An efficient offshore communication method based on integrated UAV STAR-RIS

Abstract

This invention discloses a method for efficient offshore communication based on an integrated unmanned aerial vehicle (UAV) STAR-RIS. This method relates to the field of wireless communication technology. It establishes objective functions with the goals of maximizing the capacity of the offshore communication system, minimizing the total flight energy consumption of the integrated unmanned aerial vehicle's simultaneously transmitting and reflecting reconfigurable intelligent surface system, and minimizing the total transmit power of all offshore users. The objective function is solved using an enhanced third-generation non-dominated sorting genetic algorithm using a Gaussian graph mechanism and an inverse denoising mechanism, ultimately obtaining a Pareto set. This allows users to select the desired solution to the objective function from the set of denoised solutions of the objective function based on their needs, thereby achieving offshore communication based on the integrated unmanned aerial vehicle STAR-RIS. This invention diversifies the initial solution distribution and achieves efficient solution search, improving algorithm performance, thereby providing a more efficient communication solution for offshore users and extending the service life of the offshore communication system.

Description

Technical Field

[0001] The present invention relates to the field of wireless communication technology, and in particular to an efficient offshore communication method based on an integrated unmanned aerial vehicle (UAV) STAR-RIS. Background Art

[0002] Offshore communications are a crucial component of 6G's integrated air, space, land, and sea capabilities, offering broad application prospects, such as marine environmental monitoring and offshore energy development. Traditional offshore communications systems consist of two main components: maritime satellites and ground-based base stations. While satellite-based solutions can provide wide coverage, they are hampered by high latency and limited bandwidth. Furthermore, their deployment and operation are often costly and they struggle to adapt flexibly to the dynamically changing marine environment. Therefore, drone-based solutions have emerged as an alternative to maritime satellites. Drones can overcome the difficulties of deploying fixed infrastructure at sea, offering excellent scalability and the potential to serve remote maritime users. However, drone-based solutions still face several challenges that hinder their practical application. For example, drones cannot intelligently reconfigure the wireless propagation environment, significantly limiting communication performance.

[0003] In recent years, reconfigurable intelligent surfaces (RIS) have emerged as a viable solution for intelligently reconfiguring wireless propagation environments to improve communication performance. However, RIS has limited adaptability because it primarily focuses on reflected signals and requires both the transmitter and receiver to be on the same side of the RIS. This not only limits the coverage range of the communication system but also restricts the flexibility of the transmitted signal beamforming. Therefore, a novel simultaneously transmitting and reflecting reconfigurable intelligent surface (STAR-RIS) has been proposed to provide 360° full spatial coverage, which is suitable for the wide coverage requirements of maritime communication systems.

[0004] By combining the advantages of drones and simultaneously transmissive and reflective reconfigurable smart surfaces, the Unmanned Aerial Vehicle-mounted STAR-RIS (USTAR-RIS) is a promising solution for increasing the capacity of offshore communication systems. However, as the number of maritime users increases, a single USTAR-RIS may struggle to meet throughput requirements. This means that multiple USTAR-RISs need to be deployed simultaneously to effectively serve maritime users, which can also introduce additional interference to communication links. Furthermore, due to the limited onboard energy of drones, insufficient flight energy consumption by the USTAR-RIS will significantly impact the system's communication efficiency and reduce the service life of offshore communication systems. Summary of the Invention

[0005] The present invention discloses an efficient offshore communication method based on an integrated UAV's simultaneously transmitting and reflecting reconfigurable smart surface to overcome the above technical problems.

[0006] In order to achieve the above object, the technical solution of the present invention is:

[0007] An efficient offshore communication method based on an integrated unmanned aerial vehicle STAR-RIS comprises the following steps:

[0008] S1: Obtain the three-dimensional position of the integrated UAV simultaneously transmissive and reflective reconfigurable smart surface, the decision parameters associated with the maritime user and the integrated UAV simultaneously transmissive and reflective reconfigurable smart surface, the maritime user transmission power, and the transmission / reflection factor of the integrated UAV simultaneously transmissive and reflective reconfigurable smart surface to establish an objective function with the goals of maximizing the capacity of the maritime communication system, minimizing the total flight energy consumption of the integrated UAV simultaneously transmissive and reflective reconfigurable smart surface system, and minimizing the total transmission power of all maritime users:

[0009] S2: Using the Gaussian graph mechanism to obtain the initial solution of the objective function; and based on the third-generation non-dominated sorting genetic algorithm, obtaining the set of solutions of the objective function;

[0010] S3: Based on the set of solutions to the objective function, an inverse denoising mechanism is used to obtain a set of denoised solutions to the objective function, i.e., a Pareto set. This allows users to select the solution of the objective function to be used from the set of denoised solutions to achieve offshore communication based on the integrated drone STAR-RIS.

[0011] The inverse denoising mechanism is expressed as follows:

[0012] S31: Obtain the Euclidean distance between the solution of the objective function and the ideal solution;

[0013] ,

[0014] ，

[0015] Where: The objective function is represented by Solution to The Euclidean distance of the ideal solution of the inverse iteration; Indicates the In the reverse iteration The normalized value of the solution; Indicates absolute value; is the normalized value of the ideal solution; Indicates the index number of the reverse iteration; is the total number of iterations; is the current iteration number;

[0016] S32: Obtain the probability density of the solution of the objective function;

[0017] ,

[0018] Where: The objective function is represented by The probability density of the solutions; represents the total number of populations, that is, the total number of solutions to the objective function;

[0019] S33: Obtain a set of denoised solutions of the objective function. The formula used is as follows:

[0020] ,

[0021] ,

[0022] ,

[0023] Where: Indicates intermediate calculation parameters; represents the normalization term; are the index numbers of the solutions to the objective function, and ; represents a circularly symmetric Gaussian distribution; Indicates the The objective function in the inverse iteration The original solution of a solution; Indicates that with Decreasing and increasing values from 0 to 1; Indicates the The objective function in the inverse iteration The original solution of a solution;

[0024] Then we get:

[0025] ,

[0026] Where: The objective function is represented by The denoised solution of the solution; Indicates that with Decreasing and increasing values from 0 to 1; represents the noise weight; Indicates the amount of noise.

