Communication methods, systems, storage media, and devices based on solar-blind ultraviolet detectors

Abstract

This invention discloses a communication method, system, storage medium, and device based on a solar-blind ultraviolet detector. The method includes: constructing a fixed-duration frame structure containing a synchronization segment, a control segment, a data segment, and a protection segment, and formulating a unified communication protocol; the transmitting end converts the input digital signal into a binary bit stream and frames it, determines the number of bits carried by a single symbol based on the APPM modulation order and amplitude level, and transmits an ultraviolet light signal through bit grouping, symbol mapping, Gaussian pulse shaping, digital modulation, and electro-optic conversion; the receiving end converts the ultraviolet light signal into an electrical signal, extracts pulse feature parameters after filtering, adaptive shape Gaussian matched filtering, and timing synchronization, demodulates to obtain a bit stream, and performs frame parsing to extract valid user data; frame synchronization and bit synchronization are achieved throughout the process through a synchronization control module to ensure timing matching between the transmitting and receiving ends. This invention enhances the system's adaptability to channel time-varying characteristics and environmental interference, and improves communication confidentiality and reliability.

Description

Technical Field

[0001] This invention relates to the field of communication technology, and specifically to a communication method, system, storage medium, and device based on a solar-blind ultraviolet detector. Background Technology

[0002] In modern wireless communication systems, spectrum resources are becoming increasingly scarce, and electromagnetic warfare environments are becoming more complex. Traditional radio frequency communication systems face severe challenges to their communication reliability and security when encountering strong interference, high interception risks, and complex terrain obstruction. Solar-blind ultraviolet communication technology, with its unique advantages such as non-line-of-sight transmission capability, high confidentiality, and low background noise, has irreplaceable application value in scenarios such as military communication, urban emergency command, and disaster relief in complex electromagnetic environments.

[0003] Despite the advantages mentioned above, solar-blind ultraviolet communication still faces a series of technical bottlenecks in its practical application:

[0004] The channel characteristics are complex: atmospheric scattering and absorption cause signal attenuation and limit the coverage of high-frequency signals; multipath scattering causes inter-symbol interference, which restricts the transmission rate; the superposition of Doppler frequency shift, channel time-varying characteristics and external interference increases the difficulty of system design and hinders the development of high-speed and wide-coverage wireless communication.

[0005] Lack of efficient modulation and reception technologies: To control hardware complexity and reduce costs, most current communication systems generally adopt simple OOK modulation and direct detection reception schemes. Although this scheme is easy to implement and suitable for low-data-rate scenarios, it has weak anti-interference capabilities and is difficult to cope with random fading and multipath effects in wireless channels, which easily leads to signal distortion and increased bit error rate. Its inherent problems of low modulation efficiency and limited detection accuracy cannot meet the communication requirements of high bandwidth and high reliability.

[0006] Weak anti-interference mechanisms: Most communication systems have weak anti-interference mechanisms, insufficient overall adaptability to complex environments, and poor resilience to background light fluctuations, man-made strong light interference, and time-varying channel characteristics. Natural fluctuations can interfere with signal recognition at the receiver, man-made strong light interference may directly suppress useful signals, and dynamic parameter fluctuations caused by time-varying channel characteristics further exacerbate the difficulty of signal demodulation. In battlefields with complex electromagnetic environments and dense interference sources, or in urban environments with tall buildings and chaotic light sources, system stability drops significantly, easily leading to signal interruptions, data transmission errors, and other problems, directly resulting in a lack of system robustness and inability to meet the requirements of high-reliability communication. Summary of the Invention

[0007] In view of the shortcomings of the prior art, the purpose of this invention is to provide a communication method, system, storage medium and device based on a solar-blind ultraviolet detector.

[0008] A first aspect of the present invention is to provide a communication method based on a solar-blind ultraviolet detector, the method comprising:

[0009] Construct a fixed-duration frame structure consisting of a synchronization segment, a control segment, a data segment, and a protection segment, and formulate a frame structure communication protocol that is uniformly followed by the transmitting and receiving ends;

[0010] The control transmitter converts the input digital signal into a binary bit stream, completes framing according to the frame structure communication protocol, and then modulates it according to the APPM modulation order. M With amplitude level L According to the formula The number of bits carried by a single symbol is determined, and then bit grouping, symbol mapping, Gaussian pulse shaping, and digital modulation processing are performed in sequence. After electro-optic conversion, an ultraviolet light signal is obtained and emitted outward.

[0011] The control receiver receives the ultraviolet light signal and completes photoelectric conversion to obtain an electrical signal. After sequentially filtering, adaptive shape Gaussian matching filtering, and timing synchronization processing of the electrical signal, the pulse's leading edge, width, and amplitude characteristic parameters are extracted.

[0012] The control receiver demodulates the electrical signal according to the characteristic parameters to obtain a binary bit stream, and performs frame parsing on the binary bit stream according to the frame structure communication protocol to extract valid user data;

[0013] Throughout the entire process of signal transmission at the transmitting end and signal reception and processing at the receiving end, the synchronization control module performs frame synchronization and bit synchronization control operations to achieve timing matching between the transmitting end and the receiving end.

[0014] According to one aspect of the above technical solution, the steps of constructing the frame structure and formulating the communication protocol include:

[0015] The synchronization segment duration is set to 1.024ms, the control segment duration to 2.048ms, the data segment duration to 6.144ms, and the protection segment duration to 1.024ms. The synchronization segment is divided into three sub-segments: Gaussian pulse training sequence, multipath detection sequence, and fine synchronization head. The control segment is divided into three sub-segments: physical layer control area, adaptive parameter area, and link layer control area.

[0016] The control section adaptively switches between multi-order PPM modulation modes based on the signal-to-noise ratio (SNR). The data section adopts an APPM adaptive modulation mechanism based on the SNR, and adjusts the APPM modulation order and symbol guard interval according to the severity of multipath propagation.

[0017] The protection segment dynamically adjusts the protection time of information transmission based on the system's operating distance. The total number of symbols in each segment is calculated based on the fixed duration of each segment of the frame structure and the system symbol rate. The bit length of each segment is calculated in combination with the number of bits carried by a single symbol. The processing rules and interaction standards for each segment of data at the transmitting and receiving ends are clarified.

[0018] According to one aspect of the above technical solution, the steps of processing the binary bit stream and realizing electro-optic conversion after the transmitting end completes framing include:

[0019] The framed bitstream is divided into Divide into consecutive blocks of bits and complete the process. The formula for converting a matrix from serial to parallel is as follows: ,in The total number of symbols, For the transformed matrix elements, These are the original bitstream elements;

[0020] Each group of bits is mapped to a three-dimensional modulation symbol containing the time slot position, transmission amplitude, and pulse width, forming a symbol mapping matrix;

[0021] Gaussian pulse shaping is performed based on the pulse width parameter in the symbol mapping matrix to generate a Gaussian base pulse, which is then combined with the emission amplitude parameter to obtain the actual emission pulse.

[0022] In a programmable gate array, the actual transmitted pulse is discretized and digitally modulated using a lookup table method to generate a baseband digital signal;

[0023] The baseband digital signal is sequentially converted from digital to analog and then driven by the LED to obtain a driving electrical signal, which is then input to the ultraviolet LED. The ultraviolet LED then completes the electro-optical conversion and emits an ultraviolet light signal.

