Apparatus and method for polarization sensing for extracting information from environment

Abstract

A receiver (602, 902) for: receiving (1301) polarized electromagnetic radiation, an indication of an orientation of a transmitter (601, 901), and a polarization configuration of the transmitter, where the receiver has a known orientation and polarization configuration; transforming (1302) the polarized electromagnetic radiation to a reference coordinate system to form a transformed signal according to at least one of the polarized configuration of the receiver, the polarized configuration of the transmitter, the orientation of the receiver, and the orientation of the transmitter; an indication of at least one of the reference coordinate system, the orientation of the transmitter, the orientation of the receiver, the polarization configuration of the transmitter, and the polarization configuration of the receiver, and the transformed signal are transmitted (1303) to a processor (501, 551) to infer information of a path of the polarized electromagnetic radiation. Therefore, polarization sensing can be realized on various devices.

Description

Technical Field

[0001] The present invention relates to sensing in communication networks, and more particularly to extracting information from polarized signals to infer environmental information through polarized sensing. Background Art

[0002] Mobile telecommunication technology has developed rapidly, and has shifted from a voice-centric communication usage to a data-centric service usage. The next generation of telecommunication technology will further pursue increased data channel capacity and coverage, serving more users at an unprecedented scale, and will also include new services, such as perception.

[0003] Traditionally, perception technologies have been designed as standalone functions through dedicated systems such as radar or image processing-based systems. However, the concept of integrating perception with communication has recently attracted significant attention.

[0004] The goal of combining sensing and communication functions is to achieve mutual benefits, and the prospects are promising. On the one hand, communication signals can be used for sensing purposes, which helps to achieve high-precision positioning, activity awareness or environmental reconnaissance. On the other hand, the sensing function can improve the quality of service and communication performance by achieving better interference reduction, channel prediction or beam steering / focusing / alignment.

[0005] Until now, waveform design and processing of wireless communication signals have focused on the quality and level of the signal after being processed by the antenna. This approach encourages people to regard the wireless channel, including propagation and antenna, as a black box, and infer a model for this black box through the detection signal (pilot). The goal is to obtain state information that helps to decode the embedded information. This strategy focuses on the signal-to-noise ratio before passing through the analog to digital converter (ADC). In sensing applications, a lot of information related to the environment is ignored, distorted or completely masked by useless information. The first reason for this is that radio frequency (RF) signals propagate in the field as three-dimensional vectors. All interactions between the environment and the RF signal involve the field (generally electric field). In most antennas used in wireless communication devices, these interactions are weakened because they are converted into one-dimensional signals represented by current or voltage.

[0006] Equipping wireless communication devices with sensing applications requires hardware and algorithmic tools to measure incident electric fields. Polarization is an important capability to enable such applications.

[0007] Such sensing capabilities are typically embedded in specific imaging setups or in devices deployed in locations and orientations that are controllable.

[0008] Many existing technologies rely on devices for controlling the polarization patterns of radio wave transmit and receive antennas to produce sufficient polarization diversity to detect whether there is line of sight between two devices. Therefore, such technologies require specific hardware support and configuration to switch between polarization patterns, and multiple signals must be transmitted in different polarization patterns to achieve the desired polarization diversity state.

[0009] Since most consumer off-the-shelf (COTS) wireless devices have fixed polarization radiation, such methods can only benefit a small number of wireless devices.

[0010] Generally speaking, integrating new sensing functions into wireless communication devices can have adverse effects on production costs, runtime energy consumption, and thus affect the performance of sensing or communication.

[0011] Therefore, COTS wireless communication devices are generally not capable of polarization awareness. This functionality is usually implemented using dedicated devices and setups, where the position and orientation are fixed, or dedicated hardware components are required to perform polarization awareness.

[0012] Mobile devices generally do not have this type of functionality because they can be placed anywhere and in any orientation.

[0013] It is desirable to develop a method to solve this type of problem. Summary of the invention

[0014] According to a first aspect, there is provided a receiver, the receiver being configured to: receive polarized electromagnetic radiation, an indication of the position of a transmitter emitting the polarized electromagnetic radiation, and a polarization configuration of the transmitter, wherein the receiver has a known position and polarization configuration; transform the polarized electromagnetic radiation to a reference coordinate system to form a transformed signal based on at least one of the polarization configuration of the receiver, the polarization configuration of the transmitter, the known position of the receiver, and the position of the transmitter; and send an indication of at least one of the reference coordinate system, the position of the transmitter, the position of the receiver, the polarization configuration of the transmitter, and the polarization configuration of the receiver, and the transformed signal to a processor, wherein the processor is configured to infer information of one or more paths of the polarized electromagnetic radiation between the transmitter and the receiver.

[0015] According to another aspect, a transmitter is provided. The transmitter is configured to: transmit polarized electromagnetic radiation to a receiver; receive from the receiver a measured polarization signal, an indication of the orientation of the receiver, and a polarization configuration of the receiver, wherein the transmitter has a known orientation and polarization configuration; transform the measured polarization signal to a reference coordinate system to form a transformed signal based on at least one of the polarization configuration of the receiver, the polarization configuration of the transmitter, the orientation of the receiver, and the orientation of the transmitter; and send an indication of at least one of the reference coordinate system, the orientation of the transmitter, the orientation of the receiver, the polarization configuration of the transmitter, and the polarization configuration of the receiver, and the transformed signal to a processor, wherein the processor is configured to infer information about one or more paths of the polarized electromagnetic radiation between the transmitter and the receiver.

[0016] This enables polarization awareness on a variety of devices (including those with single-polarization configurations that do not have multipolar radiation) and does not require prior knowledge of the geometry of the environment. This technology has a variety of applications, including line-of-sight path differentiation, object detection, and material identification on reflective surfaces.

[0017] The information about the one or more paths of the polarized electromagnetic radiation may include an indication of the presence of obstacles on one or more of the paths of the polarized electromagnetic radiation between the transmitter and the receiver and / or an indication of the composition and / or properties of one or more materials of the obstacles. This may enable line-of-sight path differentiation, object detection, and / or material identification of reflective surfaces.

[0018] The position of the transmitter and the position of the receiver may be determined relative to a common vector. For example, the common vector may be a vector in the direction of the center of the earth.

[0019] The position of the receiver and / or the position of the transmitter relative to the receiver may be fixed. For example, the receiver and / or the transmitter may be static. They may be placed on a fixed building or tower. The receiver and / or the transmitter may be a base station in a telecommunications network. This allows the technology to be implemented in existing communication networks.

[0020] The receiver may be configured to send the transformed signal to the transmitter for processing by the processor. In this way, the processor may infer environmental information from the transformed signal. Alternatively, the receiver may be configured to send the transformed signal to a remote device for processing by the processor. The receiver may include a transceiver configured to transmit the transformed signal to the processor. Alternatively, the receiver may include the processor, and the receiver may infer the information.

[0021] The receiver and the transmitter can both be one of a base station, a user device, and an aircraft with communication capabilities. In this way, the technology can be used in a variety of different network configurations, including static endpoints or mobile endpoints.

[0022] The receiver may be configured to receive a request from the transmitter to receive the polarized electromagnetic radiation transmitted by the transmitter. The receiver may be configured to receive the polarized electromagnetic radiation in response to accepting the request. In this way, the receiver may enter a sensing mode in which the receiver predicts a sensing signal from the transmitter.

