6G air-sea non-stationary channel modeling method and system for carrier attitude correction

Abstract

The invention relates to the technical field of communication, and particularly discloses a carrier attitude corrected 6G air-sea non-stationary channel modeling method and system, the method comprises the following steps: obtaining communication parameters between an unmanned aerial vehicle and a ship and real-time attitude data of the ship under wind wave disturbance, the attitude data at least comprising a rolling angle and a pitching angle; a ship attitude-signal angle mapping model is constructed, and the ship attitude-signal angle mapping model takes the collected dynamic attitude data as input and outputs a corrected signal incident angle and a corrected signal emergent angle; and substituting the corrected signal angle into a time-varying channel impulse response model, and constructing a 6G air-sea non-stationary channel model fused with the ship dynamic attitude. By constructing an angle correction model, the influence of ship attitude fluctuation on channel propagation is accurately quantified, the redundant calculation overhead in the modeling process is reduced, and accurate channel model support is provided for transmission performance evaluation, networking scheme optimization and transmission quality improvement of a 6G air-sea communication system.

Description

TECHNICAL FIELD

[0001] The application relates to the technical field of communication, and particularly relates to a 6G air-sea non-stationary channel modeling method and system for carrier attitude correction. BACKGROUND

[0002] At present, 5G and traditional communication technologies have been difficult to meet the urgent demand of maritime scenarios for high reliability, low latency and wide coverage communication. The next generation 6G communication system is evolving towards the direction of all-in-one integration of air, space, land and sea, aiming to build an intelligent communication network seamlessly connecting "air, space, land and sea". As one of the core enabling technologies of 6G communication, unmanned aerial vehicles (UAVs) play an irreplaceable role in filling the communication blind area of the sea and realizing air-sea collaborative coverage due to their flexible deployment and rapid response. The accuracy and practicality of UAVs directly determine the deployment effect and service quality of the communication system. However, the air-sea scenario has unique channel characteristics such as sea surface fluctuation, waveguide effect and ship attitude disturbance. The existing channel model is difficult to fully adapt to the dynamic changes of these complex scenarios. With the continuous expansion of 6G air-sea communication scenarios, higher requirements are put forward for the generality, dynamic adaptability, accuracy and engineering realizability of the channel model.

[0003] In order to efficiently and reliably carry out the actual design and performance evaluation of the 6G air-sea unmanned aerial vehicle communication system, it is particularly important to accurately characterize the air-sea wireless propagation channel by using a reasonable method and to establish a channel model that is adapted to the characteristics of the scene, reliable and accurate, and easy to apply in engineering. When designing, simulating and optimizing the 6G air-sea communication system, the complex and variable air-sea channel characteristics need to be abstracted in a mathematical way, and then a targeted channel model is formed. However, compared with traditional ground communication channels, 6G air-sea unmanned aerial vehicle communication channels have distinct scene-specific characteristics, and the influence of carrier attitude changes on the channel is particularly prominent, mainly in the following aspects: High dynamicity and non-stationarity: the high-speed movement of unmanned aerial vehicles will cause the basic distance and relative speed between the transmitter and receiver to change over time, and the dynamic attitude fluctuation of the ship under the superimposed wind and wave disturbance will further exacerbate the time-varying characteristics of the propagation path, making the channel parameters present strong non-stationarity and posing a great challenge to communication stability; Complex propagation environment and strong scene specificity: the flight altitude of unmanned aerial vehicles spans a large range, and the air-sea propagation path contains single-hop reflection caused by sea surface fluctuation, no ground buildings, vegetation and other scattering source interference, but the ship attitude fluctuation will directly change the reflection angle and effectiveness of the SB path, and the proportion and attenuation characteristics of each path are significantly different under different sea conditions, greatly increasing the complexity of channel modeling; The three-dimensional space characteristics are deeply coupled with the ship attitude: unlike the two-dimensional plane propagation in ground communication, the three-dimensional space propagation characteristics of the air-sea channel are prominent, and the roll and pitch attitude changes of the ship will directly cause the dynamic changes of the radiation pattern and gain directivity of the receiving end antenna, thereby affecting the three-dimensional angle domain fading law of signal propagation. SUMMARY

[0004] The purpose of the present application is to provide a carrier attitude corrected 6G air-sea non-stationary channel modeling method and system to solve the problems raised in the background art.

