Apparatus and method for determining line of sight (los) from intensity measurements

Abstract

A method performed by a first device includes: the first device transmitting a line-of-sight (LOS) determination request to a second device, the LOS determination request including an LOS indicator indicating the use of a LOS procedure in the LOS representation of a transmission between the first device and the second device; the second device transmitting a first set of reference signals through a first plurality of transmit resources; and the first device measuring a second set of reference signals transmitted by the second device through a second plurality of receive resources. This method includes two embodiments: one when there is LOS representation transmission between the first device and the second device, and the other when there is no LOS representation transmission between the first device and the second device.

Description

[0001] Priority claims and cross-references

[0002] This application claims the benefit of U.S. Provisional Patent Application No. 63 / 092,261, filed October 15, 2020, entitled “Apparatus and Methods for Determining Line of Sight (LOS) from Polarization Intensity Measurements,” which is hereby incorporated herein by reference in its entirety. Technical Field

[0003] The present invention generally relates to systems and methods for digital communication, and in certain embodiments, to systems and methods for determining line of sight (LOS). Background Technology

[0004] In many applications, time of flight (ToF) is used to estimate the distance between a transmitter and a receiver. ToF is defined as the duration for a wave signal to propagate between the transmitter and receiver. One method for estimating ToF is based on exchanging multiple timestamped frames between the transmitter and receiver. When the ToF is determined, the distance between the transmitter and receiver can be estimated by simply multiplying it by the speed of light. Once the distances from the unknown location to at least three fixed points (with known coordinates) are determined, the location of the unknown point can be obtained using a simple triangulation (multilateral) algorithm.

[0005] When a line-of-sight (LOS) path between the transmitter and receiver is unavailable, and communication is only non-line-of-sight (NLOS), several copies of the transmitted signal will be received due to reflections. Each copy of the signal corresponds to a different propagation path between the transmitter and receiver, and therefore has a different Time-of-Flight (ToF). In the case of NLOS, the ToF of each path corresponds to the length of the path, not the geometric distance between the transmitter and receiver. In this situation, the ToF-based path length is significantly larger than the actual distance between the transmitter and receiver, which in turn leads to errors in position estimation.

[0006] Therefore, it is necessary to know whether the propagation of the transmitted (or its copy) signal corresponds to LOS propagation in order to determine the exact distance between the transmitter and the receiver.

[0007] When position estimation is performed at the transmitter (i.e., the network), the receiver needs to transmit information about when the signal corresponds to a LOS propagation to the transmitter. Alternatively, if position estimation is performed at the receiver (i.e., the earpiece), the receiver does not need to transmit information about when the signal corresponds to a LOS propagation to the transmitter. Summary of the Invention

[0008] According to a first aspect, a method performed by a first device is provided. The method includes: the first device receiving from a second device an indicator supported by line-of-sight / non-line-of-sight (LoS / NLoS) characteristics; and based thereon, the first device transmitting a line-of-sight (LOS) determination request to the second device, the LOS determination request including an LOS indicator indicating the use of a LOS procedure in the LOS representation of a transmission between the first device and the second device; the first device receiving from the second device a first set of reference signals transmitted via a first plurality of transmission resources; and the first device measuring the first set of reference signals transmitted by the second device via a second plurality of reception resources.

[0009] According to the first aspect itself, in a first implementation of the method, the LOS indicator is a binary indicator indicating that the LOS is characterized as LOS or NLOS.

[0010] According to the first aspect itself or any of the aforementioned implementations of the first aspect, in a second implementation of the method, the LOS indicator is a multi-level soft indicator indicating the probability or confidence that the LOS is characterized as LOS or NLOS.

[0011] According to the first aspect itself or any of the aforementioned implementations of the first aspect, in a third implementation of the method, the first set of reference signals further includes: receiving each reference signal in the first set of reference signals on each receiving resource; and the first device identifying each reference signal corresponding to each receiving resource through a search process.

[0012] According to the first aspect itself or any of the aforementioned implementations of the first aspect, in a fourth implementation of the method, the search process includes the maximum coherent receiver on all possible reference signals.

[0013] According to the first aspect itself or any of the foregoing implementations of the first aspect, in a fifth implementation of the method, the first device measuring the first set of reference signals further includes: the first device measuring a plurality of channel estimates on each received resource by correlating with the corresponding reference signals; the first device determining a first arrival path for each channel estimate; and the first device measuring the reference signal received power (RSRP) on the first arrival path of each channel estimate.

[0014] According to the first aspect itself or any of the foregoing implementations of the first aspect, in a sixth implementation of the method, the method further includes: the first device sending an RSRP of a reference signal measured through each resource to the second device.

[0015] According to the first aspect itself or any of the foregoing implementations of the first aspect, in a seventh implementation of the method, the method further includes: the first device determining that the value of a given metric determined based on RSRP measurements of each reference signal on each resource does indeed satisfy a specified threshold, and based thereon, the first device determining that the LOS characterization of the transmission includes a LOS transmission.

[0016] According to the first aspect itself or any of the foregoing implementations of the first aspect, in an eighth implementation of the method, the method further includes: the first device determining that the value of a given metric determined based on RSRP measurements of each reference signal for each resource does not meet a specified threshold, and based thereon, the first device determining that the LOS characterization of the transmission includes a non-LOS (non-line of sight, NLOS) transmission.

[0017] According to the first aspect itself or any of the foregoing implementations of the first aspect, in a ninth implementation of the method, the method further includes the first device transmitting the LOS representation of the transmission.

[0018] According to the first aspect itself or any of the foregoing implementations of the first aspect, in a tenth implementation of the method, the method further includes the first device receiving the transmitted LOS representation from the second device.

[0019] According to the first aspect itself or any of the foregoing implementations of the first aspect, in the eleventh implementation of the method, measuring the plurality of reference signals includes measuring the reference signal received power (RSRP) value or the reference signal received quality (RSRQ) value.

[0020] According to the first aspect itself or any of the foregoing implementations of the first aspect, in a twelfth implementation of the method, transmitting the LOS determination request includes sending the LOS determination request or receiving the LOS determination request.

[0021] According to the first aspect itself or any of the foregoing implementations of the first aspect, in the thirteenth implementation of the method, the first device includes user equipment (UE), and the second device includes an access node.

[0022] According to the first aspect itself or any of the foregoing implementations of the first aspect, in a fourteenth implementation of the method, the LOS determination request further includes a measurement gap specifying the locations of the first resource and the second resource.

[0023] According to the first aspect itself or any of the foregoing implementations of the first aspect, in a fifteenth implementation of the method, the LOS determination request further includes a first measurement gap specifying the location of the first resource and a second measurement gap specifying the location of the second resource.

[0024] According to the first aspect itself or any of the foregoing implementations of the first aspect, in a sixteenth implementation of the method, the reference signals are transmitted one after another in chronological order.

[0025] According to a second aspect, a first device is provided. The first device includes: a non-transitory memory containing instructions and one or more processors communicating with the memory. The one or more processors execute the instructions to: receive an indicator supported by line-of-sight / non-line-of-sight (LoS / NLoS) characteristics from a second device, and based thereon transmit a line-of-sight (LOS) determination request to the second device, the LOS determination request including an LOS indicator indicating the use of a LOS procedure in the LOS representation of a transmission between the first device and the second device; measure a first signal on a first resource of a channel; and measure a second signal on a second resource of the channel, wherein the first signal and the second signal are multiplexed in the frequency domain or the code domain.

[0026] According to the second aspect itself, in a first implementation of the first device, the LOS indicator is a binary indicator indicating that the LOS is characterized as LOS or NLOS.

[0027] According to the second aspect itself or any of the foregoing implementations of the second aspect, in a second implementation of the first device, the LOS indicator is a multi-level soft indicator that indicates the probability or confidence that the LOS is characterized as LOS or NLOS.

[0028] According to the second aspect itself or any of the foregoing implementations of the second aspect, in a third implementation of the first device, the one or more processors further execute the instructions to send the measurement of the first signal and the measurement of the second signal to the second device.

[0029] According to the second aspect itself or any of the foregoing implementations of the second aspect, in a fourth implementation of the first device, the one or more processors further execute the instructions to receive the transmitted LOS representation from the second device.

[0030] According to the second aspect itself or any of the foregoing implementations of the second aspect, in a fifth implementation of the first device, the one or more processors further execute the instructions to determine that the difference between the measurement of the first signal and the measurement of the second signal satisfies a specified threshold, and based thereon determine that the LOS characterization of the transmission includes LOS transmission.

[0031] According to the second aspect itself or any of the foregoing implementations of the second aspect, in a sixth implementation of the first device, the one or more processors further execute the instructions to determine that the difference between the measurement of the first signal and the measurement of the second signal does not meet a specified threshold, and based thereon determine that the LOS characterization of the transmission includes a non-LOS (non-line of sight, NLOS) transmission.

[0032] In a seventh implementation of the first device, according to the second aspect itself or any of the foregoing implementations of the second aspect, the one or more processors further execute the instructions to send the LOS representation of the transmission.

[0033] According to the second aspect itself or any of the foregoing implementations of the second aspect, in an eighth implementation of the first device, the one or more processors further execute the instructions to send the LOS determination request or receive the LOS determination request.

[0034] According to a third aspect, a first device is provided. The first device includes: a non-transitory memory containing instructions and one or more processors communicating with the memory. The one or more processors execute the instructions to: receive an indicator supported by line-of-sight / non-line-of-sight (LoS / NLoS) characteristics from a second device, and based thereon transmit a line-of-sight (LOS) determination request to the second device, the LOS determination request including an LOS indicator indicating the use of a LOS procedure in the LOS representation of a transmission between the first device and the second device; transmit a first signal on a first resource of the channel; and transmit a second signal on a second resource of the channel, wherein the first signal and the second signal are multiplexed in the frequency domain or the code domain.

[0035] According to the third aspect itself, in the first implementation of the first device, the LOS indicator is a binary indicator indicating that the LOS is characterized as LOS or NLOS.

[0036] According to the third aspect itself or any of the aforementioned implementations of the third aspect, in a second implementation of the first device, the LOS indicator is a multi-level soft indicator that indicates the probability or confidence that the LOS is characterized as LOS or NLOS.

[0037] According to the third aspect itself or any of the foregoing implementations of the third aspect, in a third implementation of the first device, the one or more processors further execute the instructions to receive the LOS representation of the channel from the second device.

[0038] According to the third aspect itself or any of the foregoing implementations of the third aspect, in a fourth implementation of the first device, the one or more processors further execute the instructions to receive measurements of the first signal and the second signal from the second device.

[0039] According to the third aspect itself or any of the foregoing implementations of the third aspect, in a fifth implementation of the first device, the one or more processors further execute the instructions to determine that the difference between the measurement of the first signal and the measurement of the second signal satisfies a specified threshold, and based thereon, further execute the instructions to determine that the LOS characterization of the transmission includes LOS transmission.

[0040] In a sixth implementation of the first device, according to the third aspect itself or any of the foregoing implementations of the third aspect, the one or more processors further execute the instructions to send the LOS representation of the transmission.

[0041] According to the third aspect itself or any of the foregoing implementations of the third aspect, in a seventh implementation of the first device, the one or more processors further execute the instructions to determine that the difference between the measurement of the first signal and the measurement of the second signal does not meet a specified threshold, and based thereon, further execute the instructions to determine that the LOS characterization of the transmission includes a non-LOS (non-line of sight, NLOS) transmission.

[0042] In an eighth implementation of the first device, according to the third aspect itself or any of the foregoing implementations of the third aspect, the one or more processors further execute the instructions to send the LOS representation of the transmission.

[0043] The advantage of the exemplary embodiment is that it improves the ranging and positioning accuracy of devices in the communication network by correctly selecting the LOS reference signal, so as to estimate the distance between devices. Furthermore, once the distance between the transmitter and receiver is determined, the location can be determined using triangulation algorithms. Attached Figure Description

[0044] To gain a more complete understanding of the invention and its advantages, reference is now made to the following description taken in conjunction with the accompanying drawings, in which:

[0045] Figure 1 The network used for transmitting data is shown;

[0046] Figure 2A An example of a communication system is shown, in which the propagation between the transmitter and receiver via 212 and 212 is NLOS propagation;

[0047] Figure 2B An example of a communication system is shown, wherein the propagation between the transmitter and receiver via 235 is characterized as a LOS propagation (or NLOS beam, NLOS ray, NLOS path, etc.) that can be used to implement the devices and methods disclosed herein;

[0048] Figure 3A An example of a linearly polarized electromagnetic wave is shown;

[0049] Figure 3B An example of a circularly polarized electromagnetic wave is shown;

[0050] Figure 3C and Figure 3D An example of electromagnetic wave 305 during reflection is shown;

[0051] Figure 4A An example of a signal flow graph of a first exemplary embodiment of a method for determining LOS according to exemplary embodiments presented herein is shown;

[0052] Figure 4B An example of an alternative signal flow graph of a method for determining LOS according to exemplary embodiments presented herein is shown;

[0053] Figure 4C An example of another alternative signal flow graph for a method for determining LOS according to exemplary embodiments presented herein is shown;

[0054] Figure 5 An example of a communication system according to exemplary embodiments presented herein is shown, wherein propagation between the transmitter and receiver is NLOS with a cylindrical reflective surface that obstructs LOS communication (e.g., beam) with a cylindrical reflective region;

[0055] Figure 6A An example of a signal flow graph of a second exemplary embodiment of a method for determining LOS according to exemplary embodiments presented herein is shown;

[0056] Figure 6B An example of an alternative signal flow graph of a method for determining LOS according to exemplary embodiments presented herein is shown;

[0057] Figure 7 An example of a signal flow graph of a third exemplary embodiment of a method for determining LOS according to exemplary embodiments presented herein is shown;

[0058] Figure 8AA flowchart is shown of an exemplary method for UE operation in a UE-centric solution, according to exemplary embodiments presented herein;

[0059] Figure 8B A flowchart is shown of an exemplary method for gNB operation in a UE-centric solution according to the exemplary embodiments presented herein;

[0060] Figure 9A A flowchart is shown of an exemplary method for UE operation in a gNB-centric solution according to the exemplary embodiments presented herein;

[0061] Figure 9B A flowchart is shown of an exemplary method for gNB operation in a gNB-centric solution, according to an exemplary embodiment presented herein;

[0062] Figure 10 A flowchart illustrating exemplary operations occurring in a UE-centric LOS measurement solution according to the exemplary embodiments presented herein is shown;

[0063] Figure 11 A flowchart illustrating exemplary operations occurring in a gNB within a UE-centric LOS measurement solution according to the exemplary embodiments presented herein is shown;

[0064] Figure 12 An exemplary communication system according to the exemplary embodiments presented herein is illustrated;

[0065] Figure 13A and Figure 13B Exemplary apparatuses that can implement the methods and teachings according to the present invention are shown;

[0066] Figure 14 A block diagram of a computing system that can be used to implement the devices and methods disclosed herein;

[0067] Figure 15 A block diagram of an exemplary processing system for performing the methods described herein is shown;

[0068] Figure 16 A block diagram of a transceiver for sending and receiving signaling on a telecommunications network is shown, according to exemplary embodiments presented herein;

[0069] Figure 17A and Figure 17B The exemplary embodiments presented herein illustrate the polarization orientation between the gNB and the UE during LOS path propagation, using antenna beams with two orthogonal polarizations for transmission and reception.

[0070] Figures 18A to 18C The received field vector and transmitted field vector in the LCS of a receiver arriving from a given spherical direction, according to the exemplary embodiments presented herein;

[0071] Figures 19A to 19B A polarization-LOS scheme is illustrated, according to exemplary embodiments presented herein, for receiving N different field vectors, each with a different polarization orientation, by antenna resources having a single polarization orientation.

[0072] Figures 20A to 20C A polarization-LOS scheme, which receives four different field vectors, each with a different polarization orientation, from antenna resources with a single polarization orientation, according to an exemplary embodiment presented herein, is illustrated.

