Cross-domain relay type radio frequency-laser communication module and communication method

Abstract

The invention belongs to the technical field of wireless optical communication, and discloses a cross-domain relay type radio frequency-laser communication module and a communication method, and the cross-domain relay type radio frequency-laser communication module is provided with a node construction module, a relay module, a synchronous control module, a modulation-demodulation module and a situation awareness module. According to the invention, a large-scale MIMO technology, DMD structure light modulation and AWI signal modulation and demodulation technology are utilized to autonomously design a large-bandwidth and high-secrecy radio-light transmission conversion module; a high-precision synchronous control module is designed by using a GD32 chip, and low-delay and low-error-code relay type cross-domain information interconnection is ensured. Meanwhile, a high-sensitivity area array CCD detector is combined to sense the position of a light spot, an underwater speckle recognition alignment algorithm is developed based on YoLoV8, azimuth information is output to assist semi-active alignment, and then low-cost, low-time-delay, high-speed, long-distance and large-capacity all-weather cross-domain communication in complex water areas is achieved.

Description

Technical Field

[0001] The present invention belongs to the technical field of wireless optical communications, and in particular relates to a cross-domain relay radio frequency-laser communication module and a communication method. Background Art

[0002] The ocean area accounts for more than 70% of the earth's surface area. Humans have only explored 5% of the ocean area, and 95% of the vast sea area is unknown. Humans have made little use of the rich resources and energy contained in the seabed. The ocean information network is one of the important technical means for humans to care about the ocean, understand the ocean, and manage the ocean. New information network technologies represented by the Internet of Things are trying to connect all objects on land, but it is difficult to cover the vast sea area, especially the underwater world.

[0003] Ocean sensor data is important information for human beings to understand the ocean, such as ocean dynamics, ecology, geology, meteorology and other environmental information. Ocean information is generally obtained through biological, chemical and other sensing mechanisms, and these sensors are generally deployed underwater. The ocean information in the sensor is then transmitted back to the land monitoring center or the sea surface operation platform. Ocean applications such as ocean exploration, ocean data collection, environmental monitoring, and public safety services all rely on the reliable and efficient transmission of ocean information.

[0004] The transmission of ocean information needs to cross the water-air interface. However, the performance of laser communication links lags far behind that of overwater radio links, becoming a bottleneck restricting the performance of ocean information transmission networks.

[0005] Through the above analysis, the problems and defects of the prior art are as follows:

[0006] The performance of laser communication links lags far behind that of marine radio links, becoming a bottleneck restricting the performance of marine information transmission networks. Summary of the invention

[0007] In view of the problems existing in the prior art, the present invention provides a cross-domain relay radio frequency-laser communication module.

[0008] The present invention is implemented in this way: a cross-domain relay type radio frequency-laser communication module includes:

[0009] Node building module, relay module, synchronization control module, modulation and demodulation module, situation awareness module;

[0010] The node construction module is connected to the relay module and is used to construct underwater signal nodes using multi-mode blue-green laser communication technology, and to construct an overwater cellular network and aerial signal nodes using 5G radio frequency communication technology;

[0011] The relay module is connected to the node building module and the synchronization control module, and is used to use the offshore buoy / submersible buoy to perform electrical-optical signal conversion relay, and the air-sea joint networking generates cross-domain heterogeneous radio frequency-laser communication;

[0012] The synchronous control module is connected with the relay module, the modulation and demodulation module, and the situation awareness module to

[0013] The modulation and demodulation module is connected with the synchronization control module and the situation awareness module, and is used to design a high-precision synchronization control module using an FPGA chip to achieve ms-level high-precision delay control for multi-source signals in the system;

[0014] The situation awareness module is connected with the synchronization control module and the modulation and demodulation module, and is used to design a wide-angle spot positioning and situation awareness system based on YoLoV5 to quickly align the optical communication between the underwater unmanned mobile platform and the fixed station under high sea conditions.

[0015] Further, the node construction module:

[0016] It consists of an atmospheric 5G cellular communication network, a surface buoy radio frequency-laser communication conversion system, and an underwater laser communication system.

[0017] Furthermore, the atmospheric 5G cellular communication network is composed of existing airborne / land-based / space-based 5G network systems.

[0018] Furthermore, the sea surface buoy RF-laser communication conversion system includes RF 5G reception processing, information demodulation, communication laser emission module, and buoy carrier.

[0019] Furthermore, the underwater laser communication system includes an Ethernet module, an FPGA information processing module, a photoelectric conversion module, and a signal amplification processing module.

[0020] Further, the relay module:

[0021] It is a hardware device with a transmitter, a receiver, an antenna and an interface with a wireless terminal; as a bridging wireless base station, the AP is installed on the floating gateway; the transmitter and receiver are used to establish a communication connection with the mobile terminal; by using electromagnetic waves to transmit and receive data in the air, the wireless LAN uses electromagnetic waves to send and receive data in the air without the need for cable media; the AP is connected to the underwater optical communication network to build a local area network of wireless mobile terminals-AP-underwater platform.

[0022] Another object of the present invention is to provide a cross-domain relay radio frequency-laser communication module communication method comprising:

[0023] Step 1: Use the node building module to build underwater signal nodes using multi-mode blue-green laser communication technology, and use 5G radio frequency communication technology to build an overwater cellular network and build air signal nodes;

[0024] Step 2: Use the offshore buoy / submersible buoy to perform electrical-optical signal conversion and relay through the relay module, and generate cross-domain heterogeneous RF-laser communication through air-sea joint networking;

[0025] Step 3, a high-precision synchronization control module is designed by using an FPGA chip through a synchronization control module to achieve ms-level high-precision delay control for multi-source signals of the system;

[0026] Step 4, using the MIMO technology, DMD structured light modulation and AWI signal modulation and demodulation technology in parallel link coordination through the modulation and demodulation module to synchronously modulate and demodulate the radio and optical signals;

[0027] Step 5: A wide-angle spot positioning and situation awareness system was designed based on YoLoV5 through the situation awareness module to quickly align the optical communication between the underwater unmanned mobile platform and the fixed station under high sea conditions.