[0005] To achieve the above-mentioned purpose, the present application provides the following technical scheme: A carrier attitude corrected 6G air-sea non-stationary channel modeling method, the method comprising: Obtaining the communication parameters between the unmanned aerial vehicle and the ship and the real-time attitude data of the ship under the disturbance of wind and wave, the attitude data at least including roll angle and pitch angle; Constructing a ship attitude-signal angle mapping model, the ship attitude-signal angle mapping model taking the collected dynamic attitude data as input and outputting corrected signal incident angle and exit angle; Substituting the corrected signal angle into the time-varying channel impulse response model to construct a 6G air-sea non-stationary channel model integrating the dynamic attitude of the ship.

[0006] As a further scheme of the present application, the communication parameters include communication frequency, transmission power, receiving noise coefficient, antenna number, antenna polarization mode and antenna array arrangement.

[0007] As a further scheme of the present application, the real-time attitude data is obtained by deploying an inertial measurement unit and an attitude sensor on the ship.

[0008] As a further scheme of the present application, the step of correcting the geometric angle based on the real-time attitude data specifically includes: According to the position coordinates of the unmanned aerial vehicle and the ship, calculating the ideal signal exit azimuth angle, exit elevation angle, incident azimuth angle and incident elevation angle under the direct path; According to the position coordinates of the unmanned aerial vehicle, sea water fluctuation reflection cluster and the ship, calculating the ideal signal exit azimuth angle, exit elevation angle, incident azimuth angle and incident elevation angle under the reflection path; Using the roll angle and pitch angle, the ideal signal exit azimuth angle, exit elevation angle, incident azimuth angle and incident elevation angle are respectively corrected by a linear compensation formula.

[0009] As a further scheme of the present application, the time-varying channel impulse response model is: ; wherein, η 1、 η 2 respectively represent the proportion of LoS, SB component; is the power ratio of LoS component and NLoS component between the pth antenna of the UAV transmitting end and the qth antenna of the ship receiving end at t time; l k is the number of independent reflected rays contained in the kth SB cluster at t time; is the propagation time of LoS signal from UAV to ship at t time; is the total propagation time of the ray from UAV to SB cluster and then to ship at t time; K(t) is the time-varying number of sea wave fluctuation SB scattering clusters; is the channel gain of LoS component; is the channel gain of sea wave fluctuation single-hop component.

[0010] As a further scheme of the application, in the calculation of the channel gain of the LoS component, the transmitting end exit azimuth angle, exit elevation angle, receiving end incident azimuth angle and incident elevation angle in the corrected signal angle are integrated; In the calculation of the channel gain of the sea wave fluctuation single-hop component, for each reflection cluster and each ray in the cluster, the corresponding transmitting end exit azimuth angle, exit elevation angle, receiving end incident azimuth angle and incident elevation angle in the corrected signal angle are integrated.

[0011] As a further scheme of the application, in the calculation of the channel gain of the sea wave fluctuation single-hop component, at least one of the time-varying characteristics of the scattering cluster number caused by sea wave fluctuation, the time-varying characteristics of the ray number in each reflection cluster, and the propagation delay and amplitude scaling factor affected by the sea surface waveguide effect is also integrated.

[0012] The application also provides a 6G air-sea non-stationary channel modeling system for carrier attitude correction, comprising: A data acquisition module is configured to acquire communication parameters between a UAV and a ship and real-time attitude data of the ship under wind and wave disturbance, wherein the attitude data at least includes roll angle and pitch angle; A mapping model construction module is configured to construct a ship attitude-signal angle mapping model, wherein the ship attitude-signal angle mapping model takes the collected dynamic attitude data as input and outputs corrected signal incident angle and exit angle; A channel model construction module is configured to substitute the corrected signal angle into a time-varying channel impulse response model to construct a 6G air-sea non-stationary channel model integrating ship dynamic attitude.