[0073] Figure 20D A polarization-LOS scheme, which receives three different field vectors, each with a different polarization orientation, from antenna resources with a single polarization orientation, according to an exemplary embodiment presented herein, is illustrated.

[0074] Figure 20E A polarization-LOS scheme is illustrated in the case where the transmitter transmits with more than S>4 different polarization orientations, according to the exemplary embodiments presented herein;

[0075] Figure 21A A block diagram is shown for requesting and performing polarization-LOS measurements and binary decisions and reporting back to the transmitter, according to exemplary embodiments presented herein;

[0076] Figure 21B A block diagram is shown for requesting and performing polarization-LOS measurements and reporting back to the transmitter, according to exemplary embodiments presented herein; and

[0077] Figure 22 A block diagram is shown illustrating how the UE performs LOS determination according to the exemplary embodiments presented herein. Detailed Implementation

[0078] In the following description, reference is made to the accompanying drawings, which form a part of this document, in which specific exemplary embodiments that may be practiced are illustrated by way of illustration. These exemplary embodiments have been described in sufficient detail to enable those skilled in the art to practice the invention, and it should be understood that other exemplary embodiments may be utilized and structural, logical, and electrical changes may be made without departing from the scope of the invention. Therefore, the following description of exemplary embodiments is not intended to be limiting, and the scope of the invention is defined by the appended claims.

[0079] The following section discusses in detail the making and use of embodiments of the present invention. However, it should be understood that the concepts disclosed herein can be embodied in various specific contexts, and the specific exemplary embodiments discussed herein are merely illustrative and not intended to limit the scope of the claims. Furthermore, it should be understood that various changes, alternatives, and modifications can be made to this document without departing from the spirit and scope of the invention as defined by the appended claims. While aspects of the invention are primarily described in the context of 5G wireless networks, it should also be understood that these inventive aspects are applicable to 4G and 3G wireless networks.

[0080] In one exemplary embodiment, the functions or algorithms described herein may be implemented in software. The software may include computer-executable instructions stored in a computer-readable medium or computer-readable storage device (e.g., one or more non-transitory memories or other types of hardware-based local or network storage devices). Furthermore, such functions correspond to modules, which may be software, hardware, firmware, or any combination thereof. Multiple functions may be performed in one or more modules as needed; the described exemplary embodiments are merely examples. The software may execute on a digital signal processor, ASIC, microprocessor, or other type of processor running on a computer system (e.g., a personal computer, server, or other computer system), transforming such a computer system into a specifically programmed machine.

[0081] Figure 1A network 100 for transmitting data is shown. Network 100 includes an access node 110 with a coverage area 112, multiple user equipment (UE) devices 120 and 121, and a backhaul network 130. As shown, base station 110 establishes uplink (dashed lines) or downlink (solid lines) connections with UEs 120 and 121, which are used to carry wireless transmissions from UEs 120 and 121 to base station 110 and from base station 110 to UEs 120 and 121. Wireless transmissions via uplink or downlink connections may include data transmitted between UEs 120 and 121, and data transmitted to or from a remote end (not shown) via backhaul network 130. As used herein, the term access node refers to any component (or set of components) used to provide wireless access to a network, such as a base station, next-generation base station (gNB), e-UTRAN base station (eNB), macrocell base station, femtocell base station, Wi-Fi access point (AP), or other wireless-enabled device. Access nodes may provide wireless access according to one or more wireless communication protocols, such as 3GPP Long Term Evolution (LTE), Long Time Evolution Advanced (LTE-A), 5G, 5G LTE, 5G NR, High Speed ​​Packet Access (HSPA), Wi-Fi 802.11a / b / g / n / ac / ad / ax / ay / be, etc. As used herein, the term "UE" refers to any component (or set of components) capable of establishing a wireless connection with a base station, such as mobile devices, mobile stations (STAs), Internet of Things (IoT) devices (e.g., smart sensors), users, stations, and other devices that support wireless functionality. In some exemplary embodiments, network 100 may include various other wireless devices, such as relays, low-power nodes, etc.

[0082] When the direct or line-of-sight (LOS) path between the transmitter and receiver is blocked, propagation between them can occur via a non-line-of-sight (NLOS) path. In other words, signal propagation occurs through reflection and diffraction.

[0083] Figure 2AAn example of a communication system 200 is shown, wherein the propagation between transmitter 202 and receiver 204 is NLOS propagation. Communication system 200 can be used to implement the devices and methods disclosed herein. System 200 can implement one or more channel access methods, including but not limited to code division multiple access (CDMA), time division multiple access (TDMA), frequency division multiple access (FDMA), orthogonal FDMA (OFDMA), or single-carrier FDMA (SC-FDMA).

[0084] In this example, communication system 200 includes a transmitter 202 and a receiver 204. Although Figure 2A A certain number of these components or elements are shown, but system 200 may include any number of these components or elements. Figure 2A In this system, both transmitter 202 and receiver 204 can transmit and receive electromagnetic waves under multiple polarizations. Transmitter 202 and receiver 204 can be any entity capable of transmitting and receiving, including base stations, mobile terminals, access points, wireless local area network (WLAN) stations, etc.

[0085] Transmitter 202 can repeatedly transmit a reference signal as an electromagnetic (EM) wave with different polarizations (e.g., vertical, horizontal, and 45-degree polarization) to receiver 204. Receiver 204 can receive the signal transmitted by transmitter 202. For multipath propagation, each path corresponds to a copy of the same transmission (meaning each path corresponds to at least one reflection), for example... Figure 2ACopies of 210 and 212. In the case where the propagation between transmitter 202 and receiver 204 is characterized as NLOS propagation (or NLOS beam, NLOS ray, etc.), a blocker 208 is located between transmitter 202 and receiver 204. Signal copies will not pass through blocker 208; for example, signal copy 210 is blocked by blocker 208. A blocker is defined as any obstacle that attenuates electromagnetic (EM) waves below a given noise floor. If the line-of-sight path is blocked by other dispersive media (e.g., water), the delay of the EM waves may be greater than the sampling rate multiplied by the speed of light in a vacuum. In this case, propagation through the LOS path is delayed, which will lead to an overestimation of distance by TOA-based positioning techniques. A reflector 206 may also be included between transmitter 202 and receiver 204. Signal copies, such as signal copy 212, can be reflected by reflector 206 and then continue to receiver 204. Blocker 208 can block signals sent to receiver 204. In this example, for each transmission, receiver 204 receives one or more copies of the same signal propagating on different paths, where none of the copies correspond to an unobstructed (direct or LOS) path. Therefore, the communication between transmitter 202 and receiver 204 is NLOS communication.

[0086] Figure 2B An example of a communication system 230 is shown, wherein the propagation between transmitter 202 and receiver 204 is characterized as LOS propagation (or NLOS beam, NLOS ray, etc.) that can be used to implement the devices and methods disclosed herein. In this case, there is no obstruction between transmitter 202 and receiver 204, and there is an unobstructed direct path 230 between transmitter 202 and receiver 204, allowing the signal on path 230 to be unobstructed. Therefore, the communication between transmitter 202 and receiver 204 is LOS communication.

[0087] In this invention, transmitter 202 is a device that transmits signals to receiver 204 in some examples, such as an access node, base station, mobile terminal, access point, WLAN station, UE, etc. Receiver 204 is a device that receives signals from transmitter 202 in some examples, such as an access node, base station, mobile terminal, access point, WLAN station, UE, etc. In any example, the functions of transmitter 202 and receiver 204 can be interchanged.

[0088] Figure 3A An example of a linearly polarized electromagnetic wave 302 is shown. In this example, if the electric field vector E oscillates in a single fixed plane in the "z" direction (in this example), then the signal wave, such as electromagnetic wave 302, is linearly polarized (e.g., in...). Figure 3A (in the "z" direction). In Figure 3AIn the diagram, "E" represents the vector of the electric field 302 of the signal wave, "B" represents the vector of the magnetic field 306 of the signal wave, and "c" represents the propagation speed of the electromagnetic wave, which depends on the medium in which it propagates. Figure 3A The signal wave in the equation is linearly polarized because "E" oscillates only in the plane (xz), while a signal wave (e.g., an electromagnetic wave) is a combination of two vector oscillations (e.g., a magnetic field B and an electric field E). The polarization orientation (phasor) of the linearly polarized wave can then be described by an angle in the (zy) phasor plane 304 measured from the z-axis. Figure 3A In the example, the angle is 0°, and the polarization is vertically polarized, that is, along the z-axis of propagation.

[0089] Figure 3B An example of a circularly polarized electromagnetic wave 304 is shown. Figure 3B In the process, the electric intensity vector of electromagnetic wave 304 rotates 360 degrees within a period (e.g., period 306), where the period is the minimum time interval between the 360-degree rotations.

[0090] Figure 3C and Figure 3D An example of electromagnetic wave 305 during reflection is shown. Electromagnetic wave 305 is polarized. When reflected, a polarized wave (e.g., electromagnetic wave 305) undergoes a change in polarization, whereas an unreflected polarized wave would not undergo this change. Figure 3C As shown, the reflection coefficient of light with an electric field parallel to the plane of incidence becomes zero at angles between 0° and 90°. At these angles, the reflected light is linearly polarized, with its electric field vector perpendicular to the plane of incidence and parallel to the plane of the surface on which it reflects. The angle at which this occurs is called the polarization angle or Brewster's angle. At other angles, the reflected light is partially polarized. Depending on the surface and properties of the object, scattered EM waves, as opposing EM waves, will have different polarization orientations and intensities.

[0091] According to Fresnel's equation, the parallel reflection coefficient 320 is zero when the sum of the incident angle and the transmission angle equals 90°. The application of Snell's law yields the expression for the Brewster angle. Figure 3C An example is shown where the reflection coefficients of waves parallel to the incident plane and waves perpendicular to the incident plane are different. Figure 3C It also shows that when light is incident at Brewster angle, the reflected light is linearly polarized because the reflection of the parallel component is 0. Figure 3D The reflection intensities of rays parallel (parallel reflection coefficient 320) to the incident plane and rays perpendicular (perpendicular reflection coefficient 325) to the incident plane are shown.

[0092] In the following description, the transmitter and receiver refer to devices capable of transmitting and receiving electromagnetic waves with multiple polarizations. Examples of such transmitters and receivers are base stations, mobile user equipment, access points, WLAN stations, UEs, etc. An exemplary embodiment of the proposed solution includes the following basic process: (1) the transmitter and receiver mutually acknowledge that they support the features for LOS determination. For example, they may exchange messages or perform a broadcast of a message containing a field indicating feature support; (2) the receiver requests the transmitter to initiate the LOS determination process. In this request, the receiver may indicate the number of transmissions and polarization; (3) the transmitter continuously (repeatedly) transmits a reference signal (RS) during a single transmission or in different transmissions, which allows the receiver to estimate the channel impulse response. The RS is typically given by a specific bit sequence encoded in the frequency or time domain. This sequence is then modulated at a carrier frequency with a given bandwidth to form an electromagnetic waveform (radio signal). The RS bit sequence may contain additional information such as cell identification (ID), beam ID, or polarization ID. The possible set of RSs (RS resource set) must be known at the receiver. For example, in the case of a single transmission, the transmitted data consists of multiple temporal repetitions of a reference signal, each repetition having a different polarization but the same power. When multiple transmissions exist, each transmission is transmitted with a different polarization. In one exemplary embodiment, the transmitter indicates the number of repetitions and the polarization corresponding to each repetition in the preamble of its transmission; (4) the receiver determines the RS and estimates the CIR from each antenna port corresponding to a different polarization orientation. There may be multiple polarization ports available on the receiver. The receiver selects the strength of the first arrival path corresponding to each received RS and port from the estimated CIR. In one embodiment, these positive strength figures are reported back to the transmitter or network. In a second embodiment, the receiver calculates a decision value from a given metric based on the number of transmitted and received polarizations. Based on a given threshold, the receiver can then determine whether the first path corresponds to a LOS path or a NLOS path; (5) in one embodiment, the metric may be given by the difference in polarization strength. If the strength of the first reception path of each received repetition is constant relative to the transmitted polarization, the receiver concludes that the communication is LOS; (6) the receiver may notify the transmitter that the communication is LOS.

[0093] In various exemplary embodiments, the transmitter may broadcast an indication of LOS feature support, followed by the number of repetitions and the corresponding polarization for each repetition, and then broadcast reference signals under different polarizations. The receiver can then compare the strength of the first received path under different polarizations to determine whether the communication is LOS. Transmission with different polarization orientations can be implemented in different ways, for example, using two antennas with similar antenna patterns, having polarizations orthogonal to each other, such as one antenna polarized parallel to the Earth's surface and the other perpendicular to it. Any linear polarization orientation can be radiated by simultaneously transmitting the same signal at different powers on two antennas. Assuming power normalization of the RS, the power weights w_1 and w_2 of antennas 1 and 2 must satisfy w_1^2 + 2_2^2 = 1 to ensure that the normalized transmitted RS is a superposition of the two radiated RSs.

[0094] In this example, one transceiver transmits a reference signal at least twice in different polarizations (e.g., the bit sequence has orthogonal polarization), and another transceiver receives these transmissions and determines the strength of each of the received waves or each of the received bit sequence repetitions. If the two received waves (or signals) have the same strength, the transceiver concludes that the propagation of the received waves is of LOS (Longest in Hour). In some exemplary embodiments, the RS transmissions are sequential in time (i.e., one after another). In some cases, the repetitions are performed at approximately the same power, or at a power (known to the receiver), such that the receiver can compare the received strength (power) of each transmission to determine whether they have experienced any reflections.

[0095] A multipath communication channel is one in which, for each transmission from the transmitter, the receiver receives multiple copies of the transmission because propagation between the transmitter and receiver occurs via simultaneous paths. In the real world, each path corresponds to one or more reflections of the electromagnetic wave. Therefore, in the case of multipath channel propagation, for each transmission from the transmitter, the receiver may receive multiple copies of the same RS (due to reflections in the environment). In many cases, for LOS communication, there exists a single path (shortest path) corresponding to the LOS and multiple additional paths corresponding to reflections. However, if the communication is NLOS, all paths correspond to reflections (even the shortest ones), and there are no LOS paths. Therefore, in the proposed solution, the receiver must (only, at least) observe the strength of the first arrival path (corresponding to the transmission with the shortest ToF) for each polarization. The receiver retains the strength of the first arrival path (copy) from transmissions with different polarizations. If the strength of the first received path is constant with respect to the transmitting polarization, i.e., the first received path with each different polarization has the same strength with respect to different transmitter polarizations, then the transmitter and receiver are in a LOS state. A path can also be referred to as a ray.

[0096] In the method described above, if only one repetition of the bit sequence is sent (two copies in total, including the original transmission of the bit sequence), a critical situation (a very unlikely event) may occur when there is no LOS (NLOS) but multiple reflections, in which two transmitted bit sequences with different polarizations are still received with the same intensity. This occurs when the reflectors are orthogonal to each other, for example, when each reflector is at a 45-degree angle to each incident wave.

[0097] To handle this particular case in the presented solution, the transmitter sends several repetitions of the same bit sequence under different polarizations (e.g., more than two, and therefore at least three transmissions), and the receiver determines the received intensity of the first received path (ray) for each transmission. If these intensities are the same, it means that the received wave is LOS, i.e., the transmission has not been reflected.

[0098] Figure 4A An example of a signal flow diagram 400 for a method for determining LOS according to the present invention is shown. The method can be implemented as follows: Figure 2A or Figure 2B Executed within the context of the system shown, and can use linear polarization or circular polarization as such Figure 3A or Figure 3B The example shown.

[0099] In step 402, receiver 204 requests transmitter 202 to initiate the LOS determination process by sending a LOS determination request. The LOS determination request may include one or more of the number of transmissions to receiver 204 and the number of polarizations available at receiver 204. The number of transmissions to receiver 204, the number of polarizations of receiver 204, and the direction may also be pre-established by known definitions of protocols or standards.