[0028] Another object of the present invention is to provide a computer device, comprising a memory and a processor, wherein the memory stores a computer program, and when the computer program is executed by the processor, the processor executes the steps of the cross-domain relay RF-laser communication module communication method.

[0029] Another object of the present invention is to provide a computer-readable storage medium storing a computer program, which, when executed by a processor, enables the processor to execute the steps of the cross-domain relay RF-laser communication module communication method.

[0030] Another object of the present invention is to provide an information data processing terminal, which is used to implement the cross-domain relay radio frequency-laser communication module.

[0031] In combination with the above technical solutions and the technical problems solved, please analyze the advantages and positive effects of the technical solutions to be protected by the present invention from the following aspects:

[0032] First, the present invention proposes a new idea of ​​optoelectronic coordinated marine information transmission network. In the information transmission network architecture, through the efficient integration of laser communication network and radio network, and through the coordinated cooperation of optical and electrical links, the performance of the communication network is improved, and the dual-mode communication link of radio frequency-laser buoy relay communication and blue-green laser cross-air-water communication is designed. Radio frequency-laser buoy relay communication is based on multi-data networking such as air-based, land-based, space-based, and ship-borne. Two drones are grouped and mounted with dual pods. The space end has duplex two-way communication and the underwater buoy platform has half-duplex communication; the blue-green laser cross-air-water simplex one-way communication, the laser directly enters the water, and repeatedly sends information. The dual-mode communication link has mutually matched extreme distances, communication fields of view, and communication rates. It uses coarse alignment and fine tracking technology based on vision and laser spots, and is suitable for various complex waters.

[0033] The present invention proposes a relay-type cross-domain communication scheme based on the combination of radio and high-power LD / LED underwater wireless optical communication. Based on the traditional wireless optical communication transceiver, a large-scale MIMO technology, DMD structured light modulation and AWI signal modulation and demodulation technology are used to independently design a large-bandwidth, high-confidential radio-optical transmission conversion module; a high-precision synchronization control module is designed using the GD32 chip to ensure low-latency, low-error relay-type cross-domain information interconnection. At the same time, a high-sensitivity array CCD detector is combined to sense the spot position, and an underwater speckle recognition and alignment algorithm is developed based on YoLoV8, and the azimuth information is output to assist in semi-active alignment, thereby realizing low-cost, low-latency, high-speed, long-distance, large-capacity, all-weather cross-domain communication in complex waters.

[0034] It has the following features:

[0035] The overall prototype has an atmospheric distance of 3000m, a communication distance of 80m under 0.3db / m attenuation water quality, a transmission rate of 3-5Mbps, and a bit error rate of less than 7.1×10 -4 ;

[0036] The prototype is small in size, low in energy consumption, supports mounting on various above-water / underwater unmanned platforms and fixed stations, and can assist in achieving semi-active spot alignment;

[0037] The prototype has cross-domain communication capabilities under Level 3 sea conditions, strong turbulence and noisy light conditions;

[0038] The present invention is a new type of information transmission method of radio-optical relay, which breaks through the difficulties faced by existing marine information transmission from the technical principle level, and verifies the feasibility of the scheme by designing a system prototype. The difficulties of the work mainly exist in the following aspects:

[0039] 1. Design of high-precision multi-mode modulation synchronization control circuit and low-latency, high-bandwidth radio-optical relay conversion module.

[0040] 2. Realization of high-speed, long-distance, and low-error underwater communications in high-attenuation and strong turbulence environments.

[0041] 3. Implementation of beam speckle recognition, alignment and stability in wireless docking communications on mobile platforms under high sea conditions.

[0042] In response to the problem of air-sea cross-domain communication in actual combat, the present invention proposes to construct underwater signal nodes with multi-mode blue-green laser communication technology, utilizes the most critical radio frequency communication technology in 5G communication, constructs an overwater cellular network (Cellular network) to build air signal nodes, uses offshore buoys / submersibles to perform electrical-optical signal conversion and relay, and jointly forms air-sea networking to generate an overall cross-domain heterogeneous radio frequency-laser communication technology solution.

[0043] In order to solve the problems of difficult matching of multi-source control signal regulation, high delay and low conversion rate of relay-type electro-optical conversion network, a high-precision synchronization control module was designed using FPGA chip to achieve ms-level high-precision delay regulation of multi-source signals in the system; MIMO technology, DMD structured light modulation and AWI signal modulation and demodulation technology were used in parallel links to synchronously modulate and demodulate radio and optical signals to achieve low-latency, large-bandwidth relay communication conversion.

[0044] In order to solve the problems of continuous identification and adaptive analysis of light spots in complex dynamic environments, a wide-angle light spot positioning and situational awareness system was designed based on YoLoV5. It breaks through the computational constraints of existing sensing and control algorithms, solves key problems such as unclear underwater sensing and control fusion mechanism, inaccurate extreme motion model, and weak control capability, and realizes rapid alignment of optical communications between underwater unmanned mobile platforms and fixed stations under high sea conditions.

[0045] The present invention focuses on the development of new cross-domain communication technologies with long distance, high speed and low bit error rate, and comprehensively utilizes airborne / shore-based / space-based 5G networks (radio frequency, ultra-short wave), air-water interface (buoy relay), and underwater (laser, sea optical cable, hydroacoustic). Through the laser relay mode, the 5G network communication link is extended to underwater, and a global cross-media communication link is constructed to meet the large bandwidth, low latency and high-speed information interaction of water / underwater platforms in different practical production and life, and support the integrated information transmission generation of air, space, land and sea. Its main application scenarios are:

[0046] Cross-media communication between underwater platforms such as unmanned submersibles and surface platforms or shore-based data centers.

[0047] Combined with underwater acoustic communication, efficient collaborative integration of composite communications in complex multi-domain scenarios can be achieved.

[0048] As a submarine optical cable communication conversion node, it helps build a cross-media marine communication network.