[0023] The receiver may also be configured to receive one or more signals, wherein the one or more signals include the polarized electromagnetic radiation, the indication of the orientation of the transmitter, and the indication of the polarization configuration of the transmitter, and the one or more signals also include one or more transmission parameters. In this way, the receiver may learn the transmission parameters of the transmitter.

[0024] The one or more transmission parameters may include one or more of a frequency channel of the one or more signals and a selected bandwidth of the one or more signals. In this way, the receiver may receive the polarized electromagnetic radiation on a suitable channel of a suitable bandwidth.

[0025] The one or more signals may be radio frequency signals.The method may thus be used in a telecommunication network in which a plurality of devices are used to transmit and / or receive radio frequency signals.

[0026] The receiver may also be used to calculate a model for transforming polarized electromagnetic radiation subsequently received from the transmitter. This may improve the efficiency of the sensing process.

[0027] The receiver may include at least one position sensor for determining the known position of the receiver. For example, the receiver may include a gyroscope. This may be a convenient implementation because such position sensors are common components in mobile phones and other user devices.

[0028] According to yet another aspect, a method implemented at a receiver having a known position and polarization configuration is provided. The method includes: receiving polarized electromagnetic radiation, an indication of the position of a transmitter emitting the polarized electromagnetic radiation, and the polarization configuration of the transmitter; transforming the polarized electromagnetic radiation to a reference coordinate system to form a transformed signal based on at least one of the polarization configuration of the receiver, the polarization configuration of the transmitter, the known position of the receiver, and the position of the transmitter; sending an indication of at least one of the reference coordinate system, the position of the transmitter, the position of the receiver, the polarization configuration of the transmitter, and the polarization configuration of the receiver, and the transformed signal to a processor, wherein the processor is used to infer information about one or more paths of the polarized electromagnetic radiation between the transmitter and the receiver.

[0029] According to yet another aspect, a method implemented at a transmitter having a known orientation and polarization configuration is provided. The method includes: transmitting polarized electromagnetic radiation to a receiver; receiving a measured polarization signal, an indication of the orientation of the receiver, and the polarization configuration of the receiver from the receiver; transforming the measured polarization signal to a reference coordinate system to form a transformed signal based on at least one of the polarization configuration of the receiver, the polarization configuration of the transmitter, the orientation of the receiver, and the orientation of the transmitter; sending an indication of at least one of the reference coordinate system, the orientation of the transmitter, the orientation of the receiver, the polarization configuration of the transmitter, and the polarization configuration of the receiver, and the transformed signal to a processor, wherein the processor is used to infer information about one or more paths of the polarized electromagnetic radiation between the transmitter and the receiver.

[0030] These methods can enable polarization awareness on a variety of devices, including those with single-polarization configurations that do not have multipolar radiation, and do not require a priori knowledge of the geometry of the environment.

[0031] According to yet another aspect, a processor is provided, the processor being configured to process data from a receiver, wherein the data comprises a transformed signal formed by transforming polarized electromagnetic radiation received by the receiver from the transmitter to a reference coordinate system based on at least one of an orientation of the receiver, an orientation of a transmitter, a polarization configuration of the receiver, and a polarization configuration of the transmitter to infer information of one or more paths of the polarized electromagnetic radiation between the transmitter and the receiver.

[0032] The information about the one or more paths of the polarized electromagnetic radiation may include an indication of the presence of obstacles on one or more of the paths of the polarized electromagnetic radiation between the transmitter and the receiver and / or an indication of the composition and / or properties of one or more materials of the obstacles. This may enable line-of-sight path differentiation, object detection, and / or material identification of reflective surfaces.

[0033] The processor is configured to decompose the transformed signal into two or more paths and estimate the polarization of each path of the transformed signal to infer information about the path of the polarized electromagnetic radiation between the transmitter and the receiver.

[0034] The processor is configured to calculate a degree of depolarization of each of the one or more paths of the polarized electromagnetic radiation relative to the polarization emitted by the transmitter, and to infer environmental information based on the degree of depolarization. Polarized electromagnetic radiation may be depolarized to varying degrees when interacting with different materials and / or reflected from an object at different angles. Therefore, by calculating the degree of polarization, the processor can effectively infer environmental information.

[0035] The processor may also be used to form an environment map between the transmitter and the receiver. For example, through such a map, the mobile device may avoid collisions with obstacles in the surrounding environment.

[0036] The processor may be configured to estimate the ratio of the component of the electric field polarization direction in the transformed signal perpendicular to the incident plane (i.e., for obstacles in the path of the polarized electromagnetic radiation between the transmitter and the receiver) to the component of the electric field polarization direction in the transformed signal parallel to the incident plane (i.e., the ratio of the S polarization to the P polarization of the transformed signal). In this way, the processor may infer environmental information surrounding the receiver and the transmitter, including the material of reflective objects in the environment.

[0037] The processor may be configured to send the inferred information and one or more corresponding tags to a storage medium. The one or more corresponding tags may include one or more of capture time, path identification, obstacle presence and nature, angle of arrival, and relative delay. In this way, the processor may effectively map the environment.

[0038] The processor is located in one of the receiver, the transmitter, and a location remote from the receiver and the transmitter. This allows for processing flexibility.

[0039] According to yet another aspect, a method implemented at a processor is provided, the method comprising: processing data from a receiver, wherein the data comprises a transformed signal formed by transforming polarized electromagnetic radiation received by the receiver from a transmitter to a reference coordinate system based on an orientation of the receiver, an orientation of the transmitter, a polarization configuration of the receiver, and a polarization configuration of the transmitter to infer information of one or more paths of the polarized electromagnetic radiation between the transmitter and the receiver.

[0040] According to yet another aspect, a communication system is provided. The communication system comprises: a transmitter for transmitting polarized electromagnetic radiation, an indication of the position of the transmitter, and an indication of the polarization configuration of the transmitter; a receiver having a known position and polarization configuration and for receiving the polarized electromagnetic radiation, the indication of the position of the transmitter, and the indication of the polarization configuration of the transmitter; one or more processors for: transforming the polarized electromagnetic radiation received by the receiver to a reference coordinate system to form a transformed signal based on at least one of the polarization configuration of the receiver, the polarization configuration of the transmitter, the known position of the receiver, and the position of the transmitter; and processing the transformed signal to infer information about one or more paths of the polarized electromagnetic radiation between the transmitter and the receiver based on at least one of the reference coordinate system, the position of the transmitter, the position of the receiver, the polarization configuration of the transmitter, and the indication of the polarization configuration of the receiver.

[0041] The receiver may include the one or more processors, and / or the transmitter may include the one or more processors. Alternatively or in addition, the one or more processors may be located in an entity remote from the transmitter and the receiver. This may allow for processing flexibility in transforming radiation and inferring environmental information.

[0042] The position of the receiver may be an absolute position.The position of the transmitter may be an absolute position.

[0043] The orientation of the receiver may be a relative orientation. The orientation may be measured relative to the orientation of the receiver when receiving a previous signal. The orientation of the transmitter may be a relative orientation. The orientation may be measured relative to the orientation of the transmitter when transmitting a previous signal.

[0044] The receiver and the transmitter may be wireless devices in a communication network. By enabling polarization awareness, wireless devices in a communication network may have a stronger ability to measure RF propagation paths in the electric field domain. This may enable polarization awareness on a variety of devices (including those with single polarization configurations that do not have multi-polar radiation) and may not require prior knowledge of the geometry of the environment.