[0100] In step 404, transmitter 202 continuously transmits a sequence of reference signals (RS) with equal power during a single frame transmission or in different frame transmissions, wherein each RS is transmitted on one of a plurality of antenna resources. The antenna resources can be a specific beam orientation or a specific polarization, such as a linear polarization orientation. For LOS detection via polarization measurement, at least two RSs need to be transmitted sequentially on two different polarization orientations. It should be understood that the transmission can be in response to a prior request (e.g., the request in step 402) sent by receiver 204 to transmitter 202. Such a prior request (e.g., the request in step 402) can include the number and orientation of polarizations to be transmitted by transmitter 202. Transmissions under different polarizations can be implemented in different ways, for example, with two dipole antennas orthogonally oriented to each other.

[0101] For a single frame transmission, the data transmitted by transmitter 202 includes multiple repetitions (or copies) of the same bit sequence, each repetition corresponding to one of the different polarizations. The number of repetitions can be referred to as the number of polarizations in the LOS determination request, or as a predefined number agreed upon between receiver 204 and transmitter 202. For multiple frame transmissions, each frame transmission is sent with a different polarization. In an exemplary embodiment, transmitter 204 indicates, for example, in its transmission preamble (the first part of the transmission) the number of bit sequence repetitions to be followed in the transmission and the polarization corresponding to each bit sequence repetition.

[0102] It should also be understood that in some exemplary embodiments of step 404, the transmitter 202 transmits the same signal wave or the same bit sequence at least twice with the same power in the same direction (same orientation) and with different polarizations.

[0103] The number of times the same signal wave or the same sequence of bits is sent can be called the transmission count. The transmission count in the LOS determination request can specify the number of times the same signal wave or the same sequence of bits is sent.

[0104] In step 406, receiver 204 checks to determine whether a first received copy from each of the multiple polarizations has been detected and measures its power or intensity.

[0105] In the example of NLOS multipath channel propagation, each path corresponds to a copy (also called a reflection) of the transmitted signal wave. Receiver 204 receives multiple copies for each transmission because propagation between transmitter 202 and receiver 204 occurs through multiple paths. In some examples, each path corresponds to one or more reflections of the electromagnetic wave. Therefore, in the case of multipath channel propagation, for each transmission from transmitter 202, receiver 204 can receive multiple copies of the transmission (due to reflections in the environment). For LOS communication, the first receiving path (also the shortest path) corresponds to LOS communication, while the other multiple adjacent paths correspond to reflections.

[0106] After the receiver 204 measures (or detects) the first receiving path (by receiving signal) for each transmission, the receiver 204 acquires and compares the strength of each first receiving copy for multiple transmissions, wherein the first receiving copy is a copy received through the first receiving path.

[0107] For example, transmitter 202 transmits the same bit sequence twice, each time with two polarizations. These two transmissions correspond to two data transfers: a first data transfer with the same bit sequence having two polarizations (e.g., polarization A and polarization B), and a second data transfer with the same bit sequence having two polarizations (e.g., polarization C and polarization D). Receiver 204 can detect the first path of the first data transfer on the paths of polarization A and polarization B. Receiver 204 can detect the first path of the second data transfer on the paths of polarization C and polarization D. For example, the first path of the first data transfer is the path of polarization A, and the first path of the second data transfer is the path of polarization C.

[0108] In steps 408 and 410, receiver 204 determines whether the strength (or power) of each first received copy is equal. If the strength (or power) of each first received copy of the multiple transmissions for each polarization is equal (or less than a threshold), the transmission between receiver 204 and transmitter 202 is LOS; otherwise, the transmission between receiver 204 and transmitter 202 is NLOS.

[0109] For example, referring to the example presented above, receiver 204 determines whether the intensities of polarization A and polarization C are equal, based on their characterization paths.

[0110] For signal waves transmitted under circular polarization (e.g.) Figure 3B In the example shown, the received wave signal has the same intensity during the complete rotation of the LOS wave vector "E". However, for NLOS reflections, the intensity varies depending on the specific reflection (orientation of the reflecting surface). Therefore, for circularly polarized transmission, receiver 202 will compare the intensity changes of the received wave signal, and if there is (or approximately) constant intensity propagation in the received wave, the communication between transmitter 202 and receiver 204 can be LOS communication. To reduce the possibility of LOS determination errors, this technique can be combined with continuous receive or transmit beamforming, as described below.

[0111] In step 412, receiver 204 notifies transmitter 202 of the determination result.

[0112] In this example, receiver 204 characterizes the path, that is, determining whether the communication between receiver 204 and transmitter 202 on the path is LOS based on the strength of each copy of the wave signal. The process of using the results (path characterization), such as the process of determining the distance between receiver 204 and transmitter 202, can have greater confidence in the distance determined using Time-of-Flight (ToF).

[0113] In an exemplary embodiment, when communication between receiver 204 and transmitter 202 changes from LOS to NLOS (e.g., path representation changes from LOS to NLOS), the device (which may be receiver 204 or transmitter 202) may decide to initiate a handover to a different device or access point (e.g., an access node) to begin new communication, so that the device can perform LOS communication. In other words, the device initiates a handover to a different device to avoid NLOS communication. For this purpose, the device (which may be receiver 204 or transmitter 202) will periodically evaluate whether there are neighboring devices (e.g., access nodes) that can communicate with the device at LOS, and switch to the neighboring device when the current LOS communication fails or becomes NLOS. For example, such LOS-based handover can be used to obtain higher communication quality (reduced path loss) or allow for precise tracking of the device's location.

[0114] LOS determination can also allow for remote operation of devices such as drones (which could be receiver 204 or transmitter 202) to determine changes in trajectory in order to maintain LOS communication.

[0115] In one exemplary embodiment, LOS detection can be performed simultaneously with multiple receivers. For example, transmitter 202 transmits the same waveform signal to multiple receivers with different polarizations, and then requests each receiver to report whether the communication between the receiver and transmitter 202 is LOS communication. Alternatively, transmitter 202 transmits the same waveform signal with different polarizations, and then allows LOS receivers to compete for channel access through a random access channel procedure. In other words, receivers that determine they are using LOS communication initiate a random access channel procedure for channel access.

[0116] In various exemplary embodiments, the device records path characterization information that varies with location (e.g., the channel at this location is NLOS or LOS) and uses the stored information to access or discover access nodes, perform access node discovery, or for fast beamforming. For example, to minimize discovery latency, beamforming scanning can begin with the device scanning the LOS direction (determined based on the stored information), and then if the LOS direction is blocked, the device performs an additional search around the LOS direction. In other words, the device performs fast beamforming by initially scanning the LOS direction, and then if a suitable beam is not found, the device scans in directions around the LOS direction, where the LOS direction is retrieved from the stored information.

[0117] Figure 4B An example of an alternative signal flow graph 400' of a first exemplary embodiment of a method for determining LOS according to the present invention is shown. The method can be implemented as follows: Figure 2A or Figure 2BExecuted within the context of the system shown, and can use linear polarization or circular polarization as such Figure 3A or Figure 3B The example shown.

[0118] exist Figure 4B In step 402, transmitter 202 initiates a request to start the LOS procedure. Specifically, transmitter 202 sends an LOS determination request to receiver 204. The LOS determination request in step 402' includes one or more of the number of transmissions by transmitter 202 and the number of polarizations by transmitter 202. Then, in step 404', receiver 204 sends a response to transmitter 202. The response in step 404' may include an indication confirming the start of the LOS procedure. Alternatively, the response in step 404' may include one or more of the number of transmissions by receiver 204 and the number of polarizations by receiver 204.

[0119] Figure 4B The remaining steps (steps from 406' to 414') correspond to Figure 4A The steps from 404 to 412 will not be discussed here.

[0120] Figure 4C An example of another alternative signal flow graph 400” is shown, illustrating a first exemplary embodiment of a method for determining LOS according to the present invention. The method can be implemented as follows: Figure 2A or Figure 2B Executed within the context of the system shown, and can use linear polarization or circular polarization as such Figure 3A or Figure 3B The example shown.

[0121] exist Figure 4C In step 402, transmitter 202 initiates a request to start the LOS (Low Status Orientation) process. That is, transmitter 202 broadcasts an LOS determination request to a receiver, such as receiver 204. The LOS determination request in step 402 includes one or more of the number of transmissions by transmitter 202 and the number of polarizations by transmitter 202. Transmitter 202 broadcasts wave signals comprising the same bit sequence with different polarizations in a single transmission or in multiple transmissions.

[0122] Figure 4C The remaining steps (steps from 406” to 412”) are the same as Figure 4A The steps from 406 to 412 are the same and will not be discussed further here.

[0123] Before steps 402, 402', and 402'", receiver 204 may send a LOS confirmation request to transmitter 202. Transmitter 202 and receiver 204 may perform an acknowledgment process to confirm that both transmitter 202 and receiver 204 support the LOS confirmation process. The acknowledgment process may be performed by exchanging messages between receiver 204 and transmitter 202, or by transmitter 202 broadcasting messages to receiver 204.

[0124] The message indicating that receiver 204 or transmitter 202 supports LOS determination may be an enhanced directional multi-gigabit (EDMG) beam refinement protocol (BRP) request, and the EDMG BRP request includes an element indicating that the device sending the EDMG BRP request (in this example, receiver 204 or transmitter 202) supports LOS determination.

[0125] For example, an EDMG BRP request can follow the format shown in Table 1.

[0126] Table 1: First Exemplary EDMG BRP Request Format

[0127]

[0128] The first path training element indicates that the device sending the EDMG BRP request (which in this example could be receiver 204 or transmitter 202) supports the first path training process. This means that the device supports determining which path is the shortest among all paths that transmit different copies of the same bit sequence, where each copy corresponds to a polarization.

[0129] The LOS training element indicates that the first device (which can be receiver 204 or transmitter 202) sending the EDMG BRP request supports the LOS determination process, for example. Figures 4A to 4C The process is illustrated in the accompanying discussion.

[0130] In another exemplary embodiment, the first path training element may be included in the header of the EDMG BRP request. Alternatively, the first path training element may be included in a text string, for example, the text string being part of the EDMG BRP request.

[0131] As another example, an EDMG BRP request can follow the format shown in Table 2:

[0132] Table 2: Second Exemplary EDMG BRP Request Format

[0133]

[0134] If receiver 204 and transmitter 202 confirm, for example, via an EDMG BRP request that both transmitter 202 and receiver 204 support the LOS determination process, the data packet includes an indication that the copy should be used for first path beamforming training. Specifically, when the first path training element is set to a first value, such as "1", it indicates that the TRN field appended to this data packet should be used for first path beamforming training. When set to a second value, such as "0", the first path training element indicates that the TRN field appended to this data packet should be used for optimal performance beamforming training.

[0135] When the LOS training element is set to the first value, such as '1', it indicates that the TRN field appended to this packet should be used for LOS beamforming training. When the LOS training element is set to the second value, such as '0', it indicates that the TRN field appended to this packet should not be used for LOS beamforming.

[0136] In an EDMG BRP request, if the first device sending the EDMG BRP request supports the LOS determination process, both the first path training element and the LOS training element should be set to the first value, such as '1'. Otherwise, the first device sending the EDMG BRP request does not support the LOS determination process.

[0137] After the second device (which in this example could be transmitter 202 or receiver 204) receives the EDMG BRP request, the second device may send a response to the first device (that sent the EDMG BRP request) to indicate that the second device supports the LOS determination procedure. The second device may also send an EDMG BRP request to the first device to indicate that the second device also supports the LOS determination procedure.

[0138] Any response from the second device or an EDMG BRP request from the second device may include an indication that the device (first device or second device) supports the LOS determination process.

[0139] In another example, if receiver 204 and transmitter 202 confirm via a message that both transmitter 202 and receiver 204 support the dual-polarization TRN procedure, the data packet includes an indication to use first path beamforming training. The first path training element is set to a first value, such as '1', indicating that the TRN field appended to this data packet should be used for first path beamforming training. The first path training element can be set to a second value, such as '0', to indicate that the TRN field appended to this data packet should be used for optimal performance beamforming training.

[0140] The LOS training element is set to the first value, such as '1', indicating that the TRN field appended to this packet should be used for LOS beamforming training. The LOS training element is set to the second value, such as '0', indicating that the TRN field appended to this packet should not be used for LOS BF.

[0141] In an EDMG BRP request, if the first device sending the EDMG BRP request supports the LOS determination process, both the first path training element and the LOS training element should be set to the first value, such as '1'. Otherwise, the first device sending the EDMG BRP request does not support the LOS determination process.

[0142] After receiving the EDMG BRP request, the second device (which in this example could be transmitter 202 or receiver 204) can send a response to the first device (the one that sent the EDMG BRP request) to indicate that the second device supports the LOS determination procedure. Alternatively, the second device can send an EDMG BRP request to the first device to indicate that it also supports the LOS determination procedure.

[0143] Either a response from the second device or an EDMG BRP request from the second device may include instructions from the peer device instructing the LOS determination process.

[0144] Figure 5 An example of a communication system 500 is shown, wherein the propagation between transmitter 202 and receiver 204 is an NLOS with a cylindrical reflective surface 508 that obstructs LOS communication with a cylindrical reflective region 509 (e.g., beam 510). The communication system 500 can be used to implement the devices and methods disclosed herein.

[0145] In other words, each repetition (copy) at any polarization will suffer similar reflections, so at receiver 204, regardless of the polarization at transmitter 202, the first received copy of each transmission (e.g., beams 512, 512', 514, 514', 516, and 516') will have approximately the same intensity. If the transmission of transmitter 202 and the reception of receiver 204 are omnidirectional, then due to the symmetry of this structure (cylindrical reflective surface 508), receiver 204 will always receive the same wave signal regardless of the polarization at transmitter 202.

[0146] However, if receiver 204 performs beamforming reception (in the case where receiver 204 receives from a finite spatial direction (e.g., a 3D solid angle), the Time of Flight (ToF) will be the same, but the intensity of the first received ray (the first received copy) will change with the polarization wave at transmitter 202. Receiver 204 can then conclude that the propagation is NLOS.

[0147] Therefore, as an exemplary embodiment of the invention, receiver 204 can repeatedly perform beamforming reception in different spatial directions (and thus may suffer different reflections) while transmitter 202 changes the polarization of the transmitted wave. If the spatial direction is found to be invariant with respect to the polarization, the spatial direction is considered LOS. In another exemplary embodiment, transmitter 204 transmits beamforming waves in different directions, each with multiple (different) polarizations, and receiver 204 observes a change in the intensity of a first received sample with respect to the polarization; in this case, communication is considered NLOS. For example, beamforming transmission with different polarizations can be added to the aforementioned LOS process after path characterization is determined as an additional step to verify the path characterization. Beamforming transmission can also be performed during the LOS process itself when polarization and beamforming beams are combined to determine when and whether the first received copy is invariant with respect to the polarization (this only occurs in LOS communication).

[0148] Examples of beamforming implementation involve using phased array antennas, such as two-dimensional (2D) polarized antenna arrays, where each antenna has a phase shifter. Another example uses polarized horn antennas.

[0149] Figure 6A An example of a signal flow graph 600 for a method for determining LOS according to the present invention is shown. The method can be implemented as follows: Figure 2A or Figure 2B Executed within the context of the system shown, and can use linear polarization or circular polarization as such Figure 3A or Figure 3B The example shown.

[0150] In step 602, receiver 204 requests transmitter 202 to initiate the LOS determination process by sending a LOS determination request. The LOS determination request may include an indication of whether a dual-polarization process for LOS is used, where dual-polarization refers to two different polarizations in each direction. The same sequence is transmitted twice in the same direction with different polarizations, for example, with two orthogonal polarizations.

[0151] If the indication specifies the use of a LOS dual-polarization process, then transmitter 102 should transmit the same bit sequence in the waveform signal under both different polarizations. If the indication specifies that a LOS dual-polarization process is not used, then transmitter 202 transmits the bit sequence in the waveform signal, but not in dual polarization. Figure 6A An example using the LOS dual-polarization process is presented.

