Wireless optical communication system and method for high-definition audio-video transmission

Abstract

The invention relates to the technical field of audio and video transmission, and provides a wireless optical communication system and method for high-definition audio and video transmission. The wireless optical communication system for high-definition audio-video transmission comprises a transceiving module, wherein a transmitting module comprises a data transmission SFP (Small Form-factor Pluggable) assembly connected with an audio-video transmission line, an optical module assembly arranged at a transmitting end, and an FPGA (Field Programmable Gate Array) assembly arranged between the data transmission SFP assembly and the optical module assembly; the photoelectric receiving module comprises an optical receiving unit arranged at a receiving end, an output interface connected with a display, and a signal processing unit arranged between the optical receiving unit and the output interface, and the transmitting module is used for modulating video / audio data and generating a signal so as to transmit a light signal to the photoelectric receiving module; and the photoelectric receiving module performs photoelectric conversion, demodulation and decoding processing on the received light signal so as to restore video / audio data. Through the technical means of high bandwidth, low time delay and strong anti-interference, the wireless transmission quality of high-definition video and audio is improved.

Description

Technical Field

[0001] This application relates to the field of audio-visual transmission technology, and in particular to a wireless optical communication system and method for high-definition audio-visual transmission. Background Technology

[0002] With the rapid popularization of emerging applications such as 8K video, virtual reality, intelligent monitoring, and edge computing, unprecedented challenges have been posed to the bandwidth, latency, and stability of wireless transmission. In scenarios with extremely high requirements for security and real-time performance, such as medical, industrial control, and home theaters, the importance of high-definition audio-visual wireless communication lies not only in its ability to carry massive data streams, but also in the synchronization of image and sound, the smoothness of interactive experiences, and the confidentiality of data content. Future multimedia services must maintain transmission rates of tens of Gbps while controlling end-to-end latency to sub-millisecond levels to meet the stringent immediacy requirements of 8K video, AR / VR, and remote control.

[0003] Currently, mainstream high-definition audio-visual wireless communication solutions primarily rely on radio frequency (RF) technologies, including Wi-Fi 6 / 6E / 7, WiGig millimeter wave in the 60GHz band, and protocols such as Bluetooth and ZigBee for the Internet of Things (IoT). These technologies continuously improve throughput through spectrum reuse and novel antenna designs, and optimize link performance through multi-user MIMO and beamforming. Furthermore, indoor visible light communication (VLC) is beginning to be applied in specific scenarios, utilizing lighting systems for data transmission. However, neither RF nor rudimentary optical solutions can simultaneously meet the unified requirements of high bandwidth, low latency, and high stability. Summary of the Invention

[0004] In view of this, this application provides a wireless optical communication system and method for high-definition audio and video transmission to solve the problems of insufficient link reliability and latency controllability in high-definition audio and video wireless communication.

[0005] The first aspect of this application provides a wireless optical communication system for high-definition audio and video transmission. The system includes a transmitting module for connecting an audio and video transmission line and an optoelectronic receiving module for connecting a display. The transmitting module includes a data transmission SFP component connected to the audio and video transmission line, an optical module component disposed at the light emitting end, and an FPGA component disposed between the data transmission SFP component and the optical module component. The SFP component is used to convert input video / audio data into optical signals; The optical module assembly is used to convert the input transmission signal into an analog drive signal suitable for the built-in laser, so as to emit light signals into free space according to the analog drive signal; The FPGA component is used to perform protocol encapsulation, forward error correction, and signal modulation on the optical signal to generate the transmission signal. The photoelectric receiving module includes an optical receiving unit disposed at the light receiving end, an output interface connected to the display, and a signal processing unit disposed between the optical receiving unit and the output interface; The optical receiving unit is used to filter and compensate the received light signal to generate an analog signal; The signal processing unit is used to demodulate and decode the analog signal to restore the video / audio data.

[0006] In an optional implementation, the optical module assembly includes an optomechanical adjustment device for dynamically adjusting the spot size and divergence angle of the optical signal according to different transmission distances.

[0007] In one optional implementation, the light signal includes a guide light and a signal light, and the optical receiving unit further includes a dichroic mirror for separating the light signal and filtering the guide light.

[0008] In one optional embodiment, the optical receiving unit includes a photodetector and a focusing module disposed above the photodetector; The focusing module is used to focus the signal light onto the photodetector; The photodetector is used to convert the signal light into an analog electrical signal, and to amplify and filter the analog electrical signal to obtain an analog signal.

[0009] In an optional embodiment, the optical receiving unit includes an image sensor for detecting the position of the light spot of the guide light; The optical receiving unit is also used to dynamically adjust the photodetector according to the position of the light spot, so that the center point of the guiding light is aligned with the sensing area of ​​the photodetector.