[0013] Compared with the prior art, the beneficial effects of the present application are: by targeted collection of ship attitude data and construction of angle correction model, the influence of ship attitude fluctuation on channel propagation is accurately quantified, the unique propagation characteristics of air-sea scene are adapted, the redundant calculation overhead in the modeling process is reduced, and accurate channel model support is provided for transmission performance evaluation, networking scheme optimization and transmission quality improvement of 6G air-sea communication system. BRIEF DESCRIPTION OF DRAWINGS

[0014] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings needed to be used in the embodiments or prior art description will be briefly introduced as follows. Obviously, the drawings in the following description are only some embodiments of the present application.

[0015] Figure 1 A flow chart of a carrier attitude corrected 6G air-sea non-stationary channel modeling method is provided for the embodiments of the present application.

[0016] Figure 2 A 6G air-sea channel model schematic diagram is provided for the embodiments of the present application. DETAILED DESCRIPTION

[0017] In order to make the technical problems to be solved by the present application, the technical solutions and beneficial effects more clear and explicit, the present application will be further described in detail below in combination with the drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application and not to limit the present application.

[0018] Figure 1 A flow chart of a carrier attitude corrected 6G air-sea non-stationary channel modeling method is provided for the embodiments of the present application, as shown in Figure 1 The method comprises: acquiring communication parameters between the unmanned aerial vehicle and the ship and real-time attitude data of the ship under wind and wave disturbance, the attitude data at least including roll angle and pitch angle; constructing a ship attitude-signal angle mapping model, the ship attitude-signal angle mapping model taking the collected dynamic attitude data as input and outputting corrected signal incidence angle and exit angle; substituting the corrected signal angle into the time-varying channel impulse response model to construct a 6G air-sea non-stationary channel model fused with ship dynamic attitude.

[0019] As shown in Figure 1 and Figure 2 In this embodiment, the core communication parameters of the unmanned aerial vehicle (UAV) and the ship are set, including communication frequency, transmission power, number of antennas, antenna polarization mode and antenna array arrangement; The high-precision inertial measurement unit and the attitude sensor carried by the ship are used to collect dynamic attitude data of the ship in real time under the disturbance of wind and waves, and the dynamic attitude data includes ship roll angle And pitch angle ; Based on electromagnetic propagation theory, a ship attitude-signal angle mapping model is constructed, which takes the collected dynamic attitude data as input and outputs the corrected signal incident angle and exit angle. Combined with the propagation characteristics of the 6G air-sea scene, such as line-of-sight propagation, sea water fluctuation reflection propagation and sea waveguide effect propagation, the time-varying channel impulse response (CIR) expression is derived using analytical method, and the corrected angle data is substituted into the expression to construct a complete 6G air-sea non-stationary channel model.

[0020] Combined with the requirements of 6G air-sea communication scene, the core communication parameters of UAV and ship are set to provide basic configuration for channel modeling; then the high-precision inertial measurement unit (IMU) and attitude sensor carried by the ship are used to collect ship roll angle and pitch angle data in real time under the disturbance of wind and waves, and after filtering and denoising, and removing outliers, the reliability and time synchronization of the attitude data are ensured; then based on electromagnetic propagation theory, a ship attitude-signal angle mapping model is constructed, which takes the preprocessed ship attitude data as input and outputs the corrected signal incident angle and exit angle; finally, the propagation characteristics of the 6G air-sea scene, such as line-of-sight propagation, sea water fluctuation reflection propagation and sea waveguide effect propagation, are integrated, and the time-varying channel impulse response (CIR) expression is derived using analytical method, and the corrected angle data is substituted into the expression to construct a complete 6G air-sea non-stationary channel model, finally completing the full-link mapping from air-sea physical scene to mathematical model, realizing the precise modeling of air-sea channel under the coupling of ship attitude.

[0021] The present application collects ship attitude data and constructs angle correction model, accurately quantifies the influence of ship attitude fluctuation on channel propagation, adapts to the unique propagation characteristics of air-sea scene, reduces the redundant calculation overhead in the modeling process, and provides precise channel model support for transmission performance evaluation, networking scheme optimization and transmission quality improvement of 6G air-sea communication system.