[0152] In step 604, transmitter 202 transmits the same bit sequence in the wave signal under different polarizations. An example of such a bit sequence in IEEE 802.11ay is called a training TRN sequence and is transmitted in a spatial direction. The transmission may be in response to a previous LOS determination request, including an indication of which LOS dual-polarization process to use. Transmission under different polarizations can be implemented in different ways, for example, using two dipole antennas orthogonal to each other, one parallel to the Earth's surface and the other perpendicular to the Earth's surface.

[0153] For a single-frame transmission, the data transmitted by the transmitter 202 includes multiple repetitions (copy) of the same bit sequence, wherein each repetition (copy) is transmitted in one of the polarizations.

[0154] Before transmitting a wave signal comprising the same bit sequence to the receiver 204, the transmitter 202 may inform the receiver 204 of the TRN power for each polarization. The transmitter 202 may transmit the same signal wave at the same power for different polarizations, or the transmitter 202 may transmit the same signal wave at different power for different polarizations.

[0155] In step 606, receiver 204 obtains channel measurements for each polarization. Example channel measurements are presented in Table 3, which shows exemplary I-component and Q-component values ​​for different filter taps with different polarizations. The channel measurements obtained by receiver 204, with the channel measurements for the first path enabled and dual-polarization TRN enabled, can be as shown in Table 3. As shown in Table 3, for each polarization, the channel measurement includes relative I-component tap #1 polarization #1 and relative Q-component tap #1 polarization #1. Relative I-component tap #1 polarization #1 is the in-phase component of the impulse response of tap #1 (corresponding to the shortest delay) and polarization #1 in the dual-polarization TRN. Relative Q-component tap #1 polarization #1 is the quadrature component of the impulse response of tap #1 (corresponding to the shortest delay) and polarization #1 in the dual-polarization TRN.

[0156] If the dual-polarized TRN process is not combined with the first path process, the receiver 204 can feed back measurements from more than one tap (first path) to the transmitter 202, as also shown in Table 3.

[0157] In an example of a dual-polarization TRN, transmitter 202 transmits a wave signal comprising the same bit sequence in both polarizations. Therefore, receiver 204 obtains the relative Q component and relative I component for each of the two polarizations. In other examples of dual-polarization TRNs, transmitter 202 transmits a wave signal comprising the same bit sequence in two different polarizations via a multipath channel, and receiver 204 obtains the relative Q component and relative I component for each path in each of the two polarizations.

[0158] Table 3: Channel Examples with Different Polarizations

[0159]

[0160]

[0161] As shown in the example in Table 3, in a dual-polarization TRN, transmitter 202 transmits a wave signal comprising the same bit sequence in both polarizations, with N paths in each polarization. The channel measurements for the Nth path in both polarizations are also shown in Table 3. Tap #1 represents the first path measured by the receiver, and tap #N represents the Nth path measured by the receiver. The first path has the shortest delay.

[0162] In step 608, receiver 204 compares the channel measurements of the two polarizations to obtain the channel measurement difference.

[0163] In step 610, receiver 204 determines whether the channel measurement difference between the two polarizations is greater than a threshold. If the channel measurement difference between the two polarizations is greater than the threshold, receiver 204 can determine that the transmission between receiver 204 and transmitter 202 is NLOS; otherwise, the transmission is LOS. The threshold can be specified in technical standards or by the operator of the communication system. The threshold can be determined through cooperation between devices in the communication system.

[0164] If transmitter 202 transmits the same bit sequence in two polarizations, and each polarization has multiple paths, receiver 204 can compare the channel measurements of the first path in each polarization. If the channel measurement difference between the two polarizations is greater than a threshold, receiver 204 can determine that the transmission between receiver 204 and transmitter 202 is NLOS; otherwise, the transmission can be LOS. The threshold is stored in receiver 204. The threshold can be predetermined or implementation-specific. The threshold needs to be large enough to filter out possible noise and measurement errors. If the radiated power of the two polarizations at transmitter 202 is different, receiver 204 needs to consider this difference in addition to the threshold.

[0165] In step 612, receiver 204 may notify transmitter 102 of the determination result.

[0166] In this example, receiver 204 determines whether the communication between receiver 204 and transmitter 202 is LOS based on two polarized channel measurements to ensure the determination result. This makes the process of utilizing the result (path characterization), such as the process of determining the distance between receiver 204 and transmitter 202, have good determinism in the result.

[0167] In another example, receiver 204 may omit steps 608 through 612. Instead, receiver 204 sends channel measurements for each polarity to transmitter 202. Transmitter 202 receives the channel measurements for each polarity, compares the channel measurements for the two polarities, and characterizes the path by performing its own version of steps 608 and 610 (e.g., determining whether the difference between the channel measurements for the two polarities is greater than a threshold). If the difference between the channel measurements for the two polarities is greater than the threshold, transmitter 202 can determine that the transmission between receiver 204 and transmitter 202 is NLOS; otherwise, the transmission is LOS.

[0168] In an exemplary embodiment, when communication between receiver 204 and transmitter 202 changes from LOS to NLOS (e.g., path representation changes from LOS to NLOS), the device (in this example, receiver 204 or transmitter 202) may decide to switch (initiate new communication) to a different device or access point (e.g., access node) so that the device can perform LOS communication. In other words, the device initiates a switch to a different device to avoid NLOS communication. For this purpose, the device (which may be receiver 204 or transmitter 202) will periodically evaluate whether there are adjacent devices (e.g., access nodes) that can communicate with the device at LOS, and switch to the adjacent device when the current LOS communication fails or becomes NLOS. For example, such LOS-based switching can be used to obtain higher communication quality (reduced path loss) or allow for precise tracking of the device's location.

[0169] Figure 6B An example of a signal flow graph 600' for a method for determining LOS according to the present invention is shown. The method can be implemented as follows: Figure 2A or Figure 2B Executed within the context of the system shown, and can use linear polarization or circular polarization as such Figure 3A or Figure 3B The example shown.

[0170] exist Figure 6B In step 602, transmitter 202 initiates a request to start the LOS procedure. That is, transmitter 202 sends an LOS determination request to receiver 204. The LOS determination request in step 602' includes an indication of whether to use a dual-polarization procedure for LOS. Then, in step 604', receiver 204 sends a response to transmitter 202. The response in step 604' may include an indication to initiate the LOS procedure using a dual-polarization procedure.

[0171] Figure 6B The steps from 606' to 614' are... Figure 6A The steps from 604 to 612 are the same and will not be discussed further here.

[0172] Figure 7 An example of a signal flow diagram 700 for a method for determining LOS according to the present invention is shown. The method can be implemented in, for example... Figure 2A or Figure 2B Executed within the context of the system shown, and can use linear polarization or circular polarization as such Figure 3A or Figure 3B The example shown.

[0173] exist Figure 7 In step 702, transmitter 202 initiates a request to start the LOS procedure. That is, transmitter 202 broadcasts an LOS determination request to receiver 204. The LOS determination request in step 702 includes an indication that a dual-polarization procedure for LOS has been used. Then, transmitter 202 broadcasts the same bit sequence with different polarizations during a single transmission or in different transmissions, in step 704.

[0174] Figure 7 Steps 706 to 712 in the middle and Figure 6A Steps 606 to 612 are the same and will not be discussed further here.

[0175] In another example, receiver 204 may not need to perform this action. Figure 6A Steps 608 to 612 in the middle Figure 6B Steps 610' to 614' or Figure 7 Steps 708 to 712 in the above steps. Alternatively, after obtaining the channel measurement for each polarity, receiver 204 sends the channel measurement for each polarity to transmitter 202. Transmitter 202 compares the channel measurements for two polarities and characterizes the path by performing corresponding steps in its own version (e.g., determining whether the channel measurement difference between the two polarities is greater than a threshold). If the channel measurement difference between the two polarities is greater than the threshold, transmitter 202 can determine that the transmission between receiver 204 and transmitter 202 is NLOS; otherwise, the transmission is LOS.

[0176] Prior to step 702, receiver 204 may send a dual-polarization request to transmitter 202. Transmitter 202 and receiver 204 may then perform an acknowledgment process to confirm that both transmitter 202 and receiver 204 support dual-polarization TRN measurements. The acknowledgment process can be performed by exchanging messages between receiver 204 and transmitter 202, or by broadcasting messages between transmitter 202 and receiver 204.

[0177] The LOS determination request, indicating whether a dual-polarization procedure using LOS is used, can be an EDMG BRP request. The EDMG BRP request includes a dual-polarization TRN field. The dual-polarization TRN field indicates whether a device (in this example, receiver 204 or transmitter 202) is sending an EDMG BRP request to request dual-polarization TRN.

[0178] For example, an EDMG BRP request can follow the format shown in Table 4.

[0179] Table 4: Third Exemplary EDMG BRP Request Format

[0180]

[0181] In Table 4, the dual-polarization TRN element (which can also be a field) indicates whether the first device (receiver 204 or transmitter 202) sending the EDMG BRP request supports the dual-polarization TRN training process. The dual-polarization TRN element in Table 4 can also indicate whether a dual-polarization process with LOS is used. If the dual-polarization TRN element is set to a first value, such as '1', it indicates that the second device receiving the BRP is requested to send a repetition of the TRN sequence with different polarizations in the form of beams targeting the same antenna weight vector (AWV). That is, if the first device sending the EDMG BRP requests dual-polarization TRN, the dual-polarization process is used. If the dual-polarization TRN element is set to a second value, such as '0', it indicates that the TRN can be sent without polarization changes in each AWV, meaning the TRN should be sent with one polarization. That is, if the device sending the EDMG BRP does not request dual-polarization TRN, the dual-polarization process is not used.

[0182] The dual-polarized TRN element indicates whether the first device (which can be receiver 204 or transmitter 202) that sent the EDMG BRP request requested it. Figures 6A to 6B and Figure 7 The bipolarization process described in [the text].

[0183] In another example, a dual-polarized TRN element can be included in the header of an EDMG BRP request.

[0184] In another example, an indication of whether a dual-polarization process is used may be included in the receive vector (RXVECTOR) parameter or the receive vector (TXVECTOR) parameter. The RXVECTOR parameter is received by receiver 204 and represents physical layer (PHY) interaction during the reception of various physical layer convergence protocol (PLCP) protocol data unit (PPDU) formats. The RXVECTOR parameter is a parameter of receiver 204. The TXVECTOR parameter is a parameter of transmitter 202. The TXVECTOR parameter represents PHY interaction during the transmission of various PPDU formats.

[0185] Table 5 presents either the RXVECTOR parameter or the TXVECTOR parameter, which includes an indication of whether the LOS dual-polarization process is used.

[0186] Table 5: Indicators for the dual polarization process of RXVECTOR and TXVECTOR

[0187]

[0188] The dual-polarization_TRNS element in the RXVECTOR or TXVECTOR parameter indicates whether the TRN field appended to this packet has at least two distinct polarizations for each AVW. If the dual-polarization_TRNS element in the RXVECTOR or TXVECTOR parameter is set to a first value, such as '1', it indicates that the TRN field appended to the packet including the TRN has a different polarization for each beamform. If the dual-polarization_TRNS element in the RXVECTOR or TXVECTOR parameter is set to a second value, such as '0', it indicates that the TRN field appended to the packet has one polarization.

[0189] In another example, an indication of whether to use the LOS dual-polarization process can be included in the EMDG-Header-A field. The EMDG-Header-A field is the field structure and definition of a single-user (SU) PPDU. The indication of whether to use the LOS dual-polarization process included in the EMDG-Header-A field can be a dual-polarization TRN training element, examples of which are shown in Table 6 below.

[0190] Table 6: Examples of Dual Polarization Process Indicators for the EMDG-Header-A Field

[0191]

[0192] The dual-polarization TRN training element included in the EMDG-Header-A field indicates whether consecutive TRN units appended to each AVW of the data packet have different polarizations. The TRN field enables the transmitter and receiver to perform AWV training. If the dual-polarization TRN training element included in the EMDG-Header-A field is set to a first value, such as '1', it indicates that the TRN field appended to the data packet has different polarizations for each beamform. If the dual-polarization TRN training element included in the EMDG-Header-A field is set to a second value, such as '0', it indicates that the TRN field appended to the data packet has one polarization for each beamform. If the dual-polarization TRN training element included in the EMDG-Header-A field is set to a first value, such as '1', it also indicates that a dual-polarization process using LOS was employed.

[0193] In another example, the indication of whether to use the LOS dual-polarization process can be included in the EMDG-Header-A2 subfield. The EMDG-Header-A2 subfield is transmitted in the second low-density parity check (LDPC) codeword. The indication of whether to use the LOS dual-polarization process included in the EMDG-Header-A2 subfield can be a dual-polarization TRN training element, examples of which are shown in Table 7:

[0194] Table 7: Examples of Dual Polarization Process Indicators for the EMDG-Header-A2 Field

[0195]

[0196]

[0197] The dual-polarization TRN training element included in the EMDG-Header-A2 subfield indicates whether the TRN unit attached to this packet for each AVW has a different polarization. If the dual-polarization TRN training element included in the EMDG-Header-A2 subfield is set to a first value, such as '1', it indicates that the TRN field attached to the packet has a different polarization for each beamform. If the dual-polarization TRN training element included in the EMDG-Header-A2 subfield is set to a second value, such as '0', it indicates that the TRN field attached to the packet has one polarization for each beamform. If the dual-polarization TRN training element included in the EMDG-Header-A2 subfield is set to a first value, such as '1', it also indicates that a LOS dual-polarization process was used.

[0198] In Table 7, "1" indicates that the length of a dual-polarized TRN training element is one bit, and "6" indicates the bit position of the dual-polarized TRN training element. In Table 6, "1" indicates that the length of a dual-polarized TRN training element is one bit, and "48" indicates the bit position of the dual-polarized TRN training element.

[0199] In another example, an indication of whether a dual-polarization process using LOS is used can be included in the dual-polarization TRN support subfield of the beamforming capability field format. The indication of whether a dual-polarization process using LOS is used, included in the dual-polarization TRN support subfield of the beamforming capability field format, can be a dual-polarization TRN support element, examples of which are shown in Table 8 below.

[0200] Table 8: Examples of Dual Polarization Process Indicators in the Format Subfield of the Beamforming Capability Field

[0201]

[0202] The dual-polarization TRN support element, included in the beamforming capability field format, indicates whether the dual-polarization TRN process is enabled. If the dual-polarization TRN element is set to a first value, such as '1', it indicates that the dual-polarization TRN process is enabled, meaning TRN sequences can be transmitted with different polarizations, thus indicating the use of the dual-polarization TRN process. If the dual-polarization TRN support element is set to a second value, such as '0', it indicates that the dual-polarization TRN process is not enabled, meaning TRN sequences can be transmitted with a single polarization, thus indicating the use of the dual-polarization TRN process.

[0203] The dual-polarization power difference subfield indicates the difference in radiated power for each polarization. The dual-polarization power difference can be indicated as shown in Table 8.

[0204] The dual-polarization TRN support element and dual-polarization power difference can also be dual-polarization TRN capability fields, as shown in Table 9 below.

[0205] Table 9: Examples of Dual-Polarization TRN Capability Fields

[0206]

[0207]

[0208] The indication of whether to use the LOS dual-polarization process is included in the dual-polarization TRN capability field format, as shown in Table 8. The indication can also indicate whether the dual-polarization TRN process is supported. If the dual-polarization TRN element is set to a first value, such as '1', it indicates that the dual-polarization TRN process is supported, and TRN sequences can be sent with different polarities. If the dual-polarization TRN element is set to a second value, such as '0', it indicates that the dual-polarization TRN process is supported, and TRN sequences can be sent with one polarity.