[0049] Airborne or satellite platform anti-submarine laser communications.

[0050] Three-dimensional distributed sensor network applications such as coastal detection, underwater sensor data collection, navigation and control, and underwater ecological protection monitoring.

[0051] Second, in response to the problem of air-sea cross-domain communication in actual combat, it was proposed to build underwater signal nodes with multi-mode blue-green laser communication technology, utilize the most critical RF communication technology in 5G communication, build a water cellular network (Cellular network) to build air signal nodes, use offshore buoys / submersibles for electrical-optical signal conversion and relay, and jointly form an air-sea network to generate an overall plan for cross-domain heterogeneous RF-laser communication technology, and complete the first lake relay cross-domain communication experiment verification.

[0052] In order to solve the problems of difficult matching of multi-source control signal regulation, high delay and low conversion rate of relay-type electro-optical conversion network, a high-precision synchronization control module was designed for the first time using FPGA chip to achieve ms-level high-precision delay regulation for multi-source signals in the system; MIMO technology, DMD structured light modulation and AWI signal modulation and demodulation technology were used in parallel links to synchronously modulate and demodulate radio and optical signals, realizing low-latency, large-bandwidth relay-type communication conversion.

[0053] In order to solve the problems of continuous identification and adaptive analysis of light spots in complex dynamic environments, a wide-angle light spot positioning and situational awareness system was designed based on YoLoV5. It breaks through the computational constraints of existing sensing and control algorithms, solves key problems such as unclear underwater sensing and control fusion mechanism, inaccurate extreme motion model, and weak control capability, and realizes rapid alignment of optical communications between underwater unmanned mobile platforms and fixed stations under high sea conditions.

[0054] The present invention is aimed at the urgent need for efficient interconnection and intercommunication of marine information transmission networks and cross-media communication on the surface / underwater. It focuses on the development of new cross-domain communication technologies with long distance, high rate and low bit error rate. It comprehensively utilizes airborne / shore-based / space-based 5G networks (radio frequency, ultra-short wave), air-water interface (buoy relay), underwater (laser, sea optical cable, hydroacoustic), and extends the 5G network communication link to underwater through the laser relay mode, constructing a global cross-media communication link to meet the large bandwidth, low latency and high-rate information interaction of water / underwater platforms in different practical production and life, and supports the integrated information transmission generation of air, sky, land and sea. Its main application scenarios are:

[0055] 1. Cross-media communication between underwater platforms such as unmanned submersibles and surface platforms or shore-based data centers

[0056] 2. Combined with underwater acoustic communication, efficient collaborative integration of composite communications in complex multi-domain scenarios can be achieved.

[0057] 3. As a submarine cable communication conversion node, it helps build a cross-media marine communication network

[0058] 4. Airborne or satellite platform anti-submarine laser communications.

[0059] 5. Three-dimensional distributed sensor network applications such as coastal detection, underwater sensor data collection, navigation and control, and underwater ecological protection monitoring.

[0060] Third, in traditional cross-domain communication systems, communication above water and underwater faces huge challenges due to different media. Traditional wireless radio frequency technology is severely limited in underwater communication, and laser communication has high loss problems in the conversion between above water and underwater. In addition, existing systems lack efficient synchronization control and environmental perception capabilities. Especially in complex marine environments, communication links are easily interfered, resulting in unstable communication and greatly reduced data transmission rate and accuracy. These problems limit the performance of cross-domain communication systems in applications such as marine monitoring and unmanned platform control.

[0061] The present invention combines 5G radio frequency communication and multi-mode blue-green laser communication technology to build an air-sea joint cross-domain heterogeneous radio frequency-laser communication system, solving the signal conversion and transmission problems between surface and underwater communications. Using marine buoys or submerged buoys as relay equipment, efficient conversion of electrical-optical signals is achieved, ensuring communication between surface and underwater. In addition, through the high-precision synchronization control module designed with FPGA chips, the system can perform ms-level delay control on multi-source signals to ensure efficient collaboration between cross-domain communication nodes.

[0062] Compared with the prior art, the present invention has achieved significant technological progress in many aspects. First, by combining 5G communication technology and laser communication technology, the bottleneck of surface and underwater communications has been broken, and the bandwidth and stability of the system have been improved. Secondly, the high-precision delay control mechanism of the FPGA chip has greatly improved the synchronization and communication efficiency of the system, ensuring the communication stability in complex environments. Third, based on the situational awareness and light spot positioning system, the system can achieve efficient optical communication alignment under dynamic sea conditions, ensuring the quality of communication, which is especially suitable for multi-platform collaborative operations and monitoring in high-dynamic scenarios.

[0063] The cross-domain relay RF-laser communication module of the present invention has broad application prospects in the fields of ocean monitoring, military communications, unmanned platform control, etc. Its combination of 5G and laser communication technology breakthroughs has greatly improved the rate and stability of cross-domain communications, and solved the problems of signal attenuation and instability in traditional surface and underwater communication systems. By maintaining precise communication alignment under complex sea conditions, the present invention can effectively improve the reliability and accuracy of data transmission, provide more efficient communication solutions for related industries, and promote the popularization and development of cross-domain communication systems in different application scenarios. BRIEF DESCRIPTION OF THE DRAWINGS

[0064] Figure 1It is a structural block diagram of a cross-domain relay RF-laser communication module provided in an embodiment of the present invention.

[0065] Figure 2 It is a flow chart of the cross-domain relay radio frequency-laser communication module communication method provided by an embodiment of the present invention.

[0066] Figure 3 It is an overall structural diagram of the system provided by an embodiment of the present invention.

[0067] Figure 4 It is a hardware structure diagram of a radio frequency communication system provided by an embodiment of the present invention.

[0068] Figure 5 This is a physical diagram of an aerial information sending terminal provided by an embodiment of the present invention.

[0069] Figure 6 It is a block diagram of the composition of a wireless AP provided by an embodiment of the present invention.

[0070] Figure 7 It is a functional block diagram of an underwater optical communication module provided by an embodiment of the present invention.