[0024] According to one aspect of the above technical solution, the step of mapping each group of bits to a three-dimensional modulation symbol and forming a symbol mapping matrix includes:

[0025] Extract the preceding bits corresponding to the APPM modulation order from each bit group, convert them to decimal numbers, determine the time slot position corresponding to the symbol, and extract the middle bits corresponding to the amplitude level from each bit group, converting them to decimal level numbers. l According to the formula Calculate the actual launch amplitude, where, This represents the actual launch amplitude. For minimum transmission amplitude, , The step interval for amplitude quantization. For maximum launch amplitude, L The total number of levels of amplitude;

[0026] Extract the last bit of each group of bits, and select either a narrow pulse width parameter or a wide pulse width parameter from the preset parameters based on the bit value. If the number of consecutive bits with the same width reaches the preset value, dynamically adjust the current pulse width parameter according to the preset coefficient.

[0027] Based on the determined time slot position, the calculated actual transmission amplitude, the adjusted pulse width parameter, and the symbol start time, row vectors containing physical transmission parameters are generated, and all row vectors form a symbol mapping matrix.

[0028] According to one aspect of the above technical solution, the steps of performing frame synchronization and bit synchronization control operations through the synchronization control module include:

[0029] Frame synchronization control is performed: the receiving end detects the fine synchronization header sequence in the synchronization segment, determines the start position of a frame of data, and splits the continuous bit stream into structured fields of synchronization segment, control segment, data segment, and protection segment according to the calculated bit length of each segment;

[0030] Execution bit synchronization control: The receiving end scans the training sequence of the synchronization segment to coarsely locate the pulse, uses the time slot grouping correlation algorithm to accurately locate the time slot boundary, uses high-order statistical features to calibrate the consistency of the time slot spacing, and starts the adaptive digital phase-locked loop to continuously track the timing offset caused by the time-varying channel.

[0031] Set the bit synchronization related parameter constraint rules, according to the formula Set the symbol period, where For symbol period, The number of time slots per symbol. For time slot width, For inter-symbol protection time, and At the same time, set It is greater than the sum of the channel's maximum multipath delay, Gaussian pulse width, and reserved margin.

[0032] According to one aspect of the above technical solution, the steps of filtering and adaptive shape Gaussian matched filtering of the electrical signal after photoelectric conversion at the receiving end include:

[0033] The analog electrical signal after photoelectric conversion is sampled by ADC to obtain a discrete received signal sequence, and the discrete received signal sequence is pre-filtered using a digital filtering method based on adaptive threshold.

[0034] A generalized Gaussian pulse model is constructed as a matched filter template. The parameters of the generalized Gaussian pulse model are dynamically adjusted according to the channel estimation results to make the template match the pulse shape of the transmitter.

[0035] The pre-filtered signal sequence is convolved with the adjusted matched filter template to obtain the matched filtered signal sequence. The matched filtering results of the entire frame are then integrated into a vector form.

[0036] According to one aspect of the above technical solution, the receiving end extracts pulse feature parameters and completes demodulation and frame parsing steps, including:

[0037] A one-dimensional convolutional neural network is used to identify the pulse leading edge of the signal after timing synchronization, identify the arrival time of the main path and the arrival time of the multipath component of the pulse corresponding to each symbol, and filter out the significant multipath components whose amplitude exceeds the preset threshold.

[0038] The signal after timing synchronization is scanned within the time slot window. The rising edge and falling edge of the pulse are detected. The time difference between the two edges is calculated to obtain the pulse width. The sampling points of the stable high-level part of the pulse are extracted. The statistical mean of the sampling points is calculated to obtain the pulse amplitude estimate.

[0039] The pulse slot position index is determined by the timing synchronization result, and the minimum distance decision method is used according to the formula. Determine the magnitude level index, where This is an estimate of the pulse amplitude. Preset amplitude level;

[0040] The time slot position index and amplitude level index are jointly inversely mapped to restore the original bit groups and concatenate them into a binary bit stream in frame order;

[0041] Search for specific bits of the synchronization segment in the binary bit stream to determine the start position of a data frame. Split the bit stream according to the bit length of each segment, parse the control segment bit stream to extract relevant parameters, extract the data segment bit stream as valid user data, and discard the bit streams of the synchronization segment and the protection segment.

[0042] A second aspect of the present invention is to provide a communication system based on a solar-blind ultraviolet detector, applied to the method described in the above-mentioned technical solution, the system comprising:

[0043] The frame structure construction module is used to construct a fixed-duration frame structure consisting of a synchronization segment, a control segment, a data segment, and a protection segment in sequence, and to formulate a frame structure communication protocol that is uniformly followed by the transmitting end and the receiving end.

[0044] The transmitter module controls the transmitter to convert the input digital signal into a binary bit stream. After framing according to the frame structure communication protocol, it calculates the amplitude according to the APPM modulation order M and amplitude level L using the formula... The number of bits carried by a single symbol is determined, and then bit grouping, symbol mapping, Gaussian pulse shaping, and digital modulation processing are performed in sequence. After electro-optic conversion, an ultraviolet light signal is obtained and emitted outward.

[0045] The receiving module is used to control the receiving end to receive the ultraviolet light signal and complete the photoelectric conversion to obtain an electrical signal. After sequentially filtering, adaptive shape Gaussian matching filtering, and timing synchronization processing of the electrical signal, the leading edge, width, and amplitude characteristic parameters of the pulse are extracted.

[0046] The receiving module is also used to control the receiving end to demodulate the electrical signal according to the characteristic parameters to obtain a binary bit stream, and to perform frame parsing on the binary bit stream according to the frame structure communication protocol to extract valid user data;

[0047] The synchronization control module is used to perform frame synchronization and bit synchronization control operations throughout the entire process of signal transmission at the transmitting end and signal reception and processing at the receiving end, so as to achieve timing matching between the transmitting end and the receiving end.

[0048] A third aspect of the present invention is to provide a readable storage medium having computer instructions stored thereon, which, when executed by a processor, implement the steps of the communication method based on a solar-blind ultraviolet detector described in the above-described technical solution.

[0049] A fourth aspect of the present invention is to provide an electronic device, including a memory, a processor, and a computer program stored in the memory and executable on the processor, wherein the processor executes the program to implement the steps of the communication method based on a solar-blind ultraviolet detector described in the above technical solutions.

[0050] Compared with existing technologies, the communication method, system, storage medium, and device based on a solar-blind ultraviolet detector as shown in this invention have the following advantages:

[0051] This invention addresses the challenges of complex channel characteristics, lack of efficient modulation and reception technologies, and weak anti-interference mechanisms in solar-blind ultraviolet communication. It constructs a fixed-duration frame structure with clearly defined segmented functions and a unified communication protocol. Combined with APPM adaptive modulation, the number of bits per symbol is precisely determined using a formula. Through bit grouping, symbol mapping, and other processing steps, the signal transmission format is optimized, effectively combating channel multipath scattering and signal attenuation. At the receiving end, filtering, adaptive shape Gaussian matched filtering, and other multi-stage processing, coupled with precise extraction of pulse feature parameters, solve the problems of weak anti-interference and limited detection accuracy in traditional modulation and reception technologies. A synchronization control module throughout the process achieves dual control of frame synchronization and bit synchronization, ensuring timing matching between the transmitting and receiving ends and improving communication stability in complex environments. The overall technical solution significantly enhances the system's adaptability to channel time-varying characteristics and environmental interference, improves communication confidentiality and reliability, and meets the stringent requirements of high-reliability non-line-of-sight communication in scenarios such as military communication and emergency command. Attached Figure Description

[0052] The above and / or additional aspects and advantages of the present invention will become apparent and readily understood from the description of the embodiments taken in conjunction with the following drawings, in which:

[0053] Figure 1 This is a flowchart illustrating the communication method based on a solar-blind ultraviolet detector provided in an embodiment of the present invention.

