55 results about "Underwater wireless optical communications" patented technology

The application discloses an underwater wireless optical communication device based on a single photon detector, which comprises a first single photon communication device and a second single photon communication device for bidirectional communication, and each of the first single photon communication device and the second single photon communication device comprises a laser emission unit, a signal receiving unit, a signal comprehensive processing unit and a power module; the laser emission unit loads a received modulated electric signal into an optical signal and outputs the optical signal, and simultaneously emits auxiliary alignment laser for communication device alignment; the signal receiving unit converts the received optical signal into an electric signal through a single photon detector and transmits the electric signal to the outside, and simultaneously, the signal receiving unit receives auxiliary alignment laser to complete communication device alignment; the signal comprehensive processing unit converts communication information of a host computer into a modulated electric signal after receiving the communication information, transmits the modulated electric signal to the laser emission unit, demodulates and restores the electric signal transmitted by the signal receiving unit into communication information, and then transmits the communication information to the host computer. The application can improve underwater communication distance and meet the requirements of long-distance wireless optical communication in different water quality environments.

The invention provides a performance analysis method of a multi-RIS-assisted underwater wireless optical communication system under an RIS selection scheme. The performance analysis method comprises the following steps: establishing a multi-RIS-assisted underwater wireless optical communication system model under the RIS selection scheme; the method comprises the following steps: deriving a cumulative distribution function expression of an instantaneous signal-to-noise ratio between a source node and a destination node based on a multi-RIS-assisted underwater wireless optical communication system model under an RIS selection scheme; deriving a probability density function expression of an instantaneous signal-to-noise ratio between a source node and a destination node; based on the cumulative distribution function and the probability density function expression of the instantaneous signal-to-noise ratio, deriving to obtain an analytical expression of the outage probability and the M-PAM average bit error rate, and based on the obtained analytical expression, analyzing the performance of the outage probability and the M-PAM average bit error rate of the multi-RIS-assisted underwater wireless optical communication system under the RIS selection scheme. The invention shows the potential advantage of integrating multiple RISs into an underwater wireless optical communication system.

The application discloses a relay and power joint distribution method based on underwater wireless optical communication and belongs to the technical field of wireless optical communication. The system average error rate performance expression derived is used as a target function, and the Hungarian algorithm is used to distribute relay nodes for source nodes; based on the obtained source node and relay node pairing combination, the particle swarm algorithm is used to optimize the power distribution of the source node and the relay node under the constraint condition of total power, with the minimum system average error rate as the target; based on the updated power distribution result of the source node and the relay node, the system average error rate is calculated; if the absolute value of the difference between the new system average error rate and the original system average error rate is greater than a set threshold value, the Hungarian algorithm is used again to distribute relay nodes for source nodes, and the particle swarm algorithm is used to optimize the power distribution, until the absolute value of the difference between the current system average error rate and the last system average error rate is less than the set threshold value. The relay and power joint distribution method based on underwater wireless optical communication provided by the application avoids the defects of large operation amount and high complexity of the exhaustive search method, better realizes the relay distribution and power distribution problems in the weak ocean turbulence environment with lower complexity, and improves the performance of the multi-user multi-relay underwater wireless optical communication system.

The invention relates to a spread spectrum and time-digital conversion cooperative underwater communication measurement system and method, belongs to the technical field of underwater wireless optical communication, and solves the technical problems of limited communication rate and insufficient positioning precision in an underwater complex environment. The measurement system comprises a master-end underwater wireless optical communication machine and a slave-end underwater wireless optical communication machine, each of the master-end underwater wireless optical communication machine and the slave-end underwater wireless optical communication machine comprises an optical transmitting unit, an optical receiving unit, a signal processing unit, an upper computer and a shell. And the optical transmitting unit, the optical receiving unit and the upper computer are respectively connected with the signal processing unit. The optical transmitting unit, the optical receiving unit and the signal processing unit are arranged in the shell, and the upper computer is arranged outside the shell. The measurement method comprises the steps of system initialization and link establishment, communication and time service synchronization, distance measurement signal triggering and transmitting, and distance calculation and display. The method is used for underwater robot collaborative operation, ocean monitoring and deep sea detection.