[0071] Figure 8 It is a schematic diagram of the coding circuit design provided by an embodiment of the present invention.

[0072] Fig. 9 This is a circuit diagram of an encoder PCB provided by an embodiment of the present invention.

[0073] Fig.10 This is a physical diagram of the FPGA and interface module provided in the embodiment of the present invention.

[0074] Fig.11 It is a block diagram of the transmitter provided by an embodiment of the present invention.

[0075] Fig.12 It is a functional block diagram of a driving circuit provided by an embodiment of the present invention.

[0076] Fig.13 It is a schematic diagram of a transmitter circuit provided by an embodiment of the present invention.

[0077] Fig.14 It is a transmitter PCB circuit diagram provided by an embodiment of the present invention.

[0078] Fig.15 It is a block diagram of a receiving device provided in an embodiment of the present invention.

[0079] Fig.16 It is a schematic diagram of a receiver circuit provided by an embodiment of the present invention.

[0080] Fig.17 It is a circuit diagram of a receiver PCB provided by an embodiment of the present invention.

[0081] Fig.18 It is a block diagram of the decoder provided by an embodiment of the present invention.

[0082] Fig.19 It is a schematic diagram of a decoder circuit design provided by an embodiment of the present invention.

[0083] Fig. 20 It is a decoder PCB circuit diagram provided by an embodiment of the present invention.

[0084] Fig.21 It is a simulation diagram of the automatic alignment system provided by an embodiment of the present invention.

[0085] Fig. 22 4 is a performance comparison chart of various algorithms provided by the embodiments of the present invention.

[0086] Fig.23 is a design diagram of a radio frequency-laser communication module system provided by an embodiment of the present invention;

[0087] Fig.24 It is a schematic diagram of the indoor water pool experiment setting provided by an embodiment of the present invention.

[0088] Fig.25 This is a physical picture of the air information transmitting terminal provided by an embodiment of the present invention.

[0089] Fig.26 This is a physical diagram of an underwater optical communication link provided by an embodiment of the present invention.

[0090] Fig. 27 The present invention provides a host computer video receiving terminal.

[0091] Fig.28 This is a visible light interference experiment provided by an embodiment of the present invention: (a) interference transmitting end and (b) interference receiving end.

[0092] Fig.29 This is a physical picture of a propeller provided in an embodiment of the present invention.

[0093] Fig.30 This is a water turbulence interference experiment provided by an embodiment of the present invention.

[0094] Fig.31 This is a bubble group interference experiment provided by an embodiment of the present invention.

[0095] Fig.32 This is a scene map of a lake experiment provided by an embodiment of the present invention.

[0096] Figure 1 In: 1. Node construction module; 2. Relay module; 3. Synchronous control module; 4. Modulation and demodulation module; 5. Situation awareness module. DETAILED DESCRIPTION

[0097] In order to make the purpose, technical solution and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0098] like Figure 1 As shown, a cross-domain relay type radio frequency-laser communication module provided by an embodiment of the present invention includes:

[0099] Node construction module 1, relay module 2, synchronization control module 3, modulation and demodulation module 4, situation awareness module 5.

[0100] The node construction module 1 is connected to the relay module 2 and is used to construct underwater signal nodes using multi-mode blue-green laser communication technology, and to construct an overwater cellular network and an aerial signal node using 5G radio frequency communication technology;

[0101] The relay module 2 is connected to the node construction module 1 and the synchronization control module 3, and is used to use the offshore buoy / submersible buoy to perform electrical-optical signal conversion relay, and the air-sea joint networking generates cross-domain heterogeneous radio frequency-laser communication;

[0102] The synchronization control module 3 is connected with the relay module 2, the modulation and demodulation module 4, and the situation awareness module 5, and is used to

[0103] The modulation and demodulation module 4 is connected to the synchronization control module 3 and the situation awareness module 5, and is used to design a high-precision synchronization control module using an FPGA chip to achieve ms-level high-precision delay control for multi-source signals of the system;

[0104] The situation awareness module 5 is connected to the synchronization control module 3 and the modulation and demodulation module 4, and is used to design a wide-angle spot positioning and situation awareness system based on YoLoV5 to quickly align the optical communication between the underwater unmanned mobile platform and the fixed station under high sea conditions.

[0105] Node building module: It consists of an atmospheric 5G cellular communication network, a sea surface buoy radio frequency-laser communication conversion system, and an underwater laser communication system.

[0106] The atmospheric 5G cellular communication network is composed of existing airborne / land-based / space-based 5G network systems.

[0107] The sea surface buoy RF-laser communication conversion system consists of RF 5G reception processing, information demodulation, communication laser transmission module, and buoy carrier.

[0108] The underwater laser communication system consists of an Ethernet module, an FPGA information processing module, a photoelectric conversion module, and a signal amplification and processing module.

[0109] Relay module: a hardware device with a transmitter, receiver, antenna and interface with the wireless terminal; as a bridging wireless base station, the AP is installed on the floating gateway; the transmitter and receiver are used to establish a communication connection with the mobile terminal; by using electromagnetic waves to transmit and receive data in the air, the wireless LAN uses electromagnetic waves to send and receive data in the air without the need for cable media; the AP is connected to the underwater optical communication network to build a local area network of wireless mobile terminal-AP-underwater platform.

[0110] The node construction module 1 in the present invention uses multi-mode blue-green laser communication technology to build underwater communication nodes, and builds air signal nodes through 5G radio frequency communication technology to form an air-sea joint cross-domain communication system. The 5G cellular network in the atmosphere is composed of airborne, shore-based or space-based 5G network systems, which can provide high-bandwidth, low-latency connections for water communications. The buoy on the water surface acts as a communication conversion node, receiving 5G radio frequency signals and converting them into laser signals for transmission underwater. The underwater laser communication system is responsible for processing the laser signals transmitted from the buoy to realize information interaction between underwater and water.

