Unmanned aerial vehicle conduction integration method in denial environment

Abstract

The invention provides an unmanned aerial vehicle communication and guidance integration method in a denial environment, and the method comprises the steps: providing time-space reference information for an unmanned aerial vehicle through a ground base station, and assisting the positioning and communication of the unmanned aerial vehicle; in response to a positioning request signal sent by the ground terminal and received by the unmanned aerial vehicle, performing baseband modulation on the communication data to generate a communication signal, encoding the navigation data, and generating a navigation signal through direct sequence spread spectrum and superposition scrambling code; superposing the navigation signal on the communication signal to generate a conduction integrated signal, and sending the conduction integrated signal to a ground terminal; and in response to a ground terminal, receiving a conduction integrated signal sent by the unmanned aerial vehicle, demodulating a corresponding communication signal and a navigation signal, and realizing communication and terminal positioning functions under navigation rejection. Based on the scheme provided by the invention, the problem that the ground terminal cannot communicate and position in a denial environment can be solved.

Description

Technical Field

[0001] The present application relates to the field of communication technology, and in particular to a method for integrating communication and navigation of unmanned aerial vehicles in a denied environment. Background Art

[0002] The Global Navigation Satellite System (GNSS) provides users with navigation, positioning, and timing functions by broadcasting time and space information. It is increasingly widely used in military, agriculture, rescue and other fields. However, due to the fragility and publicity of GNSS, it is extremely susceptible to electromagnetic interference, deception, terrain obstruction, and multipath effects, thus forming a denial environment and affecting the transmission of space-time information. In recent years, drones have been able to quickly cover wide areas and complex terrains, respond quickly to target needs, and provide services at close range, relying on their advantages such as mobility, rapid deployment, fast response, and strong anti-interference capabilities. Therefore, in a denied environment, drones can be used to provide backup navigation services for ground users.

[0003] However, although Orthogonal Frequency Division Multiplexing (OFDM) technology performs well in processing broadband signals, its high peak-to-average power ratio (PAPR) can cause signal distortion and spectrum diffusion problems. This high PAPR phenomenon is a challenge in traditional OFDM systems and requires effective solutions to avoid signal distortion. In addition, traditional navigation and communication systems usually process navigation signals and communication signals separately, resulting in increased system complexity. In a denied environment, this separate processing method may not meet the needs of providing reliable communication and navigation services at the same time. Summary of the invention

[0004] The present application aims to solve one of the technical problems in the related art at least to some extent.

[0005] To this end, the purpose of this application is to propose an integrated communication and navigation method for UAVs in a denied environment, so as to solve the problem that ground terminals cannot communicate and locate in valleys, sea areas and other areas susceptible to terrain obstruction, electromagnetic interference and multipath effects under GNSS navigation denial.

[0006] To achieve the above-mentioned purpose, the first embodiment of the present application proposes a method for integrating communication and navigation of a drone in a denied environment, comprising:

[0007] The ground base station provides the UAV with time and space reference information to assist the positioning and communication of the UAV;

[0008] In response to the UAV receiving a positioning request signal sent by a ground terminal, baseband modulating the communication data to generate a communication signal, encoding the navigation data, and generating a navigation signal through direct-sequence spread spectrum (DSSS) and superimposing scrambling codes;

[0009] superimposing the navigation signal onto the communication signal to generate a communication and navigation integrated signal and sending it to a ground terminal;

[0010] In response to the ground terminal receiving the integrated communication and navigation signal sent by the drone, the corresponding communication signal and navigation signal are demodulated to realize the communication and terminal positioning function under navigation denial.

[0011] Optionally, the ground base station provides the UAV with time and space reference information to assist the UAV in positioning and communication, including:

[0012] A known signal is synchronously sent to the UAV through multiple ground base stations, and the accurate position of the UAV is determined by measuring the parameters of the signal, wherein the parameters of the measured signal include propagation delay and arrival angle.

