A method for establishing air-sea three-dimensional channel model suitable for different sea conditions

Abstract

The present application relates to the field of near-field transmission technology. To address the problem that traditional channel modeling methods are not applicable to air-sea channels affected by sea conditions, a method for establishing an air-sea three-dimensional channel model applicable to different sea conditions is disclosed. The method includes obtaining attribute data of a transmitter, attribute data of a receiver, the horizontal distance between the transmitter and the receiver, and the height of waves; establishing an impulse response of the air-sea channel under a direct path; establishing an impulse response of the air-sea channel under a specular reflection path when the sea condition level is 0 or 1; establishing an impulse response of the air-sea channel under a diffuse reflection path when the sea condition level is at least 2; and establishing an air-sea three-dimensional channel model based on the impulse response of the air-sea channel under the direct path, the impulse response of the air-sea channel under the specular reflection path, and the impulse response of the air-sea channel under the diffuse reflection path. This method can accurately simulate the air-sea channel and determine the impulse response of the air-sea channel under different sea conditions.

Description

Technical Field

[0001] The present application relates to the field of near-field transmission technology, and more specifically, to a method for establishing an air-sea three-dimensional channel model applicable to different sea conditions, a computer device, a computer-readable storage medium, and a computer program product. Background Art

[0002] Currently, drone communications have developed into a vital communications technology. Furthermore, with the growing demand for communications in the maritime sector, air-sea communication networks have attracted widespread attention. Wireless communication channel models play a key role in wireless communication network research, and accurate channel models are indispensable for the study and application of communication transmission.

[0003] In traditional channel modeling methods, a double-cylinder model is used to derive the envelope level crossing rate (LCR) and average fade duration (AFD) in a three-dimensional propagation environment, or a hemispherical model is established to optimize the upgraded time evolution algorithm of time-varying channel parameters, and the statistical characteristics of the geometric random channel model are studied and analyzed.

[0004] These channel modeling methods do not take into account the complexity of sea conditions. The geometry-based modeling has low complexity and is applicable to a certain type of environment, but is not suitable for air-sea channels affected by sea conditions. Summary of the Invention

[0005] In order to solve the problem that traditional channel modeling methods are not applicable to air-sea channels affected by sea conditions, the present invention provides a method for establishing an air-sea three-dimensional channel model applicable to different sea conditions, a computer device, a computer-readable storage medium and a computer program product. By establishing the air-sea three-dimensional channel model, the air-sea channel can be accurately simulated, the impulse response of the air-sea channel under different sea conditions can be determined, and the time delay autocorrelation function and frequency autocorrelation function of the air-sea three-dimensional channel model under different sea conditions can be simulated.

[0006] To achieve the above objectives, according to a first aspect of the present invention, a method for establishing an air-sea three-dimensional channel model applicable to different sea conditions is provided, the method comprising:

[0007] Acquire attribute data of the transmitter, attribute data of the receiver, the horizontal distance between the transmitter and the receiver, and the height of the waves. The attribute data of the transmitter includes the antenna length, velocity vector, and height from the sea level of the transmitter. The attribute data of the receiver includes the antenna length and velocity vector of the receiver.

[0008] The impulse response of the air-sea channel under the direct path is established based on the attribute data of the transmitter, the attribute data of the receiver, the horizontal distance between the transmitter and the receiver, and the height of the waves;

[0009] When the sea state level is 0 or 1, the impulse response of the air-sea channel under the specular reflection path is established based on the geometric relationship between the first right triangle and the second right triangle, the attribute data of the transmitter, the attribute data of the receiver, and the horizontal distance between the transmitter and the receiver; the hypotenuse vertex of the first right triangle is the projection point of the signal transmission point on the sea level and the specular reflection point, and the hypotenuse vertex of the second right triangle is the projection point of the signal transmission point on the sea level and the projection point of the signal reception point on the sea level;

[0010] When the sea state level is at least level 2, an impulse response of the air-sea channel under the diffuse reflection path is established based on the geometric relationship between the first right triangle and the second right triangle under the diffuse reflection path, attribute data of the transmitter, attribute data of the receiver, the horizontal distance between the transmitter and the receiver, and the height of the waves;

[0011] Based on the impulse responses of the air-sea channel under the direct path, the mirror reflection path, and the diffuse reflection path, a three-dimensional air-sea channel model is established, and the impulse responses of the air-sea channel under different sea conditions are calculated.

