Intelligent Unmanned Ship Channel Measurement System and Method Based on Marine Environment Information Sensing

Abstract

The present invention relates to an intelligent unmanned ship-to-unmanned ship channel measurement system and method based on marine environment information perception, including: a transmitting end and a receiving end, wherein the receiving end includes an environment information perception device; the environment information perception device collects environment information, adds a timestamp and sends it to the receiving end; the transmitting end and the receiving end perform the transmission of communication information, and add a timestamp to the communication information during the transmission process; the environment information and the communication information are aligned through the timestamp to obtain the influence of the environment information on the channel at each moment, so as to realize the measurement of the unmanned ship-to-unmanned ship channel at sea. The present invention synchronizes the communication information and the environment information by using the timestamp. By using the timestamp, the error in studying the influence of the marine environment on communication can be reduced, and the accuracy of the alignment between the environment information and the communication information can be increased, avoiding the complexity caused by rough measurement.

Description

Technical Field

[0001] The present invention relates to an intelligent unmanned ship-to-ship channel measurement system and method based on marine environmental information perception, and belongs to the technical field of marine unmanned ship communication channel measurement. Background Art

[0002] With the advent of the 6G era, communication has blossomed in various fields. The marine scenario is very important and difficult to explore in communication. Due to the evaporation duct over the sea and the wave motion on the sea surface, marine communication is full of uncertain factors. Since most of the current marine channel measurement devices do not consider the influence of the environment, there are also certain deficiencies in the analysis of channel characteristics. In order to better explore the influence of marine environmental information on the communication channel and better model the marine communication channel model, there is an urgent need for a ship-to-ship channel measurement device that can incorporate marine environmental information.

[0003] Wireless communication systems are very important for unmanned system clusters. Flexible, high-speed, and reliable communication networks are required for collaborative work between clusters. Due to the complexity of the marine environment and the increase in transmission distance, it is very difficult for unmanned marine systems to communicate with each other. Therefore, solving the problem of marine communication is of crucial importance. In terms of marine channel measurement, domestic and foreign teams have carried out a series of related work. The Wang Wei team measured the 5.2 GHz band marine ship-to-ship wireless channel in 2017 and analyzed the delay power spectrum and delay Doppler spectrum. The José team measured the channel between an unmanned aerial vehicle and an unmanned ship in 2022, established the FE2R and CE2R models of RSL, analyzed the autocorrelation characteristics of the shadow, and finally analyzed the fitting situation of the multi-path fading value with a certain distribution.

[0004] However, there is little mention of the marine measurement system that combines environmental information. Environmental information is an indispensable part of the marine communication process, especially in the case of a pure marine environment. The Yang Hang team conducted millimeter-wave ship-to-shore channel measurements in 2022. This measurement activity combined environmental information, but the environmental information was collected every few hours. Although this simplified the measurement process, it could not be combined with the channel for real-time analysis. Therefore, it is necessary to design a ship-to-ship channel measurement device that can collect environmental information in real time. Some of the previous measurement devices did not consider environmental information, and some had insufficient measurement accuracy, making it impossible to analyze the channel characteristics combined with environmental information, and thus difficult to characterize the influence of environmental factors such as waveguides and sea waves on the channel. Ship-to-ship communication of unmanned ships is an important part of marine communication. Seaway transportation and maritime operations require fast communication. Marine communication is also an essential part of the current 6G air-space-ground-sea communication sensing integration. Through intelligent ship-to-ship channel measurement based on marine environmental information perception, accurate marine environment and channel information can be obtained, which is crucial for channel characteristic analysis and modeling. Summary of the Invention

[0005] In view of the deficiencies of the prior art, the present invention proposes an intelligent ship-to-ship channel measurement system based on marine environmental information perception;

[0006] In view of the deficiency that the existing marine ship-to-ship communication channel measurement device cannot be combined with environmental information, the present invention aims to propose a new environmental information perception channel measurement system applied to unmanned ship-to-ship in the sea, which is used to measure environmental information and channel information, facilitate subsequent data analysis, and thus can better explore the channel characteristics of the marine scenario and conduct channel modeling.

[0007] The present invention also proposes an intelligent ship-to-ship channel measurement method based on marine environmental information perception.

[0008] Term Explanation:

[0009] VST (Vector Signal Transceiver): The Chinese name of VST is PXI Vector Signal Transceiver, which combines an RF and baseband vector signal analyzer and generator, a user-programmable FPGA, and high-speed serial and parallel digital interfaces, and can perform real-time signal processing and control from the baseband to millimeter waves.

[0010] LabVIEW: LabVIEW is a graphical programming environment and development platform developed by National Instruments (NI) in the United States. It is an engineering application software for data acquisition, instrument control, measurement, and automation. LabVIEW is well-known for its unique visual programming method. Users can build programs by dragging and dropping graphical components (called virtual instruments or VIs, Virtual Instrument) without writing traditional text code.