[0027] Furthermore, the objective function is established as follows:

[0028] ,

[0029] ,

[0030] Where: represents the set of objective functions; Indicates the capacity of the maritime communication system; represents the total flight energy consumption of the integrated UAV's simultaneously transmissive and reflective reconfigurable smart surface system; Indicates the total transmission power of maritime users; Representing the set of decision parameters associated with the maritime user and the simultaneously transmissive and reflective reconfigurable smart surface integrated with a UAV; Represents the set of 3D positions of the integrated drone that simultaneously transmits and reflects the reconfigurable smart surface; represents the transmission power set of maritime users; Transmission / reflection factors representing the simultaneous transmission and reflection of the reconfigurable smart surface by the integrated drone; Indicates the An integrated drone simultaneously transmits and reflects the 3D position of a reconfigurable smart surface; represents a three-dimensional space capable of deploying integrated drones that simultaneously transmit and reflect reconfigurable smart surfaces; The index number representing the array element of the simultaneously transmissive and reflective reconfigurable smart surface integrated with the UAV; The array element set representing the simultaneously transmissive and reflective reconfigurable smart surface of the integrated drone; Indicates the minimum transmission power of maritime users; Indicates the s Transmitting power of each maritime user; Indicates the maximum transmission power of maritime users; Indicates the index number of the offshore user; represents the offshore user set; Indicates the Offshore users and The decision parameters associated with the array elements of the simultaneously transmissive and reflective reconfigurable smart surface of an integrated UAV; represents the total number of simultaneously transmissive and reflective reconfigurable smart surface array elements of the integrated UAV; represents the amplitude of the transmission pattern of the reconfigurable smart surface that is simultaneously transmitted and reflected by the integrated UAV; represents the amplitude of the reflection pattern of the reconfigurable smart surface that is simultaneously transmitted and reflected by the integrated UAV; The index number of the array element of the UAV's simultaneously transmissive and reflective reconfigurable smart surface; A set of array elements representing a simultaneously transmissive and reflective reconfigurable smart surface; Phase shift representing the transmission pattern of the reconfigurable smart surface that is simultaneously transmitted and reflected by the integrated UAV; Representing the phase shift of the reflection pattern of the reconfigurable smart surface that is simultaneously transmitted and reflected by the integrated UAV; Represents the total number of reconfigurable smart surface array elements that can simultaneously transmit and reflect the drone.

[0031] Furthermore, the capacity of the maritime communication system is expressed as follows:

[0032] , , ,

[0033] Where: Indicates the capacity of the maritime communication system; represents the total number of offshore users; Indicates the index number of the offshore user; The index number representing the array element of the simultaneously transmissive and reflective reconfigurable smart surface integrated with the UAV; represents the total number of simultaneously transmissive and reflective reconfigurable smart surface array elements of the integrated UAV; Indicates the m An integrated drone can simultaneously transmit and reflect reconfigurable smart surfaces and s Transmission rate between users at sea; Representing the set of decision parameters associated with the maritime user and the simultaneously transmissive and reflective reconfigurable smart surface integrated with a UAV; Represents the set of 3D positions of the integrated drone that simultaneously transmits and reflects the reconfigurable smart surface; represents the transmission power set of maritime users; represents the transmission / reflection factor of the simultaneously transmissive and reflective reconfigurable smart surface, where Represents the reflection or transmission pattern of the reconfigurable smart surface that is simultaneously transmitted and reflected by the integrated drone. , Indicates transmission mode; Indicates reflection mode; Indicates the The user at sea sends The signal-to-interference-noise ratio of an integrated drone that simultaneously transmits and reflects the reconfigurable smart surface to the shore; are index numbers of offshore users, and ; Indicates the Offshore users and The decision parameters associated with the array elements of the simultaneously transmissive and reflective reconfigurable smart surface of an integrated UAV; Indicates the Offshore users and The decision parameters associated with the array elements of the simultaneously transmissive and reflective reconfigurable smart surface of an integrated UAV; Indicates the Transmitting power of each maritime user; Indicates the Offshore users to An integrated drone simultaneously transmits and reflects channels on a reconfigurable smart surface; represents the additive white Gaussian noise power; H represents the conjugate transpose.

[0034] Furthermore, the total flight energy consumption of the integrated UAV simultaneously transmissive and reflective reconfigurable smart surface system is expressed as follows:

[0035] , where: represents the total flight energy consumption of the integrated UAV's simultaneously transmissive and reflective reconfigurable smart surface system; Indicates the Flight energy consumption of an integrated drone with simultaneously transmissive and reflective reconfigurable smart surfaces.

[0036] Furthermore, the total transmission power of the maritime user is expressed as follows:

[0037] , where: represents the total transmission power of maritime users, Indicates the The transmission power of an offshore user.

[0038] Furthermore, the Gaussian graph mechanism is expressed as follows:

[0039] , where: The index number representing the solution of the objective function; The index number representing the dimension of the solution of the objective function; The objective function is represented by The first solution dimensions; The objective function is represented by i The first solution dimensions; Indicates return remainder when divided by 1;

[0040] Then we get:

[0041] , where: and They represent the solution of the objective function. The lower and upper bounds of the dimensions; Represents the normalized .