[0012] According to a second aspect of the present invention, a computer device is provided, which includes a memory, a processor, and a computer program stored in the memory, and the processor executes the computer program to implement the steps of any one of the above methods.

[0013] According to a third aspect of the present invention, a computer-readable storage medium is provided, on which a computer program is stored. When the computer program is executed by a processor, the steps of any of the above methods are implemented.

[0014] According to a fourth aspect of the present invention, there is also provided a computer program product, comprising a computer program, which implements the steps of any one of the above methods when executed by a processor.

[0015] In general, the above technical solutions conceived by the present invention can achieve the following beneficial effects compared with the prior art:

[0016] (1) The present invention provides a method for establishing an air-sea three-dimensional channel model suitable for different sea conditions. In combination with the actual air-sea communication environment, according to the two conditions of low sea conditions and complex sea conditions, the impulse response of the air-sea channel under the direct path, the impulse response of the air-sea channel under the mirror reflection path, and the impulse response of the air-sea channel under the diffuse reflection path are respectively established, thereby realizing the establishment of the air-sea three-dimensional channel model, being able to accurately simulate the air-sea channel and determine the impulse response of the air-sea channel under different sea conditions.

[0017] (2) The method for establishing an air-sea three-dimensional channel model applicable to different sea conditions provided by the present invention can also realize the simulation of the time delay autocorrelation function and frequency autocorrelation function of the air-sea three-dimensional channel model under different sea conditions. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the following briefly introduces the drawings required for use in the embodiments. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0019] Figure 1 A flowchart of a method for establishing an air-sea three-dimensional channel model applicable to different sea conditions provided in an embodiment of the present application;

[0020] Figure 2 A schematic diagram of direct signal transmission under different sea conditions provided by an embodiment of the present application;

[0021] Figure 3 A schematic diagram of signal mirror reflection transmission under low sea conditions provided by an embodiment of the present application;

[0022] Figure 4 A schematic diagram of diffuse reflection transmission of signals under complex sea conditions provided by an embodiment of the present application;

[0023] Figure 5 Schematic diagram of simulation results of the time delay autocorrelation function of the air-sea three-dimensional channel model under different sea conditions provided by an embodiment of the present application;

[0024] Figure 6 Schematic diagram of simulation results of the frequency autocorrelation function of the air-sea three-dimensional channel model under different sea conditions provided by an embodiment of the present application;

[0025] Figure 7 A schematic diagram of the internal structure of a computer device provided in an embodiment of the present application. DETAILED DESCRIPTION

[0026] In order to make the objectives, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely for the purpose of explaining the present invention and are not intended to limit the present invention. In addition, the technical features involved in the various embodiments of the present invention described below may be combined with each other as long as they do not conflict with each other.

[0027] The terms "first," "second," and the like in the specification and claims of this application and the accompanying drawings are used to distinguish between different objects, not to describe a particular order. Furthermore, the terms "including," "having," and any variations thereof, are intended to cover non-exclusive inclusions. For example, a process, method, system, product, or apparatus comprising a series of steps or elements is not limited to the listed steps or elements but may optionally include steps or elements not listed, or may optionally include other steps or elements inherent to the process, method, product, or apparatus.

[0028] like Figure 1 As shown, a method for establishing a three-dimensional air-sea channel model suitable for different sea conditions is provided. This method is applied to the air-sea channel between a transmitter located on land or in the air and a receiver located on the sea surface to analyze the impulse response of the air-sea channel under different sea conditions. The transmitter can be an unmanned aerial vehicle (UAV) for transmitting signals to the receiver, which can be a surface vehicle such as a ship or submarine. Furthermore, both the transmitter and receiver are equipped with antennas to achieve near-field signal transmission.

[0029] The method can be executed by a terminal or by a server communicating with the terminal via a network. The terminal may be, but is not limited to, various personal computers, laptops, smartphones, tablet computers, etc. The server may be a standalone server or a server cluster consisting of multiple servers. This method is described using the terminal as an example and includes the following steps:

[0030] Step 101: Acquire attribute data of a transmitter, attribute data of a receiver, the horizontal distance between the transmitter and the receiver, and the height of the waves.