[0013] Optionally, performing baseband modulation on the communication data to generate a communication signal includes:

[0014] The communication data is encoded and baseband modulated to generate a baseband communication signal, wherein the baseband communication signal is used for data transmission, and the transmission type of information includes text information, picture information, audio information, and video information.

[0015] Optionally, encoding the navigation data and generating a navigation signal by direct sequence spread spectrum and superimposing scrambling codes includes:

[0016] Encoding the navigation data to obtain mapped navigation information symbols, wherein the navigation data carries the transmission time and the position information of the UAV;

[0017] Use two 13-stage linear feedback shift registers to generate a Gold sequence through shifting and modulo-2 addition as a pseudo-random noise PRN code;

[0018] In each channel, the navigation information symbol is modulo-two added with a specific PRN code to generate a spread spectrum signal;

[0019] An exclusive OR operation is performed on the spread spectrum signal and a scrambling code to obtain a navigation signal modulated onto a different carrier, wherein the scrambling code is a PRN code different from the spread spectrum code.

[0020] Optionally, superimposing the navigation signal onto the communication signal to generate a communication and navigation integrated signal includes:

[0021] The navigation signal is superimposed on the communication signal, the communication signal and the navigation signal are mapped to different subcarriers, the unmapped subcarrier positions are set to zero, and an orthogonal frequency division multiplexing OFDM time domain symbol is generated by an N-point inverse fast Fourier transform IFFT, thereby generating an SCDS-OFDM (Scrambling Code-imposed DSSS-OFDM, SCDS-OFDM) communication and guidance integrated signal, and the expression of the SCDS-OFDM communication and guidance integrated signal is:

[0022]

[0023] Among them, x(t) is the integrated SCDS-OFDM communication and guidance signal after fusion, D i is the i-th navigation ranging information in an OFDM time domain symbol, C k is the kth communication data information in an OFDM time domain symbol, N c The number of subcarriers allocated to the communication data, N n is the number of subcarriers allocated for the navigation data, and N n ≤N c , N n +N c ≤N, T is the symbol duration, P n is the navigation signal power, P c is the communication signal power, and P c ≥P n , can be controlled by P n and P c The power allocation is adjusted according to the weights to reduce the mutual interference between the communication signal and the navigation signal.

[0024] Optionally, also include:

[0025] The terminal positioning under navigation denial is achieved by using the navigation signals of at least four UAVs and pseudo-range measurement method.

[0026] Optionally, the method of realizing terminal positioning under navigation denial by using at least four navigation signals and a pseudorange measurement method includes:

[0027] Calculating the three-dimensional position of the ground terminal through the navigation signals of three different drones, wherein the three-dimensional position of the ground terminal includes longitude, latitude, and altitude;

[0028] Calculating the clock error of the ground terminal using the navigation signal of the fourth UAV;

[0029] By solving the pseudo-range equations between the ground terminal and the four UAVs, the clock error and the position of the ground terminal itself are obtained.

[0030] Optionally, the pseudorange equation between the ground terminal and each UAV is:

[0031]

[0032] Among them, ρ m is the pseudorange between the ground terminal and the mth UAV, (x m ,y m ,z m ) is the known position of the mth UAV, (x r ,y r ,z r ) is the position of the ground terminal, c is the speed of light, and Δt is the clock error of the ground terminal.

[0033] To achieve the above-mentioned purpose, the second embodiment of the present application proposes an integrated communication and navigation device for a drone in a denied environment, comprising:

[0034] A receiving module, used for providing time and space reference information for the UAV from the ground base station to assist the positioning and communication of the UAV;

[0035] A generating module, in response to the UAV receiving a positioning request signal sent by a ground terminal, for baseband modulating the communication data to generate a communication signal, encoding the navigation data, and generating a navigation signal by direct sequence spread spectrum and superimposing scrambling codes;

[0036] A superposition module, used for superimposing the navigation signal on the communication signal to generate a communication and navigation integrated signal and sending it to a ground terminal;

[0037] The positioning module is responsive to the ground terminal receiving the integrated communication and navigation signal sent by the UAV, and is used to demodulate the corresponding communication signal and navigation signal to realize the communication and terminal positioning function under navigation denial.