[0045] According to another aspect, a computer-readable storage medium storing computer-readable instructions is provided. When the computer-readable instructions are executed by a computer system, the computer system performs the above method. The computer system may include one or more processors. The computer-readable storage medium may be a non-transitory computer-readable storage medium. BRIEF DESCRIPTION OF THE DRAWINGS

[0046] The present invention is described below by way of examples in conjunction with the accompanying drawings. In the accompanying drawings:

[0047] Figure 1 (a) Figure 1 (b) and Figure 1 (c) in FIG. 1 schematically shows the depolarization effect of polarized electromagnetic radiation propagating between a transmitter and a receiver.

[0048] Figure 2 The polarization diversity in the environment is schematically shown.

[0049] Figure 3 A communication network including a base station and a plurality of user equipments in an environment is schematically shown.

[0050] Figure 4 The variation of the polarization ratio (ratio of P polarization to S polarization) of different materials with the incident angle is shown.

[0051] Figure 5 (a) in the figure shows a schematic diagram of an example of a transmitting device.

[0052] Figure 5 (b) in FIG. 1 shows a schematic diagram of an example of a receiving device.

[0053] Figure 6 An environment in an urban area is shown with fixed transmitters and mobile unmanned aerial vehicles (UAVs), both used as transmitting and receiving devices in a communication network.

[0054] Figure 7 An exemplary sensing protocol initiated by a receiver in a communication network is shown.

[0055] Figure 8An exemplary sensing protocol initiated by a transmitter in a communication network is shown.

[0056] Fig. 9 An environment in an urban area is shown with two unmanned aerial vehicles (UAVs) acting as transmitting and receiving devices in a communication network.

[0057] Fig.10 An exemplary signaling flow in an awareness session initiated by a receiver in a communication network using a mobile endpoint is shown.

[0058] Fig.11 An exemplary signaling flow in an awareness session initiated using relative position by a transmitter in a communication network is shown.

[0059] Fig.12 An exemplary signaling flow in an awareness session initiated by a receiver in a communication network using relative position is shown.

[0060] Fig.13 An example of a method implemented at a receiver is shown.

[0061] Fig.14 An example of a method implemented at a transmitter is shown. DETAILED DESCRIPTION

[0062] The embodiments of the present invention can extract information from the environment around the transmitting device and the receiving device in the telecommunication network through polarization sensing when there is limited prior knowledge of the environment.

[0063] Polarization sensing is achieved through the ability to transmit and measure polarized electromagnetic waves. The way the electric and magnetic fields oscillate along the direction of wave propagation is the polarization signature of the wave.

[0064] Electromagnetic radiation can have different polarization configurations, including linear, circular, and elliptical polarization. For linear polarization, the electric field of the electromagnetic radiation is confined to a single plane along the direction of propagation. For circular polarization, the electric field has two linear components that are perpendicular to each other and have equal amplitudes, but a phase difference of π / 2. The resulting electric field rotates once around the direction of propagation, and depending on the direction of rotation, the radiation is called left-hand circularly polarized radiation or right-hand circularly polarized radiation. For elliptical polarization, the electric field describes an ellipse. This is caused by the combination of two linear components with different amplitudes and / or a phase difference other than π / 2.

[0065] In one non-limiting example, the polarization of a radio wave signal may be measured based on the strength of a linearly polarized source signal received by an antenna at a particular location in space.

[0066] In the following description, the term "transmitter" applies to a transmitting device, which transmits a polarized signal, and the term "receiver" applies to a receiving device, which receives and measures the transmitted polarized signal.

[0067] like Figure 1 As shown schematically in (a), under direct line of sight (LoS) conditions between the transmitter 101 and the receiver 102, it is expected that the receiver will observe no or very small depolarization effect on the polarized radio wave signal 103.

[0068] On the contrary, when electromagnetic waves are reflected from or transmitted through a medium, a depolarization effect occurs. Figure 1 As shown in the schematic diagram of (b), when the polarized radio wave signal 104a transmitted by the transmitter 101 encounters the obstacle 105, the transmitted wave 104b is depolarized relative to the wave 104a. Figure 1 In (c), the polarized radio wave signal 106 transmitted by the transmitter 101 propagates to the receiver 102 under direct LoS conditions, but the wave 107a encounters an obstacle 108 and the transmitted wave 107b is depolarized relative to the wave 107a.

[0069] Therefore, the first criterion for classifying direct and indirect paths between transmitter and receiver is evaluated.

[0070] Figure 2 Further illustrated is an environment 200 in which a transmitter 201 transmits a signal comprising polarized electromagnetic radiation to a receiver 202. Signal 202 propagates from transmitter 201 to receiver 202 under direct LoS conditions. However, signal 203a is reflected from boundary 204, and reflected signal 203b is depolarized relative to signal 203a. Similarly, signal 205a encounters obstacle 206, and reflected signal 205b is depolarized relative to transmitted signal 205a.

[0071] Thus, measuring depolarization in electromagnetic waves can be used to determine whether obstacles are present in an environment of a radio frequency network including multiple transmitting devices and receiving devices. For example, in environment 300, radio frequency signals can be sent between user equipment (UE) 301 and 302 and base station (BS) 303. Polarization sensing can be used to determine whether objects 304, 305 exist and / or their locations. Signals 306, 307, 308 propagate between their transmitting entities and receiving entities under direct LoS conditions, and transmitted signals 309a and 310a encounter objects 304 and 305, respectively, on their paths. Therefore, the corresponding reflected signals 309b and 310b are depolarized relative to the transmitted signals.

[0072] The depolarization phenomenon is modeled by the Fresnel equations (see, https: / / en.wikipedia.org / wiki / Fresnel_equations, etc.), which describe the reflection of electromagnetic waves on and transmission through a medium, and are modeled as the complex refractive index of the medium. This complex value represents the phase velocity (real part) and the attenuation or dielectric constant (imaginary part) of the medium.

[0073] Various materials in common environments have a certain range of refractive indices. For example, for metal surfaces with high refractive index and strong conductivity, the incident electromagnetic radio wave energy will be reflected and partially absorbed by the medium. In contrast, for concrete surfaces, the incident electromagnetic waves will be reflected and transmitted by the medium.

[0074] The measured depolarization of the transmitted electromagnetic signal can be processed using different methods to determine the material properties of the obstacle and thus estimate its nature.

[0075] The two most important orthogonal linear polarization states for reflection and transmission are called P polarization and S polarization. With respect to an obstacle, the electric field of P-polarized radiation is polarized parallel to the plane of incidence, while the electric field of S-polarized radiation is polarized perpendicular to the plane.

[0076] In one non-limiting example, the reflective material can be estimated based on the ratio of S polarization to P polarization measured by the receiver when the transmitted polarized signal is reflected from different materials. Figure 4 As shown in Figure 1, with respect to the S and P coordinate systems, the metal surface reflects almost all incident energy, while for other materials, part of the incident wave energy may be transmitted through the medium. Therefore, the reflected wave will show a different polarization mode from the wave reflected from the metal surface. Figure 4 This phenomenon is shown for various materials.

[0077] Therefore, in the following implementation, the processor can determine the ratio of the S polarization to the P polarization of the received signal, and estimate the material from which the signal is reflected and / or the angle of incidence / reflection based on the polarization ratio. Other polarization sensing methods can also be used. In this way, the processor can infer information about the environment around the receiver and transmitter through polarization sensing.