[0031] The transmitter's attribute data includes the transmitter's antenna length, velocity vector, altitude above sea level, and the transmitter's elevation (vertical tilt angle) and azimuth (horizontal tilt angle). The receiver's attribute data includes the receiver's antenna length, velocity vector, elevation, and azimuth. The wave height is the height at which the receiver rises above the waves.

[0032] Step 102: Establish an impulse response of the air-sea channel under the direct path based on the attribute data of the transmitter, the attribute data of the receiver, the horizontal distance between the transmitter and the receiver, and the height of the waves.

[0033] Step 103, when the sea condition level is level 0 or level 1, establish the impulse response of the air-sea channel under the mirror reflection path based on the geometric relationship between the first right triangle and the second right triangle, the attribute data of the transmitter, the attribute data of the receiver, and the horizontal distance between the transmitter and the receiver; the hypotenuse vertex of the first right triangle is the projection point of the signal sending point on the sea level and the mirror reflection point, and the hypotenuse vertex of the second right triangle is the projection point of the signal sending point on the sea level and the projection point of the signal receiving point on the sea level.

[0034] Step 104, when the sea condition level is at least level 2, establish the impulse response of the air-sea channel under the diffuse reflection path based on the geometric relationship between the first right triangle and the second right triangle under the diffuse reflection path, the attribute data of the transmitter, the attribute data of the receiver, the horizontal distance between the transmitter and the receiver, and the height of the waves.

[0035] Step 105: Based on the impulse response of the air-sea channel under the direct path, the impulse response of the air-sea channel under the mirror reflection path, and the impulse response of the air-sea channel under the diffuse reflection path, a three-dimensional air-sea channel model is established, and the impulse response of the air-sea channel under different sea conditions is calculated.

[0036] In the above-mentioned method for establishing the air-sea three-dimensional channel model applicable to different sea conditions, the impulse response of the air-sea channel under the direct path, the impulse response of the air-sea channel under the mirror reflection path, and the impulse response of the air-sea channel under the diffuse reflection path are respectively established according to the two conditions of low sea conditions and complex sea conditions, thereby realizing the establishment of the air-sea three-dimensional channel model, which can accurately simulate the air-sea channel and determine the impulse response of the air-sea channel under different sea conditions.

[0037] In one embodiment, the above-mentioned step 102 includes determining the vector segment and distance between the signal sending point and the signal receiving point based on the antenna length of the transmitter and the height from the sea level, the antenna length of the receiver, the horizontal distance between the transmitter and the receiver, and the height of the waves; and establishing the impulse response of the air-sea channel under the direct path based on the velocity vector of the transmitter, the velocity vector of the receiver, the vector segment and distance between the signal sending point and the signal receiving point.

[0038] For example, refer to Figure 2 The terminal determines the vector line segment between the signal transmission point T and the signal reception point R according to the following formula (1):

[0039]

[0040] Among them, L T is the transmitter antenna length, H T is the height of the transmitter from the sea level, α T is the elevation angle of the transmitter, βT is the azimuth of the transmitter, L R is the receiver antenna length, H W is the height of the wave, α R is the receiver's elevation angle, β R is the azimuth of the receiver, and D is the horizontal distance between the transmitter and the receiver.

[0041] Calculate the distance d between the signal sending point T and the signal receiving point R TR :

[0042]

[0043] Calculate the path delay under the direct path:

[0044]

[0045] Where c is the speed of light.

[0046] Transmitter's velocity vector and the receiver's velocity vector They are:

[0047]

[0048] Among them, V T is the speed of the transmitter, E T is the angle between the transmitter's velocity direction and the vertical direction, A T is the angle between the transmitter's velocity direction and the horizontal direction, V R is the speed of the receiver, A R is the angle between the velocity direction of the receiver and the horizontal direction.

[0049] According to the transmitter's velocity vector Receiver velocity vector The vector line segment between the signal sending point T and the signal receiving point R and distance d TR , calculate the impulse response of the air-sea channel under the direct path (LOS, full name is Line of sight)

[0050]

[0051] in, Indicates that the transmitter is on the path The offset generated on Indicates that the receiver is on the path The offset produced on the signal is K, the Rice factor, and λ the signal wavelength.

