP standards, but may also be called by those skilled in the art as mobile station (MS), subscriber station, mobile unit, subscriber unit, wireless unit, remote unit, mobile device, wireless device, wireless communication device, remote device, mobile subscriber station, access terminal (AT), mobile terminal, wireless terminal, remote terminal, handset, terminal, user agent, mobile client, client, or any other suitable term. A UE can be a device that provides access to network services (for example, a mobile device). A UE can take many forms and may include a variety of devices.

[0028]

[0037] In this document, a “mobile” device (e.g., UE) does not necessarily have to be mobile and may be stationary. The term mobile device or mobile equipment broadly refers to a diverse range of devices and technologies. A UE may include several hardware structural components sized, molded, and arranged to facilitate communication, such components may include antennas, antenna arrays, RF chains, amplifiers, one or more processors, etc., that are electrically coupled to one another. Some non-exclusive examples of mobile devices include mobile phones, cellular phones, smartphones, session initiation protocol (SIP) phones, laptops, personal computers (PCs), notebooks, netbooks, smartbooks, tablets, personal digital assistants (PDAs), and a wide range of embedded systems, such as those related to the “Internet of Things” (IoT). In addition, mobile devices may include automobiles or other transport vehicles, remote sensors or actuators, robots or robotics devices, satellite radios, global positioning system (GPS) devices, object tracking devices, drones, multicopters, quadcopters, remote control devices, eyewear, wearable cameras, virtual reality devices, smartwatches, health trackers or fitness trackers, and other home and / or wearable devices, digital audio players (e.g., MP3 players), cameras, and game consoles. Furthermore, mobile devices may include home audio, video, and / or multimedia devices, appliances, vending machines, intelligent lighting, home security systems, smart meters, and other digital home devices or smart home devices.In addition, mobile devices may include smart energy devices, security devices, solar panels or solar arrays, urban infrastructure devices that control power (e.g., smart grids), lighting, water, industrial automation and enterprise devices, logistics controllers, agricultural machinery, military and defense equipment, vehicles, aircraft, ships, and weapons. Furthermore, mobile devices can provide connected medical support or telemedicine support, for example, remote healthcare. Telehealth devices may also include telehealth monitoring devices and telehealth management devices, and their communications may be given preferential treatment or priority access over other types of information, for example, with regard to priority access for the transport of critical service data and / or related QoS for the transport of critical service data.

[0029]

[0038] Wireless communication between RAN100 and UE may be described as utilizing an air interface. UEs and base stations may communicate wirelessly with each other over one or more communication links using one or more carriers. The term “carrier” may refer to a set of radio frequency spectrum resources having a defined physical layer structure to support a communication link. Transmissions from a base station to one or more UEs over an air interface may be referred to as downlink (DL) transmissions. According to some aspects of this disclosure, the term downlink may refer to point-to-multipoint transmissions occurring at a scheduling entity (e.g., a base station). Another way to describe this scheme may be to use the term broadcast channel multiplexing. Transmissions from a UE to a base station may be referred to as uplink (UL) transmissions. According to further aspects of this disclosure, the term uplink may refer to point-to-point transmissions occurring at a scheduling entity (e.g., a UE).

[0030]

[0039] Generally, a base station may include a backhaul interface (not shown) to communicate with the backhaul portion of a wireless communication system. The backhaul may provide a link between the base station and the core network. Furthermore, in some examples, the backhaul network may provide interconnection between the respective base stations. Various types of backhaul interfaces may be employed, such as direct physical connections, virtual networks, and using any suitable transport network. In some embodiments, a portion of the backhaul network may be implemented using OAM transmitters and OAM receivers, each associated with its respective base station and / or portion of the core network.

[0031]

[0040] In some cases, one or more base stations within RAN100 may be configured as integrated access and backhaul (IAB) nodes, in which case the wireless spectrum can be used for both access links (i.e., wireless links with UEs) and backhaul links. This scheme is sometimes called wireless self-backhauling. By using wireless self-backhauling, rather than requiring each new base station deployment to be equipped with its own hardwired backhaul connection, the wireless spectrum used for communication between base stations and UEs can be utilized for backhaul communication, enabling faster and easier deployment of high-density small cell networks. As an addition or alternative, OAM transmission can be utilized for backhaul communication, which can reduce the impact of wireless backhaul communication on the wireless spectrum used for communication between base stations and UEs when communication with the UEs utilizes different technologies.

[0032]

[0041] Figure 1 further includes a quadcopter or drone 120 which may be configured to function as a base station. That is, in some examples, the cell may not necessarily be fixed, and the geographical area of ​​the cell may move according to the location of the mobile base station, such as the quadcopter 120.

[0033]

[0042] Each base station 110, 112, 114, 118, and 120 may be configured to provide an access point to the core network for all UEs within their respective cells. For example, UEs 122 and 124 may communicate with base station 110, UEs 126 and 128 may communicate with base station 112, UEs 130 and 132 may communicate with base station 114 via RRH 116, UE 134 may communicate with base station 118, and UE 136 may communicate with mobile base station 120.

[0034]

[0043] In some examples, a mobile network node (e.g., a quadcopter 120) may be configured to function as a UE. For example, the quadcopter 120 may operate within cell 102 by communicating with base station 110.

[0035]

[0044] In a further embodiment of RAN100, sidelink signals may be used between UEs without necessarily relying on scheduling or control information from a base station. For example, two or more UEs (e.g., UE126 and 128) may communicate with each other using peer-to-peer (P2P) signals or sidelink signals 127 without relaying communication through a base station (e.g., base station 112). In a further example, UE138 is shown to communicate with UE140 and 142, where UE138 may function as a scheduling entity or primary sidelink device, and UE140 and 142 may function as scheduled entities or non-primary (e.g., secondary) sidelink devices. In yet another example, a UE may function as a scheduling entity in a device-to-device (D2D), peer-to-peer (P2P), or vehicle-to-vehicle (V2V) network and / or a mesh network. In the mesh network example, UE140 and 142 can communicate directly with each other at will, in addition to communicating with the scheduling entity 138. Therefore, in a wireless communication system having a cellular, P2P, or mesh configuration with scheduled access to time-frequency resources, the scheduling entity and one or more scheduled entities can communicate using the scheduled resources.

[0036]

[0045] In some examples, the RAN100 may operate in the super high frequency (SHF) region, also known as the centimeter band (using a frequency band from 3 GHz to 30 GHz), the extremely high frequency (EHF) region of the spectrum, also known as the millimeter band (e.g., from 30 GHz to 300 GHz), or even higher frequency bands reaching the terahertz (THz) region. Again, in some examples, the RAN100 may support millimeter wave (mmW) communication between the UE and the base station, and the EHF antennas of each device may be smaller and more densely spaced than UHF antennas. In some examples, this may facilitate the use of antenna arrays within the device. However, the propagation of EHF transmissions may be subject to greater atmospheric attenuation than SHF or UHF transmissions, and may be over shorter distances. The techniques disclosed herein may be employed across transmissions using one or more different frequency domains, and the specified use of bands across these frequency domains may vary by country or regulatory body.

[0037] Typical multi-antenna array

[0046] In some aspects of this disclosure, a wireless communication node or device may consist of multiple antennas for, for example, beamforming techniques, multiple-input multiple-output (MIMO) techniques, and / or orbital angular momentum (OAM) modulation techniques. Figure 2 shows an example of wireless communication utilizing multiple antennas to support beamforming, MIMO, and OAM. In some examples, the system in Figure 2 may implement an aspect of RAN100. The use of such multi-antenna techniques enables the wireless communication system to leverage spatial domains to support spatial multiplexing, beamforming, and transmit diversity.

[0038]

[0047] Beamforming generally refers to the transmission or reception of directional signals. For beamformed transmission, the amplitude and phase of each antenna in an antenna array can be precoded or controlled to create a desired (e.g., directional) pattern of constructive and cancelling interference in the wavefront. In a MIMO system, the transmitter 202 includes multiple transmitting antennas 204 (e.g., N transmitting antennas), and the receiver 206 includes multiple receiving antennas 208 (e.g., M receiving antennas). Thus, there are N × M signal paths 210 from the transmitting antennas 204 to the receiving antennas 208. Each of the transmitter 202 and receiver 206 may be implemented, for example, in a scheduling entity 108, a scheduled entity 106, or any other suitable wireless communication device.

[0039]

[0048] In MIMO systems, spatial multiplexing can be used to transmit multiple different streams of data, also called layers, simultaneously on the same time-frequency resource. In some examples, a transmitter may send multiple data streams to a single receiver. In this way, a MIMO system takes advantage of the capacitive gain and / or increased data rate associated with using multiple antennas in a rich scattering environment where channel variations can be tracked. Here, the receiver may track these channel variations and provide corresponding feedback to the transmitter. In the simplest example, a rank 2 (i.e., containing two data streams) spatial multiplexed transmit in a 2x2 MIMO antenna configuration transmits two data streams through two transmitting antennas 204. Signals from each transmitting antenna 204 reach each receiving antenna 208 along different signal paths 210. Receiver 206 may then reconstruct the data streams using the signals received from each receiving antenna 208.

[0040]

[0049] The number of data streams or layers in a MIMO system corresponds to the transmission rank. Generally, the rank of a MIMO system is limited by the smaller of the number of transmitting antennas 204 or receiving antennas 208. In addition, other considerations, such as the channel state in the receiving device and the resources available for use by the transmitting device, may also affect the transmission rank. For example, a base station in a cellular RAN may assign a rank (and therefore the number of data streams) for DL ​​transmission to a particular UE based on a rank indicator (RI) that the UE transmits to the base station. The UE may determine this RI based on the antenna configuration (e.g., the number of transmitting and receiving antennas) and the signal-to-interference-and-noise ratio (SINR) measured for each of the receiving antennas. The RI may indicate, for example, the number of layers that can be supported under the current channel state. The base station may use the RI, along with resource information (e.g., available resources and the amount of data to be scheduled for the UE), to assign a DL transmission rank to the UE.

[0041]

[0050] The transmitting device determines the precoding of one or more transmitted data streams based, for example, on known channel state information of the channel through which the transmitting device transmits one or more data streams. For example, the transmitting device may transmit one or more preferred reference signals (e.g., channel state information reference signals, i.e., CSI-RS) that the receiving device can measure. The receiver can then report back the measured channel quality information (CQI) to the transmitting device. This CQI generally reports the current communication channel quality and, in some examples, the requested transport block size (TBS) for future transmissions to the receiver. In some examples, the receiver can further report back the transmitting device a precoding matrix indicator (PMI). This PMI generally reports the preferred precoding matrix of the receiving device to be used by the transmitting device and may be indexed in a predefined codebook. The transmitting device can then utilize this CQI / PMI to determine the preferred precoding matrix for transmission to the receiver.

[0042]

[0051] In some cases, RAN100 may be an example of, or may support, an OAM-based communication system, and the transmitting device 202 and / or receiving device 206 may communicate via an OAM beam. In some examples, the transmitting device 202 and / or receiving device 206 may generate and steer an OAM beam based on selecting a set of antenna elements from a planar array of antenna elements (for example, a planar array on the transmitting device 202 or receiving device 206 that may be used for MIMO communication) based on which antenna elements fall within a determined area on a planar array associated with an equally spaced circular array (UCA) for OAM communication. Additionally or alternatively, one or more transmitting devices 202 or receiving devices 206 may include components that provide spiral phase plate (SPP)-based OAM communication.

[0043]

[0052] In various examples, some or all of the RAN100's wireless resources may be scheduled to carry one or more physical channels, such as a control channel, a shared channel, and a data channel. Other resources in the RAN100 may also carry pilot or reference signals. These pilot or reference signals may enable a receiving device to perform channel estimation for the corresponding channel.

[0044]

[0053] In DL transmission, a transmitting device (e.g., a base station or scheduling entity) may allocate a set of wireless resources to carry DL control information, including one or more DL control channels that typically carry information originating from higher layers to one or more receiving devices (e.g., a UE or a scheduled entity). In addition, DL resources may typically be allocated to carry DL physical signals that do not carry information originating from higher layers. These DL physical signals may include synchronization signals, demodulation reference signals (DM-RS), phase-tracking reference signals (PT-RS), channel-state information reference signals (CSI-RS), etc.

[0045]

[0054] In UL transmission, a transmitting device (e.g., a UE or a scheduled entity) may utilize a designated set of wireless resources to carry UL control information (UCI) to a receiving device (e.g., a base station or a scheduling entity). UCI may originate from higher layers via one or more UL control channels. Furthermore, UL wireless resources may carry UL physical signals that do not typically carry information originating from higher layers, such as demodulation reference signals (DM-RS), phase-tracking reference signals (PT-RS), and sounding reference signals (SRS).

[0046]

[0055] In sidelink (SL) transmission, a transmitting device (e.g., a UE or a scheduled entity, or a base station of a scheduling entity) may utilize a designated set of wireless resources to carry SL control information (SCI) to a receiving device (e.g., another UE or a scheduled entity, or another base station of a scheduling entity). Furthermore, SL wireless resources may carry SL physical signals that do not typically carry information originating from higher layers, such as demodulation reference signals (DM-RS), phase-tracking reference signals (PT-RS), and sounding reference signals (SRS).

[0047]

[0056] In addition to control information, wireless resources may be allocated for user data or traffic data that can be carried over one or more traffic channels.

[0048] Wireless resources

[0057] Those skilled in the art will understand that various aspects of this disclosure can be applied to DFT-s-OFDMA waveforms in substantially the same manner as described below herein. That is, while some examples of this disclosure may focus on OFDM links for clarity, it should be understood that the same principles can also be applied to DFT-s-OFDM waveforms.

[0049]

[0058] In some examples, a frame might refer to a predetermined duration for wireless transmission (e.g., 10 ms). Furthermore, each frame may consist of a set of subframes (e.g., 10 subframes, each 1 ms long). A given carrier wave may contain one set of frames in the UL and another set of frames in the DL.

[0050]

[0059] A resource grid can represent time-frequency resources for a given antenna port. For example, in a MIMO implementation with multiple available antenna ports, multiple corresponding resource grids may be available for communication. As another example, different OAM modes, as described below, may be orthogonal when transmitted using the same time, frequency, and / or code resources, and therefore may be associated with independent resource grids.

[0051]

[0060] A resource grid can be divided into multiple resource elements (REs). An RE consisting of 1 subcarrier × 1 symbol is the smallest individual part of the time-frequency grid and may contain a single complex value representing data from a physical channel or signal. Depending on the modulation used in a particular implementation, each RE may represent one or more bits of information. In some examples, a block of REs may be called a physical resource block (PRB) or more simply a resource block (RB), which contains any suitable number of consecutive subcarriers in the frequency domain. In one example, an RB may contain 12 subcarriers, a number independent of the numerology used. In some examples, depending on the numerology, an RB may contain any suitable number of consecutive OFDM symbols in the time domain. This disclosure assumes, for example, that a single RB fully corresponds to a single direction of communication (either transmission or reception to a given device).

[0052]

[0061] A UE generally utilizes only a subset of the resource grid. An RB may be the smallest unit of resources that the scheduler can allocate to a UE. Therefore, the more RBs scheduled for a UE, and the higher the modulation scheme chosen for the air interface, the higher the data rate for the UE. While a UE may utilize only a subset of the resource grid (for example, to allow other UEs to communicate using the RAN), an OAM transmitter and receiver may utilize a much larger portion of the resource grid associated with one or more OAM modes. For example, there may not be other devices configured to use the same resources that are often used when utilizing mobile resources in the RAN. An OAM transmitter and receiver pair is generally spatially closely aligned, potentially reducing the ability to use antennas to communicate with other devices that are not closely aligned.

[0053]

[0062] Resources used to transmit and / or receive signals (e.g., waveforms) may include time-frequency resources, such as one or more REs and one or more RBs, within a particular resource grid. Additional or alternative resources may include layers (e.g., physical layers, media access control (MAC) layers, radio resource control (RRC) layers, etc.), codes (e.g., used to implement code division multiple access schemes), OAM modes, and arrays of antenna elements (e.g., UCA circles, parts of ULA, parts of UPA, etc.).

[0054] Channel and signal description

[0063] Various REs within the RB may carry one or more physical channels, including control channels, shared channels, and data channels. Other REs within the RB may also carry pilot or reference signals. These pilot or reference signals can enable the receiving device to perform channel estimation of the corresponding channels, which can enable coherent demodulation / detection of the control and / or data channels within the RB.

[0055]

[0064] In DL transmission, a transmitting device (e.g., a base station or UE) may allocate one or more REs (e.g., within the control domain) to carry one or more DL control channels. These DL control channels include DL control information (DCI), such as physical broadcast channels (PBCHs) and physical downlink control channels (PDCCHs), which typically carry information originating from higher layers to one or more receiving devices (e.g., UEs). In addition, the transmitting device may allocate one or more DL REs to carry DL physical signals that do not typically carry information originating from higher layers. These DL physical signals may include primary synchronization signals (PSS), secondary synchronization signals (SSS), demodulation reference signals (DM-RS), phase-tracking reference signals (PT-RS), and channel status information reference signals (CSI-RS).