[0042] Beneficial effects: The present invention provides an efficient offshore communication method based on the integrated unmanned aerial vehicle STAR-RIS. By establishing an objective function with the goals of maximizing the capacity of the offshore communication system, minimizing the total flight energy consumption of the integrated unmanned aerial vehicle's simultaneously transmitting and reflecting reconfigurable intelligent surface system, and minimizing the total transmission power of all offshore users, the objective function is solved using an enhanced third-generation non-dominated sorting genetic algorithm using a Gaussian graph mechanism and an inverse denoising mechanism, and ultimately obtaining a Pareto set, the user can select the solution of the objective function to be used from the set of denoised solutions of the objective function according to usage requirements, thereby realizing offshore communication based on the integrated unmanned aerial vehicle STAR-RIS. The present invention diversifies the initial solution distribution and completes efficient solution search through two enhanced operators, the Gaussian graph mechanism and the inverse denoising mechanism, thereby improving the algorithm performance, thereby providing a more efficient communication solution for offshore users and increasing the service life of the offshore communication system. BRIEF DESCRIPTION OF THE DRAWINGS

[0043] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following is a brief introduction to the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative labor.

[0044] Figure 1 This is a flow chart of the offshore efficient communication method based on the integrated unmanned aerial vehicle STAR-RIS of the present invention;

[0045] Figure 2 This is a flow chart of an enhanced third-generation non-dominated sorting genetic algorithm with a Gaussian graph mechanism and an inverse denoising mechanism in an embodiment of the present invention;

[0046] Figure 3 An example diagram of calculating the normalized Euclidean distance between each solution and the ideal solution in an embodiment of the present invention;

[0047] Figure 4 Schematic diagram of the offshore communication system structure of an integrated drone with simultaneous transmission and reflection of a reconfigurable intelligent surface in an embodiment of the present invention. DETAILED DESCRIPTION

[0048] To make the objectives, technical solutions, and advantages of the embodiments of the present invention more clear, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. All other embodiments obtained by ordinary technicians in this field based on the embodiments of the present invention without making any creative efforts shall fall within the scope of protection of the present invention.

[0049] This embodiment introduces an efficient offshore communication method based on integrated drone STAR-RIS, including the following steps: Figure 1 As shown:

[0050] S1: Obtain the three-dimensional position of the integrated UAV simultaneously transmissive and reflective reconfigurable smart surface, the decision parameters associated with the maritime user and the integrated UAV simultaneously transmissive and reflective reconfigurable smart surface, the maritime user transmission power, and the transmission / reflection factor of the integrated UAV simultaneously transmissive and reflective reconfigurable smart surface to establish an objective function with the goals of maximizing the capacity of the maritime communication system, minimizing the total flight energy consumption of the integrated UAV simultaneously transmissive and reflective reconfigurable smart surface system, and minimizing the total transmission power of all maritime users:

[0051] Specifically, in this embodiment, the objective function is established to maximize the capacity of the maritime communication system, minimize the total flight energy consumption of the integrated UAV simultaneous transmission and reflection reconfigurable smart surface system, and minimize the total transmission power of all maritime users.

[0052] Optimization goal 1: Maximize system capacity:

[0053] Preferably, the maritime communication system capacity is expressed as follows:

[0054] (1)

[0055] , ,

[0056] Where: Indicates the capacity of the maritime communication system; represents the total number of offshore users; Indicates the index number of the offshore user; The index number representing the array element of the simultaneously transmissive and reflective reconfigurable smart surface integrated with the UAV; represents the total number of simultaneously transmissive and reflective reconfigurable smart surface array elements of the integrated UAV; Indicates the An integrated drone can simultaneously transmit and reflect reconfigurable smart surfaces and Transmission rate between users at sea; Representing the set of decision parameters associated with the maritime user and the simultaneously transmissive and reflective reconfigurable smart surface integrated with a UAV; Represents the set of 3D positions of the integrated drone that simultaneously transmits and reflects the reconfigurable smart surface; represents the transmission power set of maritime users; represents the transmission / reflection factor of the simultaneously transmissive and reflective reconfigurable smart surface, where Represents the reflection or transmission pattern of the reconfigurable smart surface that is simultaneously transmitted and reflected by the integrated drone. , Indicates transmission mode; Indicates reflection mode; Indicates the The user at sea sends The signal-to-interference-noise ratio of an integrated drone that simultaneously transmits and reflects the reconfigurable smart surface to the shore; are index numbers of offshore users, and ; Indicates the Offshore users and The decision parameters associated with the array elements of the simultaneously transmissive and reflective reconfigurable smart surface of an integrated UAV; Indicates the Offshore users and The decision parameters associated with the array elements of the simultaneously transmissive and reflective reconfigurable smart surface of an integrated UAV; Indicates the Transmitting power of each maritime user; Indicates the Offshore users to An integrated drone simultaneously transmits and reflects channels on a reconfigurable smart surface; represents the additive white Gaussian noise power; H represents conjugate transpose;