[0052] In one embodiment, the above-mentioned step 103 includes establishing a first right triangle and a second right triangle according to the projection point of the signal sending point on the sea level, the mirror reflection point and the projection point of the signal receiving point on the sea level when the sea state level is 0 or 1; determining the coordinates of the mirror reflection point according to the geometric relationship between the first right triangle and the second right triangle, the antenna length of the transmitter and the height from the sea level, the antenna length of the receiver, and the horizontal distance between the transmitter and the receiver; determining the vector line segment and distance between the signal sending point and the mirror reflection point, and the vector line segment and distance between the mirror reflection point and the signal receiving point according to the coordinates of the mirror reflection point; and establishing the impulse response of the air-sea channel under the mirror reflection path according to the velocity vector of the transmitter, the velocity vector of the receiver, the vector line segment and distance between the signal sending point and the mirror reflection point, and the vector line segment and distance between the mirror reflection point and the signal receiving point.

[0053] For example, refer to Figure 3 , assuming that in low sea conditions (sea state level 0 or 1), the sea surface is flat and not very undulating. At this time, when the transmitter transmits the signal to the receiver, the signal will be reflected by the sea surface. In this case, the impact of the waves on the height of the receiver is 0, that is, H W If it is 0, the sea surface reflection is specular reflection.

[0054] When the signal propagates, a mirror reflection point W is formed on the sea surface. The signal propagation path includes the vector line segment between the signal sending point T and the mirror reflection point W. The vector segment between the mirror reflection point W and the signal receiving point R Since the vector segment and In the same plane, therefore, when projected on the xoy plane, the projection point T' of the signal sending point T on the sea level, the mirror reflection point W and the projection point R' of the signal receiving point R on the sea level are on a straight line.

[0055] First, the terminal establishes line segments WW' and RR' parallel to the x-axis, so that line segments T'W' and T'R" are parallel to the y-axis, obtaining the first right-angled triangle T'W'W and the second right-angled triangle T'R"R'. Among them, the hypotenuse vertices of the first right-angled triangle are the projection point T' and the mirror reflection point W of the signal sending point on the sea level, and the right-angled vertex is point W'; the hypotenuse vertices of the second right-angled triangle are the projection point T' and the projection point R of the signal receiving point on the sea level, and the right-angled vertex is point R".

[0056] Then, based on the geometric relationship between the first right triangle T'W'W and the second right triangle T'R"R', the distance between the following two points is calculated.

[0057]

[0058] According to the above formulas (7) to (10), the coordinates of the mirror reflection point W are determined as:

[0059] W(-L T ·sinα T sinβ T -d WW' ,L T ·sinα T cosβ T +d T'W' ,0)(11)

[0060] Thus, the vector line segment between the signal transmission point T and the mirror reflection point W is determined and distance d TW :

[0061]

[0062]

[0063] Determine the vector segment between the mirror reflection point W and the signal receiving point R and distance d WR :

[0064]

[0065] This allows us to determine the distance of the signal's propagation path:

[0066] d TWR =d TW +d WR (14)

[0067] Finally, according to the transmitter's velocity vector Receiver velocity vector The vector segment between the signal sending point T and the mirror reflection point W and distance d TW , the vector line segment between the mirror reflection point W and the signal receiving point R and distance d WR , establish the impulse response of the air-sea channel under the mirror reflection path

[0068]

[0069] Where θ0 is a random phase, and its value is [0,2π].

[0070] Calculate the path delay under the mirror reflection path:

[0071]

[0072] In one embodiment, the above-mentioned step 104 includes establishing a first right triangle and a second right triangle under the diffuse reflection path based on the projection point of the signal transmission point on the sea surface, the mirror reflection point, and the projection point of the signal receiving point on the sea surface when the sea state level is at least level 2; determining the coordinates of any scattering point on the surface of an equivalent cylinder based on the geometric relationship between the first right triangle and the second right triangle under the diffuse reflection path, the antenna length and height of the transmitter from the sea surface, the antenna length of the receiver, the horizontal distance between the transmitter and the receiver, and the height of the waves, where the equivalent cylinder represents a set of multiple mirror reflection points under the diffuse reflection path; determining the vector line segment and distance between the signal transmission point and the scattering point, and the vector line segment and distance between the scattering point and the signal receiving point based on the coordinates of any scattering point on the surface of the equivalent cylinder; and establishing the impulse response of the air-sea channel under the diffuse reflection path based on the velocity vector of the transmitter, the velocity vector of the receiver, the vector line segment and distance between the signal transmission point and the scattering point, and the vector line segment and distance between the scattering point and the signal receiving point.