[0011] The technical solution of the present invention is as follows:

[0012] An intelligent unmanned ship channel measurement system for unmanned ships based on marine environment information perception, including:

[0013] A transmitting end and a receiving end, and the receiving end includes an environment information perception device;

[0014] The environment information perception device collects environment information, adds a timestamp and sends it to the receiving end;

[0015] The transmitting end and the receiving end perform the transmission of communication information, and add a timestamp to the communication information during the transmission process;

[0016] Align the environment information and the communication information through the timestamp, obtain the influence of the environment information on the channel at each moment, and realize the measurement of the unmanned ship channel for unmanned ships at sea.

[0017] Preferably according to the present invention, the environment information perception device includes an FPGA development board, a temperature and humidity detection module, a wind speed and direction detection module, a wave height detection module, and a Beidou-3 module;

[0018] The FPGA development board is used to realize the overall control of the environment information perception device;

[0019] The temperature and humidity detection module is used to realize the detection of the ocean temperature and humidity;

[0020] The wind speed and direction detection module is used to detect the wind speed and direction, including the angle of the wind direction and the magnitude of the wind speed;

[0021] The wave height detection module is used to measure the height of the ocean surface waves;

[0022] The Beidou-3 module is used to attach a timestamp and location information to the environment information for subsequent data processing; the environment information includes the ocean temperature and humidity, as well as the angle of the wind direction and the magnitude of the wind speed;

[0023] After the environmental information perception device is started, the FPGA development board controls the temperature and humidity detection module, the wind speed and direction detection module, and the wave height detection module to work, continuously obtains environmental information, and sends the environmental information to the FPGA development board; after receiving the environmental information, the FPGA development board adds a timestamp and location information to the environmental information by the Beidou-3 module; the FPGA development board sends the environmental information with the timestamp and location information to the receiving end.

[0024] Further preferably, the model of the temperature and humidity detection module is DHT22.

[0025] The wind speed and direction detection module uses an integrated wind direction and speed sensor.

[0026] The Beidou-3 module uses a Beidou-3 data transmission terminal.

[0027] According to the preference of the present invention, the sending end includes a first VST, a first omnidirectional antenna, a first display, and a first keyboard and mouse;

[0028] The first VST includes a first VST radio frequency sub-board, a first Beidou module, and a first internal processor; the first VST radio frequency sub-board is used to modulate the PN pseudo-random sequence to make the signal continuously transmitted, the first Beidou module adds a timestamp and location information to the transmitted signal, and the first internal processor controls the transmission of the transmitted signal;

[0029] The first omnidirectional antenna is used for: transmitting the transmitted signal; in the sending end, the transmitted signal is a PN pseudo-random sequence, which is constructed into a signal flow graph for transmission, after being modulated by the first VST radio frequency sub-board, adding a timestamp and location information through the first Beidou module, and sending the signal through the first omnidirectional antenna.

[0030] Further preferably, both the first omnidirectional antenna and the second omnidirectional antenna are discone antennas.

[0031] According to the preference of the present invention, the receiving end further includes a second VST, a first processor, a second omnidirectional antenna, a second display, and a second keyboard and mouse;

[0032] The second VST includes a second VST radio frequency sub-board, a second Beidou module, and a second internal processor; the second VST radio frequency sub-board is used to demodulate the communication signal; the second internal processor performs data storage and control, and the second Beidou module is used to add a timestamp and location information to the received signal;

[0033] The first processor is used to save the communication information and environmental information and perform subsequent processing;

[0034] The second omnidirectional antenna is used to receive the communication signal.

[0035] Further preferably, the receiving end is placed on a receiving unmanned ship. The environmental information reception and communication information reception are carried out separately, and finally combined through timestamps. The working process of the receiving end is as follows:

[0036] The communication information reception process includes: after the second omnidirectional antenna receives the communication signal, it is transmitted to the second VST radio frequency sub-board for demodulation. The second Beidou module adds timestamps and position information to the received signal, and saves the communication information in the second VST;

[0037] The environmental information reception process includes: the environmental information is transmitted by the FPGA development board to the first processor through a transmission line.

[0038] After the information reception is completed, the received communication information is transferred to the first processor, aligned according to the timestamps in the communication information and environmental information, and the communication channel conditions at each moment are analyzed to explore the impact of environmental changes on the channel.

[0039] The method for measuring the channel between unmanned ships by an intelligent unmanned ship based on marine environmental information perception is realized through an intelligent unmanned ship channel measurement system based on marine environmental information perception, including:

[0040] Collect environmental information, add timestamps and send it to the receiving end;

[0041] Transmit communication information, and add timestamps to the communication information during the transmission process;

[0042] Align the environmental information and communication information through timestamps, obtain the impact of the environmental information at each moment on the channel, and realize the measurement of the channel between unmanned ships at sea.