[0111] Relay module 2 is responsible for the cross-domain heterogeneous electro-optical signal conversion, using offshore buoys or submerged buoys as relay devices. The relay module realizes signal transmission between the water and underwater by receiving radio frequency signals on the water and converting them into optical signals. Through wireless local area network (WLAN) and electromagnetic wave transmission technology, the connection between the aerial node and the underwater platform can be established without cable media. The receiver and transmitter in the relay module are respectively responsible for receiving signals from the aerial node and transmitting them to the underwater platform, completing the bridging function of cross-domain communication.

[0112] The synchronization control module 3 and the modulation and demodulation module 4 realize high-precision control of the cross-domain communication system through the FPGA chip. This module ensures that the communication nodes in the system remain synchronized by precisely controlling the delay of multi-source signals at the ms level, thereby avoiding signal loss or delay. The modulation and demodulation module is responsible for modulating and demodulating the received signal, converting the digital signal into an analog signal that can be transmitted via radio frequency or laser, and demodulating it into raw data when the optical signal is received. The high-precision synchronization control designed by FPGA ensures the reliable transmission of communication signals in complex environments.

[0113] The situation awareness module 5 realizes fast optical communication alignment between the underwater unmanned platform and the fixed station under complex sea conditions through the wide-angle spot positioning and situation awareness system based on YoLoV5. The module monitors the sea surface and underwater environment in real time, detects the position of the communication spot, and performs situation awareness analysis to ensure that the laser communication between the underwater and surface nodes can maintain precise alignment under high dynamic sea conditions. Through this mechanism, the present invention can ensure the stability and efficiency of optical communication in complex environments, and improve the communication quality and response speed of the overall system.

[0114] like Figure 2 As shown, the cross-domain relay type radio frequency-laser communication module communication method provided by the embodiment of the present invention includes:

[0115] S101, through the node building module, uses multi-mode blue-green laser communication technology to build underwater signal nodes, and uses 5G radio frequency communication technology to build a water cellular network to build air signal nodes;

[0116] S102, using the relay module to use the offshore buoy / submersible buoy to perform electrical-optical signal conversion and relay, and the air-sea joint networking generates cross-domain heterogeneous radio frequency-laser communication;

[0117] S103, designing a high-precision synchronization control module by using an FPGA chip through a synchronization control module to achieve ms-level high-precision delay control for multi-source signals of the system;

[0118] S104, synchronously modulating and demodulating radio and optical signals by using a modulation and demodulation module and using MIMO technology, DMD structured light modulation, and AWI signal modulation and demodulation technology in parallel link coordination;

[0119] S105, through the situation awareness module, designed a wide-angle spot positioning and situation awareness system based on YoLoV5 to quickly align the optical communication between the underwater unmanned mobile platform and the fixed station under high sea conditions.

[0120] Another object of the present invention is to provide a computer device, comprising a memory and a processor, wherein the memory stores a computer program, and when the computer program is executed by the processor, the processor executes the steps of the cross-domain relay RF-laser communication module communication method.

[0121] Another object of the present invention is to provide a computer-readable storage medium storing a computer program, which, when executed by a processor, enables the processor to execute the steps of the cross-domain relay RF-laser communication module communication method.

[0122] Another object of the present invention is to provide an information data processing terminal, which is used to implement the cross-domain relay radio frequency-laser communication module.

[0123] The present invention is specifically implemented:

[0124] This system consists of an atmospheric 5G cellular communication network, a surface buoy radio frequency-laser communication conversion system, and an underwater laser communication system. Figure 3 As shown, the atmospheric 5G cellular communication network adopts the existing airborne / shore-based / space-based 5G network system; the surface buoy RF-laser communication conversion system includes RF 5G receiving and processing, information demodulation, communication laser transmission module, buoy carrier, etc.; the underwater laser communication system includes Ethernet module, FPGA information processing module, photoelectric conversion module, signal amplification processing module, etc., which can be carried on UUV, submarine, lurking weapon and other platforms. The system extends the air 5G communication network to underwater through the RF-laser relay mode, forming a local 5G communication network of sky-air-ship-shore-sea, realizing high-speed and real-time information transmission.

[0125] 1.1 Design of air information transmitter

[0126] The aerial information transmitter consists of a drone and a radio frequency signal transmission module, which can transmit the first-person video stream captured by the drone camera in real time. This project builds a relay cellular communication network based on the 5G radio frequency communication network of the TCP / IP protocol and large-scale MIMO technology. At the same time, to ensure the security of communication, an encryption coprocessor is placed between the baseband chip and the security system CPU to achieve a gatekeeper-style physical isolation between the terminal CPU and the baseband chip, ensuring the security of the data transmission link.

[0127] Figure 4 RF communication system hardware structure diagram; Figure 5 Physical picture of the air information transmitter.

[0128] 1.2 Design of surface relay equivalent simulator

[0129] The AP surface relay communication module is a hardware device with a transmitter, a receiver, an antenna, and an interface with a wireless terminal. As a bridging wireless base station, the AP is installed on the floating gateway. The transmitter and receiver are used to establish a communication connection with mobile terminals (such as satellites, ships, ground monitoring centers, mobile PCs, mobile phones, etc.). By using electromagnetic waves to transmit and receive data in the air, the wireless LAN uses electromagnetic waves to send and receive data in the air without the need for cable media. In addition, the AP can also be connected to an underwater optical communication network to build a local area network of wireless mobile terminals-AP-underwater platforms, realizing network communication between wireless terminals and underwater optical communication equipment.

[0130] like Figure 6As shown in the figure, a typical application block diagram of a wireless AP with encryption function is shown, in which the dotted box is composed of an MCU microprocessor as the core, and SDRAM and FLASH as the peripherals to form an embedded minimum system, which constitutes a wireless AP.

[0131] The wireless AP is equipped with an Ethernet interface for connecting underwater communication links. It can also be connected to a switch through an additional Ethernet interface to expand the LAN device. The AP can be connected to peripherals such as cameras and microphones on the floating gateway through the switch, and the information monitored by the floating gateway can be viewed in real time through the LAN. The PCMCIA bus connects an IEEE802.11 wireless module to provide access services for mobile terminals (satellites, ships, ground monitoring centers, mobile PCs, mobile phones, etc.).