[0054] Figure 2 This is a structural block diagram of a communication system based on a solar-blind ultraviolet detector provided in an embodiment of the present invention. Detailed Implementation

[0055] To make the objectives, features, and advantages of the present invention more apparent and understandable, specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings. Several embodiments of the present invention are shown in the drawings. However, the present invention can be implemented in many different forms and is not limited to the embodiments described herein. Rather, these embodiments are provided so that the disclosure of the present invention will be more thorough and complete.

[0056] It should be noted that when a component is said to be "fixed to" another component, it can be directly on the other component or there may be an intervening component. When a component is said to be "connected to" another component, it can be directly connected to the other component or there may be an intervening component. The terms "vertical," "horizontal," "left," "right," and similar expressions used in this document are for illustrative purposes only.

[0057] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. The terminology used herein in the description of the invention is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. The term "and / or" as used herein includes any and all combinations of one or more of the associated listed items.

[0058] Example 1

[0059] Please see Figure 1 The first embodiment of the present invention provides a communication method based on a solar-blind ultraviolet detector, the method comprising:

[0060] Step S10: Construct a fixed-duration frame structure consisting of a synchronization segment, a control segment, a data segment, and a protection segment in sequence, and formulate a frame structure communication protocol that is uniformly followed by the transmitting end and the receiving end.

[0061] The steps of constructing the frame structure and defining the communication protocol include:

[0062] The synchronization segment duration is set to 1.024ms, the control segment duration to 2.048ms, the data segment duration to 6.144ms, and the protection segment duration to 1.024ms. The synchronization segment is divided into three sub-segments: Gaussian pulse training sequence, multipath detection sequence, and fine synchronization head. The control segment is divided into three sub-segments: physical layer control area, adaptive parameter area, and link layer control area.

[0063] The control section adaptively switches between multi-order PPM modulation modes based on the signal-to-noise ratio (SNR). The data section adopts an APPM adaptive modulation mechanism based on the SNR, and adjusts the APPM modulation order and symbol guard interval according to the severity of multipath propagation.

[0064] The protection segment dynamically adjusts the protection time of information transmission based on the system's operating distance. The total number of symbols in each segment is calculated based on the fixed duration of each segment of the frame structure and the system symbol rate. The bit length of each segment is calculated in combination with the number of bits carried by a single symbol. The processing rules and interaction standards for each segment of data at the transmitting and receiving ends are clarified.

[0065] Step S20: Control the transmitter to convert the input digital signal into a binary bit stream, complete the framing according to the frame structure communication protocol, and then adjust the modulation order according to the APPM. M With amplitude level L According to the formula The number of bits carried by a single symbol is determined, and then bit grouping, symbol mapping, Gaussian pulse shaping, and digital modulation processing are performed in sequence. After electro-optic conversion, an ultraviolet light signal is obtained and emitted outward.

[0066] The steps involved in processing the binary bit stream and performing electro-optical conversion after the transmitter completes framing include:

[0067] The framed bitstream is divided into Divide into consecutive blocks of bits and complete the process. The formula for converting a matrix from serial to parallel is as follows: ,in The total number of symbols, For the transformed matrix elements, These are the original bitstream elements;

[0068] Each group of bits is mapped to a three-dimensional modulation symbol containing the time slot position, transmission amplitude, and pulse width, forming a symbol mapping matrix;

[0069] Gaussian pulse shaping is performed based on the pulse width parameter in the symbol mapping matrix to generate a Gaussian base pulse, which is then combined with the emission amplitude parameter to obtain the actual emission pulse.

[0070] In a programmable gate array, the actual transmitted pulse is discretized and digitally modulated using a lookup table method to generate a baseband digital signal;

[0071] The baseband digital signal is sequentially converted from digital to analog and then driven by the LED to obtain a driving electrical signal, which is then input to the ultraviolet LED. The ultraviolet LED then completes the electro-optical conversion and emits an ultraviolet light signal.

[0072] The step of mapping each group of bits to a three-dimensional modulation symbol and forming a symbol mapping matrix includes:

[0073] Extract the preceding bits (first log2) of each bit group corresponding to the APPM modulation order. M (bits), convert them to decimal numbers, determine the time slot position corresponding to the symbol, and extract the middle bits of the corresponding amplitude level from each group of bits (subsequent log2). L (bits), convert them to decimal class numbers. l According to the formula Calculate the actual launch amplitude, where, This represents the actual launch amplitude. For minimum transmission amplitude, , The step interval for amplitude quantization. For maximum launch amplitude, L The total number of levels of amplitude;

[0074] Extract the last bit of each group of bits, and select either a narrow pulse width parameter or a wide pulse width parameter from the preset parameters based on the bit value. If the number of consecutive bits with the same width reaches the preset value, dynamically adjust the current pulse width parameter according to the preset coefficient.

[0075] Based on the determined time slot position, the calculated actual transmission amplitude, the adjusted pulse width parameter, and the symbol start time, row vectors containing physical transmission parameters are generated, and all row vectors form a symbol mapping matrix.

[0076] Step S30: The control receiver receives the ultraviolet light signal and completes photoelectric conversion to obtain an electrical signal. The electrical signal is then filtered, adaptive shape Gaussian matched filtering is performed, and timing synchronization processing is performed sequentially. Finally, the pulse leading edge, width, and amplitude characteristic parameters are extracted.

[0077] The steps of filtering the electrical signal after photoelectric conversion and performing adaptive shape Gaussian matched filtering at the receiving end include:

[0078] The analog electrical signal after photoelectric conversion is sampled by ADC to obtain a discrete received signal sequence, and the discrete received signal sequence is pre-filtered using a digital filtering method based on adaptive threshold.

[0079] A generalized Gaussian pulse model is constructed as a matched filter template. The parameters of the generalized Gaussian pulse model are dynamically adjusted according to the channel estimation results to make the template match the pulse shape of the transmitter.

[0080] The pre-filtered signal sequence is convolved with the adjusted matched filter template to obtain the matched filtered signal sequence. The matched filtering results of the entire frame are then integrated into a vector form.

[0081] Step S40: Control the receiving end to demodulate the electrical signal according to the characteristic parameters to obtain a binary bit stream, and perform frame parsing on the binary bit stream according to the frame structure communication protocol to extract valid user data.

[0082] The steps of extracting pulse feature parameters and performing demodulation and frame parsing at the receiving end include:

[0083] A one-dimensional convolutional neural network is used to identify the pulse leading edge of the signal after timing synchronization, identify the arrival time of the main path and the arrival time of the multipath component of the pulse corresponding to each symbol, and filter out the significant multipath components whose amplitude exceeds the preset threshold.