[0073] For example, refer to Figure 4 In complex sea conditions (sea state level 2 or above), the receiver is affected by the waves and will fluctuate with the waves, causing the antenna on the receiver to oscillate. In this case, the sea surface becomes rough and the sea surface reflection is diffuse.

[0074] Assuming that the roughness of the sea surface is not considered, and only the influence of the wave height and the receiver antenna swing on the mirror reflection point is considered, during the signal propagation process, the mirror reflection point W (i.e., the mirror reflection point in low sea conditions) is updated to W new (hereinafter referred to as equivalent specular reflection point).

[0075] First, to simplify the signal (reflected wave) propagation process, an equivalent cylinder model is established based on the mirror reflection point and the equivalent mirror reflection point, where the diameter of the equivalent cylinder is the mirror reflection point W and the equivalent mirror reflection point W. new The distance between them, the height of the equivalent cylinder is the height of the wave H W The equivalent cylinder represents a collection of multiple specular reflection points under a diffuse reflection path. Any point on the surface of the equivalent cylinder (hereinafter referred to as a scattering point) can be understood as a specular reflection point formed on the sea surface during a certain signal propagation. The more complex the sea conditions and the rougher the sea surface, the more scattering points are distributed on the surface of the equivalent cylinder.

[0076] Then, referring to the first right triangle T'W'W and the second right triangle T'R"R' established under the mirror reflection path, the first right triangle T'W'W and the second right triangle T'R"R' under the diffuse reflection path are established; according to the geometric relationship between the first right triangle T'W'W and the second right triangle T'R"R' under the diffuse reflection path, the distance between the following two points among the points T, T', W, W', R, R', and R" under the diffuse reflection path is determined:

[0077]

[0078] in, is the distance between points T' and R' under the diffuse reflection path, is the distance between points T' and R' under the diffuse reflection path, is the distance between point T and point T' under the diffuse reflection path, is the distance between points R and R' under the diffuse reflection path, is the distance between point W and point R' under the diffuse reflection path, is the distance between point T' and point W under the diffuse reflection path, is the distance between points T' and W' under the diffuse reflection path, is the distance between points R' and R" under the diffuse reflection path, is the distance between points W and W' under the diffuse reflection path.

[0079] According to the above formulas (16) and (17), the equivalent mirror reflection point W is determined new The coordinates are:

[0080]

[0081] Combining formula (11) and formula (18), we can get:

[0082] Coordinates of the bottom center point S of the equivalent cylinder:

[0083]

[0084] The diameter of the equivalent cylinder, that is, the mirror reflection point W and the equivalent mirror reflection point W new Distance between:

[0085]

[0086] Radius of the equivalent cylinder:

[0087]

[0088] Assume that from the bottom center point S of the equivalent cylinder to any scattering point S on the surface of the equivalent cylinderP The azimuth angle is μ and the elevation angle is γ, then the scattering point S P The coordinates are:

[0089]

[0090] Thus, the signal transmission point T and scattering point S are determined P The vector line segment between and distance

[0091] Determine the scattering point S P and the vector segment between the signal receiving point R and distance

[0092] This allows us to determine the distance of the signal's propagation path:

[0093]

[0094] Finally, according to the transmitter's velocity vector Receiver velocity vector Signal transmission point T and scattering point S P The vector line segment between and distance Scattering point S P and the vector segment between the signal receiving point R and distance Establishing the impulse response of the air-sea channel under diffuse reflection path

[0095] Where M is the number of scattering points distributed on the surface of the equivalent cylinder.