[0078] For reflected signals that experience depolarization, the processor can estimate the probability that the polarization deviation is caused by a potential material based on a set of known complex refractive indices. This can be accomplished using a stored database of known material properties. The processor can be used to estimate the material composition of obstacles in the path of the polarized electromagnetic radiation between the transmitter and the receiver based on the measured depolarization of the transmitted polarized electromagnetic radiation. For example, within a factory, a set of known large reflective surfaces may be metal or concrete. In urban areas, building surfaces may be composed of metal, glass, or concrete.

[0079] In other cases, the paths and materials can be estimated by calculating a model of the deviation of the depolarization relative to the expected polarization based on the known polarization configuration of the transmitter.

[0080] Through the embodiments of the present invention, two or more wireless devices, each with a single polarization configuration for the antenna, can perform polarization sensing. This method can also be applied to devices capable of multi-polarization transmission. In the embodiments of the present invention, it is assumed that the devices can self-sense their orientation in space and can self-sense their polarization configuration.

[0081] Figure 5 (a) in FIG. 1 shows a schematic diagram of an example of a transmitting device 500 (referred to herein as a transmitter). The transmitter may include at least one processor (e.g., processor 501) and at least one memory (e.g., memory 502). The memory stores code in a non-transient manner, which can be executed by one or more processors to implement the above-mentioned device in the manner described herein. The transmitter also includes a transmitting antenna 503 for transmitting polarized electromagnetic radiation and receiving other feedback signals from a receiver. The transmitter also includes an orientation sensor 504. The orientation of the transmitter mentioned herein refers to the orientation of the transmitting antenna.

[0082] Figure 5 (b) in FIG. 5 shows a schematic diagram of an example of a receiving device 550 (referred to herein as a receiver). The receiver may include at least one processor (e.g., processor 551) and at least one memory (e.g., memory 552). The memory stores code in a non-transient manner, which can be executed by one or more processors to implement the above-mentioned device in the manner described herein. The receiver also includes a receiving antenna 553 for receiving polarized electromagnetic radiation and an orientation sensor 554. The orientation of the receiver mentioned herein refers to the orientation of the receiving antenna.

[0083] As mentioned above, these devices can be equipped with orientation sensors, such as gyroscopes. Orientation sensors can be used to determine the orientation of the device. These sensors are common components in mobile phones and user equipment. For other devices that can act as transmitters and / or receivers, such as fixed base stations or access points, orientation information can be collected and configured during the deployment phase so that the devices can self-aware of their respective orientation.

[0084] As described in conjunction with the following examples, the receiver has a known orientation and polarization configuration. The receiver is used to receive polarized electromagnetic radiation from the transmitter. The transmitter may also send an indication of the orientation of the transmitter and the polarization configuration of the transmitter to the receiver.

[0085] The received polarized electromagnetic radiation may be transformed to a reference coordinate system based on at least one of a polarization configuration of the receiver, a polarization configuration of the transmitter, a known orientation of the receiver, and an orientation of the transmitter to form a transformed signal. Such transformation may be performed by the receiver, the transmitter, or a remote processing entity.

[0086] From the transformed signal, the processor can infer information about one or more paths of the polarized electromagnetic radiation between the transmitter and the receiver, such as an indication of the presence of an obstacle and / or the composition and / or properties of one or more materials of the obstacle along one or more of the paths of the polarized electromagnetic radiation between the transmitter and the receiver. This inference can be performed by the receiver, the transmitter, or a remote processing entity.

[0087] Typically, a transmitter (Tx) sends a polarized signal, along with information about the absolute position (or in some embodiments, relative position) of the transmitter in space (relative to a known common reference, such as the center of the earth) and the current polarization configuration of the transmitter in the same reference frame.

[0088] Therefore, the transmitter knows its antenna polarization configuration and orientation in space. Therefore, the transmit polarization is known in an absolute reference frame.

[0089] The receiver (Rx) acquires the polarized signal. The receiver knows its antenna polarization configuration and its orientation in space. The orientation and polarization information of the transmitter can also be provided to the receiver. The receiver can correlate the orientation of the transmitter with its own orientation. At this point, the polarized signal can be compared with the polarization configuration of the receiver in the same reference frame (i.e., the reference coordinate system).

[0090] Therefore, if the receiver knows the orientation and polarization configuration of the transmitter, the transmitted polarization and the received polarization can be expressed using the same reference frame.

[0091] The measured signal can be decomposed into subpaths and a processor located in the receiver, transmitter or remote entity can perform polarization analysis in the electric field domain.

[0092] When an electromagnetic signal propagates between a transmitter and a receiver, it may take multiple paths. For each perceived path l∈{1,…,L}, the deviation can be calculated in, is the polarization of the electromagnetic radiation measured by the receiver on path l, is the polarization of the emitted electromagnetic radiation on path l.

[0093] Once the reflective surface estimate is made, the processor can then correlate geometric information, such as the angle of arrival, with the estimate. This data correlation can be used as feedback to the system model to improve accuracy.

[0094] Therefore, in some embodiments, the transmitter has absolute control and / or awareness of field polarization transmission and position awareness, and the receiver has the ability of position awareness and field polarization measurement.

[0095] The protocol and related signaling can be used to estimate the impact of the environment on the field direction (polarization), which will be described in detail below.

[0096] In the following examples, the transmitter and receiver are nodes in a communication network. Each node is a connection point in a communication network and can be used as an endpoint for data transmission or redistribution. In the following examples, node 1 is used as a transmitting device and node 2 is used as a receiving device.

[0097] Figure 6 An urban scene in environment 600 is shown, where a base station 601 (node ​​1 / transmitter) is located on top of a building 603. The orientation and antenna polarization of base station 601 are known. UAV 602 (node ​​2 / receiver) is equipped with an orientation sensor, and the antenna polarization of UAV 602 is known and fixed.

[0098] There are several obstacles in environment 600: concrete buildings 604 and metal objects 605, such as vehicles.

[0099] like Figure 6 As shown, polarized electromagnetic signal 606 is transmitted by base station 601 and propagates to UAV 602 under direct LoS conditions.

[0100] Polarized electromagnetic signal 607a is transmitted by base station 601 and encounters building 604. Signal 607a is partially absorbed and partially reflected by building 604. Reflected signal 607b is depolarized relative to transmitted signal 607a.

[0101] Polarized electromagnetic signal 608a is transmitted by base station 601 and encounters metal object 605. A significant portion of signal 608a is reflected by metal object 605. Reflected signal 608b is depolarized relative to transmitted signal 608a.

[0102] The depolarization of the transmit signals 606 , 607 b , and 608 b may be measured by the receiver 602 .

[0103] Reference below Figure 7 and Figure 8 Two exemplary signaling protocols are described. In these examples, the sensing signal sent by the transmitter may be Figure 6 The signal received by the receiver may be Figure 6 Signals such as 606, 607b or 608b are shown.

[0104] Figure 7 An example of a sensing process initiated by receiver 602 (node ​​2) is shown. This embodiment illustrates a single-base mode (i.e., the spatial position of the transmitter is fixed, but the receiver is mobile, such as Figure 6 Polarization perception of the receiving end under the condition shown in FIG.

[0105] As shown in 701, node 2 602 sends a request to start a perception session with node 1 601. As shown in 702, node 1 601 sends back a confirmation to node 2 602, indicating that the perception service is available and node 2 can use it at any time.