[0043] According to the preference of the present invention, collecting environmental information, adding timestamps and sending it to the communication end; includes:

[0044] Turn on the FPGA development board;

[0045] Continuously receive environmental information and send it to the FPGA development board;

[0046] The Beidou-3 module adds timestamps and position information to the environmental information;

[0047] The FPGA development board sends the environmental information with time information and position information to the receiving end.

[0048] According to the preference of the present invention, transmitting communication information, and adding timestamps to the communication information during the transmission process; includes:

[0049] The sending of communication information includes:

[0050] Open LabVIEW through the first internal processor, select the real and imaginary parts of the PN pseudo-random sequence to be sent, set the center frequency, bandwidth, sampling rate, transmission frequency, and transmission port, and send the signal.

[0051] The first VST radio frequency sub-board works, modulates the signal, and adds timestamp and position information by the first Beidou module.

[0052] Send the signal through the first omnidirectional antenna.

[0053] Receiving communication information, including:

[0054] Open LabVIEW through the first processor, set the received center frequency, bandwidth, receiving time, and receiving port, and perform reception.

[0055] After the second omnidirectional antenna receives the communication signal sent by the transmitting end, it transmits it to the second VST radio frequency sub-board.

[0056] The second VST radio frequency sub-board demodulates the communication signal, and the second Beidou module adds timestamp and position information to the received signal.

[0057] The second VST radio frequency sub-board saves the demodulated communication signal in the stream disk of the second VST.

[0058] Copy the received communication signal to the first processor for subsequent processing.

[0059] Preferably according to the present invention, align the environmental information and communication information through timestamps, obtain the influence of the environmental information on the channel at each moment, and realize the channel measurement of unmanned ships at sea; including:

[0060] After the measurement work is completed, both the environmental information and the communication information carry timestamps. After finding the same time scale, intercept the data with inconsistent time and then perform data analysis.

[0061] Analyze the channel characteristics, obtain the propagation characteristics of the channel in the marine scenario, and establish a corresponding channel model according to the characteristics; specifically include: obtain the channel impulse response (Channel Impulse Response, CIR) of the data, and analyze the relevant characteristics according to the channel impulse response.

[0062] Further preferably, the channel impulse response h(t,τ) is shown in Equation (1):

[0063]

[0064] In Equation (1), τ i (t), α i (t) and φ i(t) represents the delay, amplitude, and phase of the i-th path between the transceiver, L(t) represents the total number of paths, t represents the current time, τ represents the delay, and j represents the imaginary part;

[0065] Further preferably, from the obtained channel impulse response, the power delay profile (PDPs), power dispersion diagram, root-mean-square delay spread (RMSDS), and K-factor of the channel are obtained, including:

[0066] Taking the modulus value of the channel impulse response at a moment and subtracting the gain of the transceiver to obtain the power delay spectrum Ψ(t,τ), as shown in Equation (2):

[0067]

[0068] In Equation (2), L(t) is the total number of paths at this moment, τ i is the delay of the path, δ() is the impulse function, and |h(t,τ)| 2 is the modulus value of the impulse response;

[0069] The abscissa of the power delay spectrum is the delay, and the ordinate is the power; the power delay spectrum represents the changing trend of power with delay;

[0070] Superposing the power delay spectra at all moments to obtain the power chromatogram. The abscissa of the power chromatogram is the delay, the ordinate is the time, and the chromaticity is the power; observing the changes in delay and power and the generation and extinction of clusters with the change of the distance between the transceiver through the power chromatogram;

[0071] The root-mean-square delay spread is obtained by taking the square root of the second-order central moment; the formula for obtaining the root-mean-square delay spread σ τ is shown in Equation (3):

[0072]

[0073] In Equation (3), τ i and P(τ i ) are the delay and power of the i-th multipath component (MPC) respectively, and L represents the total number of paths; taking the cumulative distribution function of the root-mean-square delay at all snapshots to study the small-scale characteristics of the channel;

[0074] The formula for obtaining the K-factor KF[dB] is shown in Equation (4):

[0075]

[0076] In Equation (4), P LOSRepresents the power of the direct path, P i Represents the power of the i-th path; The K-factor is used to describe the fading depth or severity of the signal in the channel; Taking the cumulative distribution function of the K-factor for all snapshots studies the small-scale characteristics of the channel.

[0077] The beneficial effects of the present invention are as follows:

[0078] 1. By utilizing the programmability, parallelism, low latency, power efficiency, flexibility, the ability as a hardware accelerator, and reliability of FPGA, the present invention designs an environmental information perception device for collecting environmental information.

[0079] 2. The present invention uses the Beidou-3 data transmission terminal to add timestamp and location information to the environmental information, enabling long-distance transmission of signals, overcoming the problem that 5G and Wifi cannot perform long-distance transmission, and playing an important role in subsequent research on ocean channel expansion.

[0080] 3. The present invention designs an intelligent unmanned ship for an unmanned ship channel measurement system to explore ocean communication.