[0056]

[0065] A base station (or other suitable transmitter device) may transmit synchronization signals PSS and SSS (collectively referred to as SS), and in some examples, PBCH, in a synchronization signal block (SSB) containing four consecutive OFDM symbols numbered via ascending time indices from 0 to 3. In the frequency domain, the SSB extends over 240 consecutive subcarriers, which may be numbered via ascending frequency indices from 0 to 239. Of course, this disclosure is not limited to this particular SSB configuration. Other non-limiting examples may utilize more or fewer synchronization signals, may include one or more auxiliary channels in addition to the PBCH, may omit the PBCH, and / or may utilize discontinuous symbols for the SSB within the scope of this disclosure.

[0057]

[0066] The PDCCH may carry downlink control information (DCI) for one or more UEs within a cell. This may include, but is not limited to, power control commands, scheduling information, authorizations, and / or RE assignments for DL ​​and UL transmissions.

[0058]

[0067] In UL transmissions, a transmitting device (e.g., a scheduled entity) may utilize one or more REs to carry one or more UL control channels, such as a physical uplink control channel (PUCCH) and a physical random access channel (PRACH). These UL control channels typically carry UL control information (UCI), which generally carries information originating from higher layers. Furthermore, UL REs may carry UL physical signals that do not typically carry information originating from higher layers, such as demodulation reference signals (DM-RS), phase-tracking reference signals (PT-RS), and sounding reference signals (SRS). In some examples, the control information may include scheduling requests (SRs), i.e., requests to a scheduling entity to schedule an uplink transmission. In response to an SR transmitted on a control channel, the scheduling entity may transmit downlink control information that can schedule resources for uplink packet transmissions.

[0059]

[0068] UL control information may also include hybrid automatic repeat request (HARQ) feedback, such as an acknowledgment (ACK) or negative acknowledgment (NACK), channel state information (CSI), or any other suitable UL control information. HARQ is a technique well known to those skilled in the art, in which a receiving device can verify the integrity of a packet transmission with accuracy using any suitable integrity verification mechanism, such as a checksum or cyclic redundancy check (CRC). If the receiving device confirms the integrity of the transmission, it may send an ACK; otherwise, it may send a NACK. In response to the NACK, the transmitting device may send an HARQ retransmission, which may implement chase synthesis, incremental redundancy, or the like.

[0060]

[0069] In addition to control information, one or more REs may be allocated for user data or traffic data. Such traffic may be carried over one or more traffic channels, such as a physical downlink shared channel (PDSCH) for DL ​​transmissions, or a physical uplink shared channel (PUSCH) for UL transmissions.

[0061]

[0070] Those skilled in the art will recognize that the channels or carriers described above are not necessarily all channels or carriers that may be used between a scheduling entity and one or more scheduled entities, and that other channels or carriers, such as other traffic channels, control channels, and feedback channels, may be available in addition to those shown.

[0062] Block diagram

[0071] Figure 3 is a block diagram showing an example of a hardware implementation for a transmitting device 300 employing the processing system 314. For example, the transmitting device 300 may be a user equipment (UE), a base station, or any other wireless communication node, as shown in either Figure 1 and / or Figure 2.

[0063]

[0072] The transmitting device 300 may be implemented in a processing system 314 including one or more processors 304. Examples of processors 304 include microprocessors, microcontrollers, digital signal processors (DSPs), field programmable gate arrays (FPGAs), programmable logic devices (PLDs), application-specific integrated circuits (ASICs), state machines, gate logic, discrete hardware circuits, and other suitable hardware configured to perform the various functions described throughout this disclosure. In various examples, the transmitting device 300 may be configured to implement one or more of the functions described herein. That is, a processor 304 used in the transmitting device 300 may be configured to implement one or more of the processes and procedures described below and shown in Figures 7 to 10 (for example, together with memory 305).

[0064]

[0073] In this example, the processing system 314 may be implemented in a bus architecture, commonly represented by bus 302. Bus 302 may include any number of interconnected buses and bridges, depending on the specific application and overall design constraints of the processing system 314. Bus 302 connects various circuits, including one or more processors (commonly represented by processor 304), memory 305, and computer-readable media (commonly represented by computer-readable media 306), in a communicative manner. Bus 302 may also link various other circuits, such as timing sources, peripherals, voltage regulators, and power management circuits, which are well known in the art and therefore will not be described further. Bus interface 308 provides an interface between bus 302 and transceiver 310.

[0065]

[0074] The transceiver 310 provides a communication interface or means for communicating with various other devices via a transmitting medium. In some embodiments, the transceiver 310 includes (or is coupled to) a plurality of antennas 311 (each of which may include a plurality of antenna elements). The plurality of antennas 311 may be configured as follows: similar to the equally spaced circular array (UCA) antenna described below and shown in Figure 5; similar to the coaxial multi-circular UCA configuration described below and shown in Figure 6; or as some combination of the above. In some embodiments, any configuration that enables OAM multiplexing of electromagnetic signals (e.g., RF signals, optical signals, etc.), including, but not limited to, the UCA antenna described as an example, may be applied. The plurality of antennas 311 may include, or may be configured using, any other suitably configured phase plates, spatial modulators, integrated circuits, any other suitably configured components, and / or any suitably configured combination thereof, for transmission over any suitably configured medium, including wireless air interfaces, optical fibers, etc. In some embodiments, the transceiver 310 may be configured to provide any suitably number of simultaneous signals to the antennas 311. For example, a transceiver may be configured to implement multiple transceiver units (sometimes called TXRUs) that can each transmit signals (for example, corresponding to a particular OAM mode) via a subset of antennas (corresponding to a particular equidistant circular array (UCA), as described below with reference to Figures 5 and 6). In addition, in some embodiments, such TXRUs may be configured to receive signals (for example, corresponding to a particular OAM mode) via a subset of antennas (corresponding to a particular equidistant circular array (UCA), as described below with reference to Figures 5 and 6). As described below with reference to Figure 7, the number of OAM modes that a UCA can transmit and / or receive simultaneously may be limited based on the number of TXRUs associated with the UCA. For example, a particular UCA may be configured to transmit and / or receive any two OAM modes (e.g., modes 1 and 2, modes 1 and 3, etc.) simultaneously.

[0066]

[0075] Depending on the nature of the transmitting device 300, a user interface 312 (e.g., a keyboard, display, speaker, microphone, joystick) may also be provided. Of course, such a user interface 312 is optional and may be omitted in some examples, such as a base station.

[0067]

[0076] In some aspects of this disclosure, the processor 304 may include a communication circuit 341 configured for various functions (for example, in conjunction with memory 305), including coordinating with a transceiver controller circuit 342 and / or transceiver controller instruction 362 to transmit a waveform suitable for communicating information using one or more OAM modes and / or transmit a reference signal. For example, the communication circuit 341 may be configured to implement one or more of the functions described below, for example, with respect to Figure 7, including blocks 702, 710, and / or 722; with respect to Figure 8, including blocks 802, 804, and / or 806; and with respect to Figure 10, including blocks 1010, 1014, 1016, 1018, and / or 1020.

[0068]

[0077] In some further aspects of this disclosure, the processor 304 may include a transceiver controller 342 configured for various functions (for example, in cooperation with memory 305 and / or transceiver 310), including, for example, transmitting preferred waveforms (e.g., information or data streams) and / or reference signals (e.g., DM-RS, CSI-RS, etc.) as disclosed herein. For example, the transceiver controller 342 may be configured to implement one or more of the functions described below, for example, with respect to Figure 7, including blocks 702, 710, and / or 722; with respect to Figure 8, including blocks 802, 804, and / or 806; and with respect to Figure 10, including blocks 1010, 1014, 1016, 1018, and / or 1020.

[0069]

[0078] In some further aspects of the present disclosure, the processor 304 may include a channel response determination circuit 343 configured (for example, in conjunction with memory 305) for various functions, including, for example, determining the channel response to a particular OAM mode and a particular pair of transmit and receive UCAs, and determining precoding weights for a particular OAM mode based on information about the UCA circle. In some examples, the channel response determination circuit 343 may determine the channel response to a particular OAM mode based on the radius of the UCA used to receive a reference signal, the radius of the UCA used to transmit a reference signal, the distance between the transmit and receive UCAs, and the wavelength used to transmit the reference signal. In some additional examples, the channel response determination circuit 343 may determine precoding weights for a particular OAM mode based on the channel response matrix associated with the particular OAM mode and one or more pairs of transmit and receive UCAs. For example, the channel response determination circuit 343 may be configured to implement one or more of the functions described below with respect to Figure 7, including, for example, block 724.

[0070]

[0079] The processor 304 is responsible for managing the bus 302 and general processing, including the execution of software stored on the computer-readable medium 306. When executed by the processor 304, the software causes the processing system 314 to perform various functions for any particular device, as described below. The computer-readable medium 306 and memory 305 may also be used to store data manipulated by the processor 304 when the software is executed.

[0071]

[0080] One or more processors 304 in the processing system may execute software. Software is broadly interpreted to mean instructions, instruction sets, code, code segments, program code, programs, subprograms, software modules, applications, software applications, software packages, routines, subroutines, objects, executable files, execution threads, procedures, functions, etc., whether they are called software, firmware, middleware, microcode, hardware description language, or otherwise. Software may reside on computer-readable medium 306. Computer-readable medium 306 may be non-temporary computer-readable medium. Non-temporary computer-readable media include, for example, magnetic storage devices (e.g., hard disks, floppy disks, magnetic strips), optical discs (e.g., compact discs (CDs) or digital versatile discs (DVDs)), smart cards, flash memory devices (e.g., cards, sticks, or key drives), random access memory (RAM), read-only memory (ROM), programmable ROM (PROM), erasable PROM (EPROM), electrically erasable PROM (EEPROM), registers, removable disks, and any other suitable media for storing software and / or instructions that can be accessed and read by a computer. The computer-readable media 306 may reside within the processing system 314, may reside outside the processing system 314, or may be distributed across multiple entities including the processing system 314. The computer-readable media 306 may be embodied in a computer program product. For example, a computer program product may include computer-readable media in its packaging materials.Those skilled in the art will recognize how to best achieve the functions described throughout this disclosure, depending on the specific application and the overall design constraints imposed on the entire system.

[0072]

[0081] In one or more examples, the computer-readable storage medium 306 may store computer-executable code including communication instructions 361 that constitute a transmitting device 300 for various functions, including, for example, receiving an information stream (e.g., a sequence of bits) for transmission and coordinating with a transceiver controller circuit 342 and / or transceiver controller instructions 362 to transmit a suitable waveform. For example, the communication instructions 361 may be configured to cause the transmitting device 300 to implement one or more of the functions described below, for example, including blocks 702, 710, and / or 722 in relation to Figure 7, for example, including blocks 802, 804, and / or 806 in relation to Figure 8, and for example, including blocks 1010, 1014, 1016, 1018, and / or 1020 in relation to Figure 10.

[0073]

[0082] In one or more further examples, the computer-readable storage medium 306 may store computer-executable code including transceiver controller instructions 362 that configure the transmitting device 300 for various functions, including, for example, transmitting preferred waveforms (e.g., information or data streams) and / or reference signals (e.g., DM-RS, CSI-RS, etc.) as disclosed herein. For example, the transceiver controller instructions 362 may be configured to cause the transmitting device 300 to implement one or more of the functions described below, for example, blocks 702, 710, and / or 722 in relation to Figure 7, for example, blocks 802, 804, and / or 806 in relation to Figure 8, and blocks 1010, 1014, 1016, 1018, and / or 1020 in relation to Figure 10.

[0074]

[0083] In one or more further examples, the computer-readable storage medium 306 may store computer-executable code including channel response determination instructions 363 that constitute the transmitting device 300 for various functions, including, for example, determining a channel response to a particular OAM mode and a particular pair of transmit and receive UCAs, and determining precoding weights for a particular OAM mode based on information about the UCA circle. In some examples, the channel response determination instructions 363 may determine the channel response to a particular OAM mode based on the radius of the UCA used to receive a reference signal, the radius of the UCA used to transmit a reference signal, the distance between the transmit and receive UCAs, and the wavelength used to transmit the reference signal. In some additional examples, the channel response determination instructions 363 may determine precoding weights for a particular OAM mode based on the channel response matrix associated with the particular OAM mode and one or more pairs of transmit and receive UCAs. For example, the channel response determination instructions 363 may be configured, for example, including block 724, to implement one or more of the functions described below with respect to Figure 7.

[0075]

[0084] In one configuration, the transmitting device 300 for wireless communication includes means for transmitting a reference signal (e.g., a first reference signal, a second reference signal, etc.) using a specific orbital angular momentum (OAM) mode (e.g., a first OAM mode, a second OAM mode, etc.), means for receiving information indicating a subset of antenna elements among a plurality of antenna elements to be used to transmit the first OAM mode, means for transmitting reference signal configuration information indicating that a first subset of reference signals among a plurality of reference signals is associated with the first OAM mode, and rank indicators associated with the first OAM mode, or channel quality information associated with the first OAM mode. The system includes means for receiving at least one of the following from a receiving device; means for determining a channel response to a particular OAM mode based on the radius of a first UCA used to transmit a reference signal; the radius of a third UCA used by the receiving device to receive a reference signal; the distance between the first UCA and the third UCA; and the wavelength of a waveform used to transmit the first reference signal; and / or means for determining another channel response to a particular OAM mode based on the radius of a second UCA used to transmit another reference signal; the radius of a third UCA; the distance between the first UCA and the third UCA; and the wavelength of a waveform used to transmit the first reference signal. In one embodiment, the means described above may be a processor 304 shown in Figure 3, configured to perform the functions enumerated by the means described above. In another embodiment, the means described above may be a circuit or any device configured to perform the functions enumerated by the means described above.

[0076]

[0085] Naturally, in the above example, the circuitry contained within the processor 304 is provided merely as an example, and other means for performing the functions described may be included in various aspects of this disclosure, but are not limited to, instructions stored in a computer-readable storage medium 306, or in any other suitable device or means that utilizes the processes and / or algorithms described herein with respect to, for example, Figures 7, 8, and / or 10, as described in any one of Figures 1, 2, 5, and / or 6.

[0077]

[0086] Figure 4 is a conceptual diagram showing an example of a hardware implementation for an exemplary receiving device 400 employing a processing system 414. According to various aspects of this disclosure, elements, any part of elements, or any combination of elements may be implemented in a processing system 414 including one or more processors 404. For example, the receiving device 400 may be a user equipment (UE), a base station, or any other suitable wireless communication node, as shown in either Figure 1 and / or Figure 2.

[0078]

[0087] In some embodiments, the transceiver 410 includes (or is coupled to) a plurality of antennas 411 (each of which may include a plurality of antenna elements). The plurality of antennas 411 may consist of a coaxial multicircular UCA configuration as described below and shown in Figure 5, as described below and shown in Figure 6, or a combination of two or more of the above. In some embodiments, any configuration that enables OAM multiplexing of electromagnetic signals (e.g., RF signals, optical signals, etc.), including, but not limited to, a UCA antenna as described as an example, may be applied. The plurality of antennas 411 may include, or may be configured using, any other suitably configured phase plates, spatial modulators, integrated circuits, any other suitably configured components, and / or any suitably configured combination thereof, for transmission over any suitably configured medium, including wireless air interfaces, optical fibers, etc.

[0079]

[0088] The processing system 414 may be substantially the same as the processing system 314 shown in Figure 3, and includes a bus interface 408, a bus 402, memory 405, a processor 404, and a computer-readable medium 406. Furthermore, the receiving device 400 may include a user interface 412 and a transceiver 410, substantially the same as those described above in Figure 3. That is, the processor 404 used in the receiving device 400 may be configured (for example, in conjunction with the memory 405) to implement one or more of the processes described below and shown in Figures 7, 9, and / or 10.

[0080]

[0089] In some aspects of this disclosure, the processor 404 may include a transceiver controller 441 configured (for example, in conjunction with memory 405) for various functions, including, for example, receiving and sampling waveforms (including, in some examples, one or more reference signals) and storing samples of the received waveforms in memory 405. For example, the transceiver controller 441 may be configured to implement one or more of the functions described below, including, for example, blocks 706, 714, and / or 718 with respect to Figure 7, including, for example, blocks 902, 904, and / or 906 with respect to Figure 9, and / or including, for example, blocks 1010, 1014, 1016, 1018, and / or 1020 with respect to Figure 10.

[0081]

[0090] In some further aspects of the present disclosure, the processor 404 may include a channel characterization circuit 442 configured (in conjunction with, for example, memory 405) for various functions, including, for example, measuring a channel based on a reference signal received using a particular OAM mode, and determining the channel gain between a UCA used to transmit the reference signal using a particular OAM mode and a UCA used to receive the reference signal using a particular OAM mode. In some examples, the channel characterization circuit 442 may measure a channel based on a received reference signal (e.g., received CSI-RS) transmitted and received using a particular OAM mode, and in some other examples, the channel characterization circuit 442 may determine the channel gain between a UCA antenna that transmitted the reference signal (e.g., CSI-RS) using a particular OAM mode and a UCA antenna that received the reference signal. For example, the channel characterization circuit 442 may be configured to implement one or more of the functions described below with respect to Figure 7, including, for example, block 716.