[0022] The step of setting the core communication parameters of UAV and ship specifically includes: The system sets the communication frequency, UAV transmit power, and ship receiver noise figure. The communication frequency covers the Sub-6GHz band and the millimeter-wave band. The Sub-6GHz band has a bandwidth of 10MHz-100MHz, suitable for long-distance, low-loss transmission scenarios in the air and sea. The millimeter-wave band has a bandwidth of 100MHz-1GHz, suitable for high-bandwidth, high-speed data transmission requirements, and can be dynamically switched according to the air-sea link distance and maritime business transmission needs. The UAV transmit power is dynamically adapted to the attenuation of the air-sea link. The ship receiver noise figure is set according to the anti-interference requirements of maritime communication to ensure signal reception sensitivity. The antenna configuration parameters include the number of antennas, polarization mode, and array arrangement for UAVs and ships, supporting multiple input multiple output technology; the transmitting end adopts vertical antenna polarization, and the receiving end adopts horizontal polarization mode to resist polarization distortion caused by sea surface reflection; the array arrangement adopts a uniform planar array to optimize spatial diversity gain and signal coverage in air and sea scenarios.

[0023] Real-time synchronous acquisition of ship dynamic attitude data specifically includes: High-precision inertial measurement units (IMUs) and attitude sensors are deployed in stable areas of the ship's deck. Equipment calibration is performed before deployment to ensure that angle measurement errors are less than 0.1°. Synchronously collect dynamic attitude data of the ship, with the core data being the roll angle. and pitch angle It directly characterizes the attitude fluctuations of a ship under wind and wave disturbances; Set the acquisition frequency to no less than 10Hz, and synchronize the attitude data with the communication signal data timestamp to ensure that the angle correction matches the time-varying characteristics of the channel.

[0024] As a preferred embodiment of the present invention, the step of correcting the geometric angle based on real-time attitude data specifically includes: Based on the position coordinates of the UAV and the ship, calculate the ideal signal output azimuth, output elevation angle, incident azimuth, and incident elevation angle under the direct path; Based on the position coordinates of the UAV, the seawater wave reflection cluster, and the ship, calculate the ideal signal output azimuth, output elevation, incident azimuth, and incident elevation angles along the reflection path. Using the aforementioned roll and pitch angles, the ideal signal's output azimuth, output elevation, incident azimuth, and incident elevation angles are corrected respectively through a linear compensation formula.

[0025] In this embodiment, the ship attitude-signal angle mapping model specifically includes: Let the coordinates of the UAV at time t be... The ship's coordinates are Then the position vector of the UAV pointing to the ship is ,in .

[0026] For the direct path, the ideal exit azimuth , exit elevation , incident azimuth and incident elevation are obtained according to geometric relations, as follows: ; ; ; ; Combined with the collected ship roll angle and pitch angle , the angle compensation is realized through a linear correction formula.

[0027] ; ; ; ; Similarly, for the sea wave fluctuation single-hop (SB) component, the SB kth cluster position vector: , the ideal exit azimuth , exit elevation , incident azimuth and incident elevation are obtained according to geometric relations, as follows: ; ; ; ; Combined with the collected ship roll angle and pitch angle , the angle compensation is realized through a linear correction formula.

[0028] ; ; ; ; wherein the correction coefficient 0.01 is verified through multi-scenario simulation, and can realize accurate compensation within the ship attitude fluctuation range under conventional wind and wave disturbance, and the angle unit is radian.

[0029] As a preferred embodiment of the present application, in combination with the line-of-sight propagation, sea water fluctuation reflection propagation and sea surface waveguide effect propagation characteristics of the 6G air-sea scene, the time-varying channel impulse response (CIR) expression is derived by using the analytical method, and the incident azimuth angle , the incident elevation angle , the exit azimuth angle and the exit elevation angle of the time-varying signal after step S103 are integrated into the channel gain calculation of each propagation component, so as to realize the dynamic association of the time-varying characteristics of the ship posture and the channel model. The complete channel model formula is as follows: ; Among them, η 1, η 2 respectively represent the proportion of LoS and SB components; is the power ratio of the line-of-sight component and the non-line-of-sight component between the pth antenna of the UAV transmitting end and the qth antenna of the ship receiving end at t time; l k is the number of independent reflection rays contained in the kth SB cluster at t time; is the propagation time of the line-of-sight signal from the UAV to the ship at t time; is the total propagation time of the ray from the UAV to the SB cluster and then to the ship at t time; K(t) is the time-varying number of sea water fluctuation SB scattering clusters; is the channel gain of the line-of-sight component; is the channel gain of the sea water fluctuation single-hop component; , , wherein and are the distances from the UAV to the SB cluster and from the SB cluster to the ship, respectively.