[0084] The signal after timing synchronization is scanned within the time slot window. The rising edge and falling edge of the pulse are detected. The time difference between the two edges is calculated to obtain the pulse width. The sampling points of the stable high-level part of the pulse are extracted. The statistical mean of the sampling points is calculated to obtain the pulse amplitude estimate.

[0085] The pulse slot position index is determined by the timing synchronization result, and the minimum distance decision method is used according to the formula. Determine the magnitude level index, where This is an estimate of the pulse amplitude. Preset amplitude level;

[0086] The time slot position index and amplitude level index are jointly inversely mapped to restore the original bit groups and concatenate them into a binary bit stream in frame order;

[0087] Search for specific bits of the synchronization segment in the binary bit stream to determine the start position of a data frame. Split the bit stream according to the bit length of each segment, parse the control segment bit stream to extract relevant parameters, extract the data segment bit stream as valid user data, and discard the bit streams of the synchronization segment and the protection segment.

[0088] Step S50: Throughout the entire process of signal transmission at the transmitting end and signal reception and processing at the receiving end, the synchronization control module performs frame synchronization and bit synchronization control operations to achieve timing matching between the transmitting end and the receiving end.

[0089] The steps for performing frame synchronization and bit synchronization control operations through the synchronization control module include:

[0090] Frame synchronization control is performed: the receiving end detects the fine synchronization header sequence in the synchronization segment, determines the start position of a frame of data, and splits the continuous bit stream into structured fields of synchronization segment, control segment, data segment, and protection segment according to the calculated bit length of each segment;

[0091] Execution bit synchronization control: The receiving end scans the training sequence of the synchronization segment to coarsely locate the pulse, uses the time slot grouping correlation algorithm to accurately locate the time slot boundary, uses high-order statistical features to calibrate the consistency of the time slot spacing, and starts the adaptive digital phase-locked loop to continuously track the timing offset caused by the time-varying channel.

[0092] Set the bit synchronization related parameter constraint rules, according to the formula Set the symbol period, where For symbol period, The number of time slots per symbol. For time slot width, For inter-symbol protection time, and At the same time, set It is greater than the sum of the channel's maximum multipath delay, Gaussian pulse width, and reserved margin.

[0093] Please see Figure 2 Another aspect of the present invention provides a communication system based on a solar-blind ultraviolet detector, applied to the method described in the above technical solution, the system comprising:

[0094] Frame structure construction module 10 is used to construct a fixed-duration frame structure consisting of a synchronization segment, a control segment, a data segment, and a protection segment in sequence, and to formulate a frame structure communication protocol that is uniformly followed by the transmitting end and the receiving end.

[0095] Transmitter module 20 is used to control the transmitter to convert the input digital signal into a binary bit stream. After framing according to the frame structure communication protocol, it calculates the amplitude according to the APPM modulation order M and amplitude level L using the formula... The number of bits carried by a single symbol is determined, and then bit grouping, symbol mapping, Gaussian pulse shaping, and digital modulation processing are performed in sequence. After electro-optic conversion, an ultraviolet light signal is obtained and emitted outward.

[0096] The receiving module 30 is used to control the receiving end to receive the ultraviolet light signal and complete the photoelectric conversion to obtain an electrical signal. After sequentially filtering, adaptive shape Gaussian matching filtering, and timing synchronization processing of the electrical signal, the leading edge, width, and amplitude characteristic parameters of the pulse are extracted.

[0097] The receiving end module 30 is also used to control the receiving end to demodulate the electrical signal according to the characteristic parameters to obtain a binary bit stream, and to perform frame parsing on the binary bit stream according to the frame structure communication protocol to extract valid user data;

[0098] The synchronization control module 40 is used to perform frame synchronization and bit synchronization control operations throughout the entire process of signal transmission at the transmitting end and signal reception and processing at the receiving end, so as to achieve timing matching between the transmitting end and the receiving end.

[0099] As a specific example, the communication system and method based on a solar-blind ultraviolet detector shown in this embodiment are designed to solve the problems of complex channel characteristics, inefficient modulation and reception technology, and weak anti-interference mechanism in existing solar-blind ultraviolet communication. It can realize non-line-of-sight, anti-interference, and highly secure wireless communication, and is especially suitable for military communication, emergency command, communication in complex urban environments, and civilian high-reliability communication in scenarios with strict requirements for communication reliability and security.

[0100] The system consists of a frame structure construction module, a transmitter module, a receiver module, and a synchronization control module. Each module is linked in real time with the SPI control link through a high-speed LVDS data interface to ensure efficient interaction of signal transmission and control commands.

[0101] In this embodiment, the core parameters of the system are preset after debugging as follows: APPM modulation order. M =8, amplitude level number L =4, the number of bits carried by a single symbol is determined by the formula. The calculated length is 5 bits; the total frame length is strictly set to 10.24ms, including a synchronization segment of 1.024ms, a control segment of 2.048ms, a data segment of 6.144ms, and a guard segment of 1.024ms; the transmitter uses a solar-blind ultraviolet LED array with a center wavelength of 265nm, which is within the solar-blind zone and can effectively reduce background light interference; the receiver uses a high-sensitivity solar-blind ultraviolet photomultiplier tube detector to ensure effective detection of weak light signals; symbol rate Effective data transmission rate of the system It can meet the real-time transmission needs of various data types such as voice, text, and low-resolution images.

[0102] In this embodiment, the frame structure is assembled in the order of synchronization segment, control segment, data segment, and protection segment. The duration allocation, function definition, and parameter configuration of each segment have all undergone rigorous channel adaptation optimization. Specifically:

[0103] The synchronization segment lasts 1.024ms and is divided into three functional sub-segments: a Gaussian pulse training sequence (0.4ms), a multipath detection sequence (0.3ms), and a fine synchronization head (0.324ms). The Gaussian pulse training sequence uses a peak amplitude of 0.5V. sA standard Gaussian pulse with a spectral characteristic of 0.1 μs is used to quickly start the UV LED and trigger the receiver's AGC (Automatic Gain Control) circuit to adjust the gain, stabilizing the amplitude of the input signal at the receiver between 30% and 70% of the ADC's full scale, thus avoiding distortion caused by signal saturation or excessively low amplitude. The multipath detection sequence consists of 10 equally spaced Gaussian pulses with a 30 μs interval. The parameters of each pulse are consistent with the training sequence. By detecting and analyzing this sequence at the receiver, the multipath delay distribution of the channel can be accurately measured, providing a key basis for the adaptive adjustment of subsequent modulation parameters. The precision synchronization head uses a 1024-bit pseudo-random m-sequence with good autocorrelation characteristics. The CRC-16 check algorithm ensures reliable transmission of synchronization information. The receiver performs correlation calculations on this sequence through a hardware correlator. When the correlation value exceeds a preset threshold (80% of the maximum value), the frame start position can be determined, achieving nanosecond-level time alignment with a timing error controlled within 5 ns.