[0081] 4. The present invention designs a channel measurement system that can be combined with environmental information. By using timestamps to synchronize communication information and environmental information, it is possible to accurately understand the order and time interval of information when analyzing data, help different devices achieve synchronization, ensure that the recorded information can be aligned. Using this timestamp can reduce the error in studying the impact of the ocean environment on communication, and can also increase the accuracy of alignment between environmental information and communication information, avoiding the complexity caused by rough measurement. Adding environmental information to the data processing of channel measurement can better analyze relevant characteristics. Description of the Drawings

[0082] Figure 1 Is a schematic structural diagram of the environmental information perception device;

[0083] Figure 2 Is a schematic structural diagram of the sending end;

[0084] Figure 3 Is a schematic structural diagram of the receiving end;

[0085] Figure 4 Is a schematic structural diagram of an intelligent unmanned ship to unmanned ship channel measurement system based on ocean environmental information perception;

[0086] Figure 5 Is a schematic diagram of the sending end working process;

[0087] Figure 6 Is a schematic diagram of the receiving end working process. Detailed Embodiments

[0088] The present invention will be further defined below in conjunction with the accompanying drawings of the specification and embodiments, but not limited thereto.

[0089] Embodiment 1

[0090] An intelligent unmanned ship-to-unmanned ship channel measurement system based on marine environmental information perception, as Figure 4 shown, includes:

[0091] A transmitting end and a receiving end, and the receiving end includes an environmental information perception device;

[0092] The environmental information perception device collects environmental information, adds a timestamp and sends it to the receiving end;

[0093] The transmitting end and the receiving end perform the transmission of communication information, and add a timestamp to the communication information during the transmission process;

[0094] Align the environmental information and the communication information through timestamps, obtain the influence of the environmental information on the channel at each moment, and realize the measurement of the unmanned ship-to-unmanned ship channel. The present invention is applicable to the channel measurement of typical marine scenarios.

[0095] Embodiment 2

[0096] The intelligent unmanned ship-to-unmanned ship channel measurement system based on marine environmental information perception according to Embodiment 1 is different in that:

[0097] As Figure 1 shown, the environmental information perception device includes an FPGA development board, a temperature and humidity detection module, a wind speed and direction detection module, a wave height detection module and a Beidou-3 module;

[0098] The FPGA development board is used to realize the overall control of the environmental information perception device; the FPGA development board uses the XILINX ZYNQ-7000 FPGA development board, which has the advantages of inheritance, flexibility, high performance, low power consumption, ease of use, etc.;

[0099] The temperature and humidity detection module is used to realize the detection of the temperature and humidity of the ocean;

[0100] The wind speed and direction detection module is used to detect the wind speed and direction, provide comprehensive information about the wind, including the angle of the wind direction and the magnitude of the wind speed; realize the detection of the wind speed and direction on the ocean surface;

[0101] The wave height detection module is used to measure the height of the waves on the ocean surface;

[0102] The Beidou-3 module is used to attach a timestamp and location information to the environmental information for subsequent data processing; the environmental information includes the temperature and humidity of the ocean, as well as the angle of the wind direction and the magnitude of the wind speed;

[0103] After the environmental information perception device is started, the FPGA development board controls the temperature and humidity detection module, the wind speed and direction detection module, and the wave height detection module to work, continuously obtains environmental information, and sends the environmental information to the FPGA development board; after receiving the environmental information, the FPGA development board adds a timestamp and location information to the environmental information by the Beidou-3 module; the FPGA development board sends the environmental information with timestamp and location information to the receiving end.

[0104] The model of the temperature and humidity detection module is DHT22. The temperature and humidity detection module has high temperature and humidity measurement accuracy, can provide accurate environmental data, and can realize the detection of ocean temperature and humidity.

[0105] The wind speed and direction detection module uses an integrated wind direction and speed sensor. The sensor adopts an integrated design.

[0106] The Beidou-3 module uses a Beidou-3 data transmission terminal. It is used to attach a timestamp and location information to the environmental information for subsequent data processing. The short message function of the Beidou-3 module can also transmit the information over a long distance to the shore. The short message uses satellite communication mode, which can overcome the problem that Wifi or 5G cannot send information due to too long distance.

[0107] As Figure 2 shown, the sending end includes a first VST, a first omnidirectional antenna, a first display, and a first keyboard and mouse;

[0108] The first VST includes a first VST radio frequency sub-board, a first Beidou module, and a first internal processor; for the first VST, there are two first VST radio frequency sub-boards inside the device, which can support simultaneous dual transmission and reception, with a maximum bandwidth of up to 1 GHz, and can cover the Sub 6 GHz band. After adding a spread spectrum module, it can measure higher frequency bands. The internal first VST radio frequency sub-board is used to modulate the PN pseudo-random sequence to make the signal continuously transmitted. The internal first Beidou module adds a timestamp and location information to the transmitted signal. The first VST also comes with a first internal processor. The first processor is embedded inside the chassis of the first VST and uses the Window system. The first internal processor controls the transmission of the transmitted signal;

[0109] The first omnidirectional antenna is used for: transmitting the transmitted signal; the first display and the first mouse and keyboard are used to operate the system.