[0082]

[0091] In some further aspects of the present disclosure, the processor 404 may include a channel selection circuit 443 configured for various functions (e.g., in conjunction with memory 405), which includes, for example, determining which antenna (e.g., UCA antenna) should be used to receive a reference signal associated with various OAM modes, and selecting which antenna(s) (e.g., UCA antennas) should be used by a transmitting device (e.g., transmitting device 300) to transmit a particular OAM mode. In some examples, the channel selection circuit 443 may determine which antenna should be used to receive a reference signal (e.g., CSI-RS) associated with each OAM mode based on any preferred information (e.g., the maximum number of simultaneous OAM modes that each transmitter UCA is configured to transmit, the maximum number of simultaneous OAM modes that each receiver UCA is configured to receive, etc.), and in some other examples, the channel selection circuit 443 may select which transmitter UCA should be used to transmit each OAM mode and / or assign which receiver UCA to receive each OAM mode based on the channel gain between one or more pairs of UCAs used to transmit and receive each OAM mode. For example, the channel selection circuit 443 may be configured to implement one or more of the functions described below with respect to Figure 7, including, for example, blocks 708 and / or 716.

[0083]

[0092] Furthermore, the computer-readable storage medium 406 may store computer-executable code, including transceiver controller instructions 461, which configure the receiving device 400 for various functions, including, for example, receiving and sampling a waveform (including, in some examples, one or more reference signals) and storing the samples of the received waveform in memory 405. For example, the transceiver controller instructions 461 may be configured to cause the receiving device 400 to implement one or more of the functions described below, including, for example, blocks 706, 714, and / or 718 in relation to Figure 7, including, for example, blocks 902, 904, and / or 906 in relation to Figure 9, and / or including, for example, blocks 1010, 1014, 1016, 1018, and / or 1020 in relation to Figure 10.

[0084]

[0093] In some further examples, the computer-readable storage medium 406 may store computer-executable code including channel characterization instructions 462 that configure the receiving device 400 for various functions, including, for example, measuring a channel based on a reference signal received using a particular OAM mode, and determining the channel gain between a UCA used to transmit a reference signal using a particular OAM mode and a UCA used to receive a reference signal using a particular OAM mode. In some examples, the channel characterization instructions 462 may measure a channel based on a received reference signal (e.g., received CSI-RS) transmitted and received using a particular OAM mode, and in some other examples, the channel characterization instructions 462 may determine the channel gain between a UCA antenna that transmitted a reference signal (e.g., CSI-RS) using a particular OAM mode and a UCA antenna that received the reference signal. For example, the channel characterization instructions 462 may be configured to perform one or more of the functions described below with respect to Figure 7, including, for example, block 716.

[0085]

[0094] In some further examples, the computer-readable storage medium 406 may store computer-executable code including channel selection instructions 463 that configure the receiving device 400 for various functions, including, for example, determining which antenna (e.g., UCA antenna) should be used to receive a reference signal associated with various OAM modes, and selecting which antenna(s) (e.g., UCA antennas) should be used by a transmitting device (e.g., transmitting device 300) to transmit a particular OAM mode. In some examples, the channel selection instructions 463 may determine which antenna should be used to receive a reference signal (e.g., CSI-RS) associated with each OAM mode based on any preferred information (e.g., the maximum number of simultaneous OAM modes that each transmitter UCA is configured to transmit, the maximum number of simultaneous OAM modes that each receiver UCA is configured to receive, etc.), and in some other examples, the channel selection instructions 463 may select which transmitter UCA should be used to transmit each OAM mode and / or assign a receiver UCA to receive each OAM mode based on the channel gain between one or more pairs of UCAs used to transmit and receive each OAM mode. For example, channel selection instruction 463 may be configured to implement one or more of the functions described below with respect to Figure 7, including, for example, blocks 708 and / or 716.

[0086]

[0095] In one configuration, a receiving device 400 for wireless communication includes means for receiving instructions from a transmitting device (e.g., transmitting device 300) that a specific subset of antenna elements (e.g., corresponding to a specific UCA circle) should be used to transmit a first reference signal for a first OAM mode, means for receiving instructions from a transmitting device (e.g., transmitting device 300) that a specific subset of antenna elements (e.g., corresponding to a specific UCA circle) should be used to transmit a second reference signal for a first OAM mode, means for transmitting information indicating the subset of antenna elements used to receive the first reference signal, means for receiving the first reference signal, means for receiving the second reference signal, means for receiving reference signal configuration information from a transmitting device (e.g., transmitting device 300), and that the first reference signal should be transmitted using a first UCA, and the reference signal configuration The means include means for making a determination based on information; means for measuring a channel based on a first reference signal; means for determining a first channel gain between a first UCA and a UCA used to receive the first reference signal; means for determining a second channel gain between a first UCA and a UCA used to receive a second reference signal; means for receiving information indicating the maximum number of OAM modes that a transmitting device is configured to transmit simultaneously using the first UCA; means for selecting a UCA to be used to transmit using the first OAM mode based on the first channel gain, the second channel gain, and the maximum number of OAM modes that a transmitting device is configured to transmit simultaneously using the first UCA; and / or means for transmitting information indicating a subset (e.g., UCAs) of antenna elements of a transmitting device (e.g., transmitting device 300) to transmit the first OAM mode. In one embodiment, the means described above may be a processor 404 shown in Figure 4, configured to perform the functions enumerated by the means described above. In another embodiment, the means described above may be a circuit or any device configured to perform the functions enumerated by the means described above.

[0087]

[0096] Of course, in the above example, the circuitry contained within the processor 404 is provided only as an example, and other means of performing the functions described may be included in various aspects of this disclosure, but are not limited to, instructions stored in a computer-readable storage medium 406, or any other suitable means including Figures 1, 2, 5, and / or 6, and utilizing the processes and / or algorithms described herein with respect to, for example, Figures 7, 9, and / or 10.

[0088]

[0097] In some embodiments, the Disclosure provides wireless communication techniques that utilize the orbital angular momentum (OAM) properties of electromagnetic (EM) waves to modulate carrier waves for carrying information and / or to multiplex reference signals over a common wireless resource. Systems and devices employing OAM are currently being actively developed due to their improved communication spectral efficiency, their ability to provide higher-order spatial multiplexing (e.g., as further described below) resulting in potentially higher data rates, and their potential to enable lower receiver complexity. OAM is seen as a strong candidate for future 6G communication technologies or as an extension of existing 5G technologies.

[0089] UCA configuration

[0098] Figure 5 shows an example of an equally spaced circular array (UCA) OAM configuration that supports information transmission by OAM mode selection and detection, according to several aspects of the present disclosure. In some examples, the UCA OAM configuration shown may implement an aspect of RAN 100 and may be employed by transmitting devices 202 / 300 and receiving devices 206 / 400. In this example, the transmitting device (e.g., UE or base station) may include an OAM transmitter UCA antenna 505, and the receiving device (e.g., UE or base station) may include an OAM receiver UCA antenna 510.

[0090]

[0099] In some embodiments, one or both of the OAM transmitter UCA antenna 505 or the OAM receiver UCA antenna 510 may be implemented as a planar array of antenna elements, which may be an example of a (massive or holographic) MIMO array or intelligent surface, or may function as such. In some cases, the transmitting device may identify a set of antenna elements 515 of the planar array forming the transmitter UCA, and the receiving device may identify a set of antenna elements 545 of the planar array forming the receiver UCA.

[0091]

[0100] When a set of antenna elements is selected from a planar array, the OAM transmitter may add weights 535 to each of the selected antenna elements 515 based on the OAM mode index l of the transmitted OAM beam and one or more spatial parameters associated with each antenna element. When the UCA method is used to generate the OAM beam, the transmitting device may identify a set of antenna elements 515 on a circular array of antenna elements and load a first set of weights 520 to each of the identified antenna elements based on a first OAM mode index (e.g., l=0). Furthermore, other weights may be used for the set of antenna elements 515, such as a second OAM mode index (e.g., l=+1) which may use a second set of weights 525, and a third OAM mode index (e.g., l=-1) which may use a third set of weights 530.

[0092]

[0101] For example, to generate an OAM beam with a selected OAM mode index (e.g., l=0), the OAM transmitter may load weights 535 onto each antenna element 515 on the UCA based on the angle 540 measured between the antenna element and a reference line on the UCA (e.g., the x-axis on the plane in which the UCA is located, with the origin being the center of the UCA), the OAM mode index l, and i (for example, for a complex numerical weight which may be shown as j as an alternative in some cases). In some cases, for example, the weight for antenna element n is

[0093]

number

[0094] It can be proportional to, where φ n w1 = [w 1,1 ,w 1,2 ,...,w 1,8 ] T ), a signal port may be generated. The weight 535 of each antenna element 515 is e iφl (where φ is equal to the angle of antenna element 515 in the circle (e.g., angle 540 relative to antenna element 515-g), and l is the OAM mode index), each set of weights 520-530 provides a beamformed port with an equivalent OAM mode l. Different beamforming weights e' ≠ l iφl’ By using this, multiple OAM modes are generated.

[0095]

[0102] In the OAM receiver UCA antenna 510, the receiving device may have a circularly arranged receiving antenna element 545. The channel matrix may be denoted as H from each transmitting antenna to each receiving antenna, in which case the beamformed channel matrix

[0096]

number

[0097] in the case of,

[0098]

number

[0099] Any two columns of the matrix are orthogonal, meaning that the beamformed ports do not have crosstalk. This allows OAM-based communications to efficiently achieve high levels of spatial multiplexing. Furthermore, the intrinsic-based transmit precoding weights and receive coupling weights of UCA-based OAM are equal to a discrete Fourier transform (DFT) matrix that is independent of communication parameters (e.g., distance, aperture size, and carrier frequency). Thus, UCA-based OAM can be implemented at a relatively low cost. In some cases, a receiving device may test several different OAM modes to determine the OAM mode used in a transmission (e.g., based on whether a particular OAM mode results in a successfully demodulated transmission), which may be used to identify one or more information bits of a transmission.

[0100]

[0103] In some embodiments, when the central axes of the transmitter antenna (e.g., antenna 311) and the receiver antenna (e.g., antenna 411) are closely aligned (e.g., with a misalignment of less than 0.1 milliradians (mrad)), each OAM mode is orthogonal to each other. However, if the antennas are misaligned, adjacent OAM modes may cause interference. For example, a misalignment of 1 mrad may cause significant interference between adjacent OAM modes, and with a larger misalignment, OAM modes that are farther away from a particular OAM mode may also cause interference.

[0101] Multiple coaxial UCA configurations

[0104] Figure 6 shows an example of a coaxial multicircle UCA OAM configuration that supports multiplexing and modulation of wireless transmissions by controlling OAM modes and coaxial UCA circles, according to several embodiments of the present disclosure. In some examples, the coaxial multicircle UCA OAM configuration shown may implement an embodiment of RAN100 and may be employed by transmitting devices 202 / 300 and receiving devices 206 / 400. In this example, the transmitting device (e.g., UE or base station) may include an OAM transmitter UCA antenna 605, and the receiving device (e.g., UE or base station) may include an OAM receiver UCA antenna 610.

[0102]

[0105] In some embodiments, one or both of the OAM transmitter coaxial multicircular UCA antenna 605 or the OAM receiver coaxial multicircular UCA antenna 610 may be implemented as a planar array of coaxial UCA antenna elements, as described above and shown in Figure 5. In various examples, the OAM transmitter may, but is not necessarily, include the same number of UCA circles as the OAM receiver. That is, transmitting devices 202 / 300 can communicate with receiving devices 206 / 400 using the same and different numbers of UCA circles.

[0103]

[0106] In a further aspect of the present disclosure, a transmitting device may employ, for a given transmission, a subset (e.g., one or more) of its UCA circles from its transmitter UCA antenna 605. For example, a transmitting device may multiplex multiple beams, streams, or waveforms over a given wireless resource by transmitting each such stream using different sets of one or more UCA circles. Theoretically, streams transmitted over different sets of UCA circles may be orthogonal so that a receiving device can receive these streams received over the same wireless resource (e.g., overlapping in the time and frequency domains, using the same code, etc.) and reconstruct them separately.

[0104]

[0107] In a further embodiment, the transmitting device may independently select or control the OAM mode for each of the multiplexed OAM beams. That is, the transmitting device may utilize a first set of one or more UCA circles to transmit a first OAM beam having a first OAM mode, and a second set of one or more UCA circles to transmit a second OAM beam having a second OAM mode. Here, the first OAM mode (i.e., from the first set of one or more UCA circles) may be the same as or different from the second OAM mode (i.e., from the second set of one or more UCA circles). Various options and further details of such a system are provided in the following discussion.

[0105]

[0108] In the following description, for the sake of clarity, we will refer to UCA configurations as shown in Figures 5 and 6. However, it should be noted that this disclosure is not limited to these examples. In addition, according to other aspects of this disclosure, reference signal multiplexing using multiple OAM modes may be implemented using any configuration that enables the application of OAM multiplexing of electromagnetic signals (e.g., RF signals, optical signals, etc.), including, but not limited to, the UCA antenna described as an example. Signals transmitted (e.g., multiplexed) using multiple OAM modes may be transmitted and / or received using any suitable transmitting and / or receiving configurations that include, or may be configured using, any suitably configured phase plates, spatial modulators, integrated circuits, any other suitable components, and / or any suitable combination thereof, for transmission over any suitable medium, including wireless air interfaces, optical fibers, etc.

[0106]

[0109] Generally, since different OAM modes are orthogonal when the transmitting and receiving antennas are aligned, precoding for different OAM modes in a multi-circle OAM communication system can be performed individually. An OAM receiver can measure a reference signal for each circle for each mode and determine the inter-circle precoding weights for each mode. The OAM receiver can then report the results of the measurements to the OAM transmitter. For example, based on the measured values ​​of the reference signal, the OAM receiver may report the amplitude and phase of each element of the precoding vector to the OAM transmitter. In such an example, as the number of modes and / or circles increases, the cost associated with reporting (e.g., in reducing the communication transmission capacity caused by signaling overhead) increases and can become prohibitively high. As another example, an OAM receiver may report codewords from an existing codebook associated with MIMO communication (e.g., a precoding matrix indicator (PMI)). In such an example, the codebook may be defined based on antennas in a uniform linear array (ULA) and / or a uniform planar array (UPA). As explained above, while a UCA includes multiple antennas, precoding in a multi-circle UCA communication system may be performed between UCA circles rather than between different antenna elements of each UCA (e.g., antenna element 515 in Figure 5), and the antenna elements of the UCA are not arranged in a linear or planar array. Therefore, the intercircle channel matrix of the UCA does not match the DFT of the codebook defined for ULA or UPA. This can lead to reduced beamforming gain and / or throughput compared to precoding that takes advantage of the characteristics of OAM communication systems composed of multi-circle UCAs.

[0107]

[0110] In a coaxial multi-circle OAM communication system, when the UCA circles of the transmitting and receiving devices are aligned, the channel gain of the nth OAM mode

[0108]

number

[0109] is proportional to

[0110]

Number

[0111] wherein i is In the formula, i is

[0112]

Number

[0113] and λ is the wavelength of the central frequency used to transmit the OAM mode, J n is the nth-order Bessel function, r tx is the radius of the transmitting UCA circle, r rx is the receiving UCA circle, z is the distance between the antennas, and j is

[0114]

Number

[0115] is.

[0116] Mathematical formula-based inter-circle precoding weight determination

[0111] Figure 7 is a call flow diagram showing an exemplary process of mathematical formula-based inter-circle precoding weight determination for an orbital angular momentum (OAM) communication system according to some aspects of the present disclosure. As will be described below, some or all of the features shown may be omitted in certain implementations within the scope of the present disclosure, and some of the features shown may not be required for the implementation of all embodiments. In some examples, the process shown in Figure 7 may be executed by the transmitting device 300 shown in Figure 3 or the receiving device 400 shown in Figure 4. In some examples, the process of Figure 7 may be executed by any suitable device or means that executes the functions or algorithms described below.

[0117]

[0112] In block 702, a transmitting device (e.g., transmitting device 300) may transmit a signal 704 (e.g., a waveform) which includes reference signal configuration information indicating which OAM mode is associated with each reference signal.

[0118]

[0113] Furthermore, in some embodiments, the reference signal configuration information may include information indicating which transmitting antenna should be used to transmit each reference signal (for example, corresponding to a particular UCA circle). In some embodiments, the transmission of information indicating which transmitting antenna should be used to transmit each reference signal may be omitted (for example, if all UCA circles are configured to transmit a reference signal for each OAM mode to be used).