[0106] As shown in 703, node 1 estimates the absolute orientation of the transmit antenna. For example, the absolute orientation can be determined relative to the horizon. As shown in 704, node 1 also sets its transmission parameters. These transmission parameters may include, for example but not limited to, the frequency channel of the signal, the selected bandwidth of the signal, and information about the polarization configuration of the transmit antenna and the absolute orientation of the transmit antenna.

[0107] Node 2 also estimates the absolute orientation of the receiving antenna, as shown in 705. For example, the absolute orientation may be determined relative to the horizon. Node 2 also knows the polarization configuration of the receiving antenna.

[0108] Then, node 2 may trigger a request to start the sensing process. At 706, node 2 transmits a sensing signal 707 through a transmitting antenna. The sensing signal 707 is a signal including polarized electromagnetic radiation. At 708, the receiving antenna of node 1 receives the sensing signal.

[0109] At 709, Node 1 sends the one or more transmission parameters determined above (including the polarization configuration of the transmit antenna), and the absolute position of the transmit antenna.

[0110] In some implementations, the sensing signal 707 and the transmission parameters / antenna positions 709 may be sent from node 1 to node 2 using a single signal.

[0111] Based on the received information, node 2 is able to calculate a model for transposing subsequent received signals to a unique reference.

[0112] In a non-limiting example, the reference model can be implemented as a three-dimensional matrix, where the coefficients of the matrix represent the size of the current polarization configuration of the receiving antenna of the receiving end in three-dimensional space. The absolute orientation of the antennas of node 1 and node 2 can be used to rotate this reference matrix. In another possible implementation, the rotation can be applied directly to the received signal instead of the reference matrix. The purpose of this matrix is ​​to generate a correlation metric for each receive radio frequency (RF) channel path.

[0113] At 710, node 2 performs a material identification process. Based on the RF measurement results, node 2 decomposes the acquired signal into RF propagation paths. Each receive path can be associated with a calculated reference model and the previously described techniques (e.g., polarization ratio method) are used to estimate whether the signal is in LoS on one or more paths between the transmitter and the receiver and / or the nature of the reflective surfaces present in the environment.

[0114] Node 2 can associate the information with previous estimates (e.g., the angle of arrival and relative delay of each propagation path). Optionally, this data association can be used to determine the relative position of node 2 relative to node 1.

[0115] Optionally, as shown in 711, node 2 may provide environmental information, such as the composition and location of objects on one or more paths of one or more sensing signals, to node 1. At 712, node 2 sends a signal to node 1 to end the sensing session.

[0116] Figure 8 An alternative example of a sensing process initiated by transmitter 601 (node ​​1) is shown. This embodiment illustrates a single-base mode (i.e., the spatial location of the transmitter is fixed, but the receiver is mobile, such as Figure 6 Polarization sensing of the transmitter under the condition shown in FIG.

[0117] In this embodiment, the transmitter 601 initiates a sensing session. The polarization measured by the receiving end is fed back to the transmitter, which performs RF path identification and material identification processes.

[0118] As shown in 801, the transmitter (node ​​1) 601 sends a request to start a perception session with the receiver. As shown in 802, the receiver (node ​​2) 602 sends back a confirmation, indicating that the perception service is available and the transmitter 601 can use it at any time.

[0119] As shown in 803, node 1 estimates the absolute orientation of the transmit antenna. For example, the absolute orientation can be determined relative to the horizon. As shown in 804, node 1 also sets its transmission parameters. These transmission parameters may include, for example but not limited to, information about the frequency channel, the selected bandwidth, and the polarization configuration of the transmit antenna.

[0120] Node 2 602 also estimates the absolute orientation of the receiving antenna, as shown at 805. For example, the absolute orientation may be determined relative to the horizon. Node 2 also knows the polarization configuration of the receiving antenna.

[0121] At 806, node 2 transmits a sensing signal 807 to node 1. The sensing signal 807 is a signal comprising polarized electromagnetic radiation. At 808, node 1 receives the sensing signal.

[0122] Node 1 can also send the transmission parameters of node 1 (including the polarization configuration of the transmitting antenna) to node 2 ( Figure 8 not shown).

[0123] Node 2 measures the received sensing signal. As shown in 809, node 2 then sends back to node 1 the measurement result of the received signal, as well as the absolute position and polarization configuration of the receiving antenna.

[0124] By receiving the feedback information of the signal, Node 1 can decompose the signal into one or more RF sub-paths and quantize the polarization of the signal received from the receiver (Node 2).

[0125] Node 1, upon receiving the feedback signal and the orientation and polarization configuration of the receiving antenna, is able to calculate a model for transposing the received and transmitted signals to a unique reference to estimate the polarization difference between the transmitted polarization and the sensed polarization at the receiving end.

[0126] Based on the feedback RF measurement results, node 1 decomposes the acquired signal into RF propagation paths. Each received path can be associated with a calculated reference model, and the existence of LoS and / or the nature of the reflective surfaces in the environment can be estimated, as shown in 810.

[0127] The transmitter can correlate the information with previous estimates (e.g., the angle of arrival and relative delay of each propagation path). Optionally, this data correlation can be used to determine the relative position of the receiver with respect to the transmitter.

[0128] At 811, node 1 determines whether the sensing session has ended.

[0129] Optionally, the estimation result may be shared with a receiver, as shown at 812. At 813, node 1 sends a signal to node 2 to end the sensing session.

[0130] Another application may involve both a mobile transmitter and a mobile receiver (dual mobile). Fig. 9 Two UAVs 901, 902 are shown in an urban area 900. Thus, in this scenario, both Node 1 (transmitter) and Node 2 (receiver) are aerial vehicles with communication capabilities.

[0131] Polarized electromagnetic signal 905 is transmitted by UAV 901 and propagates to UAV 902 under direct LoS conditions.

[0132] Polarized electromagnetic signal 906a is transmitted by UAV 901 and encounters building 903. Signal 906a is partially absorbed and partially reflected by building 903. Reflected signal 906b is depolarized relative to transmitted signal 906a.

[0133] Polarized electromagnetic signal 907a is transmitted by UAV 901 and encounters metal object 904. A significant portion of signal 907a is reflected by metal object 904. Reflected signal 907b is depolarized relative to transmitted signal 907a.

[0134] The depolarization of the transmit signals 905 , 906 b and 907 b may be measured by the receiver 902 .

[0135] Reference below Figures 10 to 12 describe Fig. 9 The exemplary arrangement shown has three exemplary signaling protocols that may be used.

[0136] In order to track one or more communication-capable aircraft, the polarization sensing process described below can be repeated cyclically until the sensing session ends.

[0137] When both the transmitter and the receiver are moving (for example, both the transmitter and the receiver are located on an aircraft, such as Fig. 9 In a first example (as shown), the perception process can be initiated at the receiving end.

[0138] As shown in 1001, node 2 902 sends a sense session request to node 1 901. As shown in 1002, node 1 sends back a confirmation of the session allocation and enters the sense mode.

[0139] As shown in 1003, node 2 triggers a request for the sensing process. Then, both node 1 and node 2 can enter the monitoring state, and each monitors the position of its own antenna.

[0140] Node 1 estimates the absolute orientation of the transmit antenna as shown in 1004. For example, the absolute orientation may be determined relative to the horizon. Node 1 also sets its transmission parameters as shown in 1005. These transmission parameters may include, for example but not limited to, information about the frequency channel, the selected bandwidth, and the polarization configuration and absolute orientation of the transmit antenna.