[0038] To achieve the above-mentioned purpose, the third aspect of the present application provides an electronic device, including: a processor, and a memory communicatively connected to the processor;

[0039] The memory stores computer-executable instructions;

[0040] The processor executes the computer-executable instructions stored in the memory to implement the method as described in any one of the first aspects above.

[0041] Additional aspects and advantages of the present application will be given in part in the description below, and in part will become apparent from the description below, or will be learned through the practice of the present application. BRIEF DESCRIPTION OF THE DRAWINGS

[0042] The above and / or additional aspects and advantages of the present application will become apparent and easily understood from the following description of the embodiments in conjunction with the accompanying drawings, in which:

[0043] Figure 1 It is a flowchart of a method for integrating communication and navigation of a UAV in a denied environment according to an embodiment of the present application;

[0044] Figure 2 is a modulation principle diagram of a navigation signal according to an embodiment of the present application;

[0045] Figure 3 is a schematic diagram of generating a conduction integrated signal according to an embodiment of the present application;

[0046] Figure 4 It is a flowchart of a UAV communication and navigation integrated device in a denied environment according to an embodiment of the present application;

[0047] Figure 5 It is a block diagram of an electronic device according to an embodiment of the present application. DETAILED DESCRIPTION

[0048] The embodiments of the present application are described in detail below, and examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are intended to be used to explain the present application, and should not be construed as limiting the present application.

[0049] In order to provide communication and navigation services to user terminals at the same time in a denied environment, the present application proposes a method for integrated communication and navigation of drones in a denied environment, which is used to navigate a swarm of drones in a denied environment. Specifically, the drone is equipped with communication and navigation payloads, and a communication and navigation integrated signal can be generated by integrating the communication signal and the navigation signal, and sent to the ground terminal. The ground terminal is a device used by the user, such as a mobile phone. This method can be applied to scenarios such as valleys and sea areas that are susceptible to terrain obstruction, electromagnetic interference, and multipath effects. The core of this technology is to solve the problem of high PAPR by superimposing scrambling codes, and the communication signal and navigation signal occupy different orthogonal subcarriers to achieve communication and navigation frequency domain fusion.

[0050] In the embodiment of the present application, the integrated communication and navigation signal is formed by subcarrier mapping and fusion of the communication signal and the navigation signal. Therefore, based on the integrated communication and navigation signal, it is possible to meet the communication needs of the ground terminal through the communication signal, and provide navigation services to the ground terminal through the included navigation signal. Specifically, when in a navigation denial environment, GNSS cannot transmit time and space reference information to the ground terminal, and thus cannot provide navigation services to users. The present application uses drones to provide users with backup communication and navigation positioning services. The time and frequency reference and precise location information of the drone are provided by ground base stations with precise positioning capabilities. The drone sends an SCDS-OFDM integrated communication and navigation signal to the ground terminal. The ground terminal demodulates the received integrated communication and navigation signal to obtain the corresponding communication signal and navigation signal, which are used to transmit various types of information including text information, pictures, audio, video, etc. and to realize user terminal positioning.

[0051] The following describes the integrated method for drone communication and navigation in a denied environment according to an embodiment of the present application with reference to the accompanying drawings.

[0052] Figure 1 FIG. 1 is a flow chart of a method for integrating communication and navigation of a UAV in a denied environment according to an embodiment of the present application. Figure 1 As shown, the specific steps of the method are as follows:

[0053] Step 101, the ground base station provides the UAV with time and space reference information to assist the UAV in positioning and communication.

[0054] In the embodiment of the present application, a ground base station with precise positioning capability provides the UAV with time and space reference information, thereby assisting the UAV in positioning and communication.