[0119]

[0114] In some embodiments, the transmitting device 300 may transmit information over any preferred channel (e.g., any preferred physical layer channel such as PDCCH, PUCCH, or PSCCH) via any preferred communication network (e.g., via a RAN such as RAN200 and / or via a D2D connection using one or more DL slots, one or more UL slots, one or more SL slots, etc.). In some embodiments, the transmitting device 300 may transmit information using any preferred communication interface, such as a transceiver (e.g., transceiver 310) and an antenna (e.g., antenna 311). For example, in some embodiments, the transmitting device 300 may transmit the signal 704 using a particular OAM mode and / or a plurality of OAM modes. As another example, the transmitting device 300 may transmit the signal 704 using any other preferred communication technique (one or more).

[0120]

[0115] In some embodiments, the transmitting device 300 may transmit reference signal configuration information using any preferred signaling technique or combination of techniques. For example, the transmitting device 300 may transmit reference signal configuration information using radio resource control (RRC) signaling. As another example, the transmitting device 300 may transmit reference signal configuration information using MAC control element (MAC CE) signaling. As yet another example, the transmitting device 300 may transmit reference signal configuration information using physical layer signaling (sometimes called L1 signaling), such as via downlink control information (DCI), uplink control information (UCI), or sidelink control information (SCI). As an addition or alternative, the transmitting device 300 may transmit reference signal configuration information using a combination of signaling techniques, such as one or more of RRC, MAC CE, DCI, UCI, SCI, and / or any other preferred signaling.

[0121]

[0116] In some embodiments, the reference signal configuration information may include information about channel status information reference signals (CSI-RSs) that the transmitting device 300 is scheduled to transmit. Reference signal configuration information that includes information about CSI-RSs is sometimes called CSI-RS configuration information.

[0122]

[0117] In some embodiments, the reference signal configuration information may identify which subset of antenna elements the transmitting device 300 is scheduled to use to transmit each reference signal (e.g., each CSI-RS). For example, the reference signal configuration information may specify that a first UCA circle is scheduled to transmit a first reference signal(s), and a second UCA circle is scheduled to transmit a second reference signal(s).

[0123]

[0118] In some embodiments, the reference signal configuration information may use any preferred technique or combination of techniques to identify which subset of antenna elements (e.g., corresponding to UCA circles) is associated with each reference signal. For example, the reference signal configuration information may include CSI-RS resource information, where each UCA circle may be associated with a specific resource used to transmit the reference signal (e.g., a CSI-RS resource as described in 3GPP Technical Specification 38.214) (e.g., a first UCA circle of a transmitting device may be associated with a first CSI-RS resource, a second UCA circle of a transmitting device may be associated with a second CSI-RS resource, etc.). In such an example, reference signals associated with different OAM modes may be associated with specific ports of the resource (e.g., a first OAM mode may be associated with a first port of the CSI-RS resource associated with a first UCA antenna, a second OAM mode may be associated with a second port of the CSI-RS resource associated with a first UCA antenna, etc.).

[0124]

[0119] As another example, the reference signal configuration information may include CSI-RS resource information, and each UCA circle may be associated with a specific set of resources used to transmit the reference signal (e.g., a CSI-RS resource set as described in 3GPP Technical Specification 38.331) (e.g., the first UCA circle of the transmitting device may be associated with the first CSI-RS resource set, the second UCA circle of the transmitting device may be associated with the second CSI-RS resource set, etc.). In such an example, the reference signal associated with different OAM modes may be associated with specific resources of the resource set (e.g., the first OAM mode may be associated with the first resource of the CSI-RS resource set associated with the first UCA antenna, the second OAM mode may be associated with the second resource of the CSI-RS resource set associated with the first UCA antenna, etc.).

[0125]

[0120] In some embodiments, the reference signal configuration information may include a property associated with each resource (e.g., each port of each CSI-RS resource, each resource of each CSI-RS resource set, etc.) that indicates which OAM mode should be used to transmit each reference signal (e.g., each CSI-RS). In some embodiments, the property may be an OAM mode index. For example, an OAM mode index may be represented using one or more bits (e.g., bytes) in the reference signal configuration information. In such an example, a positive or negative OAM mode may be represented using a bit (e.g., a first bit) to represent positive or negative, or using a complement code (e.g., two's complement).

[0126]

[0121] In some embodiments, the reference signal configuration information may include a property indicating the maximum number of simultaneous modes that each UCA circle of the transmitting device (e.g., a CSI-RS resource, a CSI-RS resource set, one or more ports associated with a CSI-RS resource, one or more resources associated with a CSI-RS resource set, etc.) may transmit. For example, the reference signal configuration information may include an indication that a first UCA antenna (e.g., associated with CSI-RS resource 1, associated with CSI-RS resource set 1, etc.) is configured to transmit up to a certain number of OAM modes (e.g., one mode, two modes, three modes, etc.) simultaneously, and an indication that a second UCA antenna (e.g., associated with CSI-RS resource 2, associated with CSI-RS resource set 2, etc.) is configured to transmit up to a certain number of OAM modes (e.g., one mode, two modes, three modes, etc.) simultaneously. In some embodiments, a property indicating the maximum number of simultaneous modes that each UCA circle of a transmitting device can transmit may be included in the reference signal configuration information using any preferred number of bits associated with one or more of the UCA circles. As described above with respect to Figure 3, the maximum number of OAM modes that a transmitting device 300 is configured to transmit (and / or receive) simultaneously using a particular UCA may be determined by the number of TXRUs associated with the UCA. For example, if the transmitting unit 300 includes two TXRUs associated with a first UCA, the UCA may be capable of transmitting two or fewer OAM modes simultaneously. In some embodiments, if the maximum number of simultaneous modes that a particular UCA circle of a transmitting device is configured to transmit is greater than or equal to the number of OAM modes that the transmitting device is configured to use, the information relating to the maximum number may be omitted from the reference signal configuration information.

[0127]

[0122] In block 706, a receiving device (e.g., receiving device 400) may receive the signal 704. For example, in some embodiments, the receiving device 400 may receive information over any suitable channel (e.g., any suitable physical layer channel such as PDCCH, PUCCH, or PSCCH) via any suitable communication network (e.g., via a RAN such as RAN200 and / or via a D2D connection using one or more DL slots, one or more UL slots, one or more SL slots, etc.). In some embodiments, the receiving device may receive the signal 704 using any suitable communication interface, such as a transceiver (e.g., transceiver 410) and an antenna (e.g., antenna 411). In some embodiments, the receiving device may receive the signal 704 by sampling and buffering the received wireless signal over a suitable channel and applying suitable processing to the buffered signal, such as energy sensing, demodulation (e.g., based on a channel matrix, using demodulation functions associated with the OAM mode used to transmit and receive the signal 704), decoding.

[0128]

[0123] In some embodiments, the receiving device 400 can store in memory the information received in block 706 and / or information derived from the present invention received in block 706. For example, the receiving device 400 may store information indicating which OAM mode should be used to transmit a reference signal (e.g., CSI-RS). In a more specific example, the receiving device 400 may store a list indicating which OAM mode should be used to transmit a reference signal (e.g., as described above with respect to block 702). In yet another more specific example, the receiving device 400 may store a table indicating which OAM mode should be used to transmit a reference signal (e.g., as described above with respect to block 702). In yet another more specific example, the receiving device 400 may store a value(s) indicating which OAM mode should be used to transmit a reference signal.

[0129]

[0124] As another example, the receiving device 400 may store information indicating which subset of antenna elements (e.g., which UCA circles) is associated with each reference signal. As yet another example, the receiving device 400 may store information indicating how many OAM modes each subset of antenna elements can transmit simultaneously.

[0130]

[0125] In block 708, a receiving device (e.g., receiving device 400) may determine one or more antenna elements to be used to receive a reference signal to be transmitted by the transmitting device. For example, the receiving device 400 may determine which subset of antenna elements (e.g., UCA circles) should be used to receive the CSI-RS associated with each OAM mode. In such an example, the selection may be based on a variety of considerations, such as the size of each subset of antenna elements used to receive the reference signal (e.g., the radius of each UCA circle), the number of OAM modes that a particular subset of antenna elements is configured to receive simultaneously (e.g., based on the number of TXRUs associated with the subset of antenna elements), and the total number of OAM modes to be received.

[0131]

[0126] In a more specific example, the receiving device 400 may determine that a first UCA circle should be used to receive one or more reference signals transmitted using a first OAM mode (e.g., OAM mode 1), a second UCA circle should be used to receive one or more reference signals transmitted using a first OAM mode (e.g., OAM mode 1) and a second OAM mode (e.g., OAM mode 2), and a third UCA circle should be used to receive one or more reference signals transmitted using a second OAM mode (e.g., OAM mode 2). In such an example, the first and third UCA circles may be limited to receiving one OAM mode simultaneously (e.g., if only one TXRU is associated with each UCA circle), while the second UCA circle may be configured to receive multiple OAM modes simultaneously (e.g., if two or more TXRUs are associated with the second UCA circle).

[0132]

[0127] In some embodiments, the receiving device 400 may attempt to select a receiving antenna element to be used to receive the reference signal in order to ensure that all reference signals to be transmitted by the transmitting device are associated with at least one receiving antenna (e.g., at least one UCA circle of the receiving device).

[0133]

[0128] In block 710, a transmitting device (e.g., transmitting device 300) can transmit a plurality of signals 712, each containing one or more reference signals (e.g., as multiple waveforms and / or multiplexed signals on a single waveform). In some embodiments, each reference signal transmitted in block 710 may be transmitted using a specific OAM mode and may be transmitted using a specific UCA circle.

[0134]

[0129] In some embodiments, the transmitting device 300 may transmit a signal over any suitable channel (e.g., any suitable physical layer channel such as PDCCH, PUCCH, or PSCCH) via any suitable communication network (e.g., via a RAN such as RAN200 and / or via a D2D connection using one or more DL slots, one or more UL slots, one or more SL slots, etc.). In some embodiments, the transmitting device 300 may transmit information using any suitable communication interface, such as a transceiver (e.g., transceiver 310) and an antenna (e.g., antenna 311). For example, in some embodiments, the transmitting device 300 may transmit the signal 704 using a particular OAM mode and / or a plurality of OAM modes. As another example, the transmitting device 300 may transmit the signal 704 using any other suitable communication technique (one or more).

[0135]

[0130] In some embodiments, the transmitting device may transmit multiple reference signals in parallel (for example, using the same UCA antenna or different UCA antennas). For example, since different OAM modes are generally orthogonal, the transmitting device may be configured to transmit reference signals associated with different OAM modes simultaneously. In such an example, the transmitting device may use a single UCA circle configured to transmit multiple OAM modes (for example, using multiple TXRUs associated with the UCA circle) in order to transmit reference signals for multiple modes (for example, CSI-RS) simultaneously. Alternatively, the transmitting device may use multiple UCA circles to transmit reference signals for multiple modes (for example, CSI-RS) simultaneously when at least one of the UCA circles is configured to transmit only a single OAM mode simultaneously (for example, the UCA circle is associated with a single TXRU).

[0136]

[0131] In block 714, a receiving device (e.g., receiving device 400) may receive the reference signal transmitted in signal 712 using any suitable UCA antenna (and / or any other suitable antenna). For example, in some embodiments, the receiving device 400 may receive information on any suitable channel (e.g., any suitable physical layer channel such as PDCCH, PUCCH, or PSCCH) via any suitable communication network (e.g., via a RAN such as RAN200 and / or via a D2D connection using one or more DL slots, one or more UL slots, one or more SL slots, etc.). In some embodiments, the receiving device may receive signal 712 using any suitable communication interface, such as a transceiver (e.g., transceiver 410) and an antenna (e.g., antenna 411). In some embodiments, the receiving device can receive the signal 712 by sampling and buffering the received wireless signal on a suitable channel and applying suitable processing to the buffered signal, such as energy detection, demodulation (using, for example, a demodulation function associated with the OAM mode used to transmit and receive the signal 712, and based on the channel matrix), and decoding.

[0137]

[0132] In block 716, a receiving device (e.g., receiving device 400) may estimate the channel gain for a pair of transmitting and receiving antennas (e.g., a pair of UCA circles) based on a received reference signal. In some embodiments, the receiving device 400 may use any preferred technique or combination of techniques to measure the channel between each UCA circle used to transmit a reference signal (e.g., CRI-RS) and each UCA circle used to receive a reference signal for an OAM mode. For example, based on information received in reference signal configuration information, the receiving device may measure the channel and estimate the channel gain, and / or any other preferred properties associated with the channel based on the channel measurement (e.g., channel quality indicator (CQI), rank indicator (RI), etc.). In some embodiments, the receiving device may estimate the channel gain h for a particular reference signal based on the OAM mode used to transmit the reference signal (e.g., based on the OAM mode shown in reference signal configuration information received in 706), based on a symbol x associated with the reference signal and a received signal y. For example, a receiving device may estimate the channel gain h based on the ratio of x and y (for example, using the relation h = y / x).

[0138]

[0133] In some embodiments, the receiving device 400 may determine which pair of transmitting and receiving antennas provides the best channel quality for a particular OAM mode (for example, based on the channel gain associated with the pair). For example, the receiving device 400 may allocate its UCA circle to all used OAM modes based on the number of OAM modes used by the transmitting device. As another example, the receiving device 400 may allocate its UCA circle to a particular OAM mode based on the channel quality (for example, channel gain) between its UCA circle and the UCA circle of the transmitting device for that particular OAM mode. In some embodiments, the receiving device 400 may allocate fewer of its UCA circles to that OAM mode than were used to receive that particular OAM mode in block 714.

[0139]

[0134] In some embodiments, the receiving device 400 may identify, based on a resource associated with a reference signal, which OAM modes should be received by a particular subset of the receiving antenna elements from the transmitting antenna (e.g., the UCA circle of the transmitting device). For example, the receiving device 400 may determine that a first UCA circle (e.g., Rx circle 1) and a second UCA circle (e.g., Rx circle 2) should be used to receive a first OAM mode (e.g., OAM mode 1), and that a second UCA circle (e.g., Rx circle 2) and a third UCA circle (e.g., Rx circle 3) should be used to receive a second OAM mode (e.g., OAM mode 1). In such examples, the determination may be based in part on the fact that the first and third UCA circles (e.g., Rx circle 1 and Rx circle 3) are limited to receiving a single OAM mode, and that the second UCA circle (e.g., Rx circle 2) is capable of receiving at least two OAM modes.

[0140]

[0135] In some embodiments, the receiving device may select a transmitting device resource to be used to transmit each OAM mode based on the number of OAM modes that the allocated receiving antenna and / or transmitting antenna are configured to transmit simultaneously. For example, the receiving device may select a port {port 1 of CSI-RS resource 1, port 1 of CSI-RS resource 2} for OAM mode 1 and a selected {port 2 of CSI-RS resource 2} for OAM mode 2, based on the number of simultaneous OAM modes that the transmitting antenna can transmit (for example, based on information received in reference signal configuration information) and / or based on channel measurements by the receiving device.

[0141]

[0136] In some embodiments, the receiving device 400 (and / or transmitting device 300) can determine the possible transmit / receive pairs matrix for each OAM mode based on the allocated Rx UCA circle and the selected Tx UCA circle. For example, if the receiving device allocates Rx circle 1 and Rx circle 2 to be used to receive OAM mode 1, and assigns Rx circle 2 and Rx circle 3 to be used to receive OAM mode 2, and selects {port 1 of CSI-RS resource 1, port 1 of CSI-RS resource 2} for OAM mode 1, and selects {port 2 of CSI-RS resource 2} for OAM mode 2, then OAM mode 1 may be associated with a 2x2 channel matrix and OAM mode 2 may be associated with a 2x1 channel matrix.

[0142]

[0137] In block 718, a receiving device (e.g., receiving device 400) may transmit a signal 720 (e.g., a waveform) containing information indicating which UCA circles the receiving device 400 used (and / or expects to use) to receive a reference signal (and / or other communications). For example, for each OAM mode, the receiving device 400 may include information in 714 indicating which UCA circles (one or more) the receiving device 400 used to receive the reference signal. As another example, the receiving device 400 may include information in 716 indicating which UCAs the receiving device 400 has allocated to potentially receive future signals (e.g., reference signals, communications signals, etc.) for each OAM mode. Furthermore, in some embodiments, the receiving device 400 may transmit information indicating the size of the UCA circles used to receive the reference signal and / or allocated to receive future signals.

[0143]

[0138] In some embodiments, the receiving device 400 can transmit information over any suitable channel (e.g., any suitable physical layer channel such as PDCCH, PUCCH, or PSCCH) via any suitable communication network (e.g., via a RAN such as RAN200 and / or via a D2D connection using one or more DL slots, one or more UL slots, one or more SL slots, etc.). In some embodiments, the receiving device 400 can transmit information using any suitable communication interface, such as a transceiver (e.g., transceiver 410) and an antenna (e.g., antenna 411). For example, in some embodiments, the receiving device 400 can transmit the signal 720 using a particular OAM mode and / or a plurality of OAM modes. As another example, the receiving device 400 can transmit the signal 720 using any other suitable communication technique (one or more).

[0144]

[0139] In some embodiments, the information transmitted in block 718 may include information indicating the radius of the UCA circle of the receiving device 400. For example, the receiving device 400 may include information indicating that the radius of the first UCA circle (e.g., Rx circle 1) is r1, and the radius of the second UCA circle (e.g., Rx circle 2) is r2.