[0141] Node 2 also estimates the absolute orientation of the receiving antenna, as shown at 1006. For example, the absolute orientation may be determined relative to the horizon. Node 2 also knows the polarization configuration of the receiving antenna.

[0142] At 1007 , node 1 sends one or more transmission parameters of node 1 (including the polarization configuration of the transmit antenna) and the absolute position of the transmit antenna to node 2 .

[0143] The first sensing procedure may entail performing steps of estimating the absolute orientation of the antenna and / or setting the transmission parameters of the transmitter. These steps may optionally be repeated periodically during a sensing session each time a sensing procedure is performed between the transmitter and the receiver.

[0144] As shown at 1008 , node 1 sends a polarization-aware signal 1009 to node 2 . At 1010 , node 2 receives the polarization-aware signal 1009 .

[0145] From the received information (ie the polarized signal, the absolute position of the transmit antenna and the polarization configuration of the transmit antenna) and using the known absolute position and polarization configuration of the receive antenna, the node 2 is able to calculate a model for transposing subsequent receive signals to a unique reference.

[0146] In one non-limiting example, the reference model can be implemented as a three-dimensional matrix, where the coefficients represent the size of the current polarization configuration of the receiving antenna in three-dimensional space. The absolute orientation of the antennas of node 1 and node 2 (transmit antenna and receive antenna, respectively) can be used to rotate this reference matrix. In another possible implementation, the rotation can be applied to the received signal instead of the reference matrix. The purpose of this matrix is ​​to generate a correlation metric for each receive RF channel path.

[0147] Based on the RF measurement results, node 2 may perform a material identification process (described above) by decomposing the acquired signal into RF propagation paths, as shown in 1101. Each received path may be associated with a calculated reference model and may be used to estimate whether LoS exists and / or the nature of reflective surfaces present in the environment.

[0148] Node 2 can correlate the information with previous estimates (e.g., angle of arrival and relative delay for each propagation path). This data correlation can be used for tracking purposes.

[0149] At 1012, node 2 may determine whether the receiving process has ended. If the receiving process has not ended, other iterations of the process may be performed, as shown in 1013. These steps may be repeated until the sensing session ends.

[0150] If the sensing session has ended, node 2 may share node 2's estimation data with node 1, as shown at 1014. At 1015, node 1 sends a signal to node 2 to end the sensing session.

[0151] exist Fig.10 In the example shown, the processing of inferred environmental information is performed by a processor in the receiver. The sensing process can also be initiated at the transmitter (node ​​1), and / or the processing of inferred environmental information can be performed by a processor in the transmitter, using the same process as described above. Figure 8 The process described is similar and can also be handled by a remote processing entity.

[0152] Fig.11 Another example is shown where both the transmitter and receiver are moving. In this example, the sensing process is initiated at the receiver 902 (node ​​2). In this embodiment, the position information is updated by relative reference rather than absolute reference.

[0153] As shown in 1101, node 1 901 initiates a sensing session by sending a request to node 2 902. Node 2 confirms the allocation of the session to node 1 and enters sensing mode as shown in 1102. Node 2 expects to receive a polarization signal.

[0154] As shown at 1103 , node 1 determines one or more transmission parameters (including the polarization configuration of the transmit antenna), as described above. At 1104 , node 1 transmits a polarization-aware signal 1105 to node 2 .

[0155] At 1106, node 2 receives and measures the sensing signal. Node 2 then sends back to the transmitter, at 1107, the measurement results of node 2 on the received sensing signal and the polarization of the receiving antenna. With this type of feedback information of the received signal, node 1 is sufficient to decompose this signal into one or more RF sub-paths and quantify the polarization of the signal received from the receiver (node ​​2).

[0156] At 1108 , node 1 may update one or more of its transmission parameters, and then at 1109 , node 1 sends a next polarization-aware signal 1110 , which node 2 receives at 1111 .

[0157] At 1112 , node 1 evaluates the azimuth difference of its transmit antenna when sending the previous polarization-aware signal 1105 and when sending the next polarization-aware signal 1110 .

[0158] At 1113 , node 2 also evaluates the azimuth difference of its receiving antenna when receiving the previous polarization-aware signal 1105 (at 1106 ) and when receiving the next polarization-aware signal 1110 (at 1111 ).

[0159] At 1114 , node 2 sends feedback information of the received sensing signal 1110 for signal processing by node 1 , as well as the relative position of the receiving antenna when receiving signal 1110 relative to the position of the receiving antenna when receiving the previous polarized signal 1105 .

[0160] Based on the information received by node 1, node 1 estimates the polarization azimuth offset of the transmit antenna relative to the previous transmitted signal, and the polarization azimuth offset of the receive antenna relative to the previously received feedback payload sent by node 2 (as shown in 1107).

[0161] From these two offsets, the relative physical orientation of the antenna of node 1 with respect to the antenna of node 2, and vice versa, can be calculated, which may occur in the time frame between the two polarized signal transmissions (1105 and 1110) and in the same reference coordinate system.

[0162] Based on the above understanding, at 1115, node 1 can continue to perform the material identification / location process by decomposing the feedback signal information into RF sub-paths, and continue to perform depolarization quantification on each RF sub-path. Based on the depolarization effect of each RF sub-path, an estimation result of LoS or material presence can be calculated.

[0163] At 1116, node 1 may determine whether the sensing session has ended. If so, node 1 may share the inferred environmental information with node 2, as shown at 1117. At 1118, node 1 sends a signal to node 2 to end the sensing session.

[0164] Fig.12 An alternative signaling flow for the polarization awareness process initiated at the receiver is shown. This example also includes mobile endpoints and relative bearing measurements.

[0165] As shown at 1201, node 2 initiates a sensing session by sending a request to node 1. As shown at 1202, node 1 confirms the allocation of the session for node 2. At 1203, node 2 requests a polarization signal for iteration i=1 of the sensing process.

[0166] As shown at 1204 and 1205 respectively, the transmitter and receiver are able to monitor and track the relative positions of their respective antennas.

[0167] At 1206, Node 1 determines one or more transmission parameters, as described above.

[0168] As shown at 1207, node 1 transmits an initial sensing signal 1208 to the receiver. At 1209, node 2 receives the sensing signal.

[0169] At 1210, Node 1 sends transmission parameters to Node 2, including the polarization configuration of the transmit antenna.

[0170] After a period of time, node 1 estimates the relative position of the transmitting antenna relative to the position when the initial sensing signal 1208 was transmitted at 1211, and updates the transmission parameters of node 1 at 1212. This period of time can be freely set by the application and optionally adapted to the movement time of the node. At 1213, node 1 sends the next polarized signal 1214 to node 2, and at 1215 sends the relative position of node 1 in space (estimated at 1211) and transmission parameters.

[0171] Node 2 also estimates at 1216 the relative position of the receive antenna relative to the position of the receive antenna when receiving the initial perception signal 1208 , and receives at 1217 the next perception signal 1214 .

[0172] Therefore, node 2 measures the two polarized signals 1208 and 1214 and the change in the orientation of the antenna of node 1 when transmitting the two signals. Node 2 can estimate the polarization orientation offset of the transmitter and the polarization orientation offset when transmitting the two signals 1208 and 1214.

[0173] With these two offsets, the relative physical orientation of the transmit antenna with respect to the receive antenna, and vice versa, can be calculated, which may occur in the time frame between two polarized signal transmissions and in the same reference coordinate system. Based on the above understanding, node 2 can continue to decompose the feedback signal information into RF subpaths and continue to perform depolarization quantization on each RF subpath. At 1218, an estimate of the LoS or material presence is calculated based on the depolarization effect of each RF subpath.