[0132] One SMC is configured as a standard RS232 serial interface for development and debugging and for users to configure the wireless AP function through a hyperterminal.

[0133] The wireless AP complies with the IEEE802.11b wireless communication standard and the IEEE802.3 network protocol, and supports two RJ45 interfaces to provide the connection of wired devices. Through one AP, 30 terminals can be wirelessly connected, easily achieving seamless connection from wired network to wireless network.

[0134] 1.3 Underwater optical communication module design

[0135] The underwater optical communication module uses 532nm laser as the communication carrier to achieve high-speed underwater laser communication. The module is mainly composed of encoder, FPGA and interface module, transmitter, receiver, decoder and host computer. The functional block diagram is as follows Figure 7 shown.

[0136] 1.3.1 Encoder Design

[0137] The encoder compresses and encodes the received audio and video signals, and packages them into the data format required for network transmission through steps such as bit rate control, data segmentation and network transmission.

[0138] Figure 8 Schematic diagram of coding circuit design; Fig. 9 Encoder PCB circuit diagram.

[0139] 1.3.2FPGA and interface module

[0140] FPGA and interface module are the brains of underwater communication module, and its main functions are interface communication, data processing and control. It can collect input network signal / LVDS signal / TTL signal, and transmit it to the transmitter after encoding, parallel-to-serial conversion and other processing. It can adjust the signal transmission power of the transmitter, the bias high voltage of the PMT in the receiver, the signal amplification gain and the shaping threshold to meet the requirements of different underwater communication distances and ensure the reliability of communication.

[0141] Fig.10 Physical picture of FPGA and interface module.

[0142] 1.3.3 Transmitter Design

[0143] The main function of the transmitter is to convert the electrical signals from the FPGA and interface module into optical signals in a timely and accurate manner and send them out. It is mainly composed of a modulation drive circuit, a power drive circuit and a blue-green laser. The modulation drive circuit uses intensity modulation to convert the input electrical signal into a drive signal for modulating the blue-green laser. The power drive circuit can regulate the optical power of the laser at a maximum rate of 20Mbps, monitor its own working status and laser temperature and other parameters, and transmit the information back to the host computer.

[0144] Fig.11 Transmitter block diagram; Fig.12 Functional block diagram of driving circuit; Fig.13 Transmitter circuit diagram

[0145] Fig.14 Transmitter PCB circuit diagram.

[0146] 1.3.4 Receiver Design

[0147] The main function of the receiver is to restore the optical signal detected by the receiving end to the original electrical signal in a timely and accurate manner. It is mainly composed of an optical receiving system, a photomultiplier tube (PMT), a high-voltage control circuit, a multi-stage amplifier circuit, a shaping circuit, and a decoder. The photomultiplier tube converts the received optical signal into an electrical signal and amplifies it through a multi-stage amplifier circuit. After filtering and shaping, it is transmitted to the FPGA. The multi-stage amplifier circuit has a large dynamic gain range of 80-120dB, which can dynamically amplify the weak signal received by the PMT and expand the underwater communication distance. The shaping circuit is used to digitize analog signals with slow edge changes and jitter, so that the output signal can be processed by subsequent digital circuits and reduce the bit error rate of communication. The threshold setting circuit can eliminate the influence of the input analog signal amplitude change on the shaping circuit and ensure the reliability of communication.

[0148] Fig.15 Receiver block diagram; Fig.16 Receiver circuit schematic diagram; Fig.17 Receiver PCB circuit diagram.

[0149] 1.2.5 Decoding circuit design

[0150] The decoder can decode the audio and video data output by the FPGA into original audio and video signals, and perform synchronization and buffering to achieve audio and video playback.

[0151] Fig.18 Decoder block diagram; Fig.19 Decoder circuit design schematic diagram; Fig. 20 Decoder PCB circuit diagram.

[0152] 1.4 Design of underwater speckle recognition and alignment algorithm based on YoLoV5

[0153] The YoLoV5 model uses the Pytorch framework, and the model training is very fast. It can directly perform effective reasoning on single images, batch images, videos, and even webcam port inputs. In addition, the detection speed of YoLoV5 is very fast, which can well meet the real-time detection requirements while ensuring the accuracy of the system. Based on YoLoV5, our team developed an underwater speckle recognition and alignment algorithm design, which can output spot azimuth information in real time to assist communication terminals in achieving semi-active alignment. The simulation diagram of the automatic alignment system is shown in the figure below: Fig.21 Shown

[0154] The network structure of Yolov5 is divided into four parts: input, Backbone, Neck and Prediction.

[0155] (1) Input: Mosaic data enhancement, adaptive anchor box calculation, adaptive image scaling

[0156] (2) Backbone: Focus structure, CSP structure

[0157] (3) Neck: FPN+PAN structure

[0158] (4)Prediction: GIOU_Loss

[0159] Fig. 22 This is the algorithm performance test chart conducted by the Yolov5 author on the COCO dataset:

[0160] Fig.23 Performance comparison of various algorithms

[0161] Yolov5s network is the smallest, has the lowest speed, and has the lowest AP accuracy. However, if the detection is mainly for large targets and speed is pursued, Yolov5s network is more suitable. On this basis, the other three networks continue to deepen and widen the network, and the AP accuracy continues to improve, but the speed consumption is also increasing. Since the detection speed of yolov5s is very fast, it can well meet the real-time detection requirements while ensuring that the system has a certain detection accuracy. Therefore, the system selects yolov5s as the algorithm for moving target recognition.

[0162] Module composition and workflow Fig.23 As shown:

[0163] Marine information transmission needs to go through two media, water and air. An marine information transmission network is composed of underwater platforms (including underwater equipment, underwater cruisers, etc.), surface floating gateways (including ships and buoys), aerial nodes (including satellites and helicopters or drones), etc. To ensure communication stability, underwater platforms and aerial nodes can communicate through two links.