The invention belongs to the technical field of underwater wireless optical communication, and particularly relates to an underwater wireless optical communication base station and a communication coverage method. The base station is deployed on the seabed, a binocular camera is used for collecting images of positioning markers on the underwater robot in real time, and the three-dimensional relative position of the underwater robot relative to the base station is calculated based on underwater calibration parameters. And then, the communication coverage method generates and encodes position correction information according to a preset optimal communication area threshold value, and sends the position correction information to the underwater robot through an optical communication link. By fixing the position of the base station, simplifying the alignment dimension and combining high-precision visual guidance, the communication coverage range is remarkably expanded, the complex three-dimensional alignment problem is simplified into a two-dimensional plane alignment task, and the stability and reliability of an underwater wireless optical communication link are greatly improved.

The application belongs to the technical field of underwater wireless optical communication and relates to an underwater wireless optical communication device awakened by an acoustic signal and a standby awakening communication method. The device comprises a cabin top light transmission cover, an internal light transceiving array, an acoustic communication transceiving module, a main control unit and a power module. In a standby state, the main control unit controls the power module to cut off the power supply of the internal light transceiving array and only maintains the acoustic communication transceiving module to perform low-power acoustic monitoring; when a preset acoustic awakening signal is received, the acoustic communication transceiving module triggers the main control unit to wake up and completes bidirectional handshaking through acoustic verification messages. After verification succeeds, the main control unit connects the power supply of the internal light transceiving array, establishes a high-speed optical communication link and exchanges data. The scheme can reduce the standby power consumption of an underwater communication node, reduce false awakening and improve long-term deployment capability.

The present application relates to underwater cluster vehicle positioning system and method, specifically relates to a kind of underwater cluster vehicle cooperative positioning system and method based on wireless optical communication, solve the technical problems that existing underwater cluster vehicle is difficult to guarantee the consistency and cooperation between nodes.The underwater cluster vehicle cooperative positioning system based on wireless optical communication provided by the present application is based on underwater wireless optical communication technology, communication rate is high, delay is low, transmission capacity is large, and the time reference unit of main node positioning device is used to synchronize and tame the crystal oscillator in clock synchronization and tame unit in slave node positioning device, to realize the cooperative time service of multiple slave node underwater vehicles, and further ensure positioning accuracy;At the same time, the autonomous navigation unit of underwater vehicle itself can be used, and only one main node underwater vehicle equipped with high-precision main node autonomous navigation unit and time reference unit can realize the cooperative positioning of underwater cluster vehicle.

The invention discloses a method for obtaining the optimal transmitting power and transmitting gain of a UWOC system with light beam jitter, and belongs to the technical field of underwater wireless optical communication. A mathematical expression of an instantaneous received signal-to-noise ratio gamma uw is determined according to a complex marine environment receiver received signal model, and a probability density function fh (h) of a mixed fading channel coefficient h is obtained, so that a cumulative distribution function F gamma uw (gamma uw) of the instantaneous signal-to-noise ratio gamma uw is obtained. And further solving a system average bit error rate # imgabs0 # and a partial derivative function of the bit error rate to the transmitter gain GT under OOK modulation, namely a system average bit error rate # imgabs1 #, and setting a constant value alpha of the system average bit error rate # imgabs2 #, and setting a partial derivative # imgabs3 # to form a simultaneous equation set to calculate and obtain the optimal transmitting power and transmitting gain. According to the method for acquiring the optimal transmitting power and the transmitting gain of the UWOC system provided by the invention, the optimal transmitting power and the gain value of the transmitter for ensuring normal communication of the system can be acquired under the condition that the transceiver jitters due to factors such as underwater turbulence, weak earthquakes and water body temperature changes, so that a reference is provided for upper-layer network planning of the system.