[0057] Specifically, in this embodiment, it is assumed that ; ,in ; ,as well as ,in , Indicates the An integrated drone simultaneously transmits and reflects the 3D position of a reconfigurable smart surface. , Respectively represent The three-dimensional position of the array element of the reconfigurable smart surface that transmits and reflects simultaneously on an integrated drone direction, direction, Coordinates of direction; Indicates the Offshore users and The decision parameters associated with the array elements of the reconfigurable smart surface of the integrated drone with simultaneous transmission and reflection are Offshore users and When an integrated drone is associated with a reconfigurable smart surface array element that transmits and reflects at the same time, ,otherwise ; Indicates that offshore users and A set of decision parameters associated with the array elements of the simultaneously transmissive and reflective reconfigurable smart surface of an integrated UAV; Indicates the Transmitting power of each maritime user; represents the transmission and reflection coefficient matrices; Represents the reflection or transmission pattern of the reconfigurable smart surface that is simultaneously transmitted and reflected by the integrated drone. , Indicates transmission mode; Indicates reflection mode;

[0058] Optimization goal 2: Minimize the total flight energy consumption of the integrated UAV simultaneously transmissive and reflective reconfigurable smart surface system. Specifically, the integrated UAV simultaneously transmissive and reflective reconfigurable smart surface will move to the appropriate position for reflection and emission, but it will generate additional propulsion energy consumption during the flight. Therefore, optimization goal 2 is to minimize the total flight energy consumption of the integrated UAV simultaneously transmissive and reflective reconfigurable smart surface system:

[0059] Preferably, the total flight energy consumption of the integrated UAV simultaneously transmitting and reflecting reconfigurable smart surface system is expressed as follows:

[0060] (2)

[0061] Where: represents the total flight energy consumption of the integrated UAV's simultaneously transmissive and reflective reconfigurable smart surface system; Indicates the The flight energy consumption of an integrated drone that simultaneously transmits and reflects reconfigurable smart surfaces;

[0062] Optimization goal 3: Minimize the total transmission power of all maritime users.

[0063] Preferably, the total transmission power of the maritime user is expressed as follows:

[0064] (3)

[0065] Where: represents the total transmission power of maritime users, Indicates the Transmitting power of each maritime user;

[0066] Preferably, the objective function is established as follows:

[0067] (4)

[0068] ,

[0069] Where: represents the set of objective functions; Indicates the capacity of the maritime communication system; represents the total flight energy consumption of the integrated UAV's simultaneously transmissive and reflective reconfigurable smart surface system; Indicates the total transmission power of maritime users; Representing the set of decision parameters associated with the maritime user and the simultaneously transmissive and reflective reconfigurable smart surface integrated with a UAV; Represents the set of 3D positions of the integrated drone that simultaneously transmits and reflects the reconfigurable smart surface; represents the transmission power set of maritime users; Transmission / reflection factor representing the simultaneously transmissive and reflective reconfigurable smart surface; Indicates the An integrated drone simultaneously transmits and reflects the 3D position of a reconfigurable smart surface; represents a three-dimensional space capable of deploying integrated drones that simultaneously transmit and reflect reconfigurable smart surfaces; The index number representing the array element of the simultaneously transmissive and reflective reconfigurable smart surface integrated with the UAV; The array element set representing the simultaneously transmissive and reflective reconfigurable smart surface of the integrated drone; Indicates the minimum transmission power of maritime users; Indicates the Transmitting power of each maritime user; Indicates the maximum transmission power of maritime users; Indicates the index number of the offshore user; represents the offshore user set; Indicates the Offshore users and The decision parameters associated with the array elements of the simultaneously transmissive and reflective reconfigurable smart surface of an integrated UAV; represents a set of simultaneously transmissive and reflective reconfigurable smart surfaces integrated with a drone; represents the amplitude of the transmission pattern of the reconfigurable smart surface that is simultaneously transmitted and reflected by the integrated UAV; represents the amplitude of the reflection pattern of the reconfigurable smart surface that is simultaneously transmitted and reflected by the integrated UAV; The index number of the array element of the UAV's simultaneously transmissive and reflective reconfigurable smart surface; A set of array elements representing a simultaneously transmissive and reflective reconfigurable smart surface; Phase shift representing the transmission pattern of the reconfigurable smart surface that is simultaneously transmitted and reflected by the integrated UAV; Representing the phase shift of the reflection pattern of the reconfigurable smart surface that is simultaneously transmitted and reflected by the integrated UAV; represents the total number of reconfigurable smart surface array elements that transmit and reflect simultaneously on the UAV;

[0070] S2: Using the Gaussian graph mechanism to obtain the initial solution of the objective function can improve the distribution of the initial solution; and based on the third-generation non-dominated sorting genetic algorithm, obtain the solution of the objective function;

[0071] The solution of the objective function includes: the three-dimensional position of the simultaneously transmitting and reflecting reconfigurable smart surface of the integrated UAV, the correlation between the simultaneously transmitting and reflecting reconfigurable smart surface of the integrated UAV and the offshore user, the transmitting power of the offshore user, and the transmission / reflection factor of the simultaneously transmitting and reflecting reconfigurable smart surface;

[0072] Specifically, the Gaussian graph mechanism is one of the chaotic search methods, which can transform the continuous solution space into the chaotic domain and improve the distribution of the initial solution. Its expression is:

[0073] (5)

[0074] Where: The index number representing the solution of the objective function; The index number representing the dimension of the solution of the objective function; The objective function is represented by The first solution dimensions; The objective function is represented by i The first solution dimensions; Indicates return remainder when divided by 1;

[0075] Specifically, in order to unify the chaotic domain, we Randomly set the first The first dimension of the solution , and then denormalize each dimension solution using a linear scaling method:

[0076] (6)

[0077] Where: and They represent the solution of the objective function. The lower and upper bounds of the dimensions; Represents the normalized ;

[0078] S3: Based on the set of solutions of the objective function, an inverse denoising mechanism is used to obtain the set of denoised solutions of the objective function, namely the Pareto set; so that users can select the solution of the objective function to be used from the set of denoised solutions of the objective function according to their needs, and realize offshore communication based on the integrated drone STAR-RIS.