[0209] In another example, an indication of whether to use the LOS dual-polarization process can be included in the DMG beam refinement element. The DMG beam refinement element can be referenced to Figure 9-512 of IEEE 802.11, which is incorporated herein by reference. The dual-polarization TRN element can replace the reserved bits in the same figure.

[0210] The dual-polarized TRN element in the DMG beam refinement element (as shown in Figure 9-512) can be an EDMG dual-polarized TRN channel measurement presence. An EDMG dual-polarized TRN channel measurement presence equals a first value, such as '1', indicating that the EDMG channel measurement feedback element contains a dual-polarized TRN measurement field. When the EDMG dual-polarized TRN channel measurement presence equals a second value, such as '0', it indicates that the EDMG channel measurement feedback element does not contain a dual-polarized TRN measurement field.

[0211] The dual-polarization power difference subfield represents the difference in radiated power between different polarizations. The TRN power difference value represents the difference in radiated power between consecutive TRN sequences with different polarizations, in dB.

[0212] Table 10 shows an example of the difference in radiated power between the first TRN subfield value and the second TRN subfield value.

[0213] Table 10: Examples of differences between the values ​​of the first TRN subfield and the second TRN subfield

[0214] TRN power difference bit The TRN power difference (dB) between the first TRN polarization and the second TRN polarization 000 0 001 1 010 2 011 3 or larger 101 -1 110 -2 111 -3 100 -4 or smaller

[0215] Combination Figure 6A , Figure 6B and Figure 7 The discussion and the polarization described in Tables 3 through 10 specify the details of the dual-polarization process. For example, dual-polarization involves two polarizations. In the dual-polarization process used for LOS determination, the same TRN (the same bit sequence in the wave signal) is transmitted in the same direction with two different polarizations. One of the two polarizations can be called the first polarization, and the other can be called the second polarization. Therefore, the first TRN is the TRN transmitted with the first polarization in the stated direction, and the second TRN is the TRN transmitted with the second polarization in the same direction.

[0216] from Figures 2A to 4C , Figure 5 The polarizations described in Tables 1 and 2 are different polarizations for different directions, such as vertical polarization, horizontal polarization, and 45-degree polarization. Different directional polarizations correspond to different paths.

[0217] In another example, Figures 2A to 3C , Figure 5 The LOS determination process described in Tables 1 and 2 can be compared with... Figure 6A , Figure 6B and Figure 7 This is combined with the LOS determination process described in Tables 3 through 10. The LOS determination request described in steps 402, 402', 402"', 602, 602' and 702 may include an indication of whether to use a dual-polarization process and may be combined with the first path training.

[0218] If receiver 204 and transmitter 202 acknowledge via a message that both transmitter 202 and receiver 204 support the dual-polarization TRN process and the first path training, the data packet includes an indication to use the first path beamforming training and an indication to use the dual-polarization process.

[0219] When the LOS process uses only two different polarizations of the same TRN sequence for transmission, this process is called dual-polarization TRN.

[0220] As mentioned earlier, the dual-polarization TRN process involves transmitting the same TRN sequence twice under different polarizations, and the receiver measures the received signal under each polarization.

[0221] The dual-polarization TRN process (for LOS) can be used in conjunction with first-path training or not.

[0222] If the dual-polarization TRN procedure is combined with first-path training, the receiver will only measure the first received copy (tap) of each polarization transmission. To do this, the transmission requested by the EDMG BRP should enable first-path BF and the dual-polarization TRN procedure.

[0223] The implementation solutions can be used in 3GPP new radio (NR) applications, where obtaining accurate location information may be an important consideration. For example, a potential commercial application for precise positioning could be indoor positioning using millimeter wavelength (mmW) access points. Having information about path characterization (or LOS or NLOS propagation) can improve the accuracy of positioning methods. For example, a UE can identify whether a received beam (or ray) is LOS or which received beam (or ray) is LOS, and perform positioning using only the LOS beam (or ray). In some exemplary embodiments, the LOS determination techniques described above can be applied using polarization for NR. While the description is for mmW propagation (frequency range two (FR2)), it is also applicable to microwave propagation (frequency range one (FR1)).

[0224] 3GPP has standardized various positioning technologies for Long Term Evolution (LTE). In addition, some new NR technologies have been considered. 3GPP LTE Contribution R1-1809348 provides a summary of exemplary positioning technologies, all of which are incorporated herein by reference. A partial summary of R1-1809348 is as follows.

[0225] In NR, the enhanced cell identifier (ECID) is used to estimate the UE location based on the detected cell ID, combined with auxiliary measurements. These auxiliary measurements can be Type 1 and Type 2 measurements such as the Tx-Rx time difference, the angle of arrival (AOA) of the serving cell, the reference signal received power (RSRP), the reference signal received quality (RSRQ), and related quality measurements (similar to LTE). The reference signals used in NR measurements can be the primary synchronization signal (PSS), the secondary synchronization signal (SSS), the physical random access channel (PRACH), and the sounding reference signal (SRS). Since NR does not support the LTE common reference signal (CRS), it can use cell-specific reference signals for measurements in the downlink, such as the downlink tracking reference signal (TRS) or the channel state information-reference signal (CSI-RS). In NR, ECID-based positioning can be performed on the UE side with the help of network data, or on the network side using UE measurements and gNB measurements.

[0226] In NR, the Observed Time Difference of Arrival (OTDOA) technique is a downlink positioning method where the UE measures the reference signal time difference (RSTD) between the reference gNB and its neighboring gNBs. The reference signal used for positioning in the downlink can be flexible, bandwidth-scalable, and available to all UEs. It is proposed to define a cell-specific positioning reference signal (PRS) in the NR downlink, similar to the LTE PRS, to achieve this goal. Related research includes, but is not limited to, PRS pattern design, sequence design, power enhancement, configurable IDs, co-frequency or inter-frequency RSTD measurement, support for multiple transmit-receive points (TRP) or cell PRS transmission, and integration with beam management mechanisms to support FR1 and FR2, as well as signal processing. If PRS is not permitted, another approach is to potentially reuse existing NR reference signals (e.g., TRS) with slight modifications so that they can perform the same function as PRS.

[0227] In NR, uplink time difference of arrival (UTDOA) is a network-based positioning method that uses uplink SRS to estimate the RSTD between a reference gNB and its neighboring gNBs. NR UTDOA is a mandatory feature because it is well-suited for estimating high-precision positions using network data and measurements, while saving PRS overhead since multiple gNBs can receive uplink SRS simultaneously. NR supports beam management and multiple TRPs for FR1 and FR2; therefore, NR UTDOA can be considered in combination with beam management and multiple TRP techniques to obtain high-quality UTDOA measurements.

[0228] Positioning based on uplink angle of arrival (UAOA) can be used to estimate the UE's position by measuring the AOA of the uplink reference signal. Uplink SRS can be used to measure the AOA in the gNB or TRP, but other reference signals (e.g., demodulation reference signal, DMRS) are not excluded. UAOA can be measured for elevation and zenith angles to obtain 3D position.

[0229] UAOA positioning is triggered by the location management function (LMF) of the NR positioning architecture. The LMF coordinates with the serving cell and relevant neighboring cells to provide UAOA measurements for location estimation. It can also provide relevant measurements, such as the number of antennas, to evaluate the quality of the UAOA measurements and assist the LMF in performing positioning.

[0230] Since both UTDOA and UAOA use uplink SRS for measurement and positioning, UAOA-based positioning can be applied with similar signaling procedures as those performed in UTDOA. However, additional design considerations may be necessary when both the UE and gNB or TRP use transmit beamforming (e.g., for FR2 operation).

[0231] In some cases, positioning based on the downlink angle of departure (DAOD) can be used. Similar to UAOA, estimating the UE's location based on the DAOD of multiple gNBs or TRPs is feasible. DAOD is the AOD of the strongest path from the gNB, which can be measured by the UE. For example, the UE can measure the channels on all available beams received from the gNB and feed this information back to the network so that the network can determine the AOD of the strongest path. Compared to UAOA, DAOD requires UE assistance in measurement feedback. The downlink reference signal used by the UE can be downlink PSS, SSS, CSI-RS, etc.

[0232] Although the DAOD process differs from the UAOA process, they share many commonalities, and the consistent and unified framework of ABP can be standardized.

[0233] These technologies can be categorized into one of two solutions: a UE-centric solution and an eNB-centric solution. In a UE-centric solution (e.g., TDOA), the eNB transmits some signals (e.g., reference signals, such as PRS) used by the UE to perform measurements. The UE then reports these measurements. In an eNB-centric solution (e.g., UTDOA), the eNB performs measurements on signals or messages sent by the UE. In NR, solutions can be categorized into one of two types: a UE-centric solution or a gNB-centric solution (similar to the eNB-centric solution in LTE).

[0234] An exemplary embodiment provides a LOS determination using a UE-centric solution. For OTDOA in LTE, the eNB transmits a reference signal (e.g., PRS), which the UE uses to determine the time of arrival. Measurements are performed on multiple eNBs, and the time difference between the eNBs is reported to the serving eNB. PRS configuration is performed via RRC signaling. RSTD measurements performed by the UE are also transmitted via RRC signaling. For NR, a similar approach is assumed to be reasonable, although the signaling details may differ (e.g., transmitted in physical layer messages such as downlink control information (DCI), uplink control information (UCI), via MAC messages, etc.).

[0235] Figure 8A A flowchart 800 illustrates an exemplary method for UE operation in a UE-centric solution. The UE sends an indication (box 805) that it has the capability to perform LOS measurements using signals with different polarizations. For example, the capability to perform LOS measurements could mean that the UE can perform the measurement. OTDOA capability can be defined as follows:

[0236]

[0237] You can define OTDOA-PositioningCapabilities and add the LOS-ue-Assisted field to indicate whether the UE supports LOS determination.

[0238] The UE receives RS, such as PRS configuration (box 807). In LTE, PRS configuration is received via higher-layer messages. RRC signaling indicates to the UE the measurement gaps that the PRS can expect. This process can be extended in several ways. In one example, the measurement gap is extended so that the UE can perform two measurements during the gap (once for the first polarization (e.g., horizontal polarization) and once for the second polarization (e.g., vertical polarization)). The length of the measurement gap depends on many factors, including the value of the RS used for positioning, the transmission duration (in terms of the number of orthogonal frequency division multiplexed (OFDM) symbols), the additional time required for propagation delay uncertainty, etc. In this case, the two PRSs are multiplexed onto the transmitter's time-frequency resources in a TDM manner.

[0239] The length, duration, or interval of a measurement gap is used for a single measurement, but it is desired that the UE performs two measurements simultaneously. In this case, two different PRS sequences need to be transmitted simultaneously: PRS_hor for horizontal polarization and PRS_ver for vertical polarization. These two PRS sequences (or resources) can be multiplexed at the transmitter onto time and frequency resources defined as NR resource elements using either frequency division multiplexing (FDM) or code division multiplexing (CDM).

[0240] Two different gaps are configured: one for PRS_hor and one for PRS_ver. However, this solution may only be applicable to nomadic or stationary scenarios, because in order to determine whether a ray is LOS, the UE can typically receive the signal on essentially the same channel when the gNB transmits with horizontal or vertical polarization.

[0241] The UE performs measurements (box 809). To perform measurements, the UE can typically receive a known RS. RS is typically defined by a sequence of bits and their mapped time and frequency resources, which are a set of resource elements. For LTE, a unique positioning reference signal, PRS, is defined. PRS can also be used to estimate the channel at the receiver, such as CIR.

[0242] Since the UE must measure two polarizations, it needs to know which polarization angle the gNB transmits the signal at. There are several ways to do this:

[0243] Two distinct PRS sequences can be defined: PRS_hor and PRS_ver. If these two sequences are orthogonal, the UE can even measure signals of two polarizations simultaneously and independently. A simple way to achieve this is to scramble a given PRS sequence with different orthogonal codes for use in both horizontal and vertical polarization transmissions.

[0244] The same sequence can be transmitted in two different time instances known to the UE. The time instances can usually be close enough that the channel does not change substantially.

[0245] In one exemplary embodiment, a set of two reference signal resources can be defined using one resource defined for PRS_hor and another resource defined for PRS_ver. In another exemplary embodiment, the reference signals for the two antenna ports can be defined as one antenna port for horizontal polarization measurement and the other antenna port for vertical polarization measurement. The embodiment here involves two orthogonal polarizations, but it can be directly extended to multiple different polarizations. For N different polarizations, a set of N orthogonal sequences PRS_1, ..., PRS_N can be used, where the sequence PRS_N is associated with the Nth transmitted polarization.

[0246] Reflectivity (i.e., intensity reflection coefficient) is the square of the amplitude reflection coefficient. According to Fresnel's equations and Snell's law, the reflection coefficients for parallel and orthogonal polarization can be derived as follows:

[0247]

[0248]

[0249] The incident angle on the reflecting surface between the first medium and the second medium is θ. i , and θ t It is the angle at which the electromagnetic wave propagates into the second medium. For electromagnetic waves propagating from a medium with a lower refractive index to a medium with a higher refractive index, the difference θ is... i -θ t Yes, it is positive. For the purposes of this invention, the main observation is that the reflection coefficients of parallel polarization and orthogonal polarization are different.

[0250] LOS detection requires defining UE measurements. Table 11 presents the reference signal time difference (RSTD) for UE measurements in OTDOA.

[0251] Table 11: UE Measurement RSTD for OTDOA

[0252]

[0253] For LOS detection, different measurements can be defined. In one exemplary embodiment, the measurement is the difference or ratio of RSRP measured on two PRS resources or antenna ports at the same reception time. Since UEs typically experience multipath propagation environments, it is necessary to measure the RSRP and its ratio for the same path across multiple paths. For cross-polarized antennas at the UE receiver, the measured RSRPs for each PRS of this path on both polarized antennas need to be summed. The measurement at the UE is performed for the first reception path, as the first reception path is a candidate path for LOS propagation. How to distinguish the first reception path from the next reception path is an implementation problem, where noise and resolution can affect the identification of the first reception path. The UE can report the measured RSRP for each PRS, the difference or ratio of RSRPs between two PRSs, or an indication of path characterization (e.g., LOS or NLOS), where the indication can be binary (i.e., LOS or NLOS) or multiple levels to show the probability or confidence of its estimated LOS or NLOS. In another exemplary embodiment, the UE only reports the TOA (or RSTD) of the TRP or cell that it believes has LOS communication between the UE and the TRP or cell.

[0254] First, it may be useful to define the UE measurement of the received power of RS on a single path in a multi-channel environment, as shown in Table 12. This differs from the measurement defined in the current 3GPP specification of RSRP, where the received power of all paths is considered together, as shown in, for example, the following definition in 3GPP TS 38.215 V15.2.0, which is incorporated herein by reference in its entirety. In some examples, the UE's ability to measure the first path can be transmitted to the eNB. If the UE cannot measure the first path but can only measure the set of all paths, the LOS procedure can still occur; however, LOS determination is only possible in the specific case of no reflections, i.e., only direct propagation (which is unlikely). The eNB can know the UE's limitations through previous capability exchanges.

[0255] Table 12: UE Measurement of RS Received Power

[0256]

[0257] Determining the number of resource elements for the CSI-RS RSRP within the considered measurement frequency bandwidth and measurement period is an implementation problem, constrained by the requirement to meet corresponding measurement accuracy requirements. The power of each resource element is determined based on the energy received during the useful portion of the symbol excluding the cyclic prefix (CP).

[0258] A new measurement of the received power of the reference signal on a single path in a multi-channel system can be defined as shown in Table 13.

[0259] Table 13: Single-path RSRP Measurement in Multi-channel Scenarios

[0260]

[0261] Within the considered measurement frequency bandwidth and measurement period, the number of resource elements used by the UE to determine RSRP-p can be left to the UE to implement, but the limitation is that the corresponding measurement accuracy requirements must be met. The power of each resource element can be determined based on the energy received during the useful portion of the symbol (e.g., excluding CP).