This invention provides an energy adaptive adjustment device and method for underwater wireless optical communication, relating to the field of underwater wireless optical communication. The device includes: an adaptive adjustment module, a signal processing module, an optical antenna, a tunable optical attenuator, and a beam splitter. The tunable optical attenuator adjusts the light intensity energy of the optical signal according to the feedback signal from the adaptive adjustment module. The beam splitter splits the optical signal output from the tunable optical attenuator into two paths, one transmitted to the adaptive adjustment module and the other to the signal processing module. The signal processing module generates an energy calibration result and sends it to the adaptive adjustment module, and receives the optical signal from the beam splitter, processes it, and outputs it. The adaptive adjustment module receives the signals from the beam splitter and the signal processing module, processes them, and feeds them back to the tunable optical attenuator. This invention solves the problem that the signal energy detected by the receiving end of the device cannot be adaptively adjusted, improving the practicality and robustness of the communication device.

The invention discloses an underwater wireless optical communication method and system, and the method comprises the steps: controlling a second transmitting module in a second communication terminal to generate a second initial optical signal through employing a link guide beacon sequence, and adjusting the position and direction of a first communication terminal according to the initial optical signal, so as to enable the first communication terminal to enter a communication coverage range of each other; establishing a half-duplex communication link for the two terminals according to a handshake protocol; transmitting data from a first communication data interface to a second communication terminal through the first communication terminal by using a first optical signal, and outputting the data to external equipment from a second communication data interface of the second communication terminal; transmitting the data from the second communication data interface to the first communication terminal through the second communication terminal by using a second optical signal, and outputting the data from the first communication data interface to the external equipment; the first communication terminal monitors and adjusts the relative poses of the two terminals according to the second optical signal, so that the two terminals are located in the communication coverage range of each other, the communication complexity is reduced, and the measurement precision is improved.

The present invention discloses a method for measuring the pose of a cooperative target in underwater wireless optical communication, comprising: constructing a pose measurement system; keeping two underwater wireless optical communication terminals at a predetermined distance to obtain an identifier serving as the decision basis for the image of the underwater wireless optical communication light source; turning on the underwater light array, the underwater color camera, and the two underwater wireless optical communication terminals, using the underwater color camera to capture the image of the second underwater light array and performing interference filtering processing to obtain a filtered image; performing grayscale processing and Gaussian filtering on the filtered image; obtaining the centroid coordinates of each light spot in the filtered image; obtaining the central pose of the underwater light array according to the centroid coordinates of each light spot; and obtaining the relative pose of the two underwater wireless optical communication terminals according to the pose of the center of the underwater light array. By integrating the visual guidance measurement technology and the underwater wireless optical communication system, the present invention solves the problem of pose measurement of the cooperative target in underwater wireless optical communication, with low complexity.

The invention discloses an underwater wireless optical communication transmitter based on a blue-green light phased array, and the transmitter comprises a narrow-linewidth seed laser source which is used for generating narrow-linewidth laser; the beam splitting device is used for splitting the narrow linewidth laser into a plurality of sub light beams; a blue-green laser diode array, each blue-green laser diode receives a path of sub-beam through an optical injection locking technology and outputs high-power narrow-linewidth blue-green laser, and the blue-green laser diode is based on a gallium nitride multi-quantum well structure; the phase control array corresponds to each blue-green laser diode and is used for adjusting the phase of each path of high-power narrow-linewidth blue-green laser; and the large-aperture transmitting antenna array is connected with the phase control array and is used for carrying out collimation processing on the laser beam after phase modulation and transmitting the laser beam to an underwater environment to form a large-aperture optical phased array. The device can significantly improve the power of emitted light beams, greatly improves the quality of the light beams, and improves the communication distance.