[0055] Specifically, known signals are sent to the drone synchronously through multiple ground base stations, and the exact position of the drone is determined by measuring parameters such as the signal's propagation delay and arrival angle.

[0056] Step 102, in response to the drone receiving a positioning request signal from a ground terminal, baseband modulates the communication data to generate a communication signal, encodes the navigation data, and generates a navigation signal through direct sequence spread spectrum and superimposed scrambling.

[0057] In an embodiment of the present application, the drone is used for positioning request signals. When the drone receives the positioning request signal sent by the ground terminal, the communication data and navigation data are processed to generate communication signals and navigation signals.

[0058] As a possible implementation manner, the communication data is encoded and baseband modulated to generate a baseband communication signal.

[0059] Among them, the baseband communication signal is used for data transmission, and the transmission type of information types includes text information, picture information, audio information, video information, etc.

[0060] like Figure 2 As shown, an embodiment of the present application shows a modulation principle diagram of a navigation signal, showing a navigation signal generation process using direct sequence spread spectrum and scrambling modulation technology, which includes multiple channels.

[0061] First, the navigation data is encoded to obtain the mapped navigation information symbols, and the Gold sequence generated by shifting and modulo-2 addition using two 13-level linear feedback shift registers is used as the pseudo-random noise PRN code; then, in each channel, the navigation information symbol is modulo-2 added with a specific PRN code to generate a spread spectrum signal; then, an XOR operation is performed on the spread spectrum signal and the scrambling code to obtain the navigation signal modulated onto different carriers, where the navigation data carries the transmission time and drone location information, etc., and the scrambling code is a PRN code different from the spread spectrum code.

[0062] In a possible embodiment of the present application, two 13-stage linear feedback shift registers (LFSRs) are constructed, different feedback polynomials are selected for them, and the outputs of the two LFSRs at the same time are subjected to a modulo-two addition operation to generate a Gold sequence. Since the periods of the two LFSRs are different, a series of sequences with good autocorrelation and cross-correlation characteristics can be generated by modulo-two addition. The generated Gold sequence is used to perform direct sequence spread spectrum modulation with navigation data containing positioning and time information. Since the amplitude superposition occurs when multiple subcarriers of OFDM are phase-aligned, the problem of instantaneous power being much higher than the average power is caused, resulting in an excessively high peak-to-average power ratio, causing the power amplifier to operate in a nonlinear region, thereby causing signal distortion and spectrum diffusion, and reducing system performance. Therefore, by introducing a scrambling code, the spread-spectrum navigation data is bit-wise XORed with the PRN code, the phase of the OFDM symbol is changed but the spectrum content of the signal is not affected, so that the peak power of the signal will not be concentrated at a certain moment or on a few subcarriers, thereby reducing the peak-to-average power ratio.

[0063] Step 103, superimpose the navigation signal on the communication signal to generate a communication and navigation integrated signal and send it to the ground terminal.

[0064] like Figure 3 As shown, the present application proposes a principle diagram for generating an integrated communication and navigation signal, in which a navigation signal is superimposed on a communication signal, the communication signal and the navigation signal are mapped to different subcarriers, and the position of the unmapped subcarrier is set to zero. An orthogonal frequency division multiplexing OFDM time domain symbol is generated by an N-point inverse fast Fourier transform IFFT, thereby generating an SCDS-OFDM integrated communication and navigation signal. The expression of the SCDS-OFDM integrated communication and navigation signal is:

[0065]

[0066] Among them, x(t) is the integrated SCDS-OFDM communication and guidance signal after fusion, D i is the i-th navigation ranging information in an OFDM time domain symbol, C k is the kth communication data information in an OFDM time domain symbol, N c N is the number of subcarriers allocated for communication data. n is the number of subcarriers allocated for navigation data, and N n ≤N c , N n +N c ≤N, T is the symbol duration, P n is the navigation signal power, P c is the communication signal power, and P c ≥P n , can be controlled by P n and P c The power allocation is adjusted based on the weights to reduce the mutual interference between communication signals and navigation signals.