[0262] UE reports polarization measurements (box 811). The UE can report polarization measurements to the gNB in ​​a higher-layer message. The UE can report two RSRP values ​​(or signal plus interference to noise ratio (SINR), RSRP, received signal strength indicator (RSSI), etc.) to the gNB: a first value for horizontal polarization and a second value for vertical polarization. Alternatively, the UE can also report the ratio of these two RSRP values. The UE can also determine the path representation itself (e.g., using a pre-configured threshold and having the UE compare the SINR ratio to this threshold) and report it to the gNB.

[0263] In one embodiment, polarization measurement may be included in the same message used to report RSTD measurements.

[0264] In some exemplary embodiments, the measurement is performed on the first path; however, in other exemplary embodiments, the measurement may be performed on the strongest path or a combination of the first path and the strongest path.

[0265] Figure 8B A flowchart 850 illustrates an exemplary method for gNB operation in a UE-centric solution. The gNB receives an indication that the UE has the capability to perform LOS measurements using signals with different polarizations (box 855). The gNB transmits RS, such as PRS configuration (box 857). The RS configuration can be transmitted using higher-layer signaling. The gNB receives polarization measurements (box 859). Polarization measurements can be received in a higher-layer message. The report may include two RSRP values ​​(or SINR, RSRP, RSSI, etc.): a first value for horizontal polarization and a second value for vertical polarization. Alternatively, the report may include a ratio of these two RSRP values. The UE may also determine the path representation itself (e.g., using a pre-configured threshold and having the UE compare the SINR ratio to this threshold), and the report may include the path representation.

[0266] An exemplary embodiment provides a LOS determination technique for a gNB-centric solution. In a gNB-centric solution, the UE transmits in a two-polarity manner, and the gNB performs measurements on the transmission in a manner similar to the measurements performed by the UE in a UE-centric solution. For example, the ability to perform LOS measurements could mean that either the gNB or the UE can perform the measurements.

[0267] Figure 9A A flowchart 900 illustrates an exemplary method for UE operation in a gNB-centric solution. This operation is similar to a UE-centric process, except that the UE indicates its ability to transmit using two polarizations instead of using the ability to receive using two polarizations. The UE transmits an indication that it has the ability to transmit signals with different polarizations (box 905). This indication can be transmitted using higher-layer signaling, such as in DCI. The UE receives a request to transmit using multiple polarizations (box 907). This request can be received via higher-layer signaling. The request can also configure RS (e.g., SRS), the polarization to transmit, the resource element or antenna port to use, the multiplexing to use (TDM, CDM, FDM, or a combination thereof), etc. The UE transmits RS with multiple polarizations (box 909).

[0268] For higher-level messaging regarding RS configuration, techniques similar to those described in OTDOA can be used. RS configuration can specify that the UE transmits SRS. Similar to PRS, two SRS sequences may be needed to distinguish between the two polarities, and these can be obtained by scrambling the SRS with different sequences for each of the horizontal and vertical polarizations. Different time instances can be used, but the interference experienced in the two different time instances may differ. Additional bits can be included in the DCI to indicate that the SRS needs to be transmitted in both polarizations.

[0269] Figure 9BA flowchart 950 illustrates an exemplary method for gNB operation in a gNB-centric solution. The gNB receives an indication that the UE has the capability to transmit signals with different polarizations (box 955). This indication can be transmitted using higher-layer signaling. The gNB sends a request to the UE to transmit an RS with multiple polarizations (box 957). This request can also be transmitted using higher-layer signaling. The request can also configure the RS, the polarization to be transmitted, the resource element or antenna port to use, the multiplexing to use (TDM, CDM, FDM, or a combination thereof), etc. The gNB receives the RS with multiple polarizations (box 959). The RS is received according to its configuration. In addition to receiving the RS, the gNB performs polarization measurements, also based on the RS configuration. The gNB also characterizes the path based on the polarization measurements. For example, the gNB compares the polarization measurements to a predefined threshold; if the polarization measurements meet the threshold, the UE and gNB are performing LOS communication; otherwise, they are performing NLOS communication.

[0270] In one exemplary embodiment, a method for signaling to support LOS detection is provided. The signaling may be communicated before the UE associates with an access node. Alternatively, the signaling may be communicated after or during the association of the UE with the access node. For WLAN technologies, such as devices compliant with the IEEE 802.11 standard, the information element (IE) may have fields, such as bits, indicating support for LOS detection functionality. The IE may be provided in probe request frames, probe response frames, (Re)association request frames, (Re)association response frames, beacon frames, or other types of management or action frames.

[0271] In another exemplary embodiment, a method is provided for transmitting multiple transmissions with different polarizations. The transmissions may be simultaneous or sequential, and may use the same power for each polarization, or a known and pre-established set of power for each polarization.

[0272] In another exemplary embodiment, a method for receiving multiple transmissions with different polarizations is provided. In one example, a receiver is capable of receiving in each transmitted polarization plane and distinguishing copies of the transmitted signal (beam or ray), wherein the receiver compares the received power of a first received ray for each corresponding transmitted polarization.

[0273] Other exemplary embodiments include the following methods: (1) the receiver determines that if the received power of the first received rays of various polarizations is the same, then the transmitter and receiver are LOS, otherwise the transmitter and receiver are NLOS; (2) the receiver uses the first ray received in LOS communication to determine the distance between the transmitter and receiver using the ToF of the communication; (3) the receiver determines whether the first received ray is LOS or NLOS and transmits the characterization back to the transmitter; (4) the transmitter is notified whether the communication is LOS or NLOS and the distance between the transmitter and receiver is determined using the ToF; (5) the receiver determines whether the first received ray (a copy of the signal) is LOS and uses the direction of arrival of the first ray. (6) Determine the angle of the transmitter's location using arrival (DOA) information; (7) Determine changes in LOS communication, where if the current LOS communication changes to NLOS, the receiver initiates a handover to the new LOS communication with a different transmitter; (8) Determine changes from LOS to NLOS communication and report the changes to a second device, such as a base station or AP, where the second device sends a control (e.g., link management) message to trigger a handover to the new LOS communication link with a different device (e.g., AP); (9) Periodically assess the LOS or NLOS status of communication with multiple devices and decide to switch communication to the LOS device; (10) The device periodically... (10) Assess the LOS or NLOS state of communication with the second device to remotely control the second device and modify the trajectory of the second device to maintain the LOS or NLOS communication state; (11) Assess the LOS state, record the LOS state related to location and different communication nodes (base station, access point, relay, access node, etc.), and later use it for rapid discovery and rapid attachment, such as antenna beamforming in the LOS direction, or to restore to an alternative LOS communication direction when LOS communication is blocked; (12) The device uses beamforming to communicate in the known LOS communication direction for rapid discovery, and if discovery fails, it searches in the adjacent direction of the LOS. Other examples are also possible.

[0274] Figure 10 A flowchart illustrating an exemplary operation 1000 occurring in the UE within a UE-centric LOS measurement solution is shown. Operation 1000 can indicate the actions that occur in the UE when the UE participates in a UE-centric LOS measurement solution.

[0275] Operation 1000 begins with the UE transmitting a LOS determination request (box 1005). The UE can send or receive a LOS determination request from the gNB. When a LOS determination request is received from the gNB, it may include RS configuration. The UE measures a first signal on the channel (box 1007). The first signal may be a bit sequence with a first polarization. A copy of the first signal may be received on one or more paths. The UE measures a second signal on the channel (box 1009). The second signal may be a bit sequence with a second polarization. A copy of the second signal may be received on one or more paths. The UE may send channel measurements to the access node (box 1011). In some embodiments, the UE provides channel measurements to the gNB, and the gNB performs characterization of the path itself.

[0276] The UE can perform a comparison of the difference in channel measurements with a pre-specified threshold (box 1013). In some embodiments, the UE characterizes the path and provides a characterization of the path to the gNB. If the difference in channel measurements is less than the threshold, the path is LOS (box 1015), and the UE sends the characterization to the gNB (box 1017). If the difference in channel measurements is greater than the threshold, the path is NLOS (box 1019), and the UE sends the characterization to the gNB (box 1017). If the UE does not send channel measurements, the UE can send a characterization of the path to the gNB (box 1117). While the discussion focuses on the interaction between the UE and the gNB, exemplary embodiments can also operate with other forms of communication controllers, such as APs, access nodes, base stations, etc.

[0277] Figure 11 A flowchart illustrating an exemplary operation 1100 occurring in a gNB within a UE-centric LOS measurement solution is shown. Operation 1100 can indicate the actions that occur in the gNB when the gNB participates in a UE-centric LOS measurement solution.

[0278] Operation 1100 begins with the gNB transmitting a LOS determination request (box 1105). The gNB can send the LOS determination request to the UE or receive it from the UE. The gNB transmits a first signal on the channel (box 1107). The first signal may be a bit sequence with a first polarization. The gNB transmits a second signal on the channel (box 1109). The second signal may be a bit sequence with a second polarization. The gNB may receive channel measurements from the UE (box 1111). In some embodiments, the UE provides channel measurements to the gNB, and the gNB performs a characterization of the path itself.

[0279] The gNB can perform a comparison of the difference in channel measurements with a pre-specified threshold (box 1113). In some embodiments, the gNB characterizes a path and optionally provides the path characterization to the UE. If the difference in channel measurements is less than the threshold, the path is LOS (box 1115), and the gNB optionally sends the characterization to the UE (box 1117). If the difference in channel measurements is greater than the threshold, the path is NLOS (box 1119), and the gNB optionally sends the characterization to the UE (box 1117). If the gNB does not receive channel measurements, the gNB can receive the path characterization from the UE (box 1117). While the discussion focuses on the interaction between the UE and the gNB, exemplary embodiments can also operate with other forms of communication controllers (e.g., APs, access nodes, base stations, etc.).

[0280] Figure 10 and Figure 11 A flowchart illustrating exemplary operations occurring in the UE and gNB within a UE-centric LOS measurement solution is shown. In a gNB-centric LOS measurement solution, the flowcharts of the exemplary operations occurring in the UE and gNB will be similar, except that the UE will transmit bit sequences with different polarities, and the gNB will perform channel measurements. Furthermore, in a gNB-centric LOS measurement solution, the gNB is unlikely to send channel measurements to the UE so that the UE can perform path characterization.

[0281] Figure 12 An example communication system 1200 is illustrated. Typically, system 1200 enables multiple wireless or wired users to send and receive data and other content. System 1200 may implement one or more channel access methods, such as code division multiple access (CDMA), time division multiple access (TDMA), frequency division multiple access (FDMA), orthogonal FDMA (OFDMA), single-carrier FDMA (SC-FDMA), or non-orthogonal multiple access (NOMA).

[0282] In this example, the communication system 1200 includes electronic devices (EDs) 1210a-1210c, radio access networks (RANs) 1220a-1220b, a core network 1230, a public switched telephone network (PSTN) 1240, the Internet 1250, and other networks 1260. Although Figure 12 A certain number of these components or elements are shown, but the system 1200 may include any number of these components or elements.

[0283] ED 1210a-1210c are used for operation or communication in system 1200. For example, ED 1210a-1210c are used for transmitting or receiving via wireless or wired communication channels. Each ED 1210a-1210c represents any suitable end-user equipment, which may include (or be referred to as) devices such as: user equipment / device (UE), wireless transmit or receive unit (WTRU), mobile station, fixed or mobile subscriber unit, cellular phone, personal digital assistant (PDA), smartphone, laptop computer, computer, touchpad, wireless sensor, or consumer electronics device.

[0284] In this document, RAN 1220a-1220b includes base stations 1270a-1270b. Each base station 1270a-1270b is used to establish a wireless connection with one or more of ED 1210a-1210c to enable access to the core network 1230, PSTN 1240, Internet 1250, and / or other networks 1260. For example, base stations 1270a-1270b may include (or) one or more of a number of well-known devices, such as a base transceiver station (BTS), Node-B (NodeB), evolved NodeB (eNodeB), next-generation (NG) NodeB (gNB), home NodeB, home eNodeB, site controller, access point (AP), or wireless router. ED 1210a-1210c is used for connection and communication with the Internet 1250 and can access the core network 1230, PSTN 1240 or other networks 1260.

[0285] exist Figure 12 In the illustrated embodiment, base station 1270a forms part of RAN 1220a, which may include other base stations, components, or devices. Furthermore, base station 1270b forms part of RAN 1220b, which may include other base stations, components, and / or devices. Each base station 1270a-1270b is used to transmit or receive radio signals within a specific geographical area (sometimes referred to as a "cell"). In some embodiments, multiple-input multiple-output (MIMO) technology may be used, with each cell having multiple transceivers.

[0286] Base stations 1270a-1270b communicate with one or more EDs 1210a-1210c via one or more air interfaces 1290 using wireless communication links. These air interfaces 1290 can employ any suitable wireless access technology.

[0287] It is conceivable that system 1200 can use multi-channel access capabilities, including the schemes described above. In a particular embodiment, the base station and ED implement 5G New Radio (NR), LTE, LTE-A, or LTE-B. Of course, other multiple access schemes and radio protocols can also be used.

[0288] RANs 1220a-1220b communicate with the core network 1230 to provide voice, data, application, Voice over Internet Protocol (VoIP), or other services to EDs 1210a-1210c. It is understood that RANs 1220a and 1220b, or the core network 1230, can communicate directly or indirectly with one or more other RANs (not shown). The core network 1230 can also serve as a gateway access for other networks (e.g., PSTN 1240, Internet 1250, and other networks 1260). Additionally, some or all of the EDs in EDs 1210a-1210c may include the ability to communicate with different wireless networks via different wireless links using different wireless technologies or protocols. Instead of wireless communication (or other than wireless communication), the EDs may also communicate with service providers or switches (not shown) via wired communication channels and with the Internet 1250.

[0289] Figure 12 This is an example of a communication system that can be used to... Figure 12 Various modifications can be made. For example, in any suitable configuration, the communication system 1200 may include any number of EDs, base stations, networks, or other components.

[0290] Figure 13A and Figure 13B Exemplary apparatuses that can implement the methods and teachings according to the present invention are shown. Specifically, Figure 13A An exemplary ED 1310 is shown. Figure 13B An exemplary base station 1370 is shown. These components can be used in system 1200 or any other suitable system.

[0291] like Figure 13A As shown, ED 1310 includes at least one processing unit 1300. The processing unit 1300 implements various processing operations of ED 1310. For example, the processing unit 1300 may perform signal encoding, data processing, power control, input / output processing, or any other function that enables ED 1310 to operate within system 1200. The processing unit 1300 also supports the methods and teachings described in more detail above. Each processing unit 1300 includes any suitable processing or computing device for performing one or more operations. For example, each processing unit 1300 may include a microprocessor, microcontroller, digital signal processor, field-programmable gate array, or application-specific integrated circuit.

[0292] ED 1310 also includes at least one transceiver 1302. Transceiver 1302 is used to modulate data or other content for transmission via at least one antenna or network interface controller (NIC) 1304. Transceiver 1302 is also used to demodulate data or other content received by at least one antenna 1304. Each transceiver 1302 includes any suitable structure for generating signals for wireless or wired transmission or for processing signals received wirelessly or wiredly. Each antenna 1304 includes any suitable structure for transmitting or receiving wireless or wired signals. One or more transceivers 1302 may be used in ED 1310, and one or more antennas 1304 may be used in ED 1310. Although shown as a single functional unit, transceiver 1302 may also be implemented using at least one transmitter and at least one separate receiver.

[0293] ED 1310 also includes one or more input / output devices 1306 or interfaces (e.g., wired interfaces connected to the Internet 1250). Input / output devices 1306 facilitate interaction with users or other devices on the network (network communication). Each input / output device 1306 includes any suitable structure for providing or receiving information from a user, such as a speaker, microphone, keypad, keyboard, display, or touchscreen, including network interface communication.