[0096] Calculate the path delay under diffuse reflection path:

[0097]

[0098] In one embodiment, step 105 includes establishing a three-dimensional air-sea channel model and calculating the impulse response of the air-sea channel under different sea conditions according to the following formula (27):

[0099]

[0100] Among them, the value of p is 0 or 1. When the sea state level is level 0 or level 1, the value of p is 0; when the sea state level is at least level 2, the value of p is 1. That is to say, under low sea conditions, the air-sea three-dimensional channel model includes the air-sea channel under the direct path and the air-sea channel under the mirror reflection path. The impulse response of the air-sea channel is Under complex sea conditions, the air-sea three-dimensional channel model includes the air-sea channel under the direct path and the air-sea channel under the diffuse reflection path. The impulse response of the air-sea channel is

[0101] In one embodiment, after establishing the air-sea 3D channel model, the time delay autocorrelation function (ACF) and frequency autocorrelation function (FCF) of the air-sea 3D channel model under different sea conditions are derived based on the impulse response of the air-sea channel under different sea conditions. Both the time delay autocorrelation function (ACF) and the frequency autocorrelation function (FCF) are obtained by theoretically modeling the statistical characteristics of the air-sea 3D channel model using correlation functions.

[0102] The time-delay autocorrelation function is expressed as:

[0103]

[0104] The frequency autocorrelation function is expressed as:

[0105]

[0106] By setting relevant parameters, the time delay autocorrelation function and frequency autocorrelation function of the air-sea channel were simulated under various parameter variations. To simulate real-world sea conditions, the 2020 Weihai offshore buoy observation dataset and the 2020 Dongying offshore buoy observation dataset were used. The wave height (i.e., wave height) in the air-sea 3D channel model was replaced with the maximum wave height in the dataset, and the receiver antenna orientation in the air-sea 3D channel model was replaced with the dominant wave direction in the dataset.

[0107] Figure 5 and Figure 6 The simulation results for the time delay autocorrelation function and frequency autocorrelation function of the three-dimensional air-sea channel model under different sea conditions are shown. The simulation results show that different time delays and frequency spacings significantly affect the statistical characteristics of the air-sea channel. As sea levels rise, the number of scattering points on the cylinder surface increases, significantly affecting both the time delay autocorrelation function and the frequency autocorrelation function. The amplitude of the oscillation decreases over time, eventually stabilizing at a specific amplitude. Therefore, this three-dimensional air-sea channel model closely resembles a realistic air-sea channel.

[0108] Specifically, from Figure 5 It can be seen that the time delay autocorrelation function decreases with the increase of time delay. In addition, as the sea state level increases, its decreasing speed becomes faster and faster. Figure 6 It can be seen that the frequency autocorrelation function decreases with the increase of frequency interval. Different sea conditions affect the frequency autocorrelation function, and it decreases faster and more significantly with the increase of sea state level.

[0109] In this embodiment, it is also possible to simulate the time delay autocorrelation function and frequency autocorrelation function of the air-sea three-dimensional channel model under different sea conditions.

[0110] like Figure 7 As shown, the present application also provides a computer device, which includes a memory, a processor and a computer program stored in the memory, and the processor executes the computer program to implement the steps in the above-mentioned method embodiments.

[0111] The present application also provides a computer-readable storage medium having a computer program stored thereon, which, when executed by a processor, implements the steps of the above-mentioned method embodiments. The computer-readable storage medium may include, but is not limited to, any type of disk, including a floppy disk, an optical disk, a DVD, a CD-ROM, a microdrive, a magneto-optical disk, a ROM, a RAM, an EPROM, an EEPROM, a DRAM, a VRAM, a flash memory device, a magnetic card or an optical card, a nanosystem (including a molecular memory IC), or any type of medium or device suitable for storing instructions and / or data.

[0112] The present application also provides a computer program product, including a computer program, which implements the steps in the above-mentioned method embodiments when executed by a processor.

[0113] It should be noted that for the aforementioned method embodiments, for the sake of simplicity, they are all expressed as a series of action combinations, but those skilled in the art should be aware that this application is not limited by the order of the actions described, because according to this application, certain steps can be performed in other orders or simultaneously. Secondly, those skilled in the art should also be aware that the embodiments described in the specification are all preferred embodiments, and the actions and modules involved are not necessarily required by this application.

[0114] In the above embodiments, the description of each embodiment has its own focus. For parts that are not described in detail in a certain embodiment, reference can be made to the relevant descriptions of other embodiments.