[0079] Specifically, the inverse denoising mechanism is expressed as follows: Assume is the total number of iterations, For the current number of iterations, set a variable representing the number of inverse iterations Represents the reverse iterative process. Then, the probability density of the solution of each objective function is calculated. Since the optimization problem modeled contains three optimization objectives, and each optimization objective has a different order of magnitude, the optimization objective value is first normalized using a linear scaling method, which is the opposite of the operation in formula (T-5). Then, the Euclidean distance of each solution to the ideal solution of the current iteration is evaluated:

[0080] (7)

[0081] ，

[0082] Where: The objective function is represented by Solution to The Euclidean distance of the ideal solution of the inverse iteration; Indicates the In the reverse iteration The normalized value of the solution, where , Indicates the The normalized value of the first objective function in the inverse iteration; Indicates the The second objective function in the inverse iteration The normalized value of the solution; Indicates the The normalized value of the third objective function in the inverse iteration; Indicates absolute value; is the normalized value of the ideal solution; Indicates the index number of the reverse iteration; is the total number of iterations; is the current iteration number;

[0083] Specifically, Figure 3 This example shows how to calculate the Euclidean distance of each solution to the ideal solution in a normalized bi-objective optimization problem. The probability density is then calculated using an exponential function:

[0084] (8)

[0085] Where: The objective function is represented by The probability density of the solutions; represents the total number of populations, that is, the total number of solutions to the objective function;

[0086] Specifically, after calculating the probability density of each solution, we can get the original solution ,in , The index number representing the dimension of the solution of the objective function; The objective function is represented by The first solution dimensions; The objective function is represented by The first dimension of the solution;

[0087] (9)

[0088] , ,

[0089] Where: Indicates intermediate calculation parameters; represents the normalization term; are the index numbers of the solutions to the objective function, and ; represents a circularly symmetric Gaussian distribution; Indicates the The objective function in the inverse iteration The original solution of a solution; Indicates that with Decreasing and increasing values from 0 to 1; Indicates the The objective function in the inverse iteration The original solution of a solution;

[0090] Specifically, It is a Gaussian kernel function that introduces locality. In parameter space The closeness of contribution.

[0091] Specifically, according to , we can further obtain a new solution by using inverse denoising:

[0092] (10)

[0093] Where: The objective function is represented by The denoised solution of the solution; Indicates that with Decreasing and increasing values from 0 to 1; represents the noise weight; Indicates the amount of noise;

[0094] in, is the magnitude of the change caused by the random mutation of the solution, Control the noise level .

[0095] Specifically, since the problem being modeled is a mixed-integer nonlinear optimization problem, an enhanced third-generation non-dominated sorting genetic algorithm with a Gaussian graph mechanism and an inverse denoising mechanism is employed to solve the objective function of this embodiment. The enhanced third-generation non-dominated sorting genetic algorithm of this embodiment includes two enhancement mechanisms: a Gaussian graph mechanism and an inverse denoising mechanism.

[0096] Specifically, in this embodiment, the three-dimensional position of the simultaneously transmitting and reflecting reconfigurable smart surface of the integrated UAV, the association between the simultaneously transmitting and reflecting reconfigurable smart surface of the integrated UAV and the offshore user, the transmitting power of the offshore user, and the transmission / reflection factor of the simultaneously transmitting and reflecting reconfigurable smart surface are jointly considered as the solution of an enhanced third-generation non-dominated sorting genetic algorithm with a Gaussian graph operator and an inverse denoising operator;

[0097] In this embodiment, Figure 2 As shown, the solution process is as follows:

[0098] Step 1: Use the Gaussian graph operator to initialize the 3D position of the integrated UAV's simultaneous transmission and reflection reconfigurable smart surface, the maritime user's transmission power, and the transmission / reflection factor of the simultaneous transmission and reflection reconfigurable smart surface. Then randomly initialize the association between the integrated UAV's simultaneous transmission and reflection reconfigurable smart surface and the maritime user.

[0099] Step 2: Generate the three-dimensional position of the integrated UAV's simultaneous transmission and reflection reconfigurable smart surface, the transmission power of the maritime user, and the transmission / reflection factor of the simultaneous transmission and reflection reconfigurable smart surface in the offspring population using the traditional crossover and mutation mechanism;

[0100] Step 3: Randomly update the relationship between the integrated drones of the offspring population and the simultaneous transmission and reflection of the reconfigurable smart surface and the sea users;

[0101] Step 4: Use the inverse denoising operator to update the three-dimensional position of the integrated UAV's simultaneously transmissive and reflective reconfigurable smart surface in the offspring population, the transmission power of the maritime user, and the transmission / reflection factor of the simultaneously transmissive and reflective reconfigurable smart surface;

[0102] Step 5: The iteration termination condition is whether the maximum number of iterations is reached ; If the iteration termination condition is met, output the final Pareto set, otherwise iterate and execute steps 2 to 4;