[0110] As Figure 5As shown in the figure, in the transmitting end, the transmitted signal is a PN pseudo-random sequence, which is generated by Matlab. The PN pseudo-random sequence is transmitted with its real and imaginary parts respectively through the signal flow graph constructed by the software Labview of NI Corporation (parameters such as the transmitting center frequency, bandwidth, sampling rate, transmitting power, and transmitting port are set on Labview). After being modulated by the first VST radio frequency sub-board, the first Beidou module adds a timestamp and location information, and the signal is transmitted through the first omnidirectional antenna. The transmitting end is carried on an unmanned ship, and the entire device can be powered by the battery of the unmanned ship.

[0111] Both the first omnidirectional antenna and the second omnidirectional antenna are discone antennas. The frequency range supported by the discone antenna is 0.3 - 6 GHz;

[0112] The first VST and the second VST are channel measurement devices based on the VST (Vector Signal Transceiver) of NI (National Instruments) Corporation.

[0113] As Figure 3 shown, the receiving end further includes a second VST, a first processor, a second omnidirectional antenna, a second display, and a second keyboard and mouse;

[0114] The second VST includes a second VST radio frequency sub-board, a second Beidou module, and a second internal processor; the second VST radio frequency sub-board is used to demodulate the communication signal; the second internal processor saves and controls the data, and the second Beidou module is used to add a timestamp and location information to the received signal; this device can receive signals.

[0115] The first processor uses a self-assembled host, which saves and processes a large amount of data, is used to save communication information and environmental information, and performs subsequent processing;

[0116] The second omnidirectional antenna is used to receive communication signals. The second display and the second mouse and keyboard are used to operate the system.

[0117] Further preferably, the receiving end is placed on a receiving unmanned ship, and the environmental information reception and the communication information reception are carried out separately, and finally combined through the timestamp. As Figure 6 shown, the working process of the receiving end is as follows:

[0118] The communication information reception process includes: after the second omnidirectional antenna receives the communication signal, it is transmitted to the second VST radio frequency sub-board for demodulation. The second Beidou module adds a timestamp and location information to the received signal, and saves the communication information in the second VST;

[0119] The environmental information reception process includes: the environmental information is transmitted from the FPGA development board to the first processor through a transmission line.

[0120] After the information is received, the received communication information is transferred to the first processor, aligned according to the timestamps in the communication information and the environmental information, the communication channel conditions at each moment are analyzed, and the influence of environmental changes on the channel is explored. The receiving end is also powered by the unmanned ship.

[0121] The present invention constructs a channel measurement device based on the VST (Vector Signal Transceiver) of National Instruments (NI) and an environmental information perception device based on an FPGA (Field-Programmable Gate Array) development board. By the programmability, flexibility and other characteristics of the FPGA development board, each module is controlled to collect environmental data, add timestamps and send them to the communication end; the communication sending end and the receiving end perform the transmission of communication signals, and timestamps are also added to the signals during the transmission process. Finally, the environmental information and the communication information are aligned through timestamps to study the influence of the environmental information at each moment on the channel, so as to better understand the communication channel between unmanned ships at sea. The invention is applicable to channel measurement in typical marine scenarios.

[0122] The present invention uses the VST of NI to collect channel data. The VST is a high-performance instrument for testing and measuring wireless communication systems. The VST combines signal generation, signal acquisition and signal analysis functions in one, can achieve ultra-wideband coverage, has the advantages of flexible configuration, high performance, integrated design, programmability, real-time signal processing, etc., has rich programming interfaces and software development tools, supports various automated and custom test applications, and users can develop using popular programming languages such as LabVIEW and Python. Multiple VSTs are integrated together, which simplifies the measurement device and reduces the number of devices, which is very important for channel measurement. The VST is a powerful and flexible instrument, suitable for a wide range of wireless communication test and measurement applications, including system development, verification, debugging and performance evaluation. Therefore, the present invention designs a channel measurement device based on the VST.

[0123] Embodiment 3

[0124] The intelligent unmanned ship-to-unmanned ship channel measurement method based on marine environmental information perception is realized by the intelligent unmanned ship-to-unmanned ship channel measurement system described in Embodiment 1 or 2, and includes:

[0125] Collect environmental information, add timestamps and send them to the receiving end;

[0126] Perform the transmission of communication information, and add timestamps to the communication information during the transmission process;

[0127] Align the environmental information and communication information through timestamps, obtain the impact of the environmental information on the channel at each moment, and realize the measurement of the channel between unmanned ships at sea.

[0128] Collect environmental information, add timestamps and send it to the communication end; including:

[0129] The self-assembled host turns on the FPGA development board and runs the relevant programs;

[0130] Continuously receive environmental information and send it to the FPGA development board;

[0131] The Beidou-3 module adds timestamps and location information to the environmental information; the location information is the GPS coordinates at that location, the time information is the time at the current sampling moment, and the environmental information will be saved in the form of a file after collection. The time information and location information are saved simultaneously with the GPS coordinates and time information at that moment when the environmental information sensing end collects data each time, so as to realize the correspondence between the environmental information, location information, and time information.