[0115] The above description is merely an exemplary embodiment of the present disclosure and is not intended to limit the scope of the present disclosure. That is, any equivalent changes and modifications made in accordance with the teachings of the present disclosure are still within the scope of the present disclosure. After considering the specification and practicing the disclosure herein, those skilled in the art will easily think of the implementation scheme of the present disclosure. This application is intended to cover any variations, uses or adaptations of the present disclosure, which follow the general principles of the present disclosure and include common knowledge or customary technical means in the art that are not recorded in the present disclosure. The description and examples are to be regarded as exemplary only, and the scope and spirit of the present disclosure are defined by the claims.

[0116] The technical features of the above embodiments can be combined arbitrarily. To make the description concise, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0117] It will be easily understood by those skilled in the art that the above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A method for establishing an air-sea three-dimensional channel model suitable for different sea conditions, applied to an air-sea channel between a transmitter located on land or in the air and a receiver located on the sea surface, wherein the transmitter is used to transmit a signal to the receiver, characterized in that: The antenna of the transmitter is a signal sending point, and the antenna of the receiver is a signal receiving point. When the signal propagates, it will be reflected by the sea surface and form a mirror reflection point on the sea surface. The signal propagation path includes a vector line segment between the signal sending point and the mirror reflection point, and a vector line segment between the mirror reflection point and the signal receiving point on the same plane. The method includes: Acquire attribute data of a transmitter, attribute data of a receiver, a horizontal distance between the transmitter and the receiver, and the height of waves, wherein the attribute data of the transmitter includes antenna length, velocity vector, and height from sea level of the transmitter, and the attribute data of the receiver includes antenna length and velocity vector of the receiver; Establishing an impulse response of an air-sea channel under a direct path based on the attribute data of the transmitter, the attribute data of the receiver, the horizontal distance between the transmitter and the receiver, and the height of the ocean waves; When the sea condition level is 0 or 1, an impulse response of an air-sea channel under a mirror reflection path is established based on the geometric relationship between the first right triangle and the second right triangle, the attribute data of the transmitter, the attribute data of the receiver, and the horizontal distance between the transmitter and the receiver; the hypotenuse vertex of the first right triangle is the projection point of the signal sending point on the sea level and the mirror reflection point, the hypotenuse vertex of the second right triangle is the projection point of the signal sending point on the sea level and the projection point of the signal receiving point on the sea level, and the line segment formed by the right-angled vertex of the first right triangle and the mirror reflection point is parallel to the line segment formed by the right-angled vertex of the second right triangle and the projection point of the signal receiving point on the sea level; When the sea state level is at least level 2, establishing an impulse response of an air-sea channel under a diffuse reflection path based on a geometric relationship between a first right triangle and a second right triangle under a diffuse reflection path, attribute data of the transmitter, attribute data of the receiver, a horizontal distance between the transmitter and the receiver, and a height of the sea waves; Based on the impulse response of the air-sea channel under the direct path, the impulse response of the air-sea channel under the specular reflection path, and the impulse response of the air-sea channel under the diffuse reflection path, a three-dimensional air-sea channel model is established, and the impulse response of the air-sea channel under different sea conditions is calculated, including: Among them, the value of p is 0 or 1. When the sea state level is level 0 or level 1, the value of p is 0; when the sea state level is at least level 2, the value of p is 1; is the impulse response of the air-sea channel under the direct path, is the impulse response of the air-sea channel under the mirror reflection path, is the impulse response of the air-sea channel under diffuse reflection path.

2. The method according to claim 1, wherein The step of establishing an impulse response of an air-sea channel under a direct path according to attribute data of the transmitter, attribute data of the receiver, a horizontal distance between the transmitter and the receiver, and a height of the ocean waves comprises: Determining a vector segment and a distance between a signal transmitting point and a signal receiving point based on the antenna length and height of the transmitter from the sea level, the antenna length of the receiver, the horizontal distance between the transmitter and the receiver, and the height of the waves; An impulse response of an air-sea channel under a direct path is established according to a velocity vector of the transmitter, a velocity vector of the receiver, a vector line segment and a distance between the signal transmitting point and the signal receiving point.