The application provides a high-speed light-emitting diode underwater wireless optical communication system and method, and belongs to the technical field of underwater optical communication; a transmitting end comprises successively connected adaptive coding module, 16QAM mapping module, OFDM modulation module, digital-analog conversion module and LED array light source module; a receiving end comprises successively connected photoelectric detection module, signal processing module of integrated post-equalization circuit, analog-digital conversion module, digital filter module, OFDM demodulation module, phase estimation module, 16QAM demapping module and Viterbi decoding module; the application provides a high-speed LED underwater wireless optical communication system and method based on 16-order quadrature amplitude modulation-quadrature frequency division multiplexing and hardware equalization, adopts hardware equalization to effectively expand the modulation bandwidth of the LED light source, significantly improves the transmission performance of high-frequency signals, and sufficiently utilizes the frequency spectrum resources through high-order modulation, and significantly improves the data transmission rate of the system.

The invention relates to the technical field of chips, and discloses an underwater wireless optical communication transmitter chip which comprises a continuous wave laser, an IQ modulator, an optical beam splitter, an optical phase shifter array, an antenna array and a self-adaptive light beam control module. A light beam emitted by a continuous wave laser is modulated and then transmitted to each antenna array element by a waveguide through a light beam splitter, a light phase shifter is designed on the waveguide connected with each antenna, the phase shifter is controlled by a self-adaptive light beam control module to control each path of light phase, and finally directional radiation of the light beam is realized. The main advantage of light beam steering by adopting the optical phased array technology is that large inaccurate mechanical parts or optical elements are avoided, meanwhile, sufficient receiving energy can be provided for initial detection of a target and smooth transition to a narrow beam tracking state within required capture time, and light beam drift caused by ocean turbulence can be effectively corrected. And the quality of the underwater wireless optical communication system is improved.

The application relates to underwater optical communication technology and discloses a kind of underwater wireless optical communication systems based on rotary laser transmitter, to solve the problem that transmission accuracy of existing underwater wireless laser communication technology is easily affected by transmission medium turbidity and transmission distance.The rotary laser transmitter device of the system is connected with a laser transmitter by each laser controller, and a plurality of laser transmitters are uniformly arranged on the rotary support in the circumferential direction, the device is provided with a transmission hole, and the rotary support is driven by a motor to rotate; the laser receiver receives optical signals from the rotary laser transmitter device, converts the optical signals into electrical signals, and sends the electrical signals to a data acquisition card; the data processing module processes data sent by the data acquisition card; and the control module controls the operation of the laser controller and the motor according to the processing result.The application can adaptively adjust the position and working condition of each wavelength laser transmitter of the transmitting end according to water turbidity and transmission distance, and ensure the transmission accuracy of the system.

This invention relates to a large field-of-view diversity receiver for underwater wireless optical communication, belonging to the field of underwater optical communication technology. It includes a top lens-detector module pointing vertically towards the zenith and four surrounding side lens-detector modules. The four side modules are evenly distributed along the circumference and have a uniform tilt angle relative to the zenith direction, causing the spatial fields of view of each module to partially overlap, thus synthesizing a large composite field of view. Each module consists of a defocused condenser lens and a photodetector. This invention avoids the trade-off between gain and field of view limitation of traditional single-lens receivers, relaxing communication alignment requirements while retaining the high-speed transmission advantage of small-area detectors. Combined with a signal combining algorithm, it can effectively combat underwater signal fading, making it suitable for underwater wireless optical communication systems.

The invention provides an underwater wireless optical communication adaptive transceiving system, which comprises a signal transmitter and a signal receiver, and is characterized in that the signal transmitter comprises a plurality of direct modulation semiconductor lasers and a modulation unit capable of converting digital signals into analog signals for modulation of the semiconductor lasers. The signal receiver comprises a spectroscope, an optical power meter probe and a signal receiver; the signal receiver captures optical signals through the digital signal processing module by using the plurality of optical detectors and converts the optical signals into electric signals, and the electric signals pass through the analog-to-digital converter and are output to the FPGA board card in the form of digital signals. According to the invention, service transmission can be carried out in real time, so that the problem of bandwidth limitation easily occurring when a single channel transmits a high-rate signal is solved, and the overall transmission rate or anti-interference capability of the system is further improved.