[0067] It should be noted that setting the unmapped subcarriers to zero can not only serve as a guard band to isolate the signal bandwidth to prevent mutual interference between communication signals and navigation signals, but also enhance the flexibility of the spectrum. When it is necessary to add new signals or adjust existing signals, these unmapped subcarrier positions can be used for dynamic adjustment without making major changes to the existing system. In addition, due to the orthogonal characteristics of OFDM subcarriers, although the spectrum of the communication subcarrier and the navigation subcarrier overlaps, they do not interfere with each other, making full use of spectrum resources.

[0068] Furthermore, after the UAV obtains its own location information with the assistance of the ground base station, it sends an SCDS-OFDM communication and guidance integrated signal to the ground terminal.

[0069] Step 104, in response to the ground terminal receiving the integrated communication and navigation signal sent by the UAV, the corresponding communication signal and navigation signal are demodulated to realize the communication and terminal positioning function under navigation denial.

[0070] It can be understood that the ground terminal, as a user device in the system, can be a handheld device, a vehicle-mounted device or any device that requires positioning services. It is used to receive and demodulate the SCDS-OFDM integrated communication and navigation signals, and obtain the corresponding communication signals and navigation signals by demodulating the integrated signals sent by the drone.

[0071] Among them, communication signals are used for data transmission, including various types of information such as text information, pictures, audio, video, etc.; navigation signals are used to provide navigation and positioning services.

[0072] It should be noted that in order to eliminate the influence of clock errors, the ground terminal needs to receive signals from at least four UAVs at the same time, and then use the pseudo-range measurement method through the navigation signals of at least four UAVs to achieve terminal positioning under navigation denial.

[0073] As a possible implementation method, the three-dimensional position of the ground terminal is calculated through the navigation signals of three different UAVs. The three-dimensional position of the ground terminal includes longitude, latitude, and altitude. The clock error problem of the ground terminal is solved by the navigation signal of the fourth UAV.

[0074] In the embodiment of the present application, the pseudo-range equation between the ground terminal and each drone is:

[0075]

[0076] Among them, ρ m is the pseudorange between the ground terminal and the mth UAV, (x m ,y m ,z m ) is the known position of the mth UAV, (x r ,y r ,z r ) is the position of the ground terminal, c is the speed of light, and Δt is the clock error of the ground terminal.

[0077] Finally, the ground terminal obtains the clock error Δt and its own position (x r ,y r ,z r ), thereby achieving terminal positioning under navigation denial.

[0078] In order to implement the above-mentioned embodiments, the present application also proposes an integrated communication and navigation device for drones in a denied environment.

[0079] Figure 4 1 is a block diagram of a drone communication and navigation integrated device 10 in a denied environment shown in an embodiment of the present application, including:

[0080] The receiving module 100 is used for providing the UAV with time and space reference information from the ground base station to assist the positioning and communication of the UAV;

[0081] The generating module 200 is used for baseband modulating the communication data to generate a communication signal, encoding the navigation data, and generating a navigation signal by direct sequence spread spectrum and superimposing scrambling code in response to the UAV receiving the positioning request signal sent by the ground terminal;

[0082] The superposition module 300 is used to superimpose the navigation signal on the communication signal to generate a communication and navigation integrated signal and send it to the ground terminal;

[0083] The positioning module 400, in response to the ground terminal receiving the integrated communication and navigation signal sent by the drone, is used to demodulate the corresponding communication signal and navigation signal to achieve the communication and terminal positioning function under navigation denial.

[0084] Regarding the device in the above embodiment, the specific manner in which each module performs operations has been described in detail in the embodiment of the method, and will not be elaborated here.