[0010] In an alternative implementation, the video / audio data includes electrical signals, and the SFP component includes a power line carrier communication interface for receiving video / audio data input via power lines.

[0011] A second aspect of this application provides a wireless optical communication method for high-definition audio-visual transmission, applied to the wireless optical communication system for high-definition audio-visual transmission described above, the method comprising: The transmitting module performs protocol encapsulation and high-order modulation on the received multimedia data according to a preset first protocol to obtain the baseband electrical signal driving the laser. The transmitting module performs laser driving and beam shaping processing on the baseband electrical signal according to the acquired transmission distance in order to transmit light signals; The photoelectric receiving module performs photoelectric conversion, noise suppression, and signal compensation processing on the received light signal to obtain a digital signal; The photoelectric receiving module demodulates and decodes the digital signal according to the first protocol to restore the multimedia data.

[0012] In an optional implementation, before the transmitting module transmits the light signal, the method further includes: Step S81: The transmitting module transmits calibration test light to the photoelectric receiving module according to the preset test light control signal; Step S82: The photoelectric receiving module acquires the spot image of the calibration test light in real time, and performs spot center identification and coordinate extraction on the spot image to obtain the real-time spot center coordinates; Step S83: The photoelectric receiving module performs offset calculation based on the preset target center coordinates in the optical receiving unit and the real-time light spot center coordinates to obtain the real-time offset amount. Step S84: The photoelectric receiving module generates a pulse command according to a preset command generation method and the real-time offset, and dynamically adjusts the optical receiving unit according to the pulse command; The photoelectric receiving module repeatedly executes steps S82 to S84 until the real-time offset is less than a preset offset threshold.

[0013] In an optional implementation, the multimedia data includes audio-visual data and control commands. After the photoelectric receiving module parses the multimedia data to obtain the control commands, the method further includes: The photoelectric receiving module performs Manchester encoding on the control commands to obtain uplink control data packets; The photoelectric receiving module performs pulse position mapping processing on the uplink control data packet according to the preset OOK modulation rule to obtain the uplink drive electrical signal; The photoelectric receiving module drives the built-in transmitting laser unit according to the uplink driving electrical signal to transmit an uplink optical pulse sequence to the transmitting module; After the transmitting module acquires the uplink optical pulse sequence through the optical receiver, it demodulates and decodes the uplink optical pulse sequence according to the received time sequence to obtain reconstruction control command / control command completion information. When the transmitting module receives the reconstruction control command, the transmitting module dynamically adjusts the optical signal according to the reconstruction control command.

[0014] In summary, this application includes at least the following beneficial technical effects: 1. Based on the actual transmission distance on site, the system can collect and feedback distance information in real time at the transmitting end. The FPGA calls the preset laser drive and beam shaping algorithm to automatically adjust the laser power and divergence angle, which simplifies the process of manual alignment and power setting and improves deployment efficiency.

[0015] 2. At the receiving end, the signal processing unit performs multi-stage noise suppression and decoding on the analog signal after photoelectric conversion, further repairing residual errors and ensuring high-fidelity reproduction of picture and sound. Attached Figure Description To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0016] Figure 1 This is a schematic diagram of the structure of a wireless optical communication system for high-definition audio and video transmission provided in Embodiment 1 of this application; Figure 2 This is a schematic diagram of the structure of a sending module provided in Embodiment 2 of this application; Figure 3 This is a schematic diagram of the structure of an optomechanical adjustment device provided in Embodiment 3 of this application; Figure 4 This is a flowchart illustrating a wireless optical communication method for high-definition audio and video transmission provided in an embodiment of this application. Detailed Implementation

[0017] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0018] The wireless optical communication system for high-definition audio and video transmission provided in this application embodiment is used to achieve end-to-end high-speed wireless optical transmission of audio and video data, such as video and audio data. The following explanation uses the transmission process of high-definition video / audio data between a television and a wireless set-top box router to illustrate the wireless optical communication system and method for high-definition audio and video transmission provided in this application embodiment. Specifically, the television transmits data wirelessly to the set-top box router via a television adapter. Hereinafter, the television adapter is referred to as the optoelectronic receiving module, the set-top box router as the transmitting module, and the television or other high-definition display screen as the display.

[0019] Please refer to the above. Figures 1 to 3 The wireless optical communication system for high-definition audio and video transmission provided in this application includes a transmitting module 3 connected to an audio and video transmission line 4 and a photoelectric receiving module 2 connected to a display 1. The transmitting module 3 communicates wirelessly with the photoelectric receiving module 2 via optical signals (in this application embodiment, the optical signals include guide light and signal light) to transmit high-definition audio and video data (i.e., high-definition video / audio data). The signal light uses near-infrared laser beams such as VCSEL / DML / DFB as the communication carrier for the high-definition audio and video data. The guide light uses a special image spot formed by visible light (e.g., a cross-shaped positioning spot used in this application embodiment) to facilitate manual calibration of the projection between the transmitting module 3 and the photoelectric receiving module 2 based on the projection position of the guide light. The video / audio data can be optical signals input through optical fiber cables and / or electrical signals input through network cables.