[0104] The control segment lasts 2.048ms and is divided into three parts: physical layer control (0.7ms), adaptive parameter control (0.648ms), and link layer control (0.7ms). The physical layer control segment uses a fixed format to transmit the APPM modulation order. M Amplitude level L Pulse width s The reference value (preset to 0.2μs in this embodiment) and the 8-bit quantized signal-to-noise ratio estimate provide the basic configuration for the demodulation process at the receiver. The adaptive parameter area transmits the maximum channel multipath delay and optimal modulation parameter suggestions in 32-bit floating-point format (e.g., when the multipath delay exceeds 50ns, it is recommended to adjust the modulation order). M The key information, such as the channel attenuation coefficient, is adjusted to support dynamic parameter adaptation at both the transmitting and receiving ends. The link layer control area contains a 16-bit frame number, a 16-bit data length, and a 1-bit retransmission flag. The frame number is used to solve the problem of out-of-order data transmission, the data length indicates the number of bytes of valid data in the current frame, and the retransmission flag is used to provide feedback on the data reception status and ensure error-free data transmission. The control section supports adaptive switching of multi-order PPM modulation based on the signal-to-noise ratio. When the estimated signal-to-noise ratio fed back by the receiving end is ≥15dB, 8th-order PPM modulation is used to improve parameter transmission efficiency. When the signal-to-noise ratio is <15dB, it switches to 4th-order PPM modulation to enhance anti-interference capability.

[0105] The data segment, lasting 6.144ms, is the core segment carrying valid user data. It employs an APPM adaptive modulation mechanism based on signal-to-noise ratio. Of the 5 bits of data carried per symbol, 3 bits are used to characterize the time slot position, and 2 bits are used to characterize the amplitude level. When the multipath delay maximum value is detected to be ≥50ns through the multipath detection sequence, the system automatically adjusts the APPM modulation order. M The symbol guard interval is reduced from 8 to 4, while the symbol guard interval is increased from 10μs to 20μs. This reduces the transmission rate to avoid inter-symbol interference caused by multipath effects, ensuring the reliability of data transmission. The guard interval duration is 1.024ms, mainly used to adapt to the differences in signal propagation delay at different operating distances. When the system operating distance is ≤500m, the signal propagation delay is small, and the guard time can be shortened to 0.8ms to increase the effective data transmission ratio. When the operating distance is >500m, the signal propagation delay increases, and the guard time is extended to 1.2ms to avoid signal overlap between adjacent frames and ensure the integrity of data transmission.

[0106] In this embodiment, the transmitting end and the receiving end strictly follow the preset communication protocol interaction rules, as follows:

[0107] After the receiver is powered on and initialized, it first parses the fine synchronization header of the synchronization segment to determine the frame start position, and then splits the continuous bit stream according to the preset bit length of each segment. After parsing the control segment parameters, it immediately adjusts the local matched filter template parameters, demodulation threshold, and other configurations to keep the receiver's state consistent with the transmitter's. After the demodulated data segment is completed, it feeds back the data reception status to the transmitter through the retransmission flag in the link layer control area. If the flag is "retransmission" (logic 1), the transmitter will retransmit the current frame data in subsequent frames until the receiver reports "reception successful" (logic 0).

[0108] The transmitting end processes the signal according to a standardized procedure: signal conversion → framing → bit grouping → symbol mapping → Gaussian pulse shaping → digital modulation → electro-optic conversion, ensuring that the output ultraviolet light signal meets the system protocol requirements. Specifically:

[0109] First, signal conversion is performed, transforming various types of input digital signals, such as speech signals (8kHz sampling rate, 16-bit quantization), text signals (ASCII encoding), and image signals (grayscale images, 10:1 compression ratio), into a standard binary bitstream. The input rate of the speech signal is... kbps, the text signal input rate is dynamically adjusted according to actual transmission needs, and the maximum shall not exceed the system's effective data transmission rate.

[0110] Next, framing is performed according to the frame structure protocol described above. The number of effective bits carried by each data segment is determined by the formula... Calculation, where symbol period After substituting the parameters, the effective number of bits per frame data segment is approximately 3416 bits. During the framing process, the contents of the synchronization segment, control segment, and protection segment are automatically generated and added by the system without user intervention.

[0111] Then press The framed bitstream is grouped into units of bits. For example, if the input bitstream is "101100110111010", it will be grouped into independent bit groups such as "10110", "01101", and "11010". This is implemented using the logic circuits inside the FPGA. The formula for converting a matrix from serial to parallel is as follows: ,in The total number of symbols in each data segment (in this embodiment) ), The elements of the transformed matrix, The data format after serial-to-parallel conversion is more convenient for subsequent symbol mapping processing, as it represents the elements of the original bitstream.

[0112] After the serial-to-parallel conversion is completed, each group of 5 bits is mapped to a three-dimensional modulation symbol containing the time slot position, transmit amplitude, and pulse width. This process consists of three steps:

[0113] The first step is to perform position mapping, extracting the first 3 bits of each group of bits (corresponding to...) Converting it to a decimal number will determine the time slot position corresponding to the symbol. k (Value range 0-7), time slot center time This ensures that each symbol is distributed in an orderly manner in the time domain.

[0114] The second step is to perform amplitude mapping, extracting the middle 2 bits of each group of bits (corresponding to...). Convert the base number to a decimal level number l (value range 0-3) using the formula. Calculate the actual launch amplitude, where , , For example, when l=0, A=0.2V, and when l=3, A=1.0V. Through the design of multiple amplitude levels, the bit carrying capacity of a single symbol can be increased without increasing the number of time slots.

[0115] The third step is pulse width selection. The last bit of each group of bits is extracted; this bit controls the pulse width. 0 corresponds to a narrow pulse (σ=0.15μs), and 1 corresponds to a wide pulse (σ=0.25μs). If a consecutive number of bits with the same width are detected... Then according to the formula Dynamically adjust the pulse width, where The base pulse width is α = 0.2 (width expansion factor). (Maximum allowed number of consecutive identical bits), for example, with three consecutive "1"s, σ = 0.25μs × (1 + 0.2 × 2 / 5) = 0.35μs. This dynamic adjustment mechanism avoids excessive concentration of spectral energy and reduces interference between adjacent symbols. After mapping, a sequence is formed... The symbol mapping matrix consists of matrices, with each row containing the time slot position. k Launch amplitude A Adjusted pulse width s and symbol start time (i is the symbol index), providing complete physical parameters for subsequent pulse shaping.

[0116] In this embodiment, after the symbol mapping matrix is ​​generated, the Gaussian pulse shaping stage begins, based on the pulse width parameter in the matrix. s A normalized Gaussian fundamental pulse is generated according to the time-domain expression of the Gaussian pulse, and then the fundamental pulse is compared with the emitted amplitude. A Multiplying these values ​​yields the actual transmitted pulse, which has a peak amplitude range of 0.2V-1.0V and a pulse width range of 0.15μs-0.35μs. Its spectral characteristics are well-suited to the transmission characteristics of solar-blind ultraviolet channels, reducing signal attenuation.

[0117] Digital modulation is then performed. Five Gaussian pulse samples of different widths are pre-stored in the FPGA using a lookup table (LUT). Each sample contains 1024 sampling points, covering the entire range of pulse width values. The modulation is then performed based on the current symbol... s Index and In real time, the FPGA logic circuit selects the corresponding pulse sample and multiplies it by the amplitude. A This generates a baseband digital signal with a sampling rate consistent with that of the subsequent DAC converter (1 GSps).