[0145]

[0140] In some embodiments, the receiving device 400 may include information indicating the radius of the UCA circle of the receiving device 400 in any suitable format. For example, the receiving device 400 may include an information field a, which may contain identification information and / or circle radius information (for example, as floating-point values). In a more specific example, the receiving device 400 may include a list of radius values ​​(for example, {r rx,1 ,r rx,2 ,...,r rx,n}) may include.

[0146]

[0141] As another example, the receiving device 400 may include information indicating which UCA circle was used (and / or is expected to be used) for which OAM mode, in addition to information indicating the radius of each UCA circle.

[0147]

[0142] In some embodiments, the receiving device 400 may communicate separately communication information indicating the radius of each UCA circle and information indicating which UCA circle was used (and / or is expected to be used) for each OAM mode. For example, the receiving device 400 may communicate the circle radius information with a lower periodicity than the information indicating which UCA circle was used (and / or is expected to be used) for each OAM mode. In such an example, the receiving device 400 may communicate the circle radius information periodically (at regular and / or irregular intervals, e.g., after a predetermined period of time has elapsed, after the connection has been interrupted, etc.) and / or at any other suitable time(s), such as one or more. The receiving device 400 may periodically (e.g., at regular and / or irregular intervals) communicate information indicating which UCA circle(s) were used (and / or are expected to be used) for each OAM mode, such as after receiving a reference signal (e.g., CSI-RS) and / or measuring the channel gain (e.g., accordingly).

[0148]

[0143] In some embodiments, the receiving device 400 may transmit in block 718 information in any suitable format indicating which UCA circle(s) have been used (and / or are expected to be used) for each OAM mode. For example, the transmitting device 400 may transmit information indicating which UCA circle(s) have been used (and / or are expected to be used) for each OAM mode using a bitmap in which each bit corresponds to a UCA circle of the receiving device 400. In such an example, the bitmap may have bits for each UCA circle (e.g., at least 3 bits if there are 3 UCA circles, at least 4 bits if there are 4 UCA circles, etc.), and the bit used to receive OAM mode 1 has a value (e.g., binary 1 or binary 0) indicating that the UCA circle has been used. In a more specific example, if a first UCA circle (e.g., Rx circle 1) and a second UCA circle (e.g., Rx circle 2) are used to receive a first OAM mode (e.g., OAM mode 1), and a second UCA circle (e.g., Rx circle 2) and a third UCA circle (e.g., Rx circle 3) are used to receive a second OAM mode (e.g., OAM mode 2), then the receiving device 400 may transmit a binary string "011" associated with OAM mode 1, indicating that Rx circle 1 and Rx circle 2 were used to receive OAM mode 1, and another binary string "110" associated with OAM mode 2, indicating that Rx circle 2 and Rx circle 3 were used to receive OAM mode 1. Note that in this example, the least significant bit is associated with Rx circle 1. However, this is just an example, and the bit mapping to OAM modes can be configured using any preferred method (for example, the most significant bit may be associated with Rx circle 1).

[0149]

[0144] In some embodiments, the receiving device 400 may transmit information in block 718 indicating which UCA circle(s) of the transmitting device are preferred by the receiving device for each OAM mode. For example, the receiving device 400 may indicate a CSI-RS port index or CSI-RS resource indicator (CRI) associated with a particular OAM mode and / or transmitting device UCA circle. In such an example, the receiving device 400 may transmit information indicating the preferred transmitting device UCA circle(s) (Tx UCA circle) for each OAM mode using a bitmap in which each bit corresponds to a reference signal transmitting resource. The bitmap has bits for each port associated with each Tx UCA circle in the reference signal configuration information (for example, at least 4 bits if there are two Tx UCA circles, each having 2 ports), and the bits are associated with the preferred transmitting resource for OAM mode 1, which has a value (for example, binary 1 or binary 0) indicating the preference for the UCA circle. In a more specific example, a first port associated with a first UCA circle (e.g., port 1 for Tx circle 1) and a first port associated with a second UCA circle (e.g., port 1 for Tx circle 2) may be preferred for a first OAM mode (e.g., OAM mode 1), and a second port associated with a second UCA circle (e.g., port 2 for Tx circle 2) may be preferred for a second OAM mode (e.g., OAM mode 2). The receiving device 400 may communicate this information using a binary string "0101" associated with OAM mode 1, indicating that port 1 of CSI-resource 1 (associated with two least significant bits) and port 1 of CSI-resource 2 (associated with two most significant bits) are preferred by the receiving device for mode 1, and another binary string "1000" associated with OAM mode 2, indicating that port 2 of CSI-resource 2 (associated with two least significant bits) is preferred by the receiving device for mode 2.

[0150]

[0145] In some embodiments, the receiving device 400 may transmit rank indicators (RI) and channel quality information (CQI) for each OAM mode in block 718.

[0151]

[0146] In some embodiments, the receiving device 400 may transmit information in block 718 using any preferred signaling technique and / or protocol. For example, the receiving device 400 may transmit information in block 718 using radio resource control (RRC) signaling. As another example, the receiving device 400 may transmit information in block 718 using media access control (MAC) control element (CE) signaling. As yet another example, the receiving device 400 may transmit information in block 718 using physical layer signaling (sometimes called L1 signaling) via downlink control information (DCI), uplink control information (UCI), or sidelink control information (SCI), etc. In such examples, the receiving device may transmit information in block 718 as a CSI report.

[0152]

[0147] In block 722, the transmitting device (e.g., transmitting device 300) may receive the signal 720 and information indicating which UCA circle the receiving device 400 used (and / or expected to use) to receive the reference signal using any suitable UCA antenna (and / or any other suitable antenna). For example, in some embodiments, the transmitting device 300 may receive the information over any suitable channel (e.g., any suitable physical layer channel such as PDCCH, PUCCH, or PSCCH) via any suitable communication network (e.g., via a RAN such as RAN200 and / or via a D2D connection using one or more DL slots, one or more UL slots, one or more SL slots, etc.). In some embodiments, the receiving device may receive the signal 720 using any suitable communication interface, such as a transceiver (e.g., transceiver 410) and an antenna (e.g., antenna 411). In some embodiments, the receiving device can receive the signal 720 by sampling and buffering the received wireless signal on a suitable channel and applying suitable processing to the buffered signal, such as energy detection, demodulation (using, for example, a demodulation function associated with the OAM mode used to transmit and receive the signal 720, and based on the channel matrix), and decoding.

[0153]

[0148] In block 724, a transmitting device (e.g., transmitting device 300) may determine precoding weights for multiple OAM modes based on information about the UCA circle used to receive a reference signal. As described above with respect to Figure 6 and equation (1), the channel gain between any UCA transmitter / receiver circle pair may be calculated based on the radius of each circle, the distance between the circles, and the wavelength used to transmit the OAM mode.

[0154]

[0149] In some embodiments, the transmitting device 300 may calculate the channel gain for each pair of transmitting device antennas (e.g., Tx UCA circle) and receiving device antennas (e.g., Rx UCA circle) (for example, based on equation (1)).

[0155]

[0150] In some embodiments, the transmitting device 300 may use information received from the receiving device to determine which transmitter / receiver circle pairs should be used to calculate the gain. For example, the transmitting device 300 may use information indicating which receiver UCA circle was used for each OAM (e.g., assigned by the receiving device). In a more specific example, the transmitting device 300 may use a bitmap associated with a first OAM mode to determine which Rx circle was used (and / or expected to be used) to receive the reference signal associated with the first OAM mode, and may use a bitmap associated with a second OAM mode to determine which Rx circle was used (and / or expected to be used) to receive the reference signal associated with the second OAM mode.

[0156]

[0151] As another example, the transmitting device 300 may use information indicating which transmitter UCA circle is preferred by the receiving device for each OAM mode. In a more specific example, the transmitting device 300 may use a bitmap associated with a first OAM mode to determine which Tx circle is preferred by the receiving device for transmitting a communication using the first OAM mode, and may use a bitmap associated with a second OAM mode to determine which Tx circle is preferred by the receiving device for transmitting a communication using the second OAM mode.

[0157]

[0152] In some embodiments, the transmitting device 400 may calculate a channel response matrix based on the channel gain from various pairs of UCA circles of the transmitter and receiver. For example, (for example, based on preference information from the receiving device) Tx circle 1 and Tx circle 2 (with radius r tx,1 ,r tx,2 (known as an OAM transmitter) should be used for the first OAM mode, to receive the reference signal for the first OAM mode, Rx radius r rx,1 ,r rx,2 Assuming that it has been reported that should be used and that the receiver device has reported rank L for OAM mode n (for example, as RI associated with OAM mode n), the channel response matrix may be expressed as follows:

[0158]

number

[0159] During the ceremony, J. n λ is the nth-order Bessel function, λ is the wavelength of the center frequency used to transmit the nth OAM mode, z is the distance between the antennas, and j is

[0160]

number

[0161] In some embodiments, z may be known to the transmitting and / or receiving devices (e.g., it may be given as input during the configuration process), may be measured by the transmitting and / or receiving devices (e.g., using a laser rangefinder, using global positioning data, etc.), and / or may be reported from another device (e.g., from the receiving device to the transmitting device, from the transmitting device to the receiving device, from a different device, etc.).

[0162]

[0153] In some embodiments, the transmitting device 400 provides a channel response matrix H for each OAM mode n. n The H for OAM mode n can be calculated and calculated. n The precoding vector can be determined by determining L dominant singular vectors, where L is the rank associated with OAM mode n. In some embodiments, the transmitting device uses singular value decomposition techniques, such as H n Any suitable technique or combination of techniques can be used to determine the L dominant singular vectors of the channel response matrix H. n H n =UDV H As shown above, the expression can be decomposed into the product of three matrices, where D is a diagonal matrix, U and V are orthogonal or unitary matrices, and the column of V corresponds to the largest singular value in D.

[0163]

[0154] In some embodiments, using a formula to calculate the channel response of the Tx / Rx circle pair may utilize OAM receiver feedback that indicates the Tx / Rx circle selection result and Rx radius based on calculations in the receiving device. This may reduce feedback overhead compared to reporting the amplitude and phase of each element of the precoding vector transmitted. This may also improve accuracy compared to using PMI of the codebook developed for ULA and / or UPA. In some embodiments, calculating the channel response matrix and / or precoding weights for the OAM mode may improve the beamforming gain and / or throughput of the OAM communication.

[0164]

[0155] Figure 8 is a flowchart illustrating an exemplary process by which an OAM transmitting device determines intercircle precoding weights for an OAM communication system, according to some aspects of the present disclosure.

[0165]

[0156] In block 802, a transmitting device (e.g., transmitting device 300) may transmit a reference signal for a first orbital angular momentum (OAM) mode (e.g., a channel status information reference signal (CSI-RS)) using a first subset of antenna elements (e.g., a first equally spaced circular array (UCA) circle). In some embodiments, the transmitting device 300 may transmit the reference signal over any suitable channel (e.g., any suitable physical layer channel such as PDCCH, PUCCH, or PSCCH) via any suitable communication network (e.g., via a RAN such as RAN200 and / or via a D2D connection using one or more DL slots, one or more UL slots, one or more SL slots, etc.). In some embodiments, the transmitting device 300 may transmit the reference signal using any suitable communication interface, such as a transceiver (e.g., transceiver 310) and an antenna (e.g., antenna 311). For example, in some embodiments, the transmitting device 300 may transmit the reference signal using a specific OAM mode and / or a plurality of OAM modes. As another example, the transmitting device 300 may transmit the reference signal using any other suitable communication technique(s) or technique(s).

[0166]

[0157] In block 804, the transmitting device (e.g., transmitting device 300) may transmit another reference signal (e.g., CSI-RS) for the first OAM mode using a second subset of antenna elements (e.g., a second UCA circle). In some embodiments, the transmitting device 300 may transmit the reference signal over any suitable channel (e.g., any suitable physical layer channel such as PDCCH, PUCCH, or PSCCH) via any suitable communication network (e.g., via a RAN such as RAN200 and / or via a D2D connection using one or more DL slots, one or more UL slots, one or more SL slots, etc.). In some embodiments, the transmitting device 300 may transmit the reference signal using any suitable communication interface, such as a transceiver (e.g., transceiver 310) and an antenna (e.g., antenna 311). For example, in some embodiments, the transmitting device 300 may transmit the reference signal using a particular OAM mode and / or multiple OAM modes. As another example, the transmitting device 300 may transmit a reference signal using any other suitable communication technique(s) or technique(s).

[0167]

[0158] In block 806, the transmitting device (for example, transmitting device 300) may receive information (for example, from a receiving device such as receiving device 400) indicating a subset of antenna elements to be used to transmit communications (for example, to receiving device 400) via the first OAM mode.

[0168]

[0159] Figure 9 is a flowchart illustrating an exemplary process in which an OAM receiving device determines information for a transmitting device to determine intercircle precoding weights for an OAM communication system, according to some aspects of the present disclosure.

[0169]

[0160] In block 902, a receiving device (e.g., receiving device 400) may receive instructions for a subset of antenna elements (e.g., configured as a UCA circle) to be used to transmit a first reference signal (e.g., CSI-RS) for a first OAM mode. For example, in some embodiments, the receiving device 400 may receive the instructions-encoded signal over any suitable channel (e.g., any suitable physical layer channel such as PDCCH, PUCCH, or PSCCH) via any suitable communication network (e.g., via a RAN such as RAN200 and / or via a D2D connection using one or more DL slots, one or more UL slots, one or more SL slots, etc.). In some embodiments, the receiving device may receive the instructions-encoded signal using any suitable communication interface, such as a transceiver (e.g., transceiver 410) and an antenna (e.g., antenna 411). In some embodiments, a receiving device may receive a signal encoded by instructions by sampling and buffering the received wireless signal on a suitable channel and applying suitable processing to the buffered signal, such as energy detection, demodulation (using, for example, a demodulation function associated with the OAM mode used to transmit and receive signals, and based on the channel matrix), and decoding.

[0170]

[0161] In block 904, a receiving device (e.g., receiving device 400) may receive instructions that another subset of antenna elements (e.g., configured as a second UCA circle) should be used to transmit a second reference signal (e.g., CSI-RS) for the first OAM mode. For example, in some embodiments, the receiving device 400 may receive the signal encoded in the instructions over any suitable channel (e.g., any suitable physical layer channel such as PDCCH, PUCCH, or PSCCH) via any suitable communication network (e.g., via a RAN such as RAN200 and / or via a D2D connection using one or more DL slots, one or more UL slots, one or more SL slots, etc.). In some embodiments, the receiving device may receive the signal encoded in the instructions using any suitable communication interface, such as a transceiver (e.g., transceiver 410) and an antenna (e.g., antenna 411). In some embodiments, a receiving device may receive a signal encoded by instructions by sampling and buffering the received wireless signal on a suitable channel and applying suitable processing to the buffered signal, such as energy detection, demodulation (using, for example, a demodulation function associated with the OAM mode used to transmit and receive signals, and based on the channel matrix), and decoding.

[0171]

[0162] In some embodiments, the instructions received in block 902 and the instructions received in block 904 may be received together (for example, in a single message).

[0172]

[0163] In block 906, a receiving device (for example, receiving device 400) may transmit information indicating a subset of antenna elements used to receive the first reference signal (for example, a specific UCA circle of the receiving device).

[0173]

[0164] Figure 10 shows the transmission of reference signal configuration information and the transmission of reference signals for multiple OAM modes using a plurality of equally spaced circular array circles, according to some aspects of the present disclosure.

[0174]

[0165] In Figure 10, the transmitting device 300 includes a first UCA circle 1002 and a second UCA circle 1004, and the receiving device includes a first UCA circle 1006 and a second UCA circle 1008. As described above with respect to block 702 in Figure 7, the transmitting device 300 may transmit CSI-RS configuration information which may include CSI-RS resource information 1012 in block 1010.

[0175]

[0166] In some embodiments, the CSI-RS resource information 1012 may include information identifying a CSI-RS resource that may be associated with a particular UCA circle and / or a particular OAM mode. For example, the CSI-RS resource information 1012 may include information identifying a first CSI-RS resource (e.g., CSI-RS resource 1) having two ports associated with a first OAM mode and a second OAM mode, respectively (identified, for example, based on the OAM index value associated with each port). In such an example, the first CSI-RS resource may be associated with UCA circle 1002 and may or may not explicitly identify the antenna associated with the CSI-RS resource. The CSI-RS resource information 1012 may also include information identifying a second CSI-RS resource (e.g., CSI-RS resource 2) having two ports associated with a first OAM mode and a second OAM mode, respectively.

[0176]

[0167] As another example, the CSI-RS resource information 1012 may include information identifying a first CSI-RS resource set (e.g., CSI-RS resource set 1) having two ports associated with a first OAM mode and a second OAM mode, respectively (identified, for example, based on the OAM index value associated with each port). In such an example, the first CSI-RS resource set may be associated with UCA circle 1002 and may or may not explicitly identify the antenna associated with the CSI-RS resource. The CSI-RS resource information 1012 may also include information identifying a second CSI-RS resource (e.g., CSI-RS resource 2) having two ports associated with a first OAM mode and a second OAM mode, respectively. The second CSI-RS resource set may be associated with UCA circle 1004.