The application relates to the field of underwater wireless optical communication and discloses an underwater wireless optical communication system based on index modulation technology and a multi-band CAP technology, which comprises an optical transmitting module, an optical receiving module, a transmitting end signal processing module and a receiving end signal processing module. The transmitting end signal processing module carries out sub-band multi-mode ordering mapping and multi-band CAP modulation on original data, the receiving end signal processing module carries out multi-band CAP demodulation, multi-channel DFE equalization and signal-to-noise ratio weight-assisted multi-mode demapping on digital signals, and the original data is recovered. Compared with a traditional method, the mapping relationship between data and the ordering mode of a multi-constellation pattern is established, more index bit information can be transmitted, the error code rate can be reduced through the multi-channel DFE equalization and the weight-assisted demapping scheme, and the system performance is improved.

The present invention provides an underwater wireless optical communication and detection integrated system and method, mainly solving the technical problem that the structure of independently designing and using a detection module and a communication module in the existing underwater wireless optical information system will result in a relatively large volume and high power consumption of the platform carrying the underwater wireless optical information system. It includes two communication and detection systems oppositely arranged on both sides of the detection target; the communication and detection system includes a signal generation module, a beam splitting module I, an optical system II, a coaxial optical path module I, a coaxial optical path module II, a scanning module, a window, an optical system I, a photodetector I, a detection signal processing module, a control circuit module I, an optical system III, a photodetector II, a beam splitting module II, an optical system IV, a camera, a control circuit module II, an optical system V, a photodetector III, and a communication signal processing module.

The invention relates to the technical field of underwater wireless optical communication, in particular to a full-duplex underwater wireless optical communication device and method based on a beacon-free capturing and tracking technology. The method comprises the following steps: transmitting optical signal data with a specific divergence angle through a transmitting device to cover an opposite-end communication terminal area; a CCD camera is used for collecting light signal data, the collected light signal data is preprocessed, whether a light spot is captured or not is judged through the CCD camera, and if the light spot is not captured by the CCD camera, the light spot is captured by a photon counting camera; s2, adjusting the emission light power based on the light spot captured in S2 and the number of received photons obtained by a photon detector; based on the optical signal data after the optical power is adjusted, processing the light beam through the FPGA to obtain an actual angle deviation; and adjusting the deflection angle of the FSM based on the actual angle deviation to complete link tracking. And accurate positioning is realized through a weighted centroid algorithm, the problem of rapid light beam offset caused by shaking of the underwater platform is solved, and the tracking stability is improved.

The invention discloses an underwater wireless optical communication large-dynamic-power-range receiving method. The method comprises the steps that the maximum amplitude and the minimum amplitude of a communication voltage signal are set in a control module when a signal processing module works; output voltage parameters of the adjustable voltage module and the multiplication voltage module are set in the control module in a grading manner according to the variation range of the transmittance of the communication optical signal after passing through the electrochromic glass and the working voltage range of the electrochromic glass; attenuating the communication optical signal by using the electrochromic glass; converting the attenuated communication optical signal into a communication current signal by using a photomultiplier; converting the communication current signal into a communication voltage signal by using a trans-impedance amplifier; measuring the amplitude of the communication voltage signal by using a signal monitoring module; the control module adjusts output voltage parameters of the adjustable voltage module and the multiplication voltage module according to the amplitude of the communication voltage signal, so that the amplitude of the communication voltage signal is between the maximum amplitude and the minimum amplitude, and the signal processing module recovers original communication data.