[0118] Finally, electro-optical conversion is performed. The baseband digital signal is converted into an analog signal by a 16-bit DAC converter (sampling rate 1GSps). The analog signal is amplified by the LED driver circuit and converted into a driving current of 0-200mA to drive the solar-blind ultraviolet LED array to emit ultraviolet light signals. The LED luminous power changes linearly with the driving current, with a power range of 1mW-100mW, which can be flexibly adjusted according to the communication distance.

[0119] In this embodiment, the synchronization control module is integrated into the FPGA chip, and implements dual control of frame synchronization and bit synchronization through hardware logic circuits to ensure strict timing matching between the transmitting and receiving ends, providing a precise time reference for the demodulation process. The frame synchronization process consists of three steps:

[0120] The first step is to calculate the total number of symbols and the bit length, according to the formula. Calculate the total number of symbols in each segment, where the symbol rate is... Total number of synchronization segment symbols Control section Data segment Protection section Then follow the formula Calculate the bit length of each segment to obtain the synchronization segment. Control section Data segment Since the protected segment contains no valid information, its bit length is counted as 0.

[0121] The second step is frame start positioning. The receiving end performs real-time correlation calculations on the fine synchronization header (m sequence) of the synchronization segment through a hardware correlator. When the correlation value exceeds a preset threshold, the frame start signal is immediately triggered to determine the frame start position. The error of this positioning process is ≤5ns, ensuring the accuracy of the timing reference.

[0122] The third step is bitstream segmentation. Based on the bit lengths calculated for each segment, the FPGA logic circuit splits the continuously received bitstream into structured fields for synchronization, control, data, and protection segments. The synchronization segment field is used for synchronization calibration, the control segment field is sent to the ARM processor for parsing, the data segment field is sent to the demodulation module for processing, and the protection segment field is discarded directly without further processing.

[0123] The bit synchronization process consists of five steps:

[0124] The first step is coarse pulse localization. The receiver scans the Gaussian pulse training sequence of the synchronization segment and determines the approximate position of each pulse through threshold detection (the threshold is set to 20% of the ADC full scale). The localization error of this step is ≤100ns, which provides the basis for subsequent fine localization.

[0125] The second step is precise location of the time slot boundary. The time slot grouping correlation algorithm is used to perform point-by-point correlation calculation between the received signal and the locally generated time slot template. When the correlation value reaches the peak value, the time slot boundary can be accurately located. The location error of this step is ≤10ns.

[0126] The third step is to calibrate the time slot spacing. Using the variance analysis method in higher-order statistical features, the width of all time slots is statistically analyzed to calibrate the deviation of the time slot spacing and ensure that the consistency error of the time slot width is ≤2%.

[0127] The fourth step is timing offset tracking. An adaptive digital phase-locked loop is started with a loop bandwidth of 100Hz, which can quickly track the timing offset caused by channel time-varying. After locking, the tracking error is ≤5ns, ensuring the stability of the timing reference.

[0128] The fifth step is parameter constraint, strictly adhering to preset parameter constraint rules, symbol period. (in ), time slot width This width is greater than the sum of the channel's maximum multipath delay (50ns), Gaussian pulse width (0.35μs), and reserved margin (0.1μs) (0.5μs), effectively avoiding inter-symbol interference caused by multipath effects; system bit rate It is much larger than the reciprocal of the channel multipath delay (1 / 50ns=20MHz), ensuring the timing accuracy of signal transmission.

[0129] In this embodiment, the receiving end processes the signal according to the process of "photoelectric conversion → filtering → adaptive shape Gaussian matched filtering → timing synchronization → pulse feature extraction → demodulation → frame parsing" to gradually reconstruct the original data transmitted by the transmitting end. Specifically:

[0130] First, photoelectric conversion is performed. The solar-blind ultraviolet detector converts the received ultraviolet light signal into a weak current signal. After being amplified 1000 times by the detector's internal amplifier circuit, it outputs an analog electrical signal with an amplitude range of 0.1V-1.0V. This detector features low dark current and high responsivity, enabling effective detection of weak light signals in the solar-blind band. Next, ADC sampling is performed. A 16-bit ADC converter (sampling rate 2GSps) samples the analog electrical signal at high speed, converting it into a discrete digital signal sequence. The high sampling rate ensures that the time-domain characteristics of the original signal are fully preserved, providing a high-quality data foundation for subsequent signal processing.

[0131] Then, pre-filtering is performed using a digital filtering method based on adaptive thresholds, according to the formula... Determine the filtering threshold, where (Noise standard deviation obtained through system calibration) (Number of sampling points in the sliding window) (Adaptive parameters) (Initial signal-to-noise ratio estimate), substituted with parameters, yields the calculated result. During the filtering process, the entire discrete received signal sequence is traversed, signals with amplitudes below 0.05V are identified as noise and set to zero, while signals with amplitudes above 0.05V are retained. Through this filtering process, random noise and low-amplitude interference can be effectively filtered out, thereby improving the signal-to-noise ratio of the signal.

[0132] After pre-filtering, adaptive shape Gaussian matched filtering is performed, which is crucial for improving the quality of the received signal: first, a generalized Gaussian pulse model is constructed. , g ( t () represents the time-domain expression of the generalized Gaussian impulse model.A The amplitude normalization coefficient is... s For the time-domain stretching parameters of the Gaussian pulse, c This is the order of the Gaussian function, also known as the shape index. β This is the asymmetric correction coefficient, also known as the trailing edge compensation coefficient. h It is the hyperbolic tangent function. k The shape control parameter of the hyperbolic tangent function. t Let time be the independent variable, and the initial parameter be set to... s =0.2μs, β =0、 c =2、 k =1、 A =1, this model can flexibly adapt to received pulses with different degrees of distortion;

[0133] Next, the template parameters are dynamically adjusted based on the maximum multipath delay value of the channel as resolved by the control segment. In this embodiment, it is 50ns. s Adjusted to 0.25μs (adapting to pulse time-domain broadening). β Adjusted to 0.1 (to compensate for pulse trailing distortion). c Adjust to 2.2 (enhance the attenuation steepness of the pulse) to make the shape of the matching template highly consistent with that of the received pulse;

[0134] Finally, the pre-filtered signal sequence is convolved with the adjusted template. The convolution window length is set to 2048 sampling points. Convolution can enhance the correlation peak amplitude of the signal and suppress interference signals. After matched filtering, the correlation peak amplitude of each transmitted pulse is increased by 3-5 times, and the signal-to-noise ratio is improved by 10-15dB, providing good signal conditions for subsequent pulse feature extraction.

[0135] After the matched filtering is completed, the receiver performs timing synchronization based on the timing reference provided by the synchronization control module to ensure that the processing of each symbol is carried out in the corresponding time slot, thus avoiding timing confusion between symbols.