[0177]

[0168] In block 1014, the transmitting device 300 may transmit a first CSI-RS using a first OAM mode (e.g., OAM mode 1), and in block 1016, the transmitting device 300 may transmit a second CSI-RS using a second OAM mode (e.g., OAM mode 2). In some embodiments, the transmitting device may transmit the first CSI-RS and the second CSI-RS simultaneously (e.g., using the same transmitting resources but different OAM modes) or sequentially (e.g., using different transmitting resources and different OAM modes).

[0178]

[0169] The receiving device 400 may receive the first CSI-RS and the second CSI-RS using UCA circle 1006 and / or UCA circle 1008.

[0179]

[0170] In block 1018, the transmitting device 300 may transmit a third CSI-RS using a first OAM mode (e.g., OAM mode 1), and in block 1020, the transmitting device 300 may transmit a fourth CSI-RS using a second OAM mode (e.g., OAM mode 2). In some embodiments, the transmitting device may transmit the third CSI-RS and the fourth CSI-RS simultaneously (e.g., using the same transmitting resources but different OAM modes) or sequentially (e.g., using different transmitting resources and different OAM modes). Note that the first CSI-RS and the third CSI-RS may be transmitted simultaneously if the two signals are transmitted using orthogonal resources (e.g., different wavelength resources, using different codes, etc.), but may be prohibited from being transmitted simultaneously if the transmitting resources are the same in some cases (e.g., two signals from different UCA circles having the same OAM mode are not orthogonal).

[0180]

[0171] The receiving device 400 may receive the third CSI-RS and the fourth CSI-RS using UCA circle 1006 and / or UCA circle 1008.

[0181]

[0172] As described above with respect to block 716 of Figure 7, the receiving device 400 may calculate the channel gain for one or more pairs of transmitter and receiver antennas based on the received CSI-RS. As described above with respect to block 718 of Figure 7, the receiving device 400 may report to the transmitting device 300 information that may be used to generate a precoding vector which may be used to transmit information between the transmitting device 300 and the receiving device 400.

[0182] Further examples with various characteristics:

[0173] Implementation examples are described in the following numbered clauses.

[0174] 1. An apparatus configured for wireless communication, comprising a processor, a plurality of antenna elements including a first subset of antenna elements comprising at least a first antenna element and a second antenna element, a second subset of antenna elements comprising at least a third antenna element and a fourth antenna element, and a memory coupled to the processor, wherein the processor is configured to transmit a first reference signal using a first orbital angular momentum (OAM) mode via the first subset of antenna elements, transmit a second reference signal using the first OAM mode via the second subset of antenna elements, and receive information indicating a subset of antenna elements from the plurality of antenna elements to be used to transmit the first OAM mode.

[0175] 2. The apparatus according to Clause 1, wherein the first reference signal includes a first channel status information reference signal (CSI-RS) and the second reference signal includes a second CSI-RS.

[0176] 3. The apparatus according to Clause 1, wherein the execution of an instruction further causes the processor to transmit reference signal configuration information indicating that a first subset of reference signals among a plurality of reference signals is associated with a first OAM mode.

[0177] 4. The apparatus according to Clause 3, wherein the reference signal configuration information indicates that a second subset of reference signals among a plurality of reference signals is associated with a second OAM mode.

[0178] 5. The apparatus according to Clause 3 or 4, wherein the reference signal configuration information indicates that a first subset of antenna elements should be used to transmit a first reference signal, and a second subset of antenna elements should be used to transmit a second reference signal.

[0179] 6. The apparatus according to any one of clauses 3 to 5, wherein the reference signal configuration information includes information indicating that a first subset of antenna elements corresponds to a first CSI-RS resource and information indicating that a second subset of antenna elements corresponds to a second CSI-RS resource.

[0180] 7. The apparatus according to Clause 6, wherein the reference signal configuration information includes information indicating that a first reference signal should be transmitted using a first port of a first CSI-RS resource, and information indicating that a second reference signal should be transmitted using a first port of a second CSI-RS resource.

[0181] 8. The apparatus according to Clause 7, wherein the reference signal configuration information includes information indicating that a third reference signal should be transmitted using a second port of a first CSI-RS resource, and information indicating that a fourth reference signal should be transmitted using a second port of a second CSI-RS resource.

[0182] 9. The apparatus according to any one of clauses 3 to 5, wherein the reference signal configuration information includes information indicating that a first subset of antenna elements corresponds to a first CSI-RS resource set and information indicating that a second subset of antenna elements corresponds to a second CSI-RS resource set.

[0183] 10. The apparatus according to Clause 9, wherein the reference signal configuration information includes information indicating that a first reference signal should be transmitted using a first resource of a first CSI-RS resource set, and information indicating that a second reference signal should be transmitted using a first resource of a second CSI-RS resource set.

[0184] 11. The apparatus according to Clause 10, wherein the reference signal configuration information includes information indicating that a third reference signal should be transmitted using a second resource of a first CSI-RS resource set, and information indicating that a fourth reference signal should be transmitted using a second resource of a second CSI-RS resource set.

[0185] 12. The apparatus described in any one of clauses 3 to 11, wherein the reference signal configuration information includes an OAM mode index parameter associated with the first reference signal, indicating which OAM mode should be used to transmit the first reference signal.

[0186] 13. The apparatus according to any one of clauses 1 to 12, wherein the execution of an instruction further causes the processor to transmit a third reference signal using a third resource and a second OAM mode via a first subset of antenna elements, transmit a fourth reference signal using a fourth resource and a second OAM mode via a second subset of antenna elements, and receive information indicating a subset of antenna elements from a plurality of antenna elements to be used to transmit a second OAM mode.

[0187] 14. The apparatus according to Clause 1, further comprising: a first equally spaced circular array (UCA) having a first subset of antenna elements and having a first radius; and a second UCA having a second subset of antenna elements and having a second radius and being coaxial with the first UCA.

[0188] 15. The apparatus described in any one of Clauses 1 to 14, wherein information indicating a subset of antenna elements to be used to transmit a first OAM mode includes information indicating the radius of a first equally spaced circular array (UCA) used by the receiving device to receive a first reference signal, and information indicating the radius of a second UCA used by the receiving device to receive a second reference signal.

[0189] 16. The apparatus according to Clause 15, wherein the execution of an instruction further causes the processor to receive a message comprising a first value corresponding to the radius of a first UCA used by the receiving device and a second value corresponding to the radius of a second UCA used by the receiving device.

[0190] 17. The apparatus described in Clause 16, wherein the message is received before information indicating a subset of antenna elements among a plurality of antenna elements to be used to transmit the first OAM mode.

[0191] 18. The apparatus described in Clause 16, wherein the message includes information indicating a subset of antenna elements among a plurality of antenna elements to be used to transmit a first OAM mode.

[0192] 19. The apparatus described in any one of clauses 15 to 18, wherein information indicating a subset of antenna elements from a plurality of antenna elements to be used to transmit a first OAM mode includes a string of bits associated with the first OAM mode, where each bit in the string of bits indicates whether a particular UCA of the receiving apparatus has received the first OAM mode.

[0193] 20. The apparatus according to any one of clauses 15 to 19, wherein information indicating a subset of antenna elements from a plurality of antenna elements to be used to transmit a first OAM mode includes a bitmap associated with the first OAM mode, where a first string of bits in the bitmap indicates whether a first subset of antenna elements should be used to transmit the first OAM mode, and a second string of bits in the bitmap indicates whether a second subset of antenna elements should be used to transmit the first OAM mode.

[0194] 21. The apparatus described in any one of the clauses 15 to 20, wherein the execution of an instruction further causes the processor to receive from the receiving device at least one of the rank indicator associated with the first OAM mode or channel quality information associated with the first OAM mode.

[0195] 22. The apparatus described in any one of Clauses 1 to 21, wherein the execution of an instruction further causes the processor to receive information indicating a subset of antenna elements among a plurality of antenna elements to be used to transmit a first OAM mode, via one or more physical layer signalings using at least one of radio resource control (RRC) signaling, media access control (MAC) control element (CE) signaling, or downlink control information (DCI), uplink control information (UCI), or sidelink control information (SCI).

[0196] 23. The apparatus according to any one of Clauses 1 to 22, further comprising: a first equally spaced circular array (UCA) comprising a first subset of antenna elements, the first UCA having a first radius; and a second UCA comprising a second subset of antenna elements, the second UCA having a second radius and being coaxial with the first UCA, wherein the execution of an instruction further causes a processor to determine a first channel response to a first OAM mode based on a first radius, a third radius of a third UCA used by a receiving device to receive a first reference signal, the distance between the first UCA and the third UCA, and the wavelength of a waveform used to transmit the first reference signal; and a second channel response to a first OAM mode based on a second radius, a third radius of a third UCA used by a receiving device to receive a first reference signal, the distance between the first UCA and the third UCA, and the wavelength of a waveform used to transmit the first reference signal.

[0197] 24. Instruction execution is further related to the processor.

[0183]

number

[0184] Based on this, the first channel response is determined, and in the formula, J n However, this is the Bessel function corresponding to the OAM mode n, and r tx,1 However, this is the first radius of the first UCA, and r rx,1 λ is the third radius of the third UCA, λ is the wavelength of the waveform used to transmit the first reference signal, and j is

[0185]

number

[0186] The apparatus according to Clause 23, wherein z is the distance between the first UCA and the third UCA.

[0198] 25. The apparatus according to clause 23 or 24, wherein the execution of an instruction further causes the processor to generate a channel response matrix using at least a first channel response, a second channel response, and a rank indicator (RI)L associated with a first OAM mode.

[0199] 26. The apparatus according to Clause 25, wherein instruction execution further causes the processor to determine a precoding weight vector for a first OAM mode based on L dominant singular vectors of the channel response matrix.

[0200] 27. The apparatus according to Clause 26, wherein the execution of instructions further causes the processor to determine a precoding weight vector for a first OAM mode based on the singular value decomposition of the channel response matrix.

[0201] 28. The apparatus described in any one of Clauses 1 to 27, wherein the execution of an instruction further causes the processor to transmit information indicating the maximum number of OAM modes that the apparatus is configured to transmit simultaneously using a first subset of antenna elements.

[0202] 29. An apparatus configured for wireless communication, comprising a processor, a plurality of antenna elements including a first subset of antenna elements comprising at least a first antenna element and a second antenna element, a second subset of antenna elements comprising at least a third antenna element and a fourth antenna element, and a memory coupled to the processor, wherein the memory stores instructions, and when an instruction is executed by the processor, the processor is caused to receive an instruction from a transmitter comprising a third subset of antenna elements and a fourth subset of antenna elements stating that a third subset of antenna elements should be used to transmit a first reference signal for a first orbital angular momentum (OAM) mode, an instruction from the transmitter stating that a fourth subset of antenna elements should be used to transmit a second reference signal for a first OAM mode, and information indicating a subset of antenna elements among the plurality of antenna elements used to receive the first reference signal.

[0203] 30. The apparatus described in Clause 29, wherein the first reference signal includes a first channel status information reference signal (CSI-RS) and the second reference signal includes a second CSI-RS.

[0204] 31. The apparatus according to Clause 29 or 30, wherein the execution of an instruction further causes the processor to receive a first reference signal via a first subset of antenna elements and a second reference signal via a second subset of a plurality of antenna elements.

[0205] 32. The apparatus according to any one of Clauses 29 to 31, wherein the execution of an instruction further causes the processor to receive reference signal configuration information from a transmitter, the reference signal configuration information including an instruction that a first subset of reference signals among a plurality of reference signals is associated with a first OAM mode, and the first subset of reference signals includes a first reference signal and a second reference signal.

[0206] 33. The apparatus according to Clause 32, wherein the execution of an instruction further causes the processor to determine, based on reference signal configuration information and the maximum number of OAM modes that the apparatus is configured to receive simultaneously using a first subset of antenna elements, that a first subset of antenna elements and a second subset of antenna elements should be used to receive a first reference signal, and that a first subset of antenna elements and a second subset of antenna elements should be used to receive a second reference signal.

[0207] 34. The apparatus according to clause 32 or 33, wherein the execution of an instruction further causes the processor to determine, based on reference signal configuration information, that a first reference signal should be transmitted using a first equally spaced circular array (UCA) comprising a third subset of antenna elements; to receive the first reference signal via the first subset of antenna elements; to measure a channel based on the first reference signal; and to determine the channel gain between the first UCA and the first subset of antenna elements.

[0208] 35. The apparatus according to any one of clauses 32 to 34, wherein the execution of an instruction further causes the processor to determine, based on reference signal configuration information, that a first reference signal should be transmitted using a first UCA comprising a third subset of antenna elements; to receive the first reference signal via a second subset of antenna elements; to measure a channel based on the first reference signal; and to determine the channel gain between the first UCA and the second subset of antenna elements based on the channel measurement.

[0209] 36. The apparatus described in any one of clauses 32 to 35, wherein the execution of an instruction further causes the processor to receive information indicating the maximum number of OAM modes that the transmitter is configured to transmit simultaneously using a first equally spaced circular array (UCA).

[0210] 37. The apparatus according to Clause 36, wherein the execution of an instruction further causes the processor to determine a first channel gain between a first UCA and a first subset of antenna elements, to determine a second channel gain between a first UCA and a second subset of antenna elements, and to select a UCA to be used for transmission using a first OAM mode based on the first channel gain, the second channel gain, and the maximum number of OAM modes that the transmitter is configured to transmit simultaneously using the first UCA.

[0211] 38. The device described in Clause 37, wherein the execution of the instruction further causes the processor to transmit information indicating the selected UCA to the transmitting device.

[0212] 39. The apparatus described in any one of clauses 32 to 38, wherein the reference signal configuration information includes an indication that a second subset of reference signals among a plurality of reference signals is associated with a second OAM mode.

[0213] 40. The apparatus described in any one of clauses 32 to 39, wherein the reference signal configuration information includes an instruction that a third subset of antenna elements should be used to transmit a first reference signal for a first OAM mode, and an instruction that a fourth subset of antenna elements should be used to transmit a second reference signal for a first OAM mode.

[0214] 41. The apparatus described in any one of clauses 32 to 40, wherein the reference signal configuration information includes information indicating that a third subset of antenna elements corresponds to a first CSI-RS resource and information indicating that a fourth subset of antenna elements corresponds to a second CSI-RS resource.

[0215] 42. The apparatus according to Clause 41, wherein the reference signal configuration information includes information indicating that a first reference signal should be transmitted using a first port of a first CSI-RS resource, and information indicating that a second reference signal should be transmitted using a first port of a second CSI-RS resource.

[0216] 43. The apparatus described in Clause 42, wherein the reference signal configuration information includes information indicating that a third reference signal should be transmitted using a second port of a first CSI-RS resource, and information indicating that a fourth reference signal should be transmitted using a second port of a second CSI-RS resource.

[0217] 44. The apparatus described in any one of Clauses 32 to 41, wherein the reference signal configuration information includes information indicating that a first subset of antenna elements corresponds to a first CSI-RS resource set and information indicating that a second subset of antenna elements corresponds to a second CSI-RS resource set.

[0218] 45. The apparatus according to Clause 44, wherein the reference signal configuration information includes information indicating that a first reference signal should be transmitted using a first resource of a first CSI-RS resource set, and information indicating that a second reference signal should be transmitted using a first resource of a second CSI-RS resource set.

[0219] 46. ​​The apparatus according to Clause 45, wherein the reference signal configuration information includes information indicating that a third reference signal should be transmitted using a second resource of a first CSI-RS resource set, and information indicating that a fourth reference signal should be transmitted using a second resource of a second CSI-RS resource set.

[0220] 47. The apparatus described in any one of the clauses 32 to 46, wherein the reference signal configuration information includes an OAM mode index parameter associated with the first reference signal, indicating which OAM mode should be used to transmit the first reference signal.

[0221] 48. The apparatus described in any one of clauses 29 to 47, wherein the execution of an instruction further causes the processor to receive a third reference signal using a second OAM mode via a first subset of antenna elements, receive a fourth reference signal using a second OAM mode via a second subset of antenna elements, and transmit information indicating a subset of antenna elements from a plurality of antenna elements used to receive the third reference signal and a subset of antenna elements from a plurality of antenna elements used to receive the fourth reference signal.

[0222] 49. The apparatus according to any one of the clauses 29 to 48, further comprising: a first receiver UCA having a first subset of antenna elements, wherein the first receiver UCA has a first radius; and a second receiver UCA having a second subset of antenna elements, wherein the second receiver UCA has a second radius and is coaxial with the first UCA.

[0223] 50. The apparatus described in any one of clauses 29 to 49, wherein the execution of an instruction further causes the processor to transmit information indicating a subset of antenna elements among a plurality of antenna elements to be used to transmit a first OAM mode.