[0132] The FPGA development board sends the environmental information with time information and location information to the receiving end.

[0133] Conduct the transmission of communication information, and add timestamps to the communication information during the transmission process; including:

[0134] The sending of communication information, including:

[0135] Through the first internal processor, open LabVIEW, select the real and imaginary parts of the PN pseudo-random sequence to be sent, set the center frequency, bandwidth, sampling rate, transmission frequency, and transmission port, and send the signal;

[0136] The PN (Pseudo-Noise) pseudo-random sequence is a sequence generated by a deterministic algorithm. It has pseudo-random properties, shows statistical characteristics similar to those of true random sequences, but is actually predictable. These sequences are used for coding, synchronization, and multiple access in communication systems, and are used for generating keys in the field of encryption. They are also applied to measurement and test fields such as radar signal processing and spectrum analysis.

[0137] The center frequency, bandwidth, sampling rate, transmission frequency, and transmission port are set through the LabVIEW software interface.

[0138] The first VST radio frequency sub-board works, modulates the signal, and the first Beidou module adds timestamps and location information;

[0139] Send the signal through the first omnidirectional antenna;

[0140] The receiving of communication information, including:

[0141] Open LabVIEW through the first processor, set the center frequency, bandwidth, reception time, and reception port for reception.

[0142] After the second omnidirectional antenna receives the communication signal sent by the transmitting end, it transmits the signal to the second VST radio frequency sub-board.

[0143] The second VST radio frequency sub-board demodulates the communication signal, and the second Beidou module adds timestamp and position information to the received signal.

[0144] The second VST radio frequency sub-board saves the demodulated communication signal in the stream disk of the second VST.

[0145] Copy the received communication signal to the first processor for subsequent processing.

[0146] Align the environmental information and communication information through timestamps, obtain the impact of the environmental information on the channel at each moment, and realize the channel measurement of unmanned surface vessels; including:

[0147] After the measurement is completed, both the environmental information and the communication information carry timestamps. After finding the same time scale, intercept the data with inconsistent times and then perform data analysis.

[0148] Conduct an analysis of the channel characteristics, obtain the propagation characteristics of the channel in the ocean scenario, and establish a corresponding channel model according to the characteristics; specifically including: obtaining the channel impulse response (Channel Impulse Response, CIR) of the data, and analyzing relevant characteristics based on the channel impulse response.

[0149] The channel impulse response h(t,τ) is shown in Equation (1):

[0150]

[0151] In Equation (1), τ i (t), α i (t) and φ i (t) represent the delay, amplitude, and phase of the i-th path between the transmitter and the receiver. L(t) represents the total number of paths, t represents the current moment, τ represents the delay, and j represents the imaginary part.

[0152] Through the obtained channel impulse response, obtain the power delay profile (Power Delay Profile, PDPs), power dispersion diagram, root-mean-square delay spread (Root-mean-square Delay Spread, RMSDS), and K-factor of the channel; including:

[0153] The power delay profile Ψ(t,τ) is obtained by taking the modulus of the channel impulse response at a certain moment and subtracting the gains of the transmitter and receiver, as shown in Equation (2):

[0154]

[0155] In Equation (2), L(t) is the total number of paths at this moment, τ i is the delay of the path, δ() is the impulse function, and |h(t,τ)| 2 is the modulus of the impulse response;

[0156] The abscissa of the power delay profile is the delay, and the ordinate is the power; the power delay profile represents the changing trend of power with delay;

[0157] The power delay profiles at all moments are superimposed to obtain the power chromagram. The abscissa of the power chromagram is the delay, the ordinate is the time, and the chroma is the power; the changes in the delay and power generated with the change of the distance between the transmitter and receiver and the birth and death of clusters are observed through the power chromagram;

[0158] The root mean square delay spread is obtained by taking the square root of the second-order central moment; the formula for obtaining the root mean square delay spread σ τ is shown in Equation (3):

[0159]

[0160] In Equation (3), τ i and P(τ i ) are the delay and power of the i-th multipath component (MPC) respectively, and L represents the total number of paths; the root mean square delay is a statistical indicator used to describe the delay stability, which can help evaluate the delay performance in the signal transmission or processing process. Taking the cumulative distribution function of the root mean square delay at all snapshots studies the small-scale characteristics of the channel;

[0161] The formula for obtaining the K factor KF[dB] is shown in Equation (4):

[0162]

[0163] In Equation (4), P LOS represents the power of the direct path, and P i represents the power of the i-th path; the K factor is used to describe the fading depth or severity of the signal in the channel; taking the cumulative distribution function of the K factor at all snapshots studies the small-scale characteristics of the channel;

[0164] Channel measurement activities can be designed according to one's own needs, and can be measured and compared in different ways such as different speeds, different trajectories, different frequency bands and bandwidths, different accelerations, etc. The channel characteristics are obtained using the above formula for comparison, so as to analyze the changes in channel characteristics under different motion scenarios.