[0030] As a preferred embodiment of the present application, in the calculation of the channel gain of the line-of-sight component, the exit azimuth angle and the exit elevation angle of the transmitting end and the incident azimuth angle and the incident elevation angle of the receiving end in the corrected signal angle are integrated; In the calculation of the channel gain of the sea water fluctuation single-hop component, for each reflection cluster and each ray in the cluster, the corresponding exit azimuth angle and exit elevation angle of the transmitting end and the incident azimuth angle and incident elevation angle of the receiving end in the corrected signal angle are integrated.

[0031] In the calculation of the channel gain of the sea water fluctuation single-hop component, at least one of the time-varying characteristics of the scattering cluster number caused by sea water fluctuation, the time-varying characteristics of the ray number in each reflection cluster, and the propagation delay and amplitude scaling factor affected by the sea surface waveguide effect is also integrated.

[0032] In this embodiment, the line-of-sight (LoS) component channel gain is: ; where, is the vertical (V) polarization pattern function of the pth transmit antenna: the input parameters are the modified transmit off-boresight angle and off-elevation angle , and the output is the antenna pattern gain under vertical polarization. is the horizontal (H) polarization pattern function of the qth receive antenna: the input parameters are the modified receive in-boresight angle and in-elevation angle , and the output is the antenna pattern gain under horizontal polarization. is the initial phase of the vertical polarization of the transmit end under the direct path. is the LoS component comprehensive phase factor. The specific formula is: ; where, is the cumulative Doppler shift at time t, and the time-varying Doppler shift is integrated from 0 to t to obtain the total frequency shift accumulation amount at time t, that is, the phase shift caused by the Doppler effect. Among them and are the modified transmit direction of departure (DOD) phase vector and the modified receive direction of arrival (DOA) phase vector. The formula is: ; ; Sea wave single-hop (SB) component channel gain: ; where, is the vertical (V) polarization pattern function of the pth transmit antenna: the input parameters are the modified off-boresight angle l k of the pth transmit antenna corresponding to the kth SB cluster and off-elevation angle , and the output is the antenna pattern gain under vertical polarization. is the horizontal (H) polarization pattern function of the qth receive antenna: the input parameters are the modified in-boresight angle and in-elevation angle of the qth receive antenna, and the output is the antenna pattern gain under horizontal polarization. is the initial phase of the vertical polarization of the transmit end under the direct path. is the cross-polarization amplitude scaling factor of the kth scattering cluster and the l k reflected ray of the SB component. is the SB component comprehensive phase factor, and the specific formula is: ; wherein, is the first SB cluster The first l k The t time corresponding to the ray pair is the cumulative Doppler shift, and the time-varying Doppler shift and Integrate from 0 to t to get the total frequency shift accumulation at t, which is the phase shift caused by the Doppler effect. Wherein and The corrected transmit end wave-off direction (DOD) phase vector and the corrected receive end wave-arrival direction (DOA) phase vector.

[0033] ; .

[0034] The embodiment of the application also provides a 6G air-sea non-stationary channel modeling system for carrier attitude correction, which comprises: A data acquisition module is configured to acquire communication parameters between a UAV and a ship and real-time attitude data of the ship under wind and wave disturbance, wherein the attitude data at least includes a roll angle and a pitch angle. A mapping model construction module is configured to construct a ship attitude-signal angle mapping model, wherein the ship attitude-signal angle mapping model takes the collected dynamic attitude data as input and outputs corrected signal incidence and emission angles. A channel model construction module is configured to substitute the corrected signal angles into a time-varying channel impulse response model to construct a 6G air-sea non-stationary channel model that fuses the dynamic attitude of the ship.

[0035] The above only describes the preferred embodiments of the application and is not intended to limit the application. Any modification, equivalent replacement and improvement made within the spirit and principle of the application shall be included in the protection scope of the application.