[0136] After timing synchronization is complete, the pulse feature extraction stage begins, including:

[0137] A one-dimensional convolutional neural network (1D-CNN) is used to identify the pulse leading edge. This network has an encoder-like structure. The input layer is a 1×2048 one-dimensional vector (the output of matched filtering within each symbol period). Convolutional layer 1 uses 16 5×1 convolutional kernels with a stride of 1 and "same" padding, and the activation function is ReLU, which can extract local temporal features of the signal. Max pooling layer 1 uses 2×2 pooling kernels with a stride of 2 to achieve feature dimensionality reduction and translation invariance enhancement. Convolutional layer 2 uses 32 3×1 convolutional kernels with a stride of 1 and "same" padding, and the activation function is ReLU, which further extracts higher-order features. Max pooling layer 2 uses 2×2 pooling kernels with a stride of 2 to further reduce dimensionality. The flattening layer converts the multi-dimensional feature map into a one-dimensional vector. The signal is fed into fully connected layer 1 (64 neurons, ReLU activated) and fully connected layer 2 (32 neurons, ReLU activated) for feature fusion. The output layer has 3 neurons and uses the Linear activation function to directly output the estimated delay values ​​of the main path delay and two significant multipath components. The training set of this network uses simulated multipath channel data (multipath delay 0-100ns, amplitude attenuation 10-30dB). After training, the main path delay estimation error is ≤3ns, which can accurately identify the main path and multipath components of the pulse. Pulse width discrimination is achieved by scanning the synchronized signal within a time slot window (1μs), detecting the rising edge (the moment when the amplitude rises from 0.05V to 0.1V) and falling edge (the moment when the amplitude drops from the peak value to 0.1V), according to the formula. Calculate the pulse width. At the falling edge time, For the rising edge time, the measurement error is ≤5ns; for amplitude discrimination, the sampling points of the stable high-level portion of the pulse (0.2μs after the rising edge to 0.2μs before the falling edge) are extracted, and the results are calculated according to the formula. Calculate the pulse amplitude estimate. To obtain the mean function, To stabilize the sampling point vector of the high-level portion, this method can effectively avoid the distortion effect of the pulse rising and falling edges, with an amplitude measurement error ≤2%.

[0138] After feature extraction is completed, demodulation processing is performed, including:

[0139] The pulse slot position index is determined by the timing synchronization result. k (0-7); The minimum distance decision method is adopted, according to the formula Determine the amplitude level index l (0-3), where The preset amplitude levels are (0.2V, 0.467V, 0.733V, 1.0V); ( k , lThe combination is used to look up the corresponding 5-bit original bit group through a preset inverse mapping table. For example, when k =3、 l When =1, the inverse mapping yields the bit group "10110"; the bit groups obtained from demodulating all symbols are concatenated in frame order to form a complete binary bit stream.

[0140] Finally, frame parsing is performed, including:

[0141] The algorithm searches for the m-sequence of the synchronization segment in the binary bitstream to reconfirm the frame start position and ensure the accuracy of the parsing. It then splits the bitstream according to the bit length of each segment, discarding the bitstreams of the synchronization and guard segments directly. The bitstream of the control segment is sent to the ARM processor for parsing, extracting the modulation and channel parameters to adjust the configuration for the next frame reception. Finally, the bitstream of the data segment is restored according to its original data type: voice data is restored to a 16-bit quantized audio signal with an 8kHz sampling rate, text data is restored to an ASCII-encoded character sequence, and image data is restored to compressed grayscale data. The restored original data is then output to the user application.

[0142] This embodiment addresses the challenges of complex channel characteristics, lack of efficient modulation and reception technologies, and weak anti-interference mechanisms in solar-blind ultraviolet communication. It constructs a fixed-duration frame structure with clearly defined segmented functions and a unified communication protocol. Combined with APPM adaptive modulation, the number of bits per symbol is precisely determined using a formula. Through bit grouping, symbol mapping, and other processing steps, the signal transmission format is optimized, effectively combating channel multipath scattering and signal attenuation. At the receiver, filtering, adaptive shape Gaussian matched filtering, and other multi-stage processing, coupled with precise extraction of pulse feature parameters, solve the problems of weak anti-interference and limited detection accuracy in traditional modulation and reception technologies. A synchronization control module throughout the process achieves dual control of frame synchronization and bit synchronization, ensuring timing matching between the transmitting and receiving ends and improving communication stability in complex environments. The overall technical solution significantly enhances the system's adaptability to channel time-varying characteristics and environmental interference, improves communication confidentiality and reliability, and meets the stringent requirements of high-reliability non-line-of-sight communication in scenarios such as military communication and emergency command.

[0143] Example 2

[0144] A second embodiment of the present invention provides a readable storage medium storing computer instructions that, when executed by a processor, implement the steps of the communication method based on a solar-blind ultraviolet detector described in any of the above embodiments.

[0145] Example 3

[0146] A third embodiment of the present invention provides an electronic device, including a memory, a processor, and a computer program stored in the memory and executable on the processor. When the processor executes the program, it implements the steps of the communication method based on a solar-blind ultraviolet detector described in any of the above embodiments.

[0147] In the description of this specification, references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0148] The embodiments described above are merely examples of several implementations of the present invention, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the present invention. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these all fall within the scope of protection of the present invention. Therefore, the scope of protection of this patent should be determined by the appended claims.

Claims

1. A communication method based on a solar-blind ultraviolet detector, characterized in that, The method includes: Construct a fixed-duration frame structure consisting of a synchronization segment, a control segment, a data segment, and a protection segment, and formulate a frame structure communication protocol that is uniformly followed by the transmitting and receiving ends; The control transmitter converts the input digital signal into a binary bit stream, completes framing according to the frame structure communication protocol, and then modulates it according to the APPM modulation order. M With amplitude level L According to the formula The number of bits carried by a single symbol is determined, and then bit grouping, symbol mapping, Gaussian pulse shaping, and digital modulation processing are performed in sequence. After electro-optic conversion, an ultraviolet light signal is obtained and emitted outward. The control receiver receives the ultraviolet light signal and completes photoelectric conversion to obtain an electrical signal. After sequentially filtering, adaptive shape Gaussian matching filtering, and timing synchronization processing of the electrical signal, the pulse's leading edge, width, and amplitude characteristic parameters are extracted. The control receiver demodulates the electrical signal according to the characteristic parameters to obtain a binary bit stream, and performs frame parsing on the binary bit stream according to the frame structure communication protocol to extract valid user data; Throughout the entire process of signal transmission at the transmitting end and signal reception and processing at the receiving end, the synchronization control module performs frame synchronization and bit synchronization control operations to achieve timing matching between the transmitting end and the receiving end. The steps of constructing the frame structure and defining the communication protocol include: The synchronization segment duration is set to 1.024ms, the control segment duration to 2.048ms, the data segment duration to 6.144ms, and the protection segment duration to 1.024ms. The synchronization segment is divided into three sub-segments: Gaussian pulse training sequence, multipath detection sequence, and fine synchronization head. The control segment is divided into three sub-segments: physical layer control area, adaptive parameter area, and link layer control area. The control section adaptively switches between multi-order PPM modulation modes based on the signal-to-noise ratio (SNR). The data section adopts an APPM adaptive modulation mechanism based on the SNR, and adjusts the APPM modulation order and symbol guard interval according to the severity of multipath propagation. The protection segment dynamically adjusts the protection time of information transmission based on the system's operating distance. The total number of symbols in each segment is calculated based on the fixed duration of each segment of the frame structure and the system symbol rate. The bit length of each segment is calculated in combination with the number of bits carried by a single symbol. The processing rules and interaction standards for each segment of data at the transmitting and receiving ends are clarified.