[0020] like Figure 2 as well as Figure 3 As shown, the transmitting module 3 includes a data transmission SFP (Small Form-factor Pluggable) component 31 connected to the audio-visual transmission line 4, an optical module component 33 disposed at the optical emission end, and an FPGA (Field Programmable Gate Array) component 32 disposed between the data transmission SFP component and the optical module component.

[0021] The data transmission SFP component 31 is used to establish a communication connection with an external system (i.e., the data source device for audio and video data) via the audio / video transmission line 4, including but not limited to Ethernet interfaces, HDMI high-definition interfaces, USB or Type-C ports, etc., adapting to different types of data interface connections and data input requirements. In an optional embodiment, to establish a power line-wireless optical fusion system, the data transmission SFP component 31 can also introduce the collected audio / video, multimedia control data or sensor signals into the system via the power line. To enhance the deployment flexibility of the system, the data transmission SFP component 31 in this embodiment is also configured with a power line carrier communication interface, connecting the local optical communication access point to the back-end network via the power line, realizing wireless optical transmission + power line dual-channel collaboration, thereby improving the coverage of system input data and facilitating the rapid deployment of optical communication functions on existing power distribution networks such as industrial facilities or nuclear power plants without additional wiring. The data transmission SFP component 31 has an adaptive function for multiple data conversion protocols, which can convert data signals input from HDMI data cables / USB data cables / power lines into unified optical signals, thereby transmitting the optical signals to the FPGA component 32 through optical fiber to avoid external electromagnetic interference to the input data.

[0022] The FPGA component 32 in this embodiment adopts the Xilinx UltraScale framework and is equipped with high-performance programmable devices (e.g., FPGA, ARM, or DSP chips) to perform operations on the input optical signal, including but not limited to protocol encapsulation (e.g., HDCP 2.3 encryption), forward error correction coding (e.g., LDPC code), and high-order modulation (e.g., 256-QAM OFDM or 4-PAM). This system primarily targets point-to-point communication under a single operating condition. To meet the simultaneous processing of multiple input data (e.g., dual operating conditions or multiple user access), the FPGA component 32 in this embodiment can also employ multiple access scheduling (e.g., using OFDMA for downlink resource allocation and SC-FDMA for uplink backhaul) to support the allocation requirements of various input data. Finally, the data signal output by the FPGA component 32 is also converted to an analog-to-digital converter, and a DC bias is added to the obtained transmission signal to ensure that the transmission signal meets the driving requirements of the directly modulated laser.

[0023] In this embodiment, the optical module component 33 converts the input transmission signal into an analog drive signal and drives the built-in light source to generate an adjustable intensity light signal based on the processed analog drive signal. Depending on the application scenario, the optical module component 33 can select a high-power VCSEL / DML / DFB or other near-infrared laser as the emission light source. The operating wavelength of the light source emitting the light signal in the optical module component 33 can be selected from 850nm, the communication 0 band, or the communication C band (e.g., between 1530-1565nm) to meet the requirements of high-speed, high-definition data transmission, thereby achieving an adjustable wireless data transmission rate of 10-50Gbps. For example, the optical module component 33 integrates a 1550nm DML laser, a DAC drive circuit, and a temperature control unit. The DAC drive circuit converts the digital signal (i.e., the transmission signal) input from the FPGA component 32 into an analog drive signal, thereby driving the DML laser to generate an adjustable intensity light signal to support adaptive adjustment of the 10-50Gbps rate. Simultaneously, the temperature control unit monitors the temperature of the optical module component 33 in real time. In this embodiment, the light signal includes visible guide light and near-infrared signal light. Because the signal light uses invisible near-infrared light, its communication requires extremely high beam alignment accuracy. This embodiment uses visible guide light to assist the user in aligning the transmitting module 3 and the photoelectric receiving module 2, guiding the user to perform manual calibration. The optical module component 33 in this embodiment also integrates visible light that emits wavelengths in the range of [450nm, 650nm], thereby guiding the user to complete the positioning and alignment between the modules. Simultaneously, the visible guide light does not carry communication information. For example, the optical module component 33 emits a cross-shaped positioning spot easily recognizable to the human eye as guide light. The user manually adjusts the light projection direction of the transmitting module 3 according to the projection position of the cross-shaped spot, so that the guide light is projected onto a preset specific area on the photoelectric receiving module 2, achieving an alignment error ≤ ±5cm.