[0294] In addition, ED 1310 includes at least one memory 1308. Memory 1308 stores instructions and data used, generated, or collected by ED 1310. For example, memory 1308 may store software or firmware instructions executed by one or more processing units 1300, as well as data for reducing or eliminating interference in incoming signals. Each memory 1308 includes any suitable one or more volatile or non-volatile storage and retrieval devices. Any suitable type of memory can be used, such as random access memory (RAM), read-only memory (ROM), hard disk, optical disk, subscriber identity module (SIM) card, memory stick, secure digital (SD) memory card, etc.

[0295] like Figure 13B As shown, base station 1370 includes at least one processing unit 1350, at least one transceiver 1352 (including transmitter and receiver functions), one or more antennas 1356, at least one memory 1358, and one or more input / output devices or interfaces 1366. A scheduler, as understood by those skilled in the art, is coupled to processing unit 1350. The scheduler may be included within or operate separately from base station 1370. Processing unit 1350 implements various processing operations of base station 1370, such as signal encoding, data processing, power control, input / output processing, or any other functions. Processing unit 1350 may also support the methods and teachings described in more detail above. Each processing unit 1350 includes any suitable processing or computing device for performing one or more operations. For example, each processing unit 1350 may include a microprocessor, microcontroller, digital signal processor, field-programmable gate array, or application-specific integrated circuit.

[0296] Each transceiver 1352 includes any suitable structure for generating signals for wireless or wired transmission to one or more EDs or other devices. Each transceiver 1352 also includes any suitable structure for processing signals received wirelessly or via wire from one or more EDs or other devices. Although the transmitter and receiver are shown combined as transceiver 1352, they can be separate components. Each antenna 1356 includes any suitable structure for transmitting or receiving wireless or wired signals. Although a shared antenna 1356 is shown herein coupled to transceiver 1352, one or more antennas 1356 can be coupled to one or more transceivers 1352, thus supporting separate antennas 1356 coupled to transmitters and receivers (when transmitters and receivers are configured as separate components). Each memory 1358 includes any suitable one or more volatile or non-volatile storage and retrieval devices. Each input / output device 1366 facilitates interaction with users or other devices in the network (network communication). Each input / output device 1366 includes any suitable structure for providing information to or receiving / from users, including network interface communication.

[0297] Figure 14 This is a block diagram of a computing system 1400 that can be used to implement the devices and methods disclosed herein. For example, the computing system can be any entity in a UE, access network (AN), mobility management (MM), session management (SM), user plane gateway (UPGW), or access stratum (AS). A specific device may use all of the components shown or only a subset of these components, and the degree of integration may vary from device to device. Furthermore, the device may include multiple instances of components, such as multiple processing units, multiple processors, multiple memories, multiple transmitters, multiple receivers, etc. The computing system 1400 includes a processing unit 1402. The processing unit includes a central processing unit (CPU) 1414, memory 1408, and may also include a mass storage 1404 connected to a bus 1420, a video adapter 1410, and an I / O interface 1412.

[0298] Bus 1420 can be one or more of any type of bus architecture, including a memory bus or memory controller, peripheral bus, or video bus. CPU 1414 can include any type of electronic data processor. Memory 1408 can include any type of non-transitory system memory, such as static random access memory (SRAM), dynamic random access memory (DRAM), synchronous DRAM (SDRAM), read-only memory (ROM), or combinations thereof. In one embodiment, memory 1408 can include ROM used at power-on and DRAM used for storing programs and data used during program execution.

[0299] Mass storage 1404 may include any type of non-transitory storage device for storing data, programs, and other information and making such data, programs, and other information accessible via bus 1420. Mass storage 1404 may include one or more of, for example, solid-state drives, hard disk drives, disk drives, or optical disk drives.

[0300] Video adapter 1410 and I / O interface 1412 provide interfaces to couple external input and output devices to processing unit 1402. Examples of input and output devices, as shown, include a display 1418 coupled to video adapter 1410 and a mouse, keyboard, or printer 1416 coupled to I / O interface 1412. Other devices may be coupled to processing unit 1402, and more or fewer interface cards may be used. For example, a serial interface such as Universal Serial Bus (USB) (not shown) may be used to provide interfaces for external devices.

[0301] The processing unit 1402 also includes one or more network interfaces 1406, which may include wired links such as Ethernet cables to access nodes or different networks, or wireless links. The network interface 1406 enables the processing unit 1402 to communicate with remote units via a network. For example, the network interface 1406 may provide wireless communication via one or more transmitter / transmit antennas and one or more receiver / receive antennas. In one embodiment, the processing unit 1402 is coupled to a local area network 1422 or a wide area network to perform data processing and communication with other processing units, the Internet, or remote storage facilities.

[0302] Figure 15A block diagram of an exemplary processing system 1500 for performing the methods described herein is shown. The processing system may be installed in a host device. As shown, the processing system 1500 includes a processor 1504, a memory 1506, and interfaces 1510-1514, which may or may not be as described... Figure 15 The processor 1504 can be any component or set of components for performing computational and / or other processing-related tasks, and the memory 1506 can be any component or set of components for storing programs and / or instructions executed by the processor 1504. In an exemplary embodiment, the memory 1506 includes a non-transitory computer-readable medium. Interfaces 1510, 1512, and 1514 can be any component or set of components that enable the processing system 1500 to communicate with other devices / components and / or users. For example, one or more of interfaces 1510, 1512, and 1514 can be used to transfer data, control, or management messages from the processor 1504 to applications installed in host devices and / or remote devices. As another example, one or more of interfaces 1510, 1512, and 1514 can be used to enable interaction / communication between a user or user device (e.g., a personal computer (PC)) and the processing system 1100. The processing system 1500 may include Figure 15 Additional components not shown, such as long-term memory (e.g., non-volatile memory, etc.).

[0303] In some exemplary embodiments, the processing system 1500 includes a network device that is accessing a telecommunications network or otherwise is part of a telecommunications network. In one example, the processing system 1500 is located in a network-side device in a wireless or wired telecommunications network, such as a base station, relay station, scheduler, controller, gateway, router, application server, or any other device in the telecommunications network. In other exemplary embodiments, the processing system 1500 is located in a user-side device accessing a wireless or wired telecommunications network, such as a mobile station, UE, PC, tablet computer, wearable communication device (e.g., smartwatch), or any other device used to access the telecommunications network.

[0304] In some exemplary embodiments, one or more of interfaces 1510, 1512, and 1514 connect the processing system 1500 to a transceiver for sending and receiving signaling over a telecommunications network. Figure 16A block diagram of a transceiver 1600 for sending and receiving signaling over a telecommunications network is shown. The transceiver 1600 can be installed in a host device. As shown, the transceiver 1600 includes a network-side interface 1602, a coupler 1604, a transmitter 1606, a receiver 1608, a signal processor 1610, and a device-side interface 1612. The network-side interface 1602 may include any component or set of components for sending or receiving signaling over a wireless or wired telecommunications network. The coupler 1604 may include any component or set of components for facilitating bidirectional communication over the network-side interface 1602. The transmitter 1606 may include any component or set of components (e.g., an up-converter, a power amplifier, etc.) for converting a baseband signal into a modulated carrier signal suitable for transmission over the network-side interface 1602. The receiver 1608 may include any component or set of components (e.g., a down-converter, a low-noise amplifier, etc.) for converting a carrier signal received through the network-side interface 1602 into a baseband signal. Signal processor 1610 may include any component or set of components for converting baseband signals into data signals suitable for transmission via one or more device-side interfaces 1612, or vice versa. One or more device-side interfaces 1612 may include any component or set of components for transmitting data signals between signal processor 1610 and components within a host device (e.g., processing system 1100, local area network (LAN) port, etc.).

[0305] Transceiver 1600 can transmit and receive signaling via any type of communication medium. In some exemplary embodiments, transceiver 1600 transmits and receives signaling via a wireless medium. For example, transceiver 1600 may be a wireless transceiver for communicating according to a wireless telecommunications protocol, such as a cellular protocol (e.g., LTE, etc.), a WLAN protocol (e.g., Wi-Fi, etc.), or any other type of wireless protocol (e.g., Bluetooth, near field communication, NFC, etc.). In these exemplary embodiments, network-side interface 1602 includes one or more antenna / radiating elements. For example, network-side interface 1602 may include a single antenna, multiple independent antennas, or a multi-antenna array for multi-layer communication, such as single-input multiple-output (SIMO), multiple-input single-output (MISO), multiple-input multiple-output (MIMO), etc. In other exemplary embodiments, transceiver 1600 transmits and receives signaling via a wired medium, such as twisted-pair cable, coaxial cable, or optical fiber. A particular processing system and / or transceiver may utilize all of the components shown, or only a subset of these components, and the level of integration may vary from device to device.

[0306] Figure 17A and Figure 17B The polarization orientation in the LOS path propagation 235 between gNB 110 and UE 120, such as a mobile phone, is shown. Each of them has two antenna resources, radiating EM waves with orthogonal polarization orientations in their local coordinate systems (LCS) 1711 and 1721, respectively. The orthogonality of the polarization remains unchanged in all radiation directions. Orthogonality is also maintained when the field vectors are transformed to the wave plane 1730 in the global coordinate system (GCS) 310. The field vectors are scaled in the spherical or spatial direction of the LOS path by the antenna patterns 1710 and 1720, respectively, and are given by the elevation angle θ and azimuth angle φ in GCS 310.

[0307] The transmitted field vector F with polarization orientation s in GCS txs (φ ZOD ,θ AOD The following formula is given:

[0308]

[0309] The coordinate transformation is given by three rotation angles (α, β, γ).

[0310] and ψ tx =ψ(α,β,γ,θ,φ)

[0311] The transmitted field vector will propagate via either a LOS or NLOS path. The rotation angles (α, β, γ) describe rotations around the x, y, and z axes to the LCS axes x', y', and z', respectively. If propagation occurs via an NLOS path, scattering at the object will alter the incident wave's field vector F. txs (φ ZOD ,θ AOD It emits scattered waves, where the 2D field vector is transformed into the field vector of the emitted wave by the complex 2x2 scattering matrix S.

[0312]

[0313] The scattering matrix is ​​composed of any complex number s 11 ,s 21 ,s 22 ,s 12 The following is provided:

[0314]

[0315] Therefore, due to the interaction with object 1731 during NLOS propagation, S may alter the field vector through rotation, mirroring, amplitude scaling, and phase changes, see [link to relevant documentation]. Figure 17B This will lead to depolarization of the scattered waves or changes in the polarization amplitude and orientation.

[0316] In receiving polarization F rxu The projection on the surface is an EM wave F with the receiver's u-th polarization orientation. rx,txs (φ AOD ,θ ZOD ) receiving

[0317]

[0318] The channel response along this path is invoked via the transmitting antenna s and the receiving antenna u. All path attenuation and phase are described by the scattering matrix S. Since the antenna pattern is not isotropic, the field vectors will have different gains in each spherical direction. Since the direction is generally unknown, the receiver observes the transformed field vectors in its local coordinate system (LCS). Expressing all the field vectors in (1) in the LCS, we obtain

[0319]

[0320] If the propagation occurs via a LOS path, then the scattering matrix becomes

[0321]

[0322] This will flip the horizontal component θ because the LCS of receiver 1721 and transmitter 1711 face each other in LOS orientation, see Figure 17A This is reasonable because antennas typically have directional characteristics, such as beamforming; see [reference needed]. Figure 17A and Figure 17B .

[0323] Figures 18A to 18C This diagram shows the electric field vector, also known as the phasor, of an electromagnetic wave in the far field at a given spherical (spatial) direction and instantaneous time. The field vector can be represented by a 2D vector F in the plane perpendicular to the wave direction k = k(φ,θ) in the GCS. See also... Figures 17A to 17B 1730 in the middle. Therefore, reducing the polarization of each EM wave to phasor F is sufficient.

[0324] exist Figure 18A The diagram shows up to S field vectors F′ of the transmitted RS 1810 in the transmitter's local coordinate system (LCS) 1711. tx1 ,…,F′ txS Each of the S-polarization orientations (field vectors) can be accessed through the first field vector F′. tx1 Sort by angular distance and then sort by angle in 1812. Measurement. If The transmission order is clockwise, if Then it is counterclockwise.

[0325] exist Figure 18B The image shows up to U field vectors F″ in the receiver 120's LCS 1721. rx1 ,…,F″ rxU 1801. To the first field vector F″ rx1 The angular distance is through angles Ω′1,...,Ω′ U-1 Measurement.

[0326] exist Figure 18C The diagram shows the transmitted field vector 1811 received in the receiver LCS 1721 and the receiver field vector 1801. 1811 refers to the field vector from... Figure 18A The RS 1810 transmits and receives S field vectors F″. rx1 ,…,F″ rxS The S field vectors arrive at the zenith arrival angle θ″ from the receiving LCS 1721. ZOA and azimuth arrival angle The spherical direction is given. The field vector is always orthogonal to the wave propagation direction, see 1730 in Figure 17. Therefore, the received field vector F″ of a linearly polarized wave is... rx,s =F″ r " x,txs (u = 1, ..., S) can be described in the wave plane by their angular orientation and magnitude. The field vector received through the LOS path will have the same characteristics as... Figure 18A The field vectors transmitted in the middle are spaced at the same angle, and are aligned with the first receiving polarization orientation F″. rx,1 The same angular distance Ω1,...,Ω S-1 1812 Measurement. Received transmitted field vector F″ rx,u Will have the same field vector as the receiver F″ rxs Different angular distances because the transmitter LCS 1711 and receiver LCS 1721 are not aligned. The projection of the received s-th transmitted field vector to the u-th received field vector is given by the magnitude of the first channel tap as defined in (1), and is denoted as |H u,s |=|H rxu,txs Therefore, the magnitude of the received s-th transmitted field vector can be expressed as:

[0327]

[0328] If F″ rxu and F″ rxu′ They are orthogonal. Note that the CIR tap in (1) needs to be divided by the receiver amplitude to obtain the normalized orthogonal vector F″. rxu / |F″ rxu |and F″ rxu′ / |F″ rxu′ The projection onto |, also known as the polarization vector, forms an orthogonal system of 2D polarization planes reaching the EM wave. More generally, for those orthogonal to F″ rxu Any F″ rxu′ The ratio of the two normalized projections corresponds to Figure 18C Angle α in u,s The angle α is given by the following formula. u,s

[0329]

[0330] In one embodiment, it makes U = 2 = S and Established, such as Figure 19A As shown. Without loss of generality, orientation 1 is selected as the vertical orientation, aligned with the LCS z-axis, and orientation 2 is selected as the horizontal orientation, aligned with the LCS y-axis. Figure 19A The following symbol was used: |H rxV,rxV |=|H1,1 |、|H rxH,rxV |=|H 2,1 |、|H rxV,rxH |=|H 1,2 |and|H rxH,rxH |=|H 2,2 Then, the angular distance with respect to F″1 is given by the following formula:

[0331] Where n = 1, 2

[0332] The following formula is given regarding F″2:

[0333] Where n = 1, 2,

[0334] The projection ratio must be based on the receiver's amplitude ratio a = a 1,2 =|F″ rx1 | / |F″ rx2 | Scaling, see Figure 18. For LOS paths, it must remain unchanged for n=1,2:

[0335] α n +β n mod 180° = Ω1,

[0336] This is equivalent to

[0337] α1+α2=Ω1 and β1+β2=Ω1. (3)

[0338] This can also be expressed more compactly as

[0339]

[0340] Note that the two conditions in (3) are equivalent to (4). If the receiver is power balanced, i.e., a = 1, then we get

[0341]

[0342] In another embodiment, the determination metric is given by the power distance.

[0343]

[0344] In one embodiment of the present invention, the angular spacing between the transmitter and the receiver is Ω1 = 90°, and the receiver is power balanced when a = 1.

[0345] In one embodiment of the invention, angle and power distance can be combined. Here, two different thresholds can be relaxed, and if both metric conditions are met, a LOS determination will be made.