[0174] At 1219, node 2 may determine whether the receiving process has ended. If the receiving process has not ended, other iterations of the process may be performed, as shown at 1220. These steps may be repeated until the sensing session ends.

[0175] At 1221, node 2 may determine whether the perception session has ended. If so, node 2 may share the calculated environment information with node 1, as shown in 1222. At 1223, node 2 sends a signal to node 1 to end the perception session.

[0176] In some other alternative implementations, the material identification process can be performed by a processor in an entity remote from the transmitter and receiver. In this case, the receiver sends the necessary information to the remote processor, including the azimuth and polarization configuration information of the transmitting antenna and the receiving antenna and the receiver's measurement results of one or more received signals to determine the environmental information.

[0177] Through processing algorithms used by a processor (located in the transmitting entity, receiving entity, or remote processing entity), the device can infer environmental effects, decompose the channel into several paths in the electric field domain, and / or build an environmental map. The processor can also map and / or classify the estimated environmental effects into identification assertions, such as obstruction materials and LoS presence.

[0178] In other implementations, the processor may be configured to send the inferred environmental information and one or more corresponding tags to a storage medium. The one or more corresponding tags may include one or more of capture time, path identification, obstacle presence and nature, arrival angle, and relative delay.

[0179] Fig.13 An example of a method implemented at a receiver having a known orientation and polarization configuration is shown. At step 1301, the method includes receiving polarized electromagnetic radiation, an indication of the orientation of a transmitter that transmits the polarized electromagnetic radiation, and the polarization configuration of the transmitter. At step 1302, the method includes transforming the polarized electromagnetic radiation to a reference coordinate system to form a transformed signal based on at least one of the polarization configuration of the receiver, the polarization configuration of the transmitter, the known orientation of the receiver, and the orientation of the transmitter. At step 1303, the method includes sending an indication of at least one of the reference coordinate system, the orientation of the transmitter, the orientation of the receiver, the polarization configuration of the transmitter, and the polarization configuration of the receiver, and the transformed signal to a processor, wherein the processor is used to infer information of one or more paths of the polarized electromagnetic radiation between the transmitter and the receiver.

[0180] The processor processes data from the receiver, the data including a transformed signal formed by transforming electromagnetic radiation received by the receiver from the transmitter to a reference coordinate system based on the orientation of the receiver, the orientation of the transmitter, the polarization configuration of the receiver, and the polarization configuration of the transmitter to infer information about one or more paths of the polarized electromagnetic radiation between the transmitter and the receiver.

[0181] Fig.14An example of a method implemented at a transmitter having a known orientation and polarization configuration is shown. At step 1401, the method includes: transmitting polarized electromagnetic radiation to a receiver. At step 1402, the method includes: receiving a measured polarization signal, an indication of the orientation of the receiver, and the polarization configuration of the receiver from the receiver. At 1403, the method includes: transforming the measured polarization signal to a reference coordinate system to form a transformed signal based on at least one of the polarization configuration of the receiver, the polarization configuration of the transmitter, the orientation of the receiver, and the orientation of the transmitter. At step 1404, the method includes: sending an indication of at least one of the reference coordinate system, the orientation of the transmitter, the orientation of the receiver, the polarization configuration of the transmitter, and the polarization configuration of the receiver, and the transformed signal to a processor, wherein the processor is used to infer information of one or more paths of the polarized electromagnetic radiation between the transmitter and the receiver.

[0182] By enabling polarization awareness, wireless devices in communication networks can enhance the ability to measure RF propagation paths in the electric field domain. As mentioned above, this technology has a variety of applications, including LoS path differentiation, object detection, and material identification of reflective surfaces. This technology can also be used for environmental mapping and mobile object tracking.

[0183] This application scenario can be applicable to single-base or mobile endpoints (e.g., nodes such as base stations in a communication network). The sensing session request can be initiated by any endpoint. Similarly, the estimation process can be performed by an endpoint (i.e., a transmitter or a receiver) or a remote processing device.

[0184] Compared to existing methods, with the method described in this article, devices with fixed polarization patterns can use external information (i.e., the orientation of the transmitting and receiving devices) to achieve polarization awareness without the need for multiple polarization patterns. The method described in this article does not require prior knowledge of the geometry of the environment and is applicable to any combination of near-field and far-field incidence and reception situations.

[0185] Existing commercial off-the-shelf devices do not have multipolarity capabilities but can be easily upgraded to be polarization-aware via software updates to use the techniques described in this paper.

[0186] Applicants hereby disclose separately each individual feature described herein and any combination of two or more such features. With the common knowledge of those skilled in the art, such features or combinations can be implemented as a whole according to this specification, without considering whether such features or combinations of features can solve any problem disclosed herein; and without limiting the scope of the claims. Applicants point out that aspects of the present invention may include any such individual features or combinations of features. In view of the above description, it will be obvious to those skilled in the art that various modifications can be made within the scope of the present invention.

Claims

1. A receiver (602, 902), characterized in that: Used for: receiving (1301) polarized electromagnetic radiation, an indication of the orientation of a transmitter (601, 901) emitting the polarized electromagnetic radiation, and a polarization configuration of the transmitter, wherein the receiver has a known orientation and polarization configuration; transforming (1302) the polarized electromagnetic radiation to a reference coordinate system to form a transformed signal based on at least one of the polarization configuration of the receiver, the polarization configuration of the transmitter, the known orientation of the receiver, and the orientation of the transmitter; The reference coordinate system, the orientation of the transmitter, the orientation of the receiver, an indication of at least one of the polarization configuration of the transmitter and the polarization configuration of the receiver, and the transformed signal are sent (1303) to a processor (501, 551), wherein the processor is used to infer information about one or more paths of the polarized electromagnetic radiation between the transmitter and the receiver.

2. The receiver (602, 902) according to claim 1, characterized in that The information about the one or more paths of the polarized electromagnetic radiation includes an indication of the presence of obstacles on one or more of the paths of the polarized electromagnetic radiation between the transmitter and the receiver and / or an indication of the composition and / or properties of one or more materials of the obstacles.

3. The receiver (602, 902) according to claim 1 or 2, characterized in that: The position of the transmitter and the known position of the receiver are determined relative to a common vector.

4. The receiver (602) according to any one of the preceding claims, characterized in that The position of the receiver and / or the position of the transmitter relative to the receiver is fixed.

5. The receiver (602, 902) according to any one of the preceding claims, characterized in that The receiver is used to send the transformed signal to the transmitter for processing by the processor.

6. The receiver (602, 902) according to any one of the preceding claims, characterized in that The receiver is used to send the transformed signal to a remote device for processing by the processor.

7. The receiver (602, 902) according to claim 5 or 6, characterized in that The receiver includes a transceiver for transmitting the transformed signal to the processor.

8. The receiver (602, 902) according to any one of the preceding claims, characterized in that The receiver and the transmitter are each one of a base station, a user equipment, and an aircraft having a communication function.

9. The receiver (602, 902) according to any one of the preceding claims, characterized in that The receiver is used to receive a request from the transmitter to receive the polarized electromagnetic radiation emitted by the transmitter; The receiver is for receiving the polarized electromagnetic radiation in response to accepting the request.