[0165] For the information measured by the environmental perception end, the horizontal axis is time and the vertical axis is the value of each piece of information. Since both communication information and environmental information carry timestamps, aligning the time axes can synchronize all information, thus enabling better data analysis.

Claims

1. An intelligent unmanned ship channel measurement system based on marine environment information perception, characterized in that, Including: A sending end and a receiving end, where the receiving end includes an environmental information sensing device; The environmental information sensing device collects environmental information, adds a timestamp and sends it to the receiving end; The sending end and the receiving end transmit communication information, and add a timestamp to the communication information during the transmission process; Align the environmental information and the communication information through the timestamp, obtain the influence of the environmental information on the channel at each moment, and realize the channel measurement of the unmanned ship at sea; The environmental information sensing device includes an FPGA development board, a temperature and humidity detection module, a wind speed and direction detection module, a wave height detection module and a Beidou-3 module; The FPGA development board is used to realize the overall control of the environmental information sensing device; The temperature and humidity detection module is used to detect the temperature and humidity of the ocean; The wind speed and direction detection module is used to detect the wind speed and direction, including the angle of the wind direction and the magnitude of the wind speed; The wave height detection module is used to measure the height of the ocean surface waves; The Beidou-3 module is used to attach a timestamp and location information to the environmental information for subsequent data processing; the environmental information includes the temperature and humidity of the ocean, as well as the angle of the wind direction and the magnitude of the wind speed; After the environmental information sensing device is started, the FPGA development board controls the temperature and humidity detection module, the wind speed and direction detection module, and the wave height detection module to work, continuously obtains environmental information, and sends the environmental information to the FPGA development board; after the FPGA development board receives the environmental information, the Beidou-3 module adds a timestamp and location information to the environmental information; the FPGA development board sends the environmental information with the timestamp and location information to the receiving end; The sending end includes a first PXI vector signal transceiver, a first omnidirectional antenna, a first display, and a first keyboard and mouse; The first PXI vector signal transceiver includes a first PXI vector signal transceiver RF sub-board, a first Beidou module and a first internal processor; the first PXI vector signal transceiver RF sub-board is used to modulate the PN pseudo-random sequence to make the signal continuously transmitted, the first Beidou module adds a timestamp and location information to the transmitted signal, and the first internal processor controls the transmission of the transmitted signal; The first omnidirectional antenna is used for: transmitting the transmitted signal; in the sending end, the transmitted signal is a PN pseudo-random sequence, which is constructed into a signal flow graph and transmitted. After being modulated by the first PXI vector signal transceiver RF sub-board, it is added with a timestamp and location information through the first Beidou module, and the signal is sent out through the first omnidirectional antenna; The receiving end further includes a second PXI vector signal transceiver, a first processor, a second omnidirectional antenna, a second display, and a second keyboard and mouse; The second PXI vector signal transceiver includes a second PXI vector signal transceiver RF sub-board, a second Beidou module and a second internal processor; the second PXI vector signal transceiver RF sub-board is used to demodulate the communication signal; the second internal processor saves and controls the data, and the second Beidou module is used to add a timestamp and location information to the received signal; The first processor is used to save the communication information and the environmental information and perform subsequent processing; The second omnidirectional antenna is used to receive the communication signal.

2. The unmanned ship channel measurement system for an intelligent unmanned ship based on marine environment information perception according to claim 1, wherein The model of the temperature and humidity detection module is DHT22; The wind speed and direction detection module uses an integrated wind direction and speed sensor; The Beidou-3 module uses a Beidou-3 data transmission terminal.

3. The unmanned ship channel measurement system for an intelligent unmanned ship based on marine environment information perception according to claim 1, characterized in that, Both the first omnidirectional antenna and the second omnidirectional antenna are discone antennas.

4. The unmanned ship channel measurement system for an intelligent unmanned ship based on marine environment information perception according to claim 1, characterized in that The receiving end is placed on the receiving unmanned ship. The environmental information reception and the communication information reception are carried out separately, and finally combined through timestamps. The working process of the receiving end is as follows: The communication information reception process includes: after the second omnidirectional antenna receives the communication signal, it is transmitted to the radio frequency sub-board of the second PXI vector signal transceiver for demodulation. The second Beidou module adds timestamps and position information to the received signal, and saves the communication information in the second PXI vector signal transceiver; The environmental information reception process includes: the environmental information is transmitted by the FPGA development board to the first processor through a transmission line; After the information reception is completed, the received communication information is transferred to the first processor, aligned according to the timestamps in the communication information and the environmental information, and the communication channel conditions at each moment are analyzed to explore the impact of environmental changes on the channel.