Claims

1. A 6G air-sea non-stationary channel modeling method for carrier attitude correction, characterized in that, The method includes: Acquire communication parameters between the UAV and the ship, as well as the ship's real-time attitude data under wind and wave disturbances, wherein the attitude data includes at least roll angle and pitch angle; A ship attitude-signal angle mapping model is constructed, which takes the collected dynamic attitude data as input and outputs the corrected signal incident angle and exit angle. Substituting the corrected signal angle into the time-varying channel impulse response model, a 6G air-sea non-stationary channel model incorporating ship dynamic attitude is constructed.

2. The 6G air-sea non-stationary channel modeling method for carrier attitude correction according to claim 1, characterized in that, The communication parameters include communication frequency, transmit power, receive noise figure, number of antennas, antenna polarization, and antenna array arrangement.

3. The 6G air-sea non-stationary channel modeling method for carrier attitude correction according to claim 1, characterized in that, The real-time attitude data is acquired through inertial measurement units and attitude sensors deployed on the ship.

4. The 6G air-sea non-stationary channel modeling method for carrier attitude correction according to claim 1, characterized in that, The steps for correcting geometric angles based on real-time attitude data specifically include: Based on the position coordinates of the UAV and the ship, calculate the ideal signal output azimuth, output elevation angle, incident azimuth, and incident elevation angle under the direct path; Based on the position coordinates of the UAV, the seawater wave reflection cluster, and the ship, calculate the ideal signal output azimuth, output elevation, incident azimuth, and incident elevation angles along the reflection path. Using the aforementioned roll and pitch angles, the ideal signal's output azimuth, output elevation, incident azimuth, and incident elevation angles are corrected respectively through a linear compensation formula.

5. A 6G air-sea non-stationary channel modeling method for carrier attitude correction according to claim 1, characterized in that, The time-varying channel impulse response model is as follows: ； in, η 1. η 2 represents the proportions of the Los and SB components, respectively; It is the power ratio of the line-of-sight component to the non-line-of-sight component between the p-th antenna of the UAV transmitter and the q-th antenna of the ship receiver at time t. l k Let be the number of independent reflected rays contained in the k-th SB cluster at time t; It is the propagation time of the line-of-sight signal from the UAV to the ship at time t; K(t) is the total propagation time of the ray from the UAV to the SB cluster and then to the ship at time t; K(t) is the time-varying number of SB scattering clusters caused by seawater fluctuations. For the line-of-sight component channel gain; This represents the channel gain for the single-hop component of seawater fluctuations.

6. A 6G air-sea non-stationary channel modeling method for carrier attitude correction according to claim 5, characterized in that, The calculation of the channel gain of the line-of-sight component incorporates the transmitter's outgoing azimuth angle, outgoing elevation angle, receiver's incident azimuth angle, and incident elevation angle from the corrected signal angle. In the calculation of the channel gain of the single-hop component of the seawater wave, for each reflection cluster and each ray within the cluster, the corresponding transmitter azimuth, emission elevation, receiver incident azimuth, and incident elevation angles from the corrected signal angles are incorporated.

7. A 6G air-sea non-stationary channel modeling method for carrier attitude correction according to claim 6, characterized in that, The calculation of the channel gain of the single-hop component of the seawater wave also incorporates at least one of the time-varying characteristics of the number of scattering clusters caused by the seawater wave, the time-varying characteristics of the number of rays in each reflection cluster, and the propagation delay and amplitude scaling factor affected by the sea surface waveguide effect.

8. A 6G air-sea non-stationary channel modeling system for carrier attitude correction, used to implement the 6G air-sea non-stationary channel modeling method for carrier attitude correction as described in any one of claims 1-7, characterized in that, The system includes: The data acquisition module is used to acquire communication parameters between the UAV and the ship, as well as the ship's real-time attitude data under wind and wave disturbances. The attitude data includes at least roll angle and pitch angle. The mapping model construction module is used to construct a ship attitude-signal angle mapping model. The ship attitude-signal angle mapping model takes the collected dynamic attitude data as input and outputs the corrected signal incident angle and exit angle. The channel model construction module is used to substitute the corrected signal angle into the time-varying channel impulse response model to construct a 6G air-sea non-stationary channel model that integrates the ship's dynamic attitude.

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