10. The receiver (602, 902) according to any one of the preceding claims, characterized in that The receiver is further configured to receive one or more signals, wherein the one or more signals include the polarized electromagnetic radiation, the indication of the orientation of the transmitter, and the indication of the polarization configuration of the transmitter, and the one or more signals also include one or more transmission parameters.

11. The receiver (602, 902) according to claim 10, characterized in that The one or more transmission parameters include one or more of a frequency channel of the one or more signals and a selected bandwidth of the one or more signals.

12. The receiver (602, 902) according to claim 10 or 11, characterized in that The one or more signals are radio frequency signals.

13. The receiver (602, 902) according to any one of the preceding claims, characterized in that The receiver is also configured to calculate a model for transforming subsequently received polarized electromagnetic radiation from the transmitter.

14. The receiver (602, 902) according to any one of the preceding claims, characterized in that The receiver comprises at least one position sensor for determining the position of the receiver.

15. The receiver (602, 902) according to any one of the preceding claims, characterized in that The position of the receiver and the position of the transmitter are absolute positions or relative positions.

16. A method (1300) implemented at a receiver (602, 902) having a known azimuth and polarization configuration, characterized in that: The method comprises: Receiving (1301) polarized electromagnetic radiation, an indication of the orientation of a transmitter (601, 901) emitting said polarized electromagnetic radiation, and a polarization configuration of said transmitter; transforming (1302) the polarized electromagnetic radiation to a reference coordinate system to form a transformed signal based on at least one of the polarization configuration of the receiver, the polarization configuration of the transmitter, the known orientation of the receiver, and the orientation of the transmitter; The reference coordinate system, the orientation of the transmitter, the orientation of the receiver, an indication of at least one of the polarization configuration of the transmitter and the polarization configuration of the receiver, and the transformed signal are sent (1303) to a processor (501, 551), wherein the processor is used to infer information about one or more paths of the polarized electromagnetic radiation between the transmitter and the receiver.

17. A processor (501, 551), characterized in that: Used for processing data from a receiver (602, 902), wherein the data includes a transformed signal, which is formed by transforming polarized electromagnetic radiation received by the receiver from the transmitter to a reference coordinate system based on at least one of the orientation of the receiver, the orientation of the transmitter (601, 901), the polarization configuration of the receiver and the polarization configuration of the transmitter, so as to infer information of one or more paths of the polarized electromagnetic radiation between the transmitter and the receiver.

18. The processor (501, 551) according to claim 17, characterized in that The information about the one or more paths of the polarized electromagnetic radiation includes an indication of the presence of obstacles on one or more of the paths of the polarized electromagnetic radiation between the transmitter and the receiver and / or an indication of the composition and / or properties of one or more materials of the obstacles.

19. The processor (501, 551) according to claim 17 or 18, characterized in that: The processor is configured to decompose the transformed signal into two or more paths and estimate the polarization of each path of the transformed signal to infer information about the path of the polarized electromagnetic radiation between the transmitter and the receiver.

20. The processor (501, 551) according to any one of claims 17 to 19, characterized in that: The processor is configured to calculate a degree of depolarization of each of the one or more paths of the polarized electromagnetic radiation relative to the polarization emitted by the transmitter, and to infer environmental information based on the degree of depolarization.

21. The processor (501, 551) according to any one of claims 17 to 20, characterized in that: The processor is also configured to form a map of the environment between the transmitter and the receiver.

22. The processor (501, 551) according to any one of claims 17 to 21, characterized in that: The processor is used to estimate the ratio of the component of the electric field polarization direction in the transformed signal perpendicular to the incident plane to the component of the electric field polarization direction in the transformed signal parallel to the incident plane.

23. The processor (501, 551) according to any one of claims 17 to 22, characterized in that: The processor is configured to send the inferred information and one or more corresponding tags to a storage medium.

24. The processor (501, 551) according to claim 23, characterized in that The one or more corresponding tags include one or more of capture time, path identification, obstacle presence and nature, angle of arrival, and relative delay.

25. The processor (501, 551) according to any one of claims 17 to 24, characterized in that: The processor is located in one of the receiver, the transmitter, and a location remote from the receiver and the transmitter.

26. The processor (501, 551) according to any one of claims 17 to 25, characterized in that: The position of the receiver and the position of the transmitter are absolute positions or relative positions.

27. A method implemented at a processor (501, 551), characterized in that: The method comprises processing data from a receiver (602, 902), wherein the data comprises a transformed signal formed by transforming polarized electromagnetic radiation received by the receiver from the transmitter to a reference coordinate system based on the orientation of the receiver, the orientation of the transmitter (601, 901), the polarization configuration of the receiver and the polarization configuration of the transmitter, so as to infer information of one or more paths of the polarized electromagnetic radiation between the transmitter and the receiver.

28. A transmitter (601, 901), characterized in that: Used for: transmitting (1401) polarized electromagnetic radiation toward a receiver (602, 902); receiving (1402) from the receiver a measured polarization signal, an indication of the orientation of the receiver, and a polarization configuration of the receiver, wherein the transmitter has a known orientation and polarization configuration; transforming (1403) the measured polarization signal to a reference coordinate system to form a transformed signal based on at least one of the polarization configuration of the receiver, the polarization configuration of the transmitter, the orientation of the receiver, and the orientation of the transmitter; The reference coordinate system, the orientation of the transmitter, the orientation of the receiver, an indication of at least one of the polarization configuration of the transmitter and the polarization configuration of the receiver, and the transformed signal are sent (1404) to a processor (501, 551), wherein the processor is used to infer information about one or more paths of the polarized electromagnetic radiation between the transmitter and the receiver.

29. A method (1400) implemented at a transmitter (601, 901) having a known azimuth and polarization configuration, characterized in that The method comprises: transmitting (1401) polarized electromagnetic radiation toward a receiver (602, 902); receiving (1402) from the receiver a measured polarization signal, an indication of the orientation of the receiver, and a polarization configuration of the receiver; transforming (1403) the measured polarization signal to a reference coordinate system to form a transformed signal based on at least one of the polarization configuration of the receiver, the polarization configuration of the transmitter, the orientation of the receiver, and the orientation of the transmitter; The reference coordinate system, the orientation of the transmitter, the orientation of the receiver, an indication of at least one of the polarization configuration of the transmitter and the polarization configuration of the receiver, and the transformed signal are sent (1404) to a processor (501, 551), wherein the processor is used to infer information about one or more paths of the polarized electromagnetic radiation between the transmitter and the receiver.

30. A communication system, characterized in that: include: a transmitter (601, 901) for transmitting polarized electromagnetic radiation, an indication of the orientation of said transmitter and an indication of the polarization configuration of said transmitter; a receiver (602, 902) having a known position and polarization configuration and for receiving said polarized electromagnetic radiation, said indication of said position of said transmitter and said indication of said polarization configuration of said transmitter; One or more processors (501, 551) for: transforming the polarized electromagnetic radiation received by the receiver to a reference coordinate system to form a transformed signal based on at least one of the polarization configuration of the receiver, the polarization configuration of the transmitter, the known position of the receiver, and the position of the transmitter; The transformed signal is processed to infer information about one or more paths of the polarized electromagnetic radiation between the transmitter and the receiver based on at least one of the reference coordinate system, the orientation of the transmitter, the orientation of the receiver, the polarization configuration of the transmitter, and an indication of the polarization configuration of the receiver.

31. A computer-readable storage medium (502, 552) storing computer-readable instructions, characterized in that: The computer readable instructions, when executed by a computer system, cause the computer system to perform the method of claim 16, 27 or 29.

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