[0085] Figure 5 A schematic block diagram of an example electronic device 500 that can be used to implement an embodiment of the present application is shown. The electronic device is intended to represent various forms of digital computers, such as laptop computers, desktop computers, workbenches, personal digital assistants, servers, blade servers, mainframe computers, and other suitable computers. The electronic device can also represent various forms of mobile devices, such as personal digital processing, cellular phones, smart phones, wearable devices, and other similar computing devices. The components shown herein, their connections and relationships, and their functions are merely examples and are not intended to limit the implementation of the present application described and / or required herein.

[0086] like Figure 5 As shown, the device 500 includes a computing unit 501, which can perform various appropriate actions and processes according to a computer program stored in a read-only memory (ROM) 502 or a computer program loaded from a storage unit 508 into a random access memory (RAM) 503. In the RAM 503, various programs and data required for the operation of the device 500 can also be stored. The computing unit 501, the ROM 502, and the RAM 503 are connected to each other via a bus 504. An input / output (I / O) interface 505 is also connected to the bus 504.

[0087] A number of components in the device 500 are connected to the I / O interface 505, including: an input unit 506, such as a keyboard, a mouse, etc.; an output unit 507, such as various types of displays, speakers, etc.; a storage unit 508, such as a disk, an optical disk, etc.; and a communication unit 509, such as a network card, a modem, a wireless communication transceiver, etc. The communication unit 509 allows the device 500 to exchange information / data with other devices through a computer network such as the Internet and / or various telecommunication networks.

[0088] The computing unit 501 may be a variety of general and / or special processing components with processing and computing capabilities. Some examples of the computing unit 501 include, but are not limited to, a central processing unit (CPU), a graphics processing unit (GPU), various dedicated artificial intelligence (AI) computing chips, various computing units running machine learning model algorithms, digital signal processors (DSPs), and any appropriate processors, controllers, microcontrollers, etc. The computing unit 501 performs the various methods and processes described above. For example, in some embodiments, the scheme proposed in the present application may be implemented as a computer software program, which is tangibly contained in a machine-readable medium, such as a storage unit 508. In some embodiments, part or all of the computer program may be loaded and / or installed on the device 500 via ROM 502 and / or communication unit 509. When the computer program is loaded into RAM 503 and executed by the computing unit 501, one or more steps of the method described above may be performed. Alternatively, in other embodiments, the computing unit 501 may be configured to perform the method shown in the present application in any other appropriate manner (e.g., by means of firmware).

[0089] Various implementations of the systems and techniques described above herein can be implemented in digital electronic circuit systems, integrated circuit systems, field programmable gate arrays (FPGAs), application specific integrated circuits (ASICs), application specific standard products (ASSPs), systems on chips (SOCs), load programmable logic devices (CPLDs), computer hardware, firmware, software, and / or combinations thereof. These various implementations can include: being implemented in one or more computer programs that can be executed and / or interpreted on a programmable system including at least one programmable processor, which can be a special purpose or general purpose programmable processor that can receive data and instructions from a storage system, at least one input device, and at least one output device, and transmit data and instructions to the storage system, the at least one input device, and the at least one output device.

[0090] The program code for implementing the method of the present application can be written in any combination of one or more programming languages. These program codes can be provided to a processor or controller of a general-purpose computer, a special-purpose computer, or other programmable data processing device, so that the program code, when executed by the processor or controller, implements the functions / operations specified in the flow chart and / or block diagram. The program code can be executed entirely on the machine, partially on the machine, partially on the machine and partially on a remote machine as a stand-alone software package, or entirely on a remote machine or server.