The invention discloses a channel capacity evaluation method for an MISO-UWOC system with a timing jitter error and an ocean turbulence effect, and belongs to the technical field of underwater wireless optical communication. The method comprises the following steps: firstly, modeling a channel model of composite fading factors such as GGD ocean turbulence, FFIR implicit path loss and multipath effect, and obtaining a PDF mathematical expression fh (h) of a merged equivalent fading channel coefficient h at a target node according to an equal gain merging technology (EGC); secondly, depicting deterministic jitter by using a double Dirac function, describing random jitter by using a Gaussian distribution function, and convolving the deterministic jitter and the random jitter to obtain a PDF expression f xi (xi) of a total timing jitter error xi; and finally, deducing the channel capacity expression of the MISO-UWOC system after the EGC combination is adopted by the MISO-UWOC system by using the Shannon classical channel capacity theorem. According to the method, the defect that timing jitter is ignored in traditional underwater wireless optical communication is overcome, and the actual high-speed communication requirement is better met.

The invention relates to an underwater wireless optical communication networking method and system based on an improved time slot ALOHA protocol. The method comprises the following steps: firstly, acquiring original audio and video data and processing the original audio and video data to obtain a frame coding signal; based on this, an initial time slot allocation scheme is generated by measuring the propagation time delay of an underwater node optical signal. Then, underwater environment data are collected, high-risk nodes are determined in combination with the initial time slot allocation scheme, and an optimized time slot allocation table is obtained; and then, extracting data from the optimized time slot distribution table, combining with a network load monitoring value, and optimizing a communication strategy by using a load balancing algorithm. And finally, monitoring the operation condition of the communication strategy to obtain real-time monitoring data, and performing optimization adjustment in combination with the channel state parameters to obtain final communication protocol parameters. According to the steps, data transmission conflicts are effectively reduced, the time slot utilization rate is improved, wireless optical communication networking can better adapt to the complex and changeable underwater environment, the signal interference and the packet loss rate are reduced, and stability and reliability of communication are guaranteed.

The invention provides a high-speed light-emitting diode underwater wireless optical communication system and method, and belongs to the technical field of underwater optical communication. The transmitting end comprises an adaptive coding module, a 16QAM mapping module, an OFDM modulation module, a digital-to-analog conversion module and an LED array light source module which are connected in sequence; the receiving end comprises a photoelectric detection module, a signal processing module of an integrated equalization circuit, an analog-to-digital conversion module, a digital filtering module, an OFDM demodulation module, a phase estimation module, a 16QAM demapping module and a Viterbi decoding module which are connected in sequence; according to the 16-order orthogonal amplitude modulation-orthogonal frequency division multiplexing and hardware equalization-based high-speed LED underwater wireless optical communication system and method provided by the invention, the modulation bandwidth of an LED light source is effectively expanded by adopting hardware equalization, the transmission performance of high-frequency signals is remarkably improved, spectrum resources are fully utilized through high-order modulation, and the optical communication efficiency is improved. And the data transmission rate of the system is obviously improved.

The invention discloses an underwater wireless optical communication physical layer security coding and decoding system and method based on a Polar code, and belongs to the technical field of underwater optical communication, and the system comprises a transmitting end, an underwater channel, a legal receiving end and an illegal eavesdropping end; the transmitting end carries out Polar code coding and modulation on original data and converts the original data into optical signals to be transmitted, and meanwhile, a backscattering detection module of the transmitting end evaluates signal conditions possibly detected by an illegal eavesdropping end; after being attenuated to a single photon level through an underwater channel, an optical signal is detected and decoded by a legal receiving end and an illegal eavesdropping end respectively; according to the underwater wireless optical communication physical layer safety coding and decoding system and method based on the Polar code, the reliability and safety of communication are achieved while coding and decoding are conducted on the Polar code, and information safety guarantee is provided for underwater wireless optical communication.