[0103] like Figure 4 As shown, this embodiment integrates multiple drones with a simultaneously transmitting and reflecting reconfigurable smart surface to enhance communication between offshore users and shore-based systems in the absence of a direct communication link, wherein the offshore users on both sides of the integrated drone's simultaneously transmitting and reflecting reconfigurable smart surface can utilize its ability to reflect and transmit signals, respectively. Therefore, according to the deployment of each integrated drone's simultaneously transmitting and reflecting reconfigurable smart surface, the total area is divided into a reflection area and a transmission area. The offshore user set, the array element set of the integrated drone's simultaneously transmitting and reflecting reconfigurable smart surface, and the array element set of the simultaneously transmitting and reflecting reconfigurable smart surface are represented as 、 and ,in S 、 M and N They are the total number of users at sea, the total number of array elements of the reconfigurable smart surface for simultaneous transmission and reflection of the integrated drone, and the total number of array elements of the reconfigurable smart surface for simultaneous transmission and reflection of the drone. In addition, the array elements of the reconfigurable smart surface for simultaneous transmission and reflection of the integrated drone are arranged as a uniform planar array, i.e. ,in and Respectively indicate along x and z The number of array elements in the axis is large, while the maritime users and shore-based users are equipped with single antennas. Offshore users, The three-dimensional positions of the integrated UAV transmitting and reflecting reconfigurable smart surface array element and the shore base (Base Station, BS) are respectively recorded as 、 and .in, Respectively The three-dimensional position of the user at sea is Axis coordinates and Coordinates in the axis direction; Respectively The three-dimensional position of the array element of the reconfigurable smart surface that transmits and reflects simultaneously on an integrated drone Axis coordinates, Axis coordinates and Coordinates in the axis direction; The three-dimensional position of the shore base is Axis coordinates, Axis coordinates and Coordinates in the axis direction;

[0104] Furthermore, the correlation between the sea users and the integrated drones that transmit and reflect the reconfigurable smart surface is considered. Specifically, Indicates the Offshore users and An integrated drone can simultaneously transmit and reflect reconfigurable smart surfaces, otherwise Without loss of generality, it is assumed that an integrated UAV with simultaneous transmission and reflection reconfigurable smart surface can serve multiple maritime users, but a maritime user can only be served by one integrated UAV with simultaneous transmission and reflection reconfigurable smart surface. Therefore, In order to reduce communication interference, this embodiment assumes that the channels used by maritime users associated with different integrated drones that simultaneously transmit and reflect reconfigurable smart surfaces are orthogonal to each other. For the association, we express the matrix of transmission coefficient and reflection coefficient as:

[0105] and

[0106] ,

[0107] in and are the amplitude and phase shift, respectively, where , According to the law of conservation of energy, the amplitude must satisfy .

[0108] Specifically, assuming For the The transmission power of a maritime user, and Respectively represent An integrated drone simultaneously transmits and reflects the reconfigurable smart surface to the shore-based channel and the Offshore users to An integrated drone simultaneously transmits and reflects channels on a reconfigurable smart surface. is additive Gaussian white noise with a mean of zero and a variance of ,Right now , Indicates the mean And the variance is The circularly symmetric complex Gaussian distribution of Indicates the intermediate calculation parameters used to refer to. Without loss of generality, and Following the Rician fading channel model, it is shown as follows:

[0109] ,

[0110] (11)

[0111] Where: is the channel power at a reference distance of 1 meter; and Respectively represent the shore to the An integrated drone simultaneously transmits and reflects the distance and the first An integrated drone simultaneously transmits and reflects reconfigurable smart surfaces to the The distance to the user at sea; is the path loss exponent, is the Rice factor. and Respectively represent An integrated drone simultaneously transmits and reflects the reconfigurable smart surface to the shore-based channel and the Offshore users to The Rician fading of the channel where an integrated drone simultaneously transmits and reflects on the reconfigurable smart surface is a random scattering component with zero mean and unity variance. and Respectively represent An integrated drone simultaneously transmits and reflects the reconfigurable smart surface to the shore-based channel and the Offshore users to The deterministic LoS channel components of the channel where an integrated drone simultaneously transmits and reflects on the reconfigurable smart surface are expressed as follows:

[0112] ,

[0113] (12)

[0114] in: is the gap between the array elements of the simultaneously transmissive and reflective reconfigurable smart surface; is the wavelength; Indicates the Kronecker product; Indicates the The arrival angle of the integrated drone that simultaneously transmits and reflects the reconfigurable smart surface to the shore base, where , Indicates the x-axis coordinate of the shore base in the geodetic coordinate system; Indicates shore-based to The distance between USTAR-RIS; Indicates the An integrated drone simultaneously transmits and reflects the zenith angle of the reconfigurable smart surface to the shore, where , Indicates the z-axis coordinate of the shore base in the geodetic coordinate system; Indicates the Offshore users to The arrival angle of an integrated drone that simultaneously transmits and reflects the reconfigurable smart surface, where , Indicates the Offshore users to The distance at which an integrated drone simultaneously transmits and reflects the reconfigurable smart surface; Indicates the Offshore users to The zenith angle of the reconfigurable smart surface is simultaneously transmitted and reflected by an integrated drone, where ; represents transpose; Indicates the operation of finding the two norm;

[0115] The shore-based The first integrated drone to simultaneously transmit and reflect reconfigurable smart surfaces The signal-to-interference-and-noise ratio of a maritime user can be given by the following formula:

[0116] (13)

[0117] Where: Indicates the The user at sea sends The signal-to-interference-noise ratio of an integrated drone that simultaneously transmits and reflects the reconfigurable smart surface to the shore; are index numbers of offshore users, and ; Indicates the Offshore users and The decision parameters associated with the array elements of the simultaneously transmissive and reflective reconfigurable smart surface of an integrated UAV; Indicates the Offshore users and The decision parameters associated with the array elements of the simultaneously transmissive and reflective reconfigurable smart surface of an integrated UAV; Indicates the Transmitting power of each maritime user; Indicates the Offshore users to An integrated drone simultaneously transmits and reflects channels on a reconfigurable smart surface; represents the additive white Gaussian noise power; H represents conjugate transpose;

[0118] The corresponding transmission rate is then given by:

[0119] (14)