[0091] In the context of the present application, a machine-readable medium may be a tangible medium that may contain or store a program for use by or in conjunction with an instruction execution system, device, or equipment. A machine-readable medium may be a machine-readable signal medium or a machine-readable storage medium. A machine-readable medium may include, but is not limited to, an electronic, magnetic, optical, electromagnetic, infrared, or semiconductor system, device, or equipment, or any suitable combination of the foregoing. A more specific example of a machine-readable storage medium may include an electrical connection based on one or more lines, a portable computer disk, a hard disk, a random access memory (RAM), a read-only memory (ROM), an erasable programmable read-only memory (EPROM or flash memory), an optical fiber, a portable compact disk read-only memory (CD-ROM), an optical storage device, a magnetic storage device, or any suitable combination of the foregoing.

[0092] To provide interaction with a user, the systems and techniques described herein can be implemented on a computer having: a display device (e.g., a CRT (cathode ray tube) or LCD (liquid crystal display) monitor) for displaying information to the user; and a keyboard and pointing device (e.g., a mouse or trackball) through which the user can provide input to the computer. Other types of devices can also be used to provide interaction with the user; for example, the feedback provided to the user can be any form of sensory feedback (e.g., visual feedback, auditory feedback, or tactile feedback); and input from the user can be received in any form (including acoustic input, voice input, or tactile input).

[0093] The systems and techniques described herein can be implemented in a computing system that includes backend components (e.g., as a data server), or a computing system that includes middleware components (e.g., an application server), or a computing system that includes frontend components (e.g., a user computer with a graphical user interface or a web browser through which a user can interact with implementations of the systems and techniques described herein), or a computing system that includes any combination of such backend components, middleware components, or frontend components. The components of the system can be interconnected by any form or medium of digital data communication (e.g., a communication network). Examples of communication networks include: a local area network (LAN), a wide area network (WAN), the Internet, and a blockchain network.

[0094] A computer system may include a client and a server. The client and the server are generally remote from each other and usually interact through a communication network. The relationship between the client and the server is generated by computer programs running on the corresponding computers and having a client-server relationship with each other. The server may be a cloud server, also known as a cloud computing server or cloud host, which is a host product in the cloud computing service system to solve the defects of difficult management and weak business scalability in traditional physical hosts and VPS services ("Virtual Private Server", or "VPS" for short). The server may also be a server of a distributed system, or a server combined with a blockchain.

[0095] It should be understood that the various forms of processes shown above can be used to reorder, add or delete steps. For example, the steps recorded in this application can be executed in parallel, sequentially or in different orders, as long as the expected results of the technical solution of this application can be achieved, and this document is not limited here.

[0096] The above specific implementations do not constitute a limitation on the protection scope of this application. It should be understood by those skilled in the art that various modifications, combinations, sub-combinations and substitutions can be made according to design requirements and other factors. Any modifications, equivalent substitutions and improvements made within the spirit and principles of this application should be included in the protection scope of this application.

Claims

1. A method for integrated communication and navigation of unmanned aerial vehicles in a denied environment, characterized in that: include: The ground base station provides the UAV with time and space reference information to assist the positioning and communication of the UAV; In response to the UAV receiving a positioning request signal sent by a ground terminal, baseband modulating the communication data to generate a communication signal, encoding the navigation data, and generating a navigation signal by direct sequence spread spectrum and superimposing scrambling codes; superimposing the navigation signal onto the communication signal to generate a communication and navigation integrated signal and sending it to a ground terminal; In response to the ground terminal receiving the communication and navigation integrated signal sent by the UAV, the corresponding communication signal and navigation signal are demodulated to realize the communication and terminal positioning function under navigation denial.

2. The method according to claim 1, characterized in that The ground base station provides the UAV with time and space reference information to assist the positioning and communication of the UAV, including: A known signal is synchronously sent to the UAV through multiple ground base stations, and the accurate position of the UAV is determined by measuring the parameters of the signal, wherein the parameters of the measured signal include propagation delay and arrival angle.

3. The method according to claim 1, characterized in that The baseband modulation of the communication data to generate a communication signal comprises: The communication data is encoded and baseband modulated to generate a baseband communication signal, wherein the baseband communication signal is used for data transmission, and the transmission type of information includes text information, picture information, audio information, and video information.