5. The method for measuring the channel between unmanned vessels based on marine environment information perception is realized by the system for measuring the channel between unmanned vessels based on marine environment information perception according to any one of claims 1-4, and is characterized in that, Including: Collect environmental information, add timestamps and send it to the receiving end; Carry out the transmission of communication information, and add timestamps to the communication information during the transmission process; Align the environmental information and the communication information through timestamps, obtain the impact of the environmental information at each moment on the channel, and realize the channel measurement of unmanned ships at sea for unmanned ships.

6. The method for measuring the channel of an unmanned ship by an intelligent unmanned ship based on marine environment information perception according to claim 5, characterized in that, Collect environmental information, add timestamps and send it to the communication end; Including: Turn on the FPGA development board; Continuously receive environmental information and send it to the FPGA development board; The Beidou-3 module adds timestamps and position information to the environmental information; The FPGA development board sends the environmental information with time information and position information to the receiving end.

7. The method for measuring the channel of an unmanned ship by an intelligent unmanned ship based on marine environment information perception according to claim 5, wherein Carry out the transmission of communication information, and add timestamps to the communication information during the transmission process; Including: The sending of communication information, including: Open LabVIEW through the first internal processor, select the real and imaginary parts of the PN pseudo-random sequence to be sent, set the center frequency, bandwidth, sampling rate, transmission frequency, and transmission port, and send the signal; The radio frequency sub-board of the first PXI vector signal transceiver works, modulates the signal, and the first Beidou module adds timestamps and position information; Send the signal out through the first omnidirectional antenna; The reception of communication information, including: Open LabVIEW through the first processor, set the received center frequency, bandwidth, reception time, and reception port, and carry out the reception; After the second omnidirectional antenna receives the communication signal sent by the transmitting end, it is transmitted to the radio frequency sub-board of the second PXI vector signal transceiver; The radio frequency sub-board of the second PXI vector signal transceiver demodulates the communication signal, and the second Beidou module adds timestamps and position information to the received signal; The radio frequency sub-board of the second PXI vector signal transceiver saves the demodulated communication signal in the stream disk of the second PXI vector signal transceiver; Copy the received communication signal to the first processor for subsequent processing.

8. The method for measuring the channel of an unmanned ship by an intelligent unmanned ship based on marine environment information perception according to claim 5, characterized in that Align the environmental information and the communication information through timestamps, obtain the impact of the environmental information at each moment on the channel, and realize the channel measurement of unmanned ships at sea for unmanned ships; Including: After the measurement work is completed, both the environmental information and the communication information are timestamped. After finding the same time scale and intercepting the data with inconsistent times, data analysis is performed. Perform channel characteristic analysis to obtain the propagation characteristics of the channel in the ocean scenario, and establish a corresponding channel model according to the characteristics. Specifically, it includes: obtaining the channel impulse response of the data, and analyzing the relevant characteristics based on the channel impulse response.

9. The method for measuring the unmanned ship channel of the intelligent unmanned ship based on marine environment information perception according to claim 8, wherein, The channel impulse response h(t,τ) is shown in Equation (1): In Equation (1), τ i (t), α i (t) and φ i (t) represent the delay, amplitude, and phase of the i-th path between the transmitter and the receiver, L(t) represents the total number of paths, t represents the current time, τ represents the delay, and j represents the imaginary part.

10. The method for measuring the unmanned ship channel of the intelligent unmanned ship based on marine environment information perception according to claim 9, wherein Through the obtained channel impulse response, obtain the power delay spectrum, power dispersion diagram, root mean square delay spread, and K factor of the channel. It includes: Take the modulus value of the channel impulse response at a certain moment and subtract the gain of the transceiver to obtain the power delay spectrum Ψ(t,τ), as shown in Equation (2): In Equation (2), L(t) is the total number of paths at this moment, τ i is the time delay of the path, δ() is the impulse function, and |h(t,τ)| 2 is the modulus value of the impulse response; The abscissa of the power delay spectrum is the delay, and the ordinate is the power; the power delay spectrum represents the change trend of power with delay. Superimpose the power delay spectra at all moments to obtain the power chromatogram. The abscissa of the power chromatogram is the delay, the ordinate is the time, and the chromaticity is the power; observe the changes in delay, power, and the birth and death of clusters with the change of the distance between the transceiver through the power chromatogram. The root-mean-square (RMS) delay spread is obtained by taking the square root of the second central moment; the formula for calculating the RMS delay spread σ τ is shown in Equation (3) as follows: In Equation (3), τ i and P(τ i ) are the delay and power of the i-th multipath component respectively, and L represents the total number of paths; the cumulative distribution function of the root mean square delay for all snapshots is taken to study the small-scale characteristics of the channel; The formula for calculating the K factor KF[dB] is shown in Equation (4): In Equation (4), P LOS represents the power of the direct path, and P i represents the power of the i-th path; the K factor is used to describe the fading depth or severity of the signal in the channel; taking the cumulative distribution function of the K factor for all snapshots studies the small-scale characteristics of the channel.

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