[0164] The first is that the aerial node and the floating gateway on the water surface transmit signals through radio frequency or optical signals. The images, sounds and other signals captured by the aerial node can be transmitted to the floating gateway on the water surface. The floating gateway on the water surface transmits the images, sounds and other signals to the underwater platform through the optical communication terminal, and finally realizes the wireless transmission of aerial signals to the bottom of the water. There are two communication modes between the aerial node and the floating gateway on the water surface in this link:

[0165] (1) Use wireless AP bridge communication to transmit data through wireless signals. There is no need to deploy a complex wired network. The network deployment is more flexible and convenient. It is suitable for crossing obstacles, complex geographical environments or temporary network connections. This communication method is suitable for airspace communication, with a communication distance greater than 500M and a rate greater than 1M.

[0166] (2) When the radio interference is large and the wireless AP bridge cannot be used, laser communication is used. Laser communication has strong anti-interference ability against electromagnetic interference and signal attenuation. The laser beam is not easily interfered by external electromagnetic waves during transmission, and can maintain high signal quality and stability. This communication method is suitable for airspace communication and short-distance cross-domain communication. The airspace communication distance is greater than 500m and the rate is greater than 1M.

[0167] The second is that the aerial node directly transmits images, sounds and other signals to the underwater platform through the optical communication terminal. This link is a cross-domain direct communication. The wireless AP bridge cannot achieve cross-domain communication, so the link can only be achieved using laser communication. The cross-domain communication distance is greater than 40m and the rate is greater than 1M.

[0168] This invention proposes a relay-type cross-domain communication solution based on the combination of radio and high-power LD / LED underwater wireless optical communication. On the basis of traditional wireless optical communication transceiver, a large-bandwidth, high-confidentiality radio-optical transmission conversion module is independently designed using large-scale MIMO technology, DMD structured light modulation and AWI signal modulation and demodulation technology; a high-precision synchronization control module is designed using the GD32 chip to ensure low-latency, low-error relay-type cross-domain information interconnection. At the same time, a high-sensitivity area array CCD detector is used to sense the spot position, and an underwater speckle recognition and alignment algorithm is developed based on YoLoV8, and azimuth information is output to assist semi-active alignment, thereby realizing low-cost, low-latency, high-speed, long-distance, large-capacity, all-weather cross-domain communication in complex waters. This work has the following functions:

[0169] 1. The overall prototype has an atmospheric distance of 3000m, a communication distance of 80m under 0.3db / m attenuation water quality, a transmission rate of 3-5Mbps, and a bit error rate of less than 7.1×10-4;

[0170] 2. The prototype is small in size, low in energy consumption, supports mounting on various above-water / underwater unmanned platforms and fixed stations, and can assist in achieving semi-active spot alignment;

[0171] 3. The prototype has the ability to communicate across domains under level 3 sea conditions, strong turbulence and noisy light conditions;

[0172] Relevant evidence of the technical effects achieved by the embodiments of the present invention.

[0173] In order to test the cross-domain communication performance of the system, a drone is used outdoors as an aerial information transmitter to transmit the camera's video stream in real time; the underwater optical communication module is made watertight, and an underwater optical communication link is built in the indoor pool; the received video stream is displayed in real time on the host computer. The indoor pool is 24 meters long, 1.7 meters wide, and 1 meter deep. At the same time, a complex hydrological environment with visible light interference, turbulence interference, and bubble interference is constructed to test the system's anti-interference communication performance. The experimental scene is set up as follows: Fig.24 As shown in the figure, the actual picture of the aerial node is as follows Fig.25 As shown in Figure 2, the underwater optical communication link is Fig.26 To increase the underwater transmission distance, two plane reflectors are placed in the water to extend the underwater link length. The experimental results show that when the air node is 500 meters away from the pool and the underwater link is up to 50 meters, high-definition video can still be transmitted in real time, with a communication rate of 10Mbps and a bit error rate of less than 1x10 -7 , Fig.28 The host computer receives the video stream of the aerial node in real time.

[0174] 1. Visible light interference experiment

[0175] In order to verify the interference of visible light on underwater optical communication, a high-power LED white light was placed above the pool to simulate visible light, irradiating the transmitter, optical path, and receiver respectively. The experimental scene is as follows: Fig. 27 As shown. Observe the video transmission and measure the communication rate and bit error rate. The results show that the information transmission is normal, the communication rate and bit error rate are basically unchanged, indicating that the system has good anti-visible light interference ability.

[0176] 2. Turbulence interference experiment

[0177] In order to verify the anti-interference ability of the system to water turbulence and waves, a propeller is used near the optical path to stir the water to generate waves and turbulence. Fig.29 As shown in the figure, the experimental scenario is as follows Fig.30 The information transmission rate and bit error rate were measured, and the results showed that the bit error rate increased to 3.12x10 -5 , but video transmission is basically unaffected.

[0178] 3. Bubble interference experiment

[0179] There are many tiny bubbles in seawater, which will increase the attenuation and scattering of light, thus affecting the distance and bit error rate of optical communication. To verify the system's ability to resist bubble interference, bubble stones are placed at the bottom of the pool and inflated with an air pump to generate a large number of bubble groups. The experimental scene is as follows: Fig.31 The experimental results show that under the interference of the bubble group, the maximum bit error rate can reach 6.47x10 -4 .

[0180] In order to test the engineering application value of this system, our team conducted an air-underwater cross-domain communication experiment in an outdoor lake. In this experiment, two ships were equipped with underwater transmitters and underwater receivers to dive to a depth of 3m underwater. The underwater receiver ship also carried a relay device to simulate a buoy. The experimental site is shown in the figure below. Fig.32 As shown. When the aerial platform height is 500m and the underwater terminal distance is 80m, the received image is still clear, the real-time performance is high, and the communication rate reaches 5Mbps. The water quality of the on-site experiment was tested and the transmission loss was 0.3dB / m.