[0224] 51. The apparatus according to Clause 50, wherein information indicating a subset of antenna elements among a plurality of antenna elements to be used to transmit a first OAM mode includes information indicating the radius of a first equally spaced circular array (UCA) used by the apparatus to receive a first reference signal and information indicating the radius of a second UCA used by the apparatus to receive a second reference signal.

[0225] 52. The apparatus according to Clause 51, wherein the execution of an instruction further causes the processor to send a message comprising a first value corresponding to the radius of a first UCA and a second value corresponding to the radius of a second UCA.

[0226] 53. The apparatus described in Clause 52, wherein a message is transmitted before information indicating a subset of antenna elements among a plurality of antenna elements to be used to transmit the first OAM mode.

[0227] 54. The apparatus described in Clause 52, wherein the message includes information indicating a subset of antenna elements among a plurality of antenna elements to be used to transmit a first OAM mode.

[0228] 55. The apparatus described in any one of the clauses 51 to 54, wherein information indicating a subset of antenna elements to be used to transmit a first OAM mode includes a string of bits associated with the first OAM mode, where each bit in the string of bits indicates whether a particular UCA of the apparatus has received the first OAM mode.

[0229] 56. The apparatus according to any one of clauses 51 to 55, wherein information indicating a subset of antenna elements from a plurality of antenna elements to be used to transmit a first OAM mode includes a bitmap associated with the first OAM mode, where a first string of bits in the bitmap indicates whether a first subset of antenna elements should be used to transmit the first OAM mode, and a second string of bits in the bitmap indicates whether a second subset of antenna elements should be used to transmit the first OAM mode.

[0230] 57. The apparatus described in any one of the clauses 51 to 56, wherein the execution of an instruction further causes the processor to transmit to the transmitter at least one of the rank indicator associated with the first OAM mode or channel quality information associated with the first OAM mode.

[0231] 58. The apparatus described in any one of the clauses 51 to 57, wherein the execution of an instruction further causes the processor to transmit information indicating a subset of antenna elements among a plurality of antenna elements to be used to transmit a first OAM mode, via one or more physical layer signalings using at least one of radio resource control (RRC) signaling, media access control (MAC) control element (CE) signaling, or downlink control information (DCI), uplink control information (UCI), or sidelink control information (SCI).

[0232] 59. The apparatus described in any one of Clauses 29 to 58, wherein the execution of an instruction further causes the processor to transmit information indicating a subset of antenna elements among a plurality of antenna elements used to receive a first reference signal, via one or more physical layer signalings using at least one of radio resource control (RRC) signaling, media access control (MAC) control element (CE) signaling, or downlink control information (DCI), uplink control information (UCI), or sidelink control information (SCI).

[0233] 60. A wireless communication method comprising: transmitting a first reference signal using a first orbital angular momentum (OAM) mode via a first subset of antenna elements from a plurality of antenna elements; transmitting a second reference signal using the first OAM mode via a second subset of antenna elements from a plurality of antenna elements; and receiving information indicating a subset of antenna elements from a plurality of antenna elements to be used to transmit the first OAM mode.

[0234] 61. The method according to Clause 60, wherein the first reference signal includes a first channel status information reference signal (CSI-RS) and the second reference signal includes a second CSI-RS.

[0235] 62. The method according to clause 60, further comprising transmitting reference signal configuration information indicating that a first subset of reference signals among a plurality of reference signals is associated with a first OAM mode.

[0236] 63. The method according to Clause 62, wherein the reference signal configuration information indicates that a second subset of reference signals among multiple reference signals is associated with a second OAM mode.

[0237] 64. The method according to clause 62 or 63, wherein reference signal configuration information indicates that a first subset of antenna elements should be used to transmit a first reference signal, and a second subset of antenna elements should be used to transmit a second reference signal.

[0238] 65. The method according to any one of the clauses 62 to 64, wherein the reference signal configuration information includes information indicating that a first subset of antenna elements corresponds to a first CSI-RS resource and information indicating that a second subset of antenna elements corresponds to a second CSI-RS resource.

[0239] 66. The method according to Clause 65, wherein the reference signal configuration information includes information indicating that a first reference signal should be transmitted using a first port of a first CSI-RS resource, and information indicating that a second reference signal should be transmitted using a first port of a second CSI-RS resource.

[0240] 67. The method according to Clause 66, wherein the reference signal configuration information includes information indicating that a third reference signal should be transmitted using a second port of a first CSI-RS resource, and information indicating that a fourth reference signal should be transmitted using a second port of a second CSI-RS resource.

[0241] 68. The method according to any one of the clauses 62 to 64, wherein the reference signal configuration information includes information indicating that a first subset of antenna elements corresponds to a first CSI-RS resource set and information indicating that a second subset of antenna elements corresponds to a second CSI-RS resource set.

[0242] 69. The method according to Clause 68, wherein the reference signal configuration information includes information indicating that a first reference signal should be transmitted using a first resource of a first CSI-RS resource set, and information indicating that a second reference signal should be transmitted using a first resource of a second CSI-RS resource set.

[0243] 70. The method according to Clause 69, wherein the reference signal configuration information includes information indicating that a third reference signal should be transmitted using a second resource of a first CSI-RS resource set, and information indicating that a fourth reference signal should be transmitted using a second resource of a second CSI-RS resource set.

[0244] 71. The method according to any one of the clauses 62 to 70, wherein the reference signal configuration information includes an OAM mode index parameter associated with the first reference signal that indicates which OAM mode should be used to transmit the first reference signal.

[0245] 72. The method according to any one of the clauses 60 to 71, further comprising transmitting a third reference signal using a third resource and a second OAM mode via a first subset of antenna elements, transmitting a fourth reference signal using a fourth resource and a second OAM mode via a second subset of antenna elements, and receiving information indicating a subset of antenna elements from a plurality of antenna elements to be used to transmit the second OAM mode.

[0246] 73. The method according to Clause 60, wherein a first subset of antenna elements is contained within a first equally spaced circular array (UCA) having a first radius, and a second subset of antenna elements is contained within a second UCA having a second radius and being coaxial with the first UCA.

[0247] 74. The method according to any one of the clauses 60 to 73, wherein information indicating a subset of antenna elements to be used to transmit a first OAM mode includes information indicating the radius of a first equally spaced circular array (UCA) used by a receiving device to receive a first reference signal, and information indicating the radius of a second UCA used by a receiving device to receive a second reference signal.

[0248] 75. The method according to clause 74, further comprising receiving a message including a first value corresponding to the radius of a first UCA used by the receiving device and a second value corresponding to the radius of a second UCA used by the receiving device.

[0249] 76. The method of Clause 75, wherein a message is received before information indicating a subset of antenna elements among a plurality of antenna elements to be used to transmit a first OAM mode.

[0250] 77. The method according to Clause 75, wherein the message includes information indicating a subset of antenna elements among a plurality of antenna elements to be used to transmit a first OAM mode.

[0251] 78. The method according to any one of the clauses 15 to 18, wherein information indicating a subset of antenna elements from a plurality of antenna elements to be used to transmit a first OAM mode includes a string of bits associated with the first OAM mode, where each bit in the string of bits indicates whether a particular UCA of a receiving device has received the first OAM mode.

[0252] 79. The method according to any one of the clauses 74 to 78, wherein information indicating a subset of antenna elements from a plurality of antenna elements to be used to transmit a first OAM mode includes a bitmap associated with the first OAM mode, where a first string of bits in the bitmap indicates whether a first subset of antenna elements should be used to transmit the first OAM mode, and a second string of bits in the bitmap indicates whether a second subset of antenna elements should be used to transmit the first OAM mode.

[0253] 80. The method according to any one of the clauses 74 to 79, further comprising receiving from a receiving device at least one of the following: a rank indicator associated with a first OAM mode, or channel quality information associated with a first OAM mode.

[0254] 81. The method according to any one of the clauses 1 to 21, further comprising receiving information indicating a subset of antenna elements of a plurality of antenna elements to be used to transmit a first OAM mode via one or more physical layer signalings using at least one of radio resource control (RRC) signaling, media access control (MAC) control element (CE) signaling, or downlink control information (DCI), uplink control information (UCI), or sidelink control information (SCI).

[0255] 82. The method according to any one of the clauses 60 to 81, wherein a first subset of antenna elements is contained in a first equally spaced circular array (UCA) having a first radius, and a second subset of antenna elements is contained in a second UCA having a second radius and being coaxial with the first UCA, and the method further comprises determining a first channel response to a first OAM mode based on the first radius, a third radius of a third UCA used by a receiving device to receive a first reference signal, the distance between the first UCA and the third UCA, and the wavelength of a waveform used to transmit the first reference signal; and determining a second channel response to a first OAM mode based on the second radius, a third radius of a third UCA used by a receiving device to receive a first reference signal, the distance between the first UCA and the third UCA, and the wavelength of a waveform used to transmit the first reference signal.

[0256] 83. Relationships

[0187]

number

[0188] The method further includes determining the first channel response based on the formula, where Jn However, this is the Bessel function corresponding to the OAM mode n, and r tx,1 However, this is the first radius of the first UCA, and r rx,1 λ is the third radius of the third UCA, λ is the wavelength of the waveform used to transmit the first reference signal, and j is

[0189]

number

[0190] The method according to Clause 82, wherein z is the distance between the first UCA and the third UCA.

[0257] 84. The method according to clause 82 or 83, further comprising generating a channel response matrix using at least a first channel response, a second channel response, and a rank indicator (RI)L associated with a first OAM mode.

[0258] 85. The method according to clause 84, further comprising determining a precoding weight vector for a first OAM mode based on L dominant singular vectors of the channel response matrix.

[0259] 86. The method according to clause 85, further comprising determining a precoding weight vector for a first OAM mode based on a singular value decomposition of the channel response matrix.

[0260] 87. The method according to any one of the clauses 60 to 86, further comprising transmitting information indicating the maximum number of OAM modes that the device is configured to transmit simultaneously using a first subset of antenna elements.

[0261] 88. A wireless communication method comprising: receiving, in a receiving device including a plurality of antenna elements including a first subset of antenna elements and a second subset of antenna elements, an instruction that a third subset of antenna elements should be used to transmit a first reference signal for a first orbital angular momentum (OAM) mode from a transmitting device including a third subset of antenna elements and a fourth subset of antenna elements; receiving, in a receiving device including a plurality of antenna elements including a first subset of antenna elements and a second subset of antenna elements, an instruction that a fourth subset of antenna elements should be used to transmit a second reference signal for a first OAM mode; and transmitting information indicating a subset of antenna elements among the plurality of antenna elements used to receive the first reference signal.

[0262] 89. The method according to Clause 88, wherein the first reference signal includes a first channel status information reference signal (CSI-RS) and the second reference signal includes a second CSI-RS.

[0263] 90. The method according to clause 88 or 89, further comprising receiving a first reference signal through a first subset of antenna elements among a plurality of antenna elements, and receiving a second reference signal through a second subset of the plurality of antenna elements.

[0264] 91. The method according to any one of the clauses 88 to 90, further comprising receiving reference signal configuration information from a transmitter, wherein the reference signal configuration information includes an instruction that a first subset of reference signals among a plurality of reference signals is associated with a first OAM mode, and the first subset of reference signals includes a first reference signal and a second reference signal.

[0265] 92. The method according to Clause 91, further comprising determining, based on reference signal configuration information and the maximum number of OAM modes configured to be simultaneously received by the Method using a first subset of antenna elements, that a first subset of antenna elements and a second subset of antenna elements should be used to receive a first reference signal, and that a first subset of antenna elements and a second subset of antenna elements should be used to receive a second reference signal.

[0266] 93. The method according to clause 91 or 92, further comprising: determining, based on reference signal configuration information, that a first reference signal should be transmitted using a first equally spaced circular array (UCA) comprising a third subset of antenna elements; receiving the first reference signal via the first subset of antenna elements; measuring a channel based on the first reference signal; and determining the channel gain between the first UCA and the first subset of antenna elements.

[0267] 94. The method according to any one of the clauses 91 to 93, further comprising: determining, based on reference signal configuration information, that a first reference signal should be transmitted using a first UCA having a third subset of antenna elements; receiving the first reference signal via a second subset of antenna elements; measuring a channel based on the first reference signal; and determining the channel gain between the first UCA and the second subset of antenna elements based on the channel measurement.

[0268] 95. The method according to any one of the clauses 91 to 94, further comprising receiving information indicating the maximum number of OAM modes that the transmission method is configured to transmit simultaneously using a first equally spaced circular array (UCA).

[0269] 96. The method according to Clause 95, further comprising determining a first channel gain between a first UCA and a first subset of antenna elements; determining a second channel gain between a first UCA and a second subset of antenna elements; and selecting a UCA to be used for transmission using a first OAM mode based on the first channel gain, the second channel gain, and the maximum number of OAM modes that the transmitter is configured to transmit simultaneously using the first UCA.

[0270] 97. The method of Clause 96, further comprising transmitting information indicating the selected UCA to the transmitting device.

[0271] 98. The method described in any one of the clauses 91 to 97, wherein the reference signal configuration information includes an indication that a second subset of reference signals among a plurality of reference signals is associated with a second OAM mode.

[0272] 99. The method according to any one of the clauses 91 to 98, wherein the reference signal configuration information includes an instruction that a third subset of antenna elements should be used to transmit a first reference signal for a first OAM mode, and an instruction that a fourth subset of antenna elements should be used to transmit a second reference signal for a first OAM mode.

[0273] 100. The method according to any one of the clauses 91 to 99, wherein the reference signal configuration information includes information indicating that a third subset of antenna elements corresponds to a first CSI-RS resource and information indicating that a fourth subset of antenna elements corresponds to a second CSI-RS resource.

[0274] 101. The method according to clause 100, wherein the reference signal configuration information includes information indicating that a first reference signal should be transmitted using a first port of a first CSI-RS resource, and information indicating that a second reference signal should be transmitted using a first port of a second CSI-RS resource.

[0275] 102. The method according to Clause 101, wherein the reference signal configuration information includes information indicating that a third reference signal should be transmitted using a second port of a first CSI-RS resource, and information indicating that a fourth reference signal should be transmitted using a second port of a second CSI-RS resource.

[0276] 103. The method according to any one of the clauses 91 to 100, wherein the reference signal configuration information includes information indicating that a first subset of antenna elements corresponds to a first CSI-RS resource set and information indicating that a second subset of antenna elements corresponds to a second CSI-RS resource set.

[0277] 104. The method according to Clause 103, wherein the reference signal configuration information includes information indicating that a first reference signal should be transmitted using a first resource of a first CSI-RS resource set, and information indicating that a second reference signal should be transmitted using a first resource of a second CSI-RS resource set.

[0278] 105. The method according to Clause 104, wherein the reference signal configuration information includes information indicating that a third reference signal should be transmitted using a second resource of a first CSI-RS resource set, and information indicating that a fourth reference signal should be transmitted using a second resource of a second CSI-RS resource set.

[0279] 106. The method according to any one of the clauses 91 to 105, wherein the reference signal configuration information includes an OAM mode index parameter associated with the first reference signal that indicates which OAM mode should be used to transmit the first reference signal.

[0280] 107. The method according to any one of the clauses 88 to 106, further comprising receiving a third reference signal using a second OAM mode via a first subset of antenna elements, receiving a fourth reference signal using a second OAM mode via a second subset of antenna elements, and transmitting information indicating a subset of antenna elements from a plurality of antenna elements used to receive the third reference signal and a subset of antenna elements from a plurality of antenna elements used to receive the fourth reference signal.

[0281] 108. The method according to any one of the clauses 88 to 107, wherein a first subset of antenna elements is included in a first receiver circular array (UCA) having a first radius, and a second subset of antenna elements is included in a second receiver UCA having a second radius and being coaxial with the first UCA.

[0282] 109. The method according to any one of the clauses 88 to 108, further comprising transmitting information indicating a subset of antenna elements from a plurality of antenna elements to be used to transmit a first OAM mode.

[0283] The method according to clause 109, wherein information indicating a subset of antenna elements among a plurality of antenna elements to be used for transmitting the first OAM mode includes information indicating the radius of a first uniform circular array (UCA) used by the method for receiving a first reference signal and information indicating the radius of a second UCA used by the method for receiving a second reference signal.

[0284] The method according to clause 110, further comprising transmitting a message including a first value corresponding to the radius of the first UCA and a second value corresponding to the radius of the second UCA.

[0285] The method according to clause 111, wherein the message is transmitted before information indicating a subset of antenna elements among a plurality of antenna elements to be used for transmitting the first OAM mode.

[0286] The method according to clause 111, wherein the message includes information indicating a subset of antenna elements among a plurality of antenna elements to be used for transmitting the first OAM mode.

[0287] The method according to any one of clauses 110 to 113, wherein information indicating a subset of antenna elements among a plurality of antenna elements to be used for transmitting the first OAM mode includes a string of bits associated with the first OAM mode, and each bit in the string of bits indicates whether a particular UCA of the method has received the first OAM mode.