[0120] in, Indicates the An integrated drone can simultaneously transmit and reflect reconfigurable smart surfaces and Transmission rate between users at sea;

[0121] Furthermore, the two-dimensional flight power of the integrated UAV to simultaneously transmit and reflect the reconfigurable smart surface is considered:

[0122] (15)

[0123] in: 、 、 、 、 、 、 , These are constant parameters related to the UAV model and flight environment. The integrated drone can simultaneously transmit and reflect reconfigurable smart surfaces at a flight speed of Flight power at 1000 Hz; Indicates flight speed;

[0124] Therefore, the flight energy consumption of the integrated UAV's simultaneously transmissive and reflective reconfigurable smart surface system in two-dimensional space only depends on the flight speed. In addition, the flight energy consumption model is extended to three-dimensional space and can be approximately expressed as:

[0125] (16)

[0126] in: The flight energy consumption of the integrated UAV's simultaneously transmissive and reflective reconfigurable smart surface system in two-dimensional space is represented; Indicates the total flight time; express The instantaneous flight speed of the integrated drone simultaneously transmits and reflects the reconfigurable smart surface; Indicates the moment; express l The flight power of the reconfigurable smart surface that is simultaneously transmissive and reflective is integrated into the drone at all times; Simultaneously transmit and reflect the quality of reconfigurable smart surfaces for integrated drones; express The instantaneous flight speed of the integrated drone simultaneously transmits and reflects the reconfigurable smart surface; represents the initial velocity of the integrated UAV that simultaneously transmits and reflects the reconfigurable smart surface; and are the final and initial positions of the integrated drone’s simultaneous transmission and reflection reconfigurable smart surface, respectively; is the gravity factor.

[0127] Beneficial Effects: The present invention provides an efficient offshore communication method based on the integrated unmanned aerial vehicle STAR-RIS. By establishing objective functions with the goals of maximizing the capacity of the offshore communication system, minimizing the total flight energy consumption of the integrated unmanned aerial vehicle's simultaneously transmitting and reflecting reconfigurable smart surface system, and minimizing the total transmission power of all offshore users, the objective function is solved using an enhanced third-generation non-dominated sorting genetic algorithm using a Gaussian graph mechanism and an inverse denoising mechanism. Ultimately, a Pareto set is obtained, allowing users to select the solution of the objective function to be used from the set of denoised solutions of the objective function according to their needs, thereby realizing offshore communication based on the integrated unmanned aerial vehicle STAR-RIS. The present invention considers a multi-objective optimization problem aimed at simultaneously maximizing the system capacity, minimizing the total flight energy consumption of the integrated unmanned aerial vehicle's simultaneously transmitting and reflecting reconfigurable smart surface system, and minimizing the total transmission power of all offshore users. Since this problem is a hybrid multi-objective optimization problem with both continuous and discrete solution spaces, a multi-objective evolutionary algorithm is used to address it. An enhanced third-generation non-dominated sorting genetic algorithm (ENSGA-GID) with Gaussian map operator and inverse denoising operator is proposed. ENSGA-GID has two enhanced operators, namely the Gaussian map mechanism and the inverse denoising mechanism. It diversifies the initial solution distribution and completes efficient solution search, improving algorithm performance and thus providing a more efficient communication solution for maritime users.

[0128] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the above embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the above embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. An efficient offshore communication method based on integrated UAV STAR-RIS, characterized in that: The steps include: S1: Obtain the three-dimensional position of the integrated UAV simultaneously transmissive and reflective reconfigurable smart surface, the decision parameters associated with the maritime user and the integrated UAV simultaneously transmissive and reflective reconfigurable smart surface, the maritime user transmission power, and the transmission / reflection factor of the integrated UAV simultaneously transmissive and reflective reconfigurable smart surface to establish an objective function with the goals of maximizing the capacity of the maritime communication system, minimizing the total flight energy consumption of the integrated UAV simultaneously transmissive and reflective reconfigurable smart surface system, and minimizing the total transmission power of all maritime users: S2: Using the Gaussian graph mechanism to obtain the initial solution of the objective function; and based on the third-generation non-dominated sorting genetic algorithm, obtaining the set of solutions of the objective function; S3: Based on the set of solutions to the objective function, an inverse denoising mechanism is used to obtain a set of denoised solutions to the objective function, i.e., a Pareto set. This allows users to select the solution of the objective function to be used from the set of denoised solutions to achieve offshore communication based on the integrated drone STAR-RIS. The inverse denoising mechanism is expressed as follows: S31: Obtain the Euclidean distance between the solution of the objective function and the ideal solution; Where: The objective function is represented by Solution to The Euclidean distance of the ideal solution of the inverse iteration; Indicates the In the reverse iteration The normalized value of the solution; Indicates absolute value; is the normalized value of the ideal solution; Indicates the index number of the reverse iteration; is the total number of iterations; is the current iteration number; S32: Obtain the probability density of the solution of the objective function; Where: The objective function is represented by The probability density of the solutions; represents the total number of populations, that is, the total number of solutions to the objective function; S33: Obtain a set of denoised solutions of the objective function. The formula used is as follows: Where: Indicates intermediate calculation parameters; represents the normalization term; are the index numbers of the solutions to the objective function, and ; represents a circularly symmetric Gaussian distribution; Indicates the The objective function in the inverse iteration The initial solution of the solution; Indicates that with Decreasing and increasing values from 0 to 1; Indicates the The objective function in the inverse iteration The initial solution of the solution; Then we get: Where: The objective function is represented by The denoised solution of the solution; Indicates that with Decreasing and increasing values from 0 to 1; represents the noise weight; Indicates the amount of noise.