2. The communication method based on a solar-blind ultraviolet detector according to claim 1, characterized in that, The steps for the transmitter to process the binary bit stream and perform electro-optic conversion after completing framing include: The framed bitstream is divided into Divide into consecutive blocks of bits and complete the process. The formula for converting a matrix from serial to parallel is as follows: ,in The total number of symbols, For the transformed matrix elements, These are the original bitstream elements; Each group of bits is mapped to a three-dimensional modulation symbol containing the time slot position, transmission amplitude, and pulse width, forming a symbol mapping matrix; Gaussian pulse shaping is performed based on the pulse width parameter in the symbol mapping matrix to generate a Gaussian base pulse, which is then combined with the emission amplitude parameter to obtain the actual emission pulse. In a programmable gate array, the actual transmitted pulse is discretized and digitally modulated using a lookup table method to generate a baseband digital signal; The baseband digital signal is sequentially converted from digital to analog and then driven by the LED to obtain a driving electrical signal, which is then input to the ultraviolet LED. The ultraviolet LED then completes the electro-optical conversion and emits an ultraviolet light signal.

3. The communication method based on a solar-blind ultraviolet detector according to claim 2, characterized in that, The steps of mapping each group of bits to three-dimensional modulation symbols and forming a symbol mapping matrix include: Extract the preceding bits corresponding to the APPM modulation order from each bit group, convert them to decimal numbers, determine the time slot position corresponding to the symbol, and extract the middle bits corresponding to the amplitude level from each bit group, converting them to decimal level numbers. l According to the formula Calculate the actual launch amplitude, where, This represents the actual launch amplitude. For minimum transmission amplitude, , The step interval for amplitude quantization. For maximum launch amplitude, L The total number of levels of amplitude; Extract the last bit of each group of bits, and select a narrow pulse width parameter or a wide pulse width parameter from the preset parameters according to the bit value of that bit. If the number of consecutive bits with the same width reaches the preset value, dynamically adjust the current pulse width parameter according to the preset coefficient. Based on the determined time slot position, the calculated actual transmission amplitude, the adjusted pulse width parameter, and the symbol start time, a row vector containing the physical transmission parameters is generated, and all row vectors form a symbol mapping matrix.

4. The communication method based on a solar-blind ultraviolet detector according to claim 1, characterized in that, The steps for performing frame synchronization and bit synchronization control operations through the synchronization control module include: Frame synchronization control is performed: the receiver detects the fine synchronization header sequence in the synchronization segment, determines the start position of a frame of data, and splits the continuous bit stream into structured fields of synchronization segment, control segment, data segment, and protection segment according to the calculated bit length of each segment; Execution bit synchronization control: The receiving end scans the training sequence of the synchronization segment to coarsely locate the pulse, accurately locates the time slot boundary through the time slot grouping correlation algorithm, calibrates the consistency of the time slot spacing using high-order statistical features, and starts the adaptive digital phase-locked loop to continuously track the timing offset caused by the time-varying channel. Set the bit synchronization related parameter constraint rules, according to the formula Set the symbol period, where For symbol period, The number of time slots per symbol. For time slot width, For inter-symbol protection time, and At the same time, set It is greater than the sum of the channel's maximum multipath delay, Gaussian pulse width, and reserved margin.

5. The communication method based on a solar-blind ultraviolet detector according to claim 1, characterized in that, The receiving end performs filtering and adaptive shape Gaussian matched filtering on the electrical signal after photoelectric conversion, including: The analog electrical signal after photoelectric conversion is sampled by ADC to obtain a discrete received signal sequence, and the discrete received signal sequence is pre-filtered using a digital filtering method based on adaptive threshold. A generalized Gaussian pulse model is constructed as a matched filter template. The parameters of the generalized Gaussian pulse model are dynamically adjusted according to the channel estimation results to make the template match the pulse shape of the transmitter. The pre-filtered signal sequence is convolved with the adjusted matched filter template to obtain the matched filtered signal sequence. The matched filtering results of the entire frame are then integrated into a vector form.

6. The communication method based on a solar-blind ultraviolet detector according to claim 1, characterized in that, The receiving end extracts pulse feature parameters and completes demodulation and frame parsing steps, including: A one-dimensional convolutional neural network is used to identify the pulse leading edge of the signal after timing synchronization, identify the arrival time of the main path and the arrival time of the multipath component of the pulse corresponding to each symbol, and filter out the significant multipath components whose amplitude exceeds the preset threshold. The signal after timing synchronization is scanned within the time slot window. The rising edge and falling edge of the pulse are detected. The time difference between the two edges is calculated to obtain the pulse width. The sampling points of the stable high-level part of the pulse are extracted. The statistical mean of the sampling points is calculated to obtain the pulse amplitude estimate. The pulse slot position index is determined by the timing synchronization result, and the minimum distance decision method is used according to the formula. Determine the magnitude level index, where This is an estimate of the pulse amplitude. Preset amplitude level; The time slot position index and amplitude level index are jointly inversely mapped to restore the original bit groups and concatenate them into a binary bit stream in frame order; Search for specific bits of the synchronization segment in the binary bit stream to determine the start position of a data frame. Split the bit stream according to the bit length of each segment, parse the control segment bit stream to extract relevant parameters, extract the data segment bit stream as valid user data, and discard the bit streams of the synchronization segment and the protection segment.

7. A communication system based on a solar-blind ultraviolet detector, characterized in that, The system, applicable to the method of any one of claims 1-6, comprises: The frame structure construction module is used to construct a fixed-duration frame structure consisting of a synchronization segment, a control segment, a data segment, and a protection segment in sequence, and to formulate a frame structure communication protocol that is uniformly followed by the transmitting end and the receiving end. The transmitter module controls the transmitter to convert the input digital signal into a binary bit stream, completes framing according to the frame structure communication protocol, and then modulates the signal according to the APPM modulation order. M With amplitude level L According to the formula The number of bits carried by a single symbol is determined, and then bit grouping, symbol mapping, Gaussian pulse shaping, and digital modulation processing are performed in sequence. After electro-optic conversion, an ultraviolet light signal is obtained and emitted outward. The receiving module is used to control the receiving end to receive the ultraviolet light signal and complete the photoelectric conversion to obtain an electrical signal. After sequentially filtering, adaptive shape Gaussian matching filtering, and timing synchronization processing of the electrical signal, the leading edge, width, and amplitude characteristic parameters of the pulse are extracted. The receiving module is also used to control the receiving end to demodulate the electrical signal according to the characteristic parameters to obtain a binary bit stream, and to perform frame parsing on the binary bit stream according to the frame structure communication protocol to extract valid user data; The synchronization control module is used to perform frame synchronization and bit synchronization control operations throughout the entire process of signal transmission at the transmitting end and signal reception and processing at the receiving end, so as to achieve timing matching between the transmitting end and the receiving end.

8. A readable storage medium having computer instructions stored thereon, characterized in that, When executed by the processor, this instruction implements the steps of the communication method based on a solar-blind ultraviolet detector as described in any one of claims 1-6.

9. An electronic device comprising a memory, a processor, and a computer program stored in the memory and executable on the processor, characterized in that, When the processor executes the program, it implements the steps of the communication method based on a solar-blind ultraviolet detector as described in any one of claims 1-6.

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