3. The method according to claim 1, wherein When the sea state level is level 0 or level 1, establishing an impulse response of an air-sea channel under a specular reflection path according to a geometric relationship between a first right triangle and a second right triangle, attribute data of the transmitter, attribute data of the receiver, and a horizontal distance between the transmitter and the receiver, includes: When the sea state level is 0 or 1, the first right triangle and the second right triangle are established based on the projection point of the signal sending point on the sea level, the mirror reflection point and the projection point of the signal receiving point on the sea level; determining the coordinates of the specular reflection point based on the geometric relationship between the first right triangle and the second right triangle, the antenna length and height of the transmitter from the sea level, the antenna length of the receiver, and the horizontal distance between the transmitter and the receiver; Determining, according to the coordinates of the mirror reflection point, a vector line segment and a distance between the signal sending point and the mirror reflection point, and a vector line segment and a distance between the mirror reflection point and the signal receiving point; An impulse response of the air-sea channel under the mirror reflection path is established based on the velocity vector of the transmitter, the velocity vector of the receiver, the vector line segment and distance between the signal sending point and the mirror reflection point, and the vector line segment and distance between the mirror reflection point and the signal receiving point.

4. The method according to claim 3, wherein The method includes establishing an impulse response of an air-sea channel under a diffuse reflection path based on a geometric relationship between a first right triangle and a second right triangle under a diffuse reflection path, attribute data of the transmitter, attribute data of the receiver, a horizontal distance between the transmitter and the receiver, and a height of the ocean waves when the sea state level is at least level 2, including: When the sea state level is at least level 2, the first right triangle and the second right triangle under the diffuse reflection path are established based on the projection point of the signal sending point on the sea level, the mirror reflection point, and the projection point of the signal receiving point on the sea level; Determining the coordinates of any scattering point on the surface of an equivalent cylinder based on a geometric relationship between the first right triangle and the second right triangle under the diffuse reflection path, the antenna length and height of the transmitter from sea level, the antenna length of the receiver, the horizontal distance between the transmitter and the receiver, and the height of the ocean waves, where the equivalent cylinder represents a collection of multiple specular reflection points under the diffuse reflection path; Determine, according to the coordinates of any scattering point on the surface of the equivalent cylinder, a vector line segment and a distance between the signal sending point and the scattering point, and a vector line segment and a distance between the scattering point and the signal receiving point; An impulse response of an air-sea channel under a diffuse reflection path is established based on a velocity vector of the transmitter, a velocity vector of the receiver, a vector line segment and a distance between the signal sending point and the scattering point, and a vector line segment and a distance between the scattering point and the signal receiving point.

5. The method according to claim 4, wherein The method further comprises: When the sea condition level is at least level 2, an equivalent cylindrical model is established based on the distance between the mirror reflection point and the equivalent mirror reflection point and the height of the waves, and the equivalent mirror reflection point is the updated mirror reflection point.

6. The method according to claim 5, wherein The determining the coordinates of any scattering point on the surface of the equivalent cylinder based on the geometric relationship between the first right triangle and the second right triangle under the diffuse reflection path, the antenna length and height of the transmitter from the sea level, the antenna length of the receiver, the horizontal distance between the transmitter and the receiver, and the height of the waves includes: determining the coordinates of the equivalent specular reflection point according to the geometric relationship between the first right triangle and the second right triangle under the diffuse reflection path, the antenna length and height of the transmitter from the sea level, the antenna length of the receiver, the horizontal distance between the transmitter and the receiver, and the height of the waves; The coordinates of any scattering point on the surface of the equivalent cylinder are determined according to the coordinates of the equivalent mirror reflection point.

7. The method according to claim 1, wherein The method further comprises: According to the impulse responses of the air-sea channel under different sea conditions, the time delay autocorrelation function and the frequency autocorrelation function of the air-sea three-dimensional channel model under different sea conditions are determined.

8. A computer device, characterized in that: The method comprises a memory, a processor and a computer program stored in the memory, wherein the processor executes the computer program to implement the steps of the method according to any one of claims 1 to 7.

9. A computer-readable storage medium having a computer program stored thereon, characterized in that: When the computer program is executed by a processor, the steps of the method according to any one of claims 1 to 7 are implemented.

10. A computer program product comprising a computer program, characterized in that When the computer program is executed by a processor, the steps of the method according to any one of claims 1 to 7 are implemented.

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