The application discloses a wireless optical communication method based on cooperative non-orthogonal multiple access and multi-user diversity, and mainly solves the problems of few accessible users and low user resource utilization in the prior art. The implementation scheme is as follows: a cooperative non-orthogonal multiple access underwater multi-user diversity wireless optical communication system is constructed; a source node selects far users and near users with the best channel according to a multi-user scheduling algorithm; the source node superimposes far user signals and near user signals in a power domain, and simultaneously sends the superimposed signals to the far users and the near users; the near users demodulate their own signals through serial interference cancellation; the near users send signals to the far users as relays by using a decode-and-forward protocol or an amplify-and-forward protocol; and the far users demodulate their own signals by selecting and combining two signals sent by the source node and the relay node. The application improves the number of user access, the source node can serve multiple user groups at the same time, and the system interruption performance is improved, and the application can be used in a multi-user underwater wireless optical communication system.

The invention discloses a large dynamic underwater wireless optical signal detection method based on state counting, and belongs to the technical field of underwater wireless optical communication and signal detection. The method comprises the following steps of: firstly, performing M-time up-sampling on a received signal, and setting a judgment threshold to count photon state count in each symbol period; secondly, a truncated sub-Poisson distribution model is provided according to the truncation characteristic of the symbol 1 under the strong light condition, the probability quality function of the truncated sub-Poisson distribution model can accurately describe the state number distribution rule, and Poisson distribution modeling is adopted under the weak light condition; and finally, estimating distribution parameters of symbols' 0 'and' 1 'according to the pilot signal, and performing symbol judgment based on a maximum likelihood detection method. The method has the advantages of being simple in structure and low in calculation complexity, the detection performance and robustness of the system are remarkably improved, and the method is suitable for complex underwater wireless optical communication scenes.

The invention discloses an efficient underwater optical detector based on a wavelength shift optical fiber. The photoelectric conversion efficiency and the detection sensitivity of an underwater optical detection system are improved. The specific implementation method comprises the following steps: 1, mounting a reflector behind the WSF array to improve the absorption and conversion proportion of the detector to incident blue light; 2, a reflector is installed at the tail end of the WSF array to guide excitation green light which is propagated in the back direction to a photoelectric detector to improve the signal intensity; and thirdly, the output of the WSF array is combined into one optical fiber by the optical fiber combiner, and exciting light is converged to a working area of the photoelectric detector. The method is not only suitable for underwater wireless optical communication, but also provides important technical support for various scientific researches related to the underwater environment, including marine biology and marine physics.

The invention relates to the technical field of underwater comprehensive docking systems, and discloses an underwater docking system integrating navigation, wireless communication and wireless power supply, which comprises a connection end and an execution end, the connection end and the execution end are in two-way communication based on a long-distance light guiding and low-speed data link, an electric energy, communication and guiding control module, a wireless electric energy transmission module and a short-distance high-speed data link, and the execution end enters optical guiding through sound guiding. The connection end and the execution end switch low-speed or laser high-speed communication and start energy complementation according to the distance, light vision guidance is modulated, so that the system has an underwater wireless optical communication function, and meanwhile, the underwater attenuation of light is lower than that of radio. Therefore, low-speed data transmission is achieved while guiding is conducted through the execution end in the recycling process, and under detection and switching of the guiding control module and the wireless electric energy transmission module, high-speed communication and wireless energy supplementation are started after the execution end reaches the connection end.

A synchronization method for a photon counting type underwater wireless optical OOK communication system, including the design of a transmission data structure and a synchronization method. The design of the data structure includes the design of the sending frame structure and the division of the received signal. The data is transmitted in the form of continuous frames, and the synchronization sequence is periodically embedded in the transmitted data. Before synchronization, the received signal is divided into slices of the same length; during synchronization, based on a frame-long received signal, the maximum likelihood joint estimation method is used to establish the corresponding optimization problem to find the synchronization sequence position, and some simplification is used to reduce the complexity of solving the original optimization problem. The present application solves the problem of poor transmission performance of the underwater wireless optical OOK communication system from the perspective of signal synchronization. The synchronization method is simple in form, and the complexity of the method is reduced by simplification, which is more suitable for the photon counting type underwater wireless optical OOK communication system. The present application can improve the synchronization performance with low complexity and improve the reliability of the photon counting type underwater wireless optical OOK communication system.