[0181] Table 2 Summary of laser communication bit error rates at different distances

[0182]

[0183] The maximum air-water cross-domain communication distance experiment and anti-interference experiment under different hydrological conditions were carried out in the laboratory pool and the outdoor lake. The results show that the system has strong anti-visible light and turbulence interference capabilities; when the air transmission distance is 500m and the underwater transmission distance is 80m, the communication rate can reach 5Mpbs and the bit error rate does not exceed 7.1×10-4. The experiment verifies that this work has low latency, high rate, long distance, large capacity and high reliability communication capabilities, and has high engineering application value.

[0184] It should be noted that the embodiments of the present invention can be implemented by hardware, software, or a combination of software and hardware. The hardware part can be implemented using dedicated logic; the software part can be stored in a memory and executed by an appropriate instruction execution system, such as a microprocessor or dedicated design hardware. It can be understood by a person of ordinary skill in the art that the above-mentioned devices and methods can be implemented using computer executable instructions and / or contained in a processor control code, such as a carrier medium such as a disk, CD or DVD-ROM, a programmable memory such as a read-only memory (firmware), or a data carrier such as an optical or electronic signal carrier. Such code is provided on the carrier medium. The device and its modules of the present invention can be implemented by hardware circuits such as very large-scale integrated circuits or gate arrays, semiconductors such as logic chips, transistors, etc., or programmable hardware devices such as field programmable gate arrays, programmable logic devices, etc., can also be implemented by software executed by various types of processors, and can also be implemented by a combination of the above-mentioned hardware circuits and software, such as firmware.

[0185] The above description is only a specific implementation mode of the present invention, but the protection scope of the present invention is not limited thereto. Any modifications, equivalent substitutions and improvements made by any technician familiar with the technical field within the technical scope disclosed by the present invention and within the spirit and principle of the present invention should be covered by the protection scope of the present invention.

Claims

1. A cross-domain relay radio frequency-laser communication module, characterized in that: The cross-domain relay radio frequency-laser communication module includes: Node building module, relay module, synchronization control module, modulation and demodulation module, situation awareness module; The node construction module is connected to the relay module and is used to construct underwater signal nodes using multi-mode blue-green laser communication technology, and to construct an overwater cellular network and aerial signal nodes using 5G radio frequency communication technology; The relay module is connected to the node building module and the synchronization control module, and is used to use the offshore buoy / submersible buoy to perform electrical-optical signal conversion relay, and the air-sea joint networking generates cross-domain heterogeneous radio frequency-laser communication; The synchronous control module is connected with the relay module, the modulation and demodulation module, and the situation awareness module to The modulation and demodulation module is connected with the synchronization control module and the situation awareness module, and is used to design a high-precision synchronization control module using an FPGA chip to achieve ms-level high-precision delay control for multi-source signals in the system; The situation awareness module is connected with the synchronization control module and the modulation and demodulation module, and is used to design a wide-angle spot positioning and situation awareness system based on YoLoV5 to quickly align the optical communication between the underwater unmanned mobile platform and the fixed station under high sea conditions.

2. The cross-domain relay RF-laser communication module according to claim 1, characterized in that: The node building blocks: It consists of an atmospheric 5G cellular communication network, a surface buoy radio frequency-laser communication conversion system, and an underwater laser communication system.

3. The cross-domain relay RF-laser communication module according to claim 2, characterized in that: The atmospheric 5G cellular communication network is composed of existing airborne / land-based / space-based 5G network systems.

4. The cross-domain relay RF-laser communication module according to claim 2, characterized in that: The sea surface buoy radio frequency-laser communication conversion system includes radio frequency 5G receiving and processing, information demodulation, communication laser emission module, and buoy carrier.

5. The cross-domain relay RF-laser communication module according to claim 2, characterized in that: The underwater laser communication system comprises an Ethernet module, an FPGA information processing module, a photoelectric conversion module, and a signal amplification processing module.

6. The cross-domain relay RF-laser communication module according to claim 1, characterized in that: The relay module is a hardware device with a transmitter, a receiver, an antenna and an interface with a wireless terminal; as a bridging wireless base station, the AP is installed on the floating gateway; the transmitter and the receiver are used to establish a communication connection with the mobile terminal; by using electromagnetic waves to transmit and receive data in the air, the wireless local area network uses electromagnetic waves to send and receive data in the air without the need for cable media; the AP is connected to the underwater optical communication network to build a local area network of wireless mobile terminal-AP-underwater platform.

7. A communication method for a cross-domain relay type RF-laser communication module implementing the cross-domain relay type RF-laser communication module as claimed in any one of claims 1 to 6, characterized in that: include: Step 1: Use the node building module to build underwater signal nodes using multi-mode blue-green laser communication technology, and use 5G radio frequency communication technology to build an overwater cellular network and build air signal nodes; Step 2: Use the offshore buoy / submersible buoy to perform electrical-optical signal conversion and relay through the relay module, and generate cross-domain heterogeneous RF-laser communication through air-sea joint networking; Step 3, a high-precision synchronization control module is designed by using an FPGA chip through a synchronization control module to achieve ms-level high-precision delay control for multi-source signals of the system; Step 4, using the MIMO technology, DMD structured light modulation and AWI signal modulation and demodulation technology in parallel link coordination through the modulation and demodulation module to synchronously modulate and demodulate the radio and optical signals; Step 5: A wide-angle spot positioning and situation awareness system was designed based on YoLoV5 through the situation awareness module to quickly align the optical communication between the underwater unmanned mobile platform and the fixed station under high sea conditions.

8. A computer device, characterized in that: The computer device includes a memory and a processor, the memory stores a computer program, and when the computer program is executed by the processor, the processor executes the steps of the cross-domain relay RF-laser communication module communication method as described in claim 7.

9. A computer-readable storage medium storing a computer program. When the computer program is executed by a processor, the processor executes the steps of the cross-domain relay RF-laser communication module communication method as described in claim 7.

10. An information data processing terminal, characterized in that: The information data processing terminal is used to implement the cross-domain relay RF-laser communication module as described in any one of claims 1-6.

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