[0288] The method according to any one of clauses 110 to 114, wherein information indicating a subset of antenna elements among a plurality of antenna elements to be used for transmitting the first OAM mode includes a bitmap associated with the first OAM mode, a first string of bits in the bitmap indicates whether a first subset of antenna elements should be used for transmitting the first OAM mode, and a second string of bits in the bitmap indicates whether a second subset of antenna elements should be used for transmitting the first OAM mode.

[0289] 116. The method of any one of the provisions of 110 to 115, further comprising transmitting to the transmission method at least one of the rank indicator associated with the first OAM mode or channel quality information associated with the first OAM mode.

[0290] 117. The method according to any one of the clauses 110 to 116, further comprising transmitting information indicating a subset of antenna elements of a plurality of antenna elements to be used to transmit a first OAM mode via one or more physical layer signalings using radio resource control (RRC) signaling, media access control (MAC) control element (CE) signaling, or downlink control information (DCI), uplink control information (UCI), or sidelink control information (SCI).

[0291] 118. The method of any one of the clauses 88 to 117, further comprising transmitting information indicating a subset of antenna elements among a plurality of antenna elements used to receive a first reference signal via one or more physical layer signalings using radio resource control (RRC) signaling, media access control (MAC) control element (CE) signaling, or downlink control information (DCI), uplink control information (UCI), or sidelink control information (SCI).

[0292] 119. A device for wireless communications, comprising a processor and memory communicatively coupled to at least one processor, wherein the processor is configured to perform the method described in any one of the clauses 60 to 118.

[0293] 120. A non-temporary computer-readable medium for storing computer executable code, wherein the computer executable code comprises code, and the code causes a computer to cause a processor to implement any of the methods described in clauses 60 to 118.

[0294] 121. A device for wireless communications, comprising at least one means for performing the method described in any one of the clauses 60 to 118.

[0191]

[0295] One or more of the components, steps, features, and / or functions shown in Figures 1 to 10 may be rearranged and / or combined into a single component, step, feature, or function, or may be embodied in several components, steps, or functions. Additional elements, components, steps, and / or functions may also be added without departing from the novel features disclosed herein. The apparatus, devices, and / or components shown in Figures 1 to 10 may be configured to implement one or more of the methods, features, or steps described herein. Furthermore, the novel algorithms described herein may be efficiently implemented in software and / or incorporated into hardware.

[0192]

[0296] It should be understood that the specific order or hierarchy of steps in the disclosed method is an example of an exemplary process. It should also be understood that the specific order or hierarchy of steps in the method may be rearranged based on design preferences. The appended claims for the method illustrate various step elements in a sample order and are not intended to be limited to the specific order or hierarchy presented unless specifically enumerated herein.

[0193]

[0297] The foregoing description is provided to enable any person skilled in the art to practice the various embodiments described herein. Various modifications to these embodiments will be readily apparent to a person skilled in the art, and the general principles defined herein may also be applied to other embodiments. Accordingly, the claims should not be limited to the embodiments shown herein, but should be given all scope consistent with the language of the claims, and references to singular elements should mean "one or more" rather than "one unique" unless otherwise explicitly stated. Unless otherwise explicitly stated, the term "several" refers to one or more. The phrase "at least one of" in an enumeration of items refers to any combination of those items, including a single element. For example, "at least one of a, b, or c" is intended to encompass a, b, c, a and b, a and c, b and c, and a, b, and c. All structural and functional equivalents of the elements of the various embodiments described throughout this disclosure, known to a person skilled in the art or to be known thereafter, are expressly incorporated herein by reference and are intended to be encompassed by the claims. Furthermore, nothing disclosed herein is intended to be made public, whether or not such disclosure is expressly enumerated in the claims. The invention described in the original claims of this application is listed below. [C1] A device configured for wireless communication, Processor and A plurality of antenna elements, including a first subset of antenna elements comprising at least a first antenna element and a second antenna element, and a second subset of antenna elements comprising at least a third antenna element and a fourth antenna element, The memory coupled to the aforementioned processor, The memory stores instructions, and when an instruction is executed by the processor, the processor receives A first reference signal is transmitted using a first orbital angular momentum (OAM) mode via the first subset of antenna elements. The second subset of antenna elements is used to transmit the second reference signal using the first OAM mode. Information is received indicating a subset of the antenna elements among the plurality of antenna elements to be used to transmit the first OAM mode. Device. [C2] The apparatus according to C1, wherein the first reference signal includes a first channel status information reference signal (CSI-RS) and the second reference signal includes a second CSI-RS. [C3] The execution of the above instruction further results in the processor: To transmit reference signal configuration information indicating that a first subset of reference signals among multiple reference signals is associated with the first OAM mode, The apparatus described in C1. [C4] The apparatus according to C3, wherein the reference signal configuration information indicates that a second subset of reference signals among the plurality of reference signals is associated with a second OAM mode. [C5] The apparatus according to C3, wherein the reference signal configuration information includes information indicating that the first subset of antenna elements corresponds to a first CSI-RS resource, and information indicating that the second subset of antenna elements corresponds to a second CSI-RS resource. [C6] The execution of the above instruction further causes the processor to: The rank indicator associated with the first OAM mode, or Channel quality information associated with the first OAM mode To cause at least one of the following to be received by the receiving device. The apparatus described in C1. [C7] A first equally spaced circular array (UCA) comprising the first subset of antenna elements, the first UCA having a first radius, A second UCA comprising the second subset of antenna elements, having a second radius and being coaxial with the first UCA, Furthermore, The execution of the aforementioned instruction further causes the processor to: Based on the first radius, the third radius of the third UCA used by the receiving device to receive the first reference signal, the distance between the first UCA and the third UCA, and the wavelength of the waveform used to transmit the first reference signal, the first channel response to the first OAM mode is determined. A second channel response to the first OAM mode is determined based on the second radius, the third radius of the third UCA used by the receiving device to receive the first reference signal, the distance between the first UCA and the third UCA, and the wavelength of the waveform used to transmit the first reference signal. The apparatus described in C1. [C8] A device configured for wireless communication, Processor and A plurality of antenna elements, including a first subset of antenna elements comprising at least a first antenna element and a second antenna element, and a second subset of antenna elements comprising at least a third antenna element and a fourth antenna element, The memory coupled to the aforementioned processor, The memory stores instructions, and when an instruction is executed by the processor, the processor receives An instruction is received from a transmitting device including the third subset of antenna elements and the fourth subset of antenna elements that the third subset of antenna elements should be used to transmit a first reference signal for the first orbital angular momentum (OAM) mode, The transmitting device receives an instruction that the fourth subset of antenna elements should be used to transmit the second reference signal for the first OAM mode. To transmit information indicating a subset of the antenna elements among the plurality of antenna elements used to receive the first reference signal, Device. [C9] The execution of the above instruction further causes the processor to: The first reference signal is received through the first subset of antenna elements among the plurality of antenna elements. The second reference signal is received via the second subset of the plurality of antenna elements. The device described in C8. [C10] The execution of the above instruction further causes the processor to: The transmitter receives reference signal configuration information, the reference signal configuration information includes an instruction that a first subset of reference signals among a plurality of reference signals is associated with the first OAM mode, and the first subset of reference signals includes the first reference signal and the second reference signal. The device described in C8. [C11] The execution of the above instruction further results in the processor: Based on the reference signal configuration information, it is determined that the first reference signal should be transmitted using a first equally spaced circular array (UCA) comprising the third subset of antenna elements. The first reference signal is received via the first subset of antenna elements. The channel is measured based on the first reference signal. The channel gain between the first UCA and the first subset of antenna elements is determined. The apparatus described in C10. [C12] The execution of the above instruction further results in the processor: The apparatus according to C10, which causes the transmitting device to receive information indicating the maximum number of OAM modes that are configured to be transmitted simultaneously using a first equally spaced circular array (UCA). [C13] The execution of the above instruction further causes the processor to: Determine the first channel gain between the first UCA and the first subset of antenna elements. Determine the second channel gain between the first UCA and the second subset of antenna elements. The apparatus according to C12, which causes the UCA to be used to transmit using the first OAM mode based on the first channel gain, the second channel gain, and the maximum number of OAM modes in which the transmitting device is configured to transmit simultaneously using the first UCA. [C14] The execution of the above instruction further results in the processor: The apparatus according to C8, which transmits information indicating a subset of antenna elements among the plurality of antenna elements to be used to transmit the first OAM mode. [C15] The information indicating a subset of antenna elements among the plurality of antenna elements to be used to transmit the first OAM mode is Information indicating the radius of a first equally spaced circular array (UCA) used by the device to receive the first reference signal, Information indicating the radius of the second UCA used by the device to receive the second reference signal, Apparatus as described in C14, including. [C16] A method of wireless communication, Transmitting a first reference signal using a first orbital angular momentum (OAM) mode via a first subset of antenna elements among multiple antenna elements, Transmitting a second reference signal using the first OAM mode via a second subset of antenna elements among multiple antenna elements, Receiving information indicating a subset of antenna elements among the plurality of antenna elements to be used to transmit the first OAM mode, Methods that include... [C17] The method according to C16, wherein the first reference signal includes a first channel status information reference signal (CSI-RS) and the second reference signal includes a second CSI-RS. [C18] Transmitting reference signal configuration information indicating that a first subset of reference signals among multiple reference signals is associated with the first OAM mode. The method described in C16, further including the method described in C16. [C19] The method according to C18, wherein the reference signal configuration information indicates that a second subset of reference signals among the plurality of reference signals is associated with a second OAM mode. [C20] The method according to C18, wherein the reference signal configuration information includes information indicating that the first subset of antenna elements corresponds to a first CSI-RS resource, and information indicating that the second subset of antenna elements corresponds to a second CSI-RS resource. [C21] Rank indicator associated with the first OAM mode, or Channel quality information associated with the first OAM mode Receiving at least one of the following from the receiving device The method described in C16, further including the method described in C16. [C22] The first subset of antenna elements is contained within a first equally spaced circular array (UCA) having a first radius. The second subset of antenna elements is contained within a second UCA having a second radius and being coaxial with the first UCA. The method described above is Determining a first channel response to the first OAM mode based on the first radius, the third radius of a third UCA used by a receiving device to receive the first reference signal, the distance between the first UCA and the third UCA, and the wavelength of the waveform used to transmit the first reference signal. Determining the second channel response to the first OAM mode based on the second radius, the third radius of the third UCA used by the receiving device to receive the first reference signal, the distance between the first UCA and the third UCA, and the wavelength of the waveform used to transmit the first reference signal, The method described in C16, further including the method described in C16. [C23] A method of wireless communication, An instruction that the third subset of antenna elements should be used to transmit a first reference signal for the first orbital angular momentum (OAM) mode is received from a transmitting device including a third subset of antenna elements and a fourth subset of antenna elements in a receiving device including a plurality of antenna elements including a first subset of antenna elements and a second subset of antenna elements, Receiving an instruction from the transmitting device that the fourth subset of antenna elements should be used to transmit the second reference signal for the first OAM mode, and transmitting information indicating a subset of antenna elements among the plurality of antenna elements used to receive the first reference signal, Methods that include... [C24] Receiving the first reference signal via the first subset of antenna elements among the plurality of antenna elements, The second reference signal is received via the second subset of the plurality of antenna elements, The method described in C23, further including the method described in C23. [C25] Receiving reference signal configuration information from the transmitting device. The method of C23, further comprising the following: the reference signal configuration information includes an instruction that a first subset of reference signals among a plurality of reference signals is associated with the first OAM mode, and the first subset of reference signals includes the first reference signal and the second reference signal. [C26] Determining, based on the reference signal configuration information, that the first reference signal should be transmitted using a first equally spaced circular array (UCA) comprising the third subset of antenna elements, The first reference signal is received via the first subset of antenna elements, Measuring the channel based on the first reference signal, Determining the channel gain between the first UCA and the first subset of antenna elements, The method described in C25, which further includes the method described in C25. [C27] Receiving information indicating the maximum number of OAM modes that the transmitter is configured to transmit simultaneously using a first equally spaced circular array (UCA). The method described in C25, which further includes the method described in C25. [C28] Determining the first channel gain between the first UCA and the first subset of antenna elements, Determining the second channel gain between the first UCA and the second subset of antenna elements, Selecting a UCA to be used for transmission using the first OAM mode based on the first channel gain, the second channel gain, and the maximum number of OAM modes in which the transmitter is configured to transmit simultaneously using the first UCA; The method described in C27, which further includes the method described in C27. [C29] Transmitting information indicating a subset of antenna elements among the plurality of antenna elements to be used to transmit the first OAM mode. The method described in C23, further including the method described in C23. [C30] The information indicating a subset of antenna elements among the plurality of antenna elements to be used to transmit the first OAM mode is Information indicating the radius of a first equally spaced circular array (UCA) used by the method to receive the first reference signal, Information indicating the radius of the second UCA used by the method to receive the second reference signal, Methods of C29, including those described above.

Claims

1. A device configured for wireless communication, Processor and A plurality of antenna elements, including a first subset of antenna elements comprising at least a first antenna element and a second antenna element, and a second subset of antenna elements comprising at least a third antenna element and a fourth antenna element, The memory coupled to the aforementioned processor, The memory stores instructions, and when an instruction is executed by the processor, the processor receives A first reference signal is transmitted using a first orbital angular momentum (OAM) mode via the first subset of antenna elements. The second reference signal is transmitted using the first OAM mode via the second subset of antenna elements. The system transmits reference signal configuration information that shows the relationship between each reference signal and a subset of the antenna elements. Information is received indicating a subset of the antenna elements among the plurality of antenna elements to be used to transmit the first OAM mode. Device.

2. The apparatus according to claim 1, wherein the first reference signal includes a first channel state information reference signal (CSI-RS), and the second reference signal includes a second CSI-RS.

3. The execution of the aforementioned instruction further causes the processor to: To transmit reference signal configuration information indicating that a first subset of reference signals among multiple reference signals is associated with the first OAM mode, The apparatus according to claim 1.

4. The apparatus according to claim 3, wherein the reference signal configuration information indicates that a second subset of reference signals among the plurality of reference signals is associated with a second OAM mode.

5. The apparatus according to claim 3, wherein the reference signal configuration information includes information indicating that the first subset of antenna elements corresponds to a first CSI-RS resource, and information indicating that the second subset of antenna elements corresponds to a second CSI-RS resource.

6. The execution of the aforementioned instruction further causes the processor to: The rank indicator associated with the first OAM mode, or Channel quality information associated with the first OAM mode To cause at least one of the following to be received by the receiving device, The apparatus according to claim 1.

7. A first equally spaced circular array (UCA) comprising the first subset of antenna elements, the first UCA having a first radius, A second UCA comprising the second subset of antenna elements, having a second radius and being coaxial with the first UCA, Furthermore, The execution of the aforementioned instruction further causes the processor to: Based on the first radius, the third radius of the third UCA used by the receiving device to receive the first reference signal, the distance between the first UCA and the third UCA, and the wavelength of the waveform used to transmit the first reference signal, the first channel response to the first OAM mode is determined. The second channel response to the first OAM mode is determined based on the second radius, the third radius of the third UCA used by the receiving device to receive the first reference signal, the distance between the first UCA and the third UCA, and the wavelength of the waveform used to transmit the first reference signal. The apparatus according to claim 1.

8. A method of wireless communication, Transmitting a first reference signal using a first orbital angular momentum (OAM) mode via a first subset of antenna elements among multiple antenna elements, Transmitting a second reference signal using the first OAM mode via a second subset of antenna elements among multiple antenna elements, Transmitting reference signal configuration information that shows the relationship between each reference signal and a subset of the antenna elements, Receiving information indicating a subset of antenna elements among the plurality of antenna elements to be used to transmit the first OAM mode, Methods that include...

9. The method according to claim 8, wherein the first reference signal includes a first channel state information reference signal (CSI-RS), and the second reference signal includes a second CSI-RS.

10. Transmitting reference signal configuration information indicating that a first subset of reference signals among multiple reference signals is associated with the first OAM mode. The method according to claim 8, further comprising:

11. The method according to claim 10, wherein the reference signal configuration information indicates that a second subset of reference signals among the plurality of reference signals is associated with a second OAM mode.

12. The method according to claim 10, wherein the reference signal configuration information includes information indicating that the first subset of antenna elements corresponds to a first CSI-RS resource, and information indicating that the second subset of antenna elements corresponds to a second CSI-RS resource.

13. The rank indicator associated with the first OAM mode, or Channel quality information associated with the first OAM mode Receiving at least one of the following from the receiving device The method according to claim 8, further comprising:

14. The first subset of antenna elements is contained within a first equally spaced circular array (UCA) having a first radius. The second subset of antenna elements is contained within a second UCA having a second radius and being coaxial with the first UCA. The method described above is Determining a first channel response to the first OAM mode based on the first radius, the third radius of a third UCA used by a receiving device to receive the first reference signal, the distance between the first UCA and the third UCA, and the wavelength of the waveform used to transmit the first reference signal, Determining the second channel response to the first OAM mode based on the second radius, the third radius of the third UCA used by the receiving device to receive the first reference signal, the distance between the first UCA and the third UCA, and the wavelength of the waveform used to transmit the first reference signal, The method according to claim 8, further comprising:

Images