[0024] In one alternative implementation (e.g.) Figure 3As shown in the figure, the optical module assembly 33 of this application embodiment also includes an optomechanical adjustment device 331 disposed at the light source emitting end, used to dynamically adjust the spot size and divergence angle of the emitted light signal according to different transmission distances in the actual use environment. According to the product's requirements for data transmission rate and the spot size of the signal light, the focusing degree of the signal light and the guiding light beam can be adjusted by the mechanical structure of the optomechanical adjustment device 331. The optomechanical adjustment device 331 in this application embodiment integrates a stepper motor, a threaded lens sleeve adjusted by the motor, and a collimating lens linked to the threaded lens sleeve. The system adjusts the mechanical structure of the optomechanical adjustment device 331 to make the beam divergence angle approximately 7.3 mrad, and adjusts the spot size of the beam projected onto the photoelectric receiving module 2 according to the distance between the modules, so that the photoelectric receiving module 2 can accurately collect the signal light. For example, when the distance between the modules is greater than 50 cm, the diameter of the spot projected onto the photoelectric receiving module 2 is approximately 4 mm.

[0025] The photoelectric receiving module 2 of this application embodiment includes an optical receiving unit disposed at the light receiving end, an output interface connected to the display 1, and a signal processing unit disposed between the optical receiving unit and the output interface.

[0026] The optical receiving unit for receiving light signals integrates a photodetector (e.g., a near-infrared avalanche photodiode (APD) or a PIN detector) and a focusing module disposed above the photodetector. The focusing module is used to focus the signal light onto the photodetector. The photodetector also integrates a high-bandwidth transimpedance amplifier (TIA). In this embodiment, the photodetector converts the detected signal light into an analog electrical signal via the APD, and then amplifies and filters the converted analog electrical signal via the TIA to obtain an analog signal, which is finally transmitted to the signal processing unit. In an optional embodiment, to filter invalid light (e.g., to separate the guide light from the signal light in a mixed light signal), the optical receiving unit also includes a dichroic mirror disposed above the focusing module. The dichroic mirror separates and filters the received light to obtain the signal light carrying information.

[0027] In an optional implementation, the optical receiving unit can also integrate an image sensor (e.g., a CMOS camera sensor). The optical receiving unit uses the image sensor to detect the position of the light spot projected onto the photoelectric receiving module 2. After manual alignment by the user, the optical receiving unit can also drive a drive motor integrated on the photodetector based on the detected real-time light spot position, thereby dynamically adjusting the photodetector to align the center point of the guide light with the defined sensing area on the photodetector. Achieving fine alignment between modules through the image sensor allows for the establishment of more precise data links between modules. Once the data link is established, the modules are triggered to transmit multimedia data.

[0028] The signal processing unit used in this embodiment integrates an analog-to-digital converter and a demodulation chip to demodulate and decode the analog signal. After obtaining the analog signal, the signal processing unit performs modulation demapping, error correction decoding, and protocol parsing on the analog signal to ultimately restore the complete multimedia data. The output interface transmits the restored multimedia data to the display 1 or an upper-layer application platform. To support multiple output standards, the output interface used in this embodiment can integrate USB, HDMI, and Type-C interfaces, etc., to transmit the restored data to the display 1, thereby completing various application functions including 8K TV picture restoration, industrial terminal data presentation, and remote interactive command feedback.

[0029] In an optional implementation, the wireless optical communication system for high-definition audio and video transmission can also employ a bidirectional communication architecture, enabling the photoelectric receiving module 2 to have optical transmission capabilities and the transmitting module 3 to have optical reception capabilities. Under this bidirectional communication architecture, the photoelectric receiving module 2 can also transmit uplink data such as commands and status information back to the transmitting module 3, forming a closed-loop interactive communication structure between the photoelectric receiving module 2 and the transmitting module 3.

[0030] Please refer to the above. Figure 1 as well as Figure 4 The wireless optical communication process between the transmitting module and the photoelectric receiving module for high-definition audio and video transmission is as follows: Step S1: The transmitting module performs protocol encapsulation and high-order modulation on the received multimedia data according to the preset first protocol to obtain the baseband electrical signal driving the laser.

[0031] First, the transmitting module encapsulates the input multimedia data according to a preset first protocol (i.e., the HDCP 2.3 standard protocol). Within the data transmission SFP component, the multimedia data is converted into an optical signal and transmitted to the FPGA component via optical fiber. Protocol encapsulation effectively prevents information leakage during transmission by adding an encrypted frame header and a timestamp to the optical signal. For example, when an 8K video stream is input via an HDMI interface, the FPGA component adds a 128-bit HDCP 2.3 encrypted header to each data packet to prevent content piracy, while inserting a 32-bit timestamp to ensure audio-visual synchronization. Subsequently, high-order modulation is performed