4. The method according to claim 1, characterized in that: The encoding of the navigation data and generating a navigation signal by direct sequence spread spectrum and superimposed scrambling code comprises: Encoding the navigation data to obtain mapped navigation information symbols, wherein the navigation data carries the transmission time and the position information of the UAV; Use two 13-stage linear feedback shift registers to generate a Gold sequence through shifting and modulo-2 addition as a pseudo-random noise PRN code; In each channel, the navigation information symbol is modulo-two added with a specific PRN code to generate a spread spectrum signal; An exclusive OR operation is performed on the spread spectrum signal and a scrambling code to obtain a navigation signal modulated onto a different carrier, wherein the scrambling code is a PRN code different from the spread spectrum code.

5. The method according to claim 1, characterized in that The step of superimposing the navigation signal onto the communication signal to generate a communication and navigation integrated signal comprises: The navigation signal is superimposed on the communication signal. The communication signal and the navigation signal are mapped to different subcarriers. The unmapped subcarrier positions are set to zero. An orthogonal frequency division multiplexing OFDM time domain symbol is generated by an N-point inverse fast Fourier transform IFFT, thereby generating an SCDS-OFDM communication and guidance integrated signal. The expression of the SCDS-OFDM communication and guidance integrated signal is: Among them, x(t) is the integrated SCDS-OFDM communication and guidance signal after fusion, D i is the i-th navigation ranging information in an OFDM time domain symbol, C k is the kth communication data information in an OFDM time domain symbol, N c The number of subcarriers to allocate the communication data, N n is the number of subcarriers allocated for the navigation data, and N n ≤N c , N n +N c ≤N, T is the symbol duration, P n is the navigation signal power, P c is the communication signal power, and P c ≥P n , can be controlled by P n and P c The power allocation is adjusted according to the weights to reduce the mutual interference between the communication signal and the navigation signal.

6. The method according to claim 1, characterized in that Also includes: The terminal positioning under navigation denial is achieved by using the navigation signals of at least four UAVs and pseudo-range measurement method.

7. The method according to claim 6, characterized in that The method of realizing terminal positioning under navigation denial by using at least four navigation signals and a pseudorange measurement method includes: Calculating the three-dimensional position of the ground terminal through the navigation signals of three different drones, wherein the three-dimensional position of the ground terminal includes longitude, latitude, and altitude; Calculating the clock error of the ground terminal using the navigation signal of the fourth UAV; By solving the pseudo-range equation between the ground terminal and each UAV, the clock error and the position of the ground terminal itself are obtained.

8. The method according to claim 7, characterized in that The pseudo-range equation between the ground terminal and each UAV is: Among them, ρ m is the pseudorange between the ground terminal and the mth UAV, (x m ,y m ,z m ) is the known position of the mth UAV, (x r ,y r ,z r ) is the position of the ground terminal, c is the speed of light, and Δt is the clock error of the ground terminal.

9. An integrated navigation and communication device for drones in a denial environment, characterized in that: include: A receiving module, used for providing time and space reference information for the UAV from the ground base station to assist the positioning and communication of the UAV; A generating module, in response to the UAV receiving a positioning request signal sent by a ground terminal, is used to baseband modulate the communication data to generate a communication signal, encode the navigation data, and generate a navigation signal by direct sequence spread spectrum and superposition scrambling code; A superposition module, used for superimposing the navigation signal on the communication signal to generate a communication and navigation integrated signal and sending it to a ground terminal; The positioning module is responsive to the ground terminal receiving the integrated communication and navigation signal sent by the UAV, and is used to demodulate the corresponding communication signal and navigation signal to realize the communication and terminal positioning function under navigation denial.

10. An electronic device, characterized in that: include: A processor, and a memory communicatively connected to the processor; The memory stores computer-executable instructions; The processor executes the computer-executable instructions stored in the memory to implement the method according to any one of claims 1 to 8.

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