[0346] Figure 19BThe diagram shows the field vector in the waveplane with a given spherical orientation for a typical LOS polarization process of a receiver with only one polarization orientation (i.e., U = 1). The transmitter will transmit the field vector through the waveplane with respect to the first polarization orientation F″ of the transmitter. tx1 Angles Ω1,...,Ω measured in 1911 S-1 Given S = N different polarization orientations, multiple RS are transmitted. All transmitted polarization orientations are defined by their angles Ω1 ≤ ... ≤ Ω. S-1 The increasing order is known to the transmitter. In one embodiment, the receiver also needs to know the angle of the transmitted polarization orientation when performing LOS characterization. In one embodiment, the receiver observes all S different RS through U receiver polarization orientations, with an angular spacing of Ω′1≤...≤Ω′. U-1 In one embodiment, the receiver is oriented only with receiver polarization F″ at U=1. rx Observe as shown by the dotted purple arrow 1901.

[0347] Figure 19B The transmit polarization orientation in transmitter LCS 1921 is shown. The polarization orientation is determined by the first polarization orientation F′ in transmitter LCS. tx1 Angle Measurement. The metric d will depend on the first received channel taps |H1|,…,|H N All amplitudes.

[0348] exist Figures 20A to 20C The text shows the use of... The angular spacing gives the signaling process for the four polarization orientations, the angular spacing corresponding to the signaling process from... Figure 18A The first transmitted polarization orientation F′ in txV =F′ tx1 The angles measured by 1810 are Ω1 = 45°, Ω2 = 90°, and Ω3 = 135°. All four polarization signals will pass through the tap |H of the first receive channel. n |=|H rxV,txn The intensity (amplitude) of | gives the orientation of a single receiver F″ rx1 =F″ rxV Measurement. In one embodiment, the LOS determination is made by evaluating the following metrics:

[0349]

[0350] Among them, the measured first channel tap amplitude is as follows Sort in descending order.

[0351] Figure 20D The signaling procedure is illustrated with only three transmit polarization orientations and a single receive polarization orientation. In one embodiment, the metric would be:

[0352]

[0353] in Metrics require knowledge of the transmit polarization order. Throughout all polarization-LOS processes, the LOS threshold ρ will depend on other parameters, such as the receive signal-to-noise ratio (SNR), Rice's K-factor, and the scene clutter density.

[0354] For each of the standardized metrics d above, a specific fixed threshold 1 > ρ > 0 must be selected. If the metric satisfies d(H) < ρ, the detection algorithm determines the LOS path; otherwise, it determines the NLOS path. In one embodiment, the power-based metric d... power and angle-based metric d angle It can be combined such that if d angle (H)<ρ angle,c and d power (H)<ρ power,c If true, the combined detection algorithm determines the LOS path. Here, ρ angle,c and ρ power,c It can be composed of some scaling factors c angle c power >1 gives the relaxation threshold

[0355] ρ angle,c =c angle ρ angle and ρ power,c =c power ρ power .

[0356] In addition, the threshold may depend on the SNR at the receiver and the expected prior LOS probability, or any other prior information.

[0357] For example, through

[0358]

[0359] The SNR is derived from the average RSRP of all receiver polarizations and the noise floor observed at the receiver on each link's FAP. A large threshold would result in insufficient NLOS cancellation for angle-based metrics, therefore a ρ-based threshold is used. max The maximum threshold is set to 0.5. Based on the scene's LOS statistics, this maximum threshold may be further optimized. Additionally, the minimum threshold ρ... min This can be used to adjust the fixed offset or shift in the decision metric. This is because channel distortion itself will result in a metric that is greater than zero. The actual LOS path may still be interfered with or distorted by other nearby NLOS paths, thus causing the LOS metric value to shift.

[0360] In another embodiment, the transmitter can transmit more than S>4 different polarization orientations, such as Figure 20E As shown. Assume the transmitter sends PRS signals through S polarization orientations, these polarization orientations are transmitted via... Separation and sorting are performed counter-clockwise, which will be observed clockwise at the receiver; see [link / reference]. Figure 20E If U = 2, then the receiver can be configured according to its first polarization orientation F″. rx1 The angular distance α measured by (2) 1,s Where s = 1, ..., S. If U = 1, and the transmitted polarization is power balanced, then the receiver can receive the signal through the maximum value of |H| for a given M. M |To scale the measurement|H s |=|H rx1,txs | and the angle can be approximated by the following equation:

[0361] Where s = 1, 2, ..., S.

[0362] If S increases, the approximation error |α 1s -α s The relative angular distances transmitted are uniformly distributed in the first quadrant I, that is, for s = 1, ..., S-1, The intermediate angle index is defined by the following equation:

[0363]

[0364] The receiver first identifies the first received polarization F″. rxtx1 Is it located in Figure 20E Quadrant I / III or Quadrant II / IV. If The first received polarization corresponds to the case in quadrant II / IV; otherwise, it corresponds to quadrant I / III. This defines the index of the angle at which the sign needs to be switched.

[0365]

[0366] in Let n represent the smallest integer n > a. Then, the decision metric is given by the following formula:

[0367]

[0368] For S = 2, this simplifies to (5). Based on S, a normalization factor c(S) can be found such that...

[0369]

[0370] An optimized threshold ρ can be designed based on S, LOS probability, SNR, and the statistics of the scattering matrix. angle,S This determines whether to use the LOS or NLOS path as described above.

[0371] Figure 21A A block diagram illustrating polarization-LOS characterization is shown. A receiver, such as a UE, is requesting a Pol-LOS procedure from one or more transmitters, which transmits equal power RS ​​on multiple different polarization orientations. The UE needs to know the polarization signaling scheme in order to select the correct metric d to make a LOS or NLOS decision in 2114. The result is reported to the transmitter in 2116. The result can be binary (hard value) or numerical (soft value).

[0372] Figure 21B A block diagram is shown for polarization LOS measurement performed by receiver 204. The receiver will report the measurement results. In one embodiment, the receiver can only report the RSRP sequence of the FAP.

[0373] In one embodiment, the UE can perform LOS determination itself without being detected by the network, such as... Figure 22 As shown. If the UE knows or is able to identify the polarization orientation in RS sequence 2202 through step 2206, the above metric allows for UE-based LOS determination in 2114. This can be referred to as UE-based LOS determination. The signaling for implementing this solution is described below. Note that the signaling is not UE-specific and can also be used for network-based solutions. For this purpose, existing positioning SIBs can be used. More specifically, the information element (IE) SIBPos defined in TS38.331 and shown below can be used:

[0374]

[0375] The description of the `assistanceDataSIB` element (version suffix omitted) in TS37-355 is as follows:

[0376]

[0377] The field `assistanceDataElement` is defined as follows:

[0378] assistanceDataElement The assistanceDataElement OCTET STRING depends on posSibType and is specified in Table 7.2-1. Note.

[0379] For Table 7.2-1, a new row has been added to indicate UE-based LOS determination (the new row is highlighted):

[0380] Table 7.2-1: Mapping from posSibType to assistanceDataElement

[0381]

[0382]

[0383] In one embodiment, a new SIB type is defined to indicate two (or more) polarized PRS locations. The location server uses IE NR-DL-PRS-LOSAssistanceData to provide DL-PRS assistance data.

[0384] An IE named NR-TRP-LOS-AssistanceData is defined. An example description is given below (the version suffix is ​​omitted and the field names / types defined in TS37355 are used).

[0385]

[0386]

[0387] Another way to represent the information element NR-TRP-LOS-AssistanceData is as follows:

[0388]

[0389] In this embodiment, NR-TRP-LOS-AssistanceData uses a similar structure to NR-DL-PRS-AssistanceData, but with two PRS sequences: one for horizontal polarization and one for vertical polarization. Other embodiments using slightly different signaling are possible: for example, the distinction between horizontal and vertical polarization can be made in the NR-DL-PRS-AssistanceDataPerFreq IE or in NR-DL-PRS-AssistanceDataPerTRP. For example, one possibility is to add a field to NR-DL-PRS-AssistanceDataPerTRP to indicate polarization (BOOLEAN if there are two polarizations, otherwise INTEGER), and modify other IEs accordingly.

[0390] It should also be noted that in other embodiments, the LOS determination can be linked to a single positioning technique (e.g., TDOA). In this case, the NR LOS Assistance Data can be defined as posSIBType6-Y, or even omitted and defined in the NR-DL-PRS-Assistance Data modified for version 17 (or others) to indicate a multi-polarized PRS.

[0391] UE LOS / NLOS determination from multiple PRS received from multiple cells can be transmitted to the location server via IEProvideLOSInformation:

[0392]

[0393]

[0394] The LOS result is an integer indicating that the LOS has been determined, where 0 represents total blockage and 97 represents total LOS. In different embodiments, the LOS result may simply mean a priority order based on a higher number of measurements that are interpreted as having higher priority.

[0395] In one embodiment, LOS determination performed by the UE can be used for sidelink positioning, such as for car-to-car radar / communication, to avoid collisions or track the distance and speed of nearby vehicles. Here, the UE (vehicle) can apply LOS determination in wireless sidelink communication.

[0396] U.S. Provisional Application No. 62 / 738845, entitled “Method for LOS Determination,” filed September 28, 2018, and U.S. Provisional Application No. 62 / 746472, entitled “Method and Apparatus for Determining Line of Sight (LOS),” filed October 16, 2018, are incorporated herein by reference in their entirety.

[0397] While combinations of features are shown in the examples, not all features need to be combined to achieve the benefits of the various exemplary embodiments of the invention. In other words, a system or method designed according to exemplary embodiments of the invention does not necessarily include any of the features shown in the drawings or in all portions schematically illustrated in the drawings. Furthermore, selected features of one exemplary embodiment may be combined with selected features of other exemplary embodiments.

[0398] In some exemplary embodiments, some or all of the functions or processes of one or more devices are implemented or supported by a computer program formed of computer-readable program code and embodied in a computer-readable medium. The phrase "computer-readable program code" includes any type of computer code, including source code, object code, and executable code. The phrase "computer-readable medium" includes any type of medium accessible by a computer, such as read-only memory (ROM), random access memory (RAM), hard disk drive, compact disc (CD), digital video disc (DVD), or any other type of storage.

[0399] It may be advantageous to define certain words and phrases used in this patent document. The terms “include” and “comprise” and their derivatives mean including but not limited to. The term “or” is inclusive and means and / or. The phrases “associated with” and “associated therewith” and their derivatives mean including, including in, interconnected with, containing, contained in, connected to or connected with, coupled to or coupled with, able to communicate with, cooperate with, intersect, juxtapose, proximate, bound to or bound with, have, have its properties, etc.

[0400] While certain exemplary embodiments and generally associated methods have been described in this invention, changes and arrangements of these exemplary embodiments and methods will be apparent to those skilled in the art. Therefore, the description of the exemplary embodiments above does not limit or restrict the invention. Other changes, substitutions, and modifications are possible without departing from the spirit and scope of the invention as defined by the appended claims.

Claims

1. A method performed by a first device, the method comprising: The method includes: The first device receives an indicator from the second device that supports line-of-sight / non-line-of-sight LoS / NLoS features; The first device transmits a line-of-sight (LOS) determination request to the second device, the LOS determination request including an LOS indicator indicating the use of a LOS procedure in the LOS representation of the transmission between the first device and the second device; The first device receives a first set of reference signals transmitted through a first plurality of transmission resources from the second device; The first device measures the first set of reference signals transmitted by the second device through a second plurality of receiving resources; Each reference signal in the first set of reference signals is received on each receiving resource; and The first device identifies each reference signal corresponding to each received resource through a search process; The search process described therein includes the maximum correlation receiver on all possible reference signals.

2. The method according to claim 1, characterized in that, The LOS indicator is a binary indicator that indicates whether the LOS is characterized as LOS or NLOS.

3. The method according to claim 1, characterized in that, The LOS indicator is a multi-level soft indicator that indicates the probability or confidence level of the LOS being characterized as LOS or NLOS.

4. The method according to claim 1, characterized in that, The first device also includes measuring the first set of reference signals: The first device measures multiple channel estimates on each received resource by associating them with corresponding reference signals; The first device determines the first arrival path for each channel estimate; and The first device measures the reference signal received power (RSRP) on the first arrival path estimated for each channel.

5. The method according to claim 4, characterized in that, It also includes RSRP, which is a reference signal of the measurement of each resource sent by the first device to the second device.

6. The method according to claim 4, characterized in that, Also includes: The first device determines that the value of a given metric, determined based on the RSRP measurement of each reference signal on each resource, does indeed satisfy a specified threshold, and based on this, The first device determines that the LOS characterization of the transmission includes LOS transmission.

7. The method according to claim 4, characterized in that, Also includes: The first device determines that the value of a given metric, determined based on RSRP measurements of each reference signal for each resource, does not meet a specified threshold, and based on this, The first device determines that the LOS characterization of the transmission includes NLOS transmission.

8. The method according to claim 7, characterized in that, It also includes the LOS representation of the transmission sent by the first device.

9. The method according to claim 1, characterized in that, It also includes the LOS representation of the transmission received by the first device from the second device.

10. The method according to claim 1, characterized in that, Measuring the first set of reference signals includes measuring the reference signal received power (RSRP) or the reference signal received quality (RSRQ).

11. The method according to claim 1, characterized in that, Transmitting the LOS determination request includes: sending the LOS determination request or receiving the LOS determination request.

12. The method according to claim 1, characterized in that, The first device includes a user equipment (UE), and the second device includes an access node.

13. The method according to claim 1, characterized in that, The LOS determination request also includes a measurement gap specifying the locations of the first plurality of transmit resources and the second plurality of receive resources.

14. The method according to claim 1, characterized in that, The LOS determination request further includes a first measurement gap specifying the location of the first plurality of transmit resources and a second measurement gap specifying the location of the second plurality of receive resources.

15. The method according to claim 1, characterized in that, The reference signals are sent one after another in chronological order.

16. A first device, characterized in that, The first device includes: Including non-transitory memory for instructions; and One or more processors communicating with the memory, the one or more processors executing the instructions to: Receive an indicator of line-of-sight / non-line-of-sight LoS / NLoS feature support from the second device, and transmit a line-of-sight LOS determination request to the second device based on this, the LOS determination request including an LOS indicator indicating the use of a LOS procedure in the LOS representation of the transmission between the first device and the second device; Receive from the second device a first set of reference signals transmitted through a first plurality of transmission resources, the first set of reference signals including a first signal and a second signal; The first signal is measured on the first resource of the channel; The second signal is measured on a second resource of the channel, wherein the first signal and the second signal are multiplexed in the frequency domain or the code domain; Each reference signal in the first set of reference signals is received on each receiving resource; and The first device identifies each reference signal corresponding to each received resource through a search process; The search process described therein includes the maximum correlation receiver on all possible reference signals.

17. The first device according to claim 16, characterized in that, The LOS indicator is a binary indicator that indicates whether the LOS is characterized as LOS or NLOS.

18. The first device according to claim 16, characterized in that, The LOS indicator is a multi-level soft indicator that indicates the probability or confidence level of the LOS being characterized as LOS or NLOS.

19. The first device according to claim 16, characterized in that, The one or more processors also execute the instructions to send the measurement of the first signal and the measurement of the second signal to the second device.

20. The first device according to claim 16, characterized in that, The one or more processors also execute the instructions to receive the transmitted LOS representation from the second device.

21. The first device according to claim 16, characterized in that, The one or more processors further execute the instructions to determine that the difference between the measurement of the first signal and the measurement of the second signal satisfies a specified threshold, and based thereon determine that the LOS characterization of the transmission includes a LOS transmission.

22. The first device according to claim 16, characterized in that, The one or more processors further execute the instructions to determine that the difference between the measurement of the first signal and the measurement of the second signal does not meet a specified threshold, and based thereon determine that the LOS characterization of the transmission includes an NLOS transmission.

23. The first device according to claim 16, characterized in that, The one or more processors also execute the instructions to send the LOS representation of the transmission.

24. The first device according to claim 16, characterized in that, The one or more processors also execute the instructions to send or receive the LOS determination request.

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