2. The offshore efficient communication method based on integrated drone STAR-RIS according to claim 1, characterized in that: The objective function is established as follows: Where: represents the set of objective functions; Indicates the capacity of the maritime communication system; represents the total flight energy consumption of the integrated UAV's simultaneously transmissive and reflective reconfigurable smart surface system; Indicates the total transmission power of maritime users; Representing the set of decision parameters associated with the maritime user and the simultaneously transmissive and reflective reconfigurable smart surface integrated with a UAV; Represents the set of 3D positions of the integrated drone that simultaneously transmits and reflects the reconfigurable smart surface; represents the transmission power set of maritime users; Transmission / reflection factors representing the simultaneous transmission and reflection of the reconfigurable smart surface by the integrated drone; Indicates the An integrated drone simultaneously transmits and reflects the 3D position of a reconfigurable smart surface; represents a three-dimensional space capable of deploying integrated drones that simultaneously transmit and reflect reconfigurable smart surfaces; The index number representing the array element of the simultaneously transmissive and reflective reconfigurable smart surface of the integrated UAV; The array element set representing the simultaneously transmissive and reflective reconfigurable smart surface of the integrated drone; Indicates the minimum transmission power of maritime users; Indicates the Transmitting power of each maritime user; Indicates the maximum transmission power of maritime users; Indicates the index number of the offshore user; represents the offshore user set; Indicates the Offshore users and The decision parameters associated with the array elements of the simultaneously transmissive and reflective reconfigurable smart surface of an integrated UAV; represents the total number of simultaneously transmissive and reflective reconfigurable smart surface array elements of the integrated UAV; represents the amplitude of the transmission pattern of the reconfigurable smart surface that is simultaneously transmitted and reflected by the integrated UAV; represents the amplitude of the reflection pattern of the reconfigurable smart surface that is simultaneously transmitted and reflected by the integrated UAV; The index number of the array element of the UAV's simultaneously transmissive and reflective reconfigurable smart surface; A set of array elements representing a simultaneously transmissive and reflective reconfigurable smart surface; Phase shift representing the transmission pattern of the reconfigurable smart surface that is simultaneously transmitted and reflected by the integrated UAV; Representing the phase shift of the reflection pattern of the reconfigurable smart surface that is simultaneously transmitted and reflected by the integrated UAV; Represents the total number of reconfigurable smart surface array elements that can simultaneously transmit and reflect the drone.

3. The offshore efficient communication method based on integrated UAV STAR-RIS according to claim 2 is characterized in that: The maritime communication system capacity is expressed as follows: Where: Indicates the capacity of the maritime communication system; represents the total number of offshore users; Indicates the index number of the offshore user; The index number representing the array element of the simultaneously transmissive and reflective reconfigurable smart surface of the integrated UAV; represents the total number of simultaneously transmissive and reflective reconfigurable smart surface array elements of the integrated UAV; Indicates the An integrated drone can simultaneously transmit and reflect reconfigurable smart surfaces and Transmission rate between users at sea; Representing the set of decision parameters associated with the maritime user and the simultaneously transmissive and reflective reconfigurable smart surface integrated with a UAV; Represents the set of 3D positions of the integrated drone that simultaneously transmits and reflects the reconfigurable smart surface; represents the transmission power set of maritime users; represents the transmission / reflection factor of the simultaneously transmissive and reflective reconfigurable smart surface, where Represents the reflection or transmission pattern of the reconfigurable smart surface that is simultaneously transmitted and reflected by the integrated drone. , Indicates transmission mode; Indicates reflection mode; Indicates the The user at sea sends The signal-to-interference-noise ratio of an integrated drone that simultaneously transmits and reflects the reconfigurable smart surface to the shore; are index numbers of offshore users, and ; Indicates the Offshore users and The decision parameters associated with the array elements of the simultaneously transmissive and reflective reconfigurable smart surface of an integrated UAV; Indicates the Offshore users and The decision parameters associated with the array elements of the simultaneously transmissive and reflective reconfigurable smart surface of an integrated UAV; Indicates the Transmitting power of each maritime user; Indicates the Offshore users to An integrated drone simultaneously transmits and reflects channels on a reconfigurable smart surface; represents the additive white Gaussian noise power; H represents conjugate transpose; Indicates the Offshore users to An integrated drone simultaneously transmits and reflects channels on a reconfigurable smart surface; Indicates the An integrated drone simultaneously transmits and reflects the channel from the reconfigurable smart surface to the shore base.

4. The offshore efficient communication method based on integrated drone STAR-RIS according to claim 2, characterized in that: The total flight energy consumption of the integrated UAV simultaneously transmissive and reflective reconfigurable smart surface system is expressed as follows: Where: represents the total flight energy consumption of the integrated UAV's simultaneously transmissive and reflective reconfigurable smart surface system; Indicates the Flight energy consumption of an integrated drone with simultaneously transmissive and reflective reconfigurable smart surfaces.

5. The offshore efficient communication method based on integrated UAV STAR-RIS according to claim 2, characterized in that: The total transmission power of maritime users is expressed as follows: Where: represents the total transmission power of maritime users, Indicates the The transmission power of an offshore user.

6. The offshore efficient communication method based on integrated drone STAR-RIS according to claim 1, characterized in that: The Gaussian graph mechanism is expressed as follows: Where: The index number representing the solution of the objective function; The index number representing the dimension of the solution of the objective function; The objective function is represented by The first solution dimensions; The objective function is represented by The first solution dimensions; Indicates return Divide by the remainder of Then we get: Where: and They represent the solution of the objective function. The lower and upper bounds of the dimensions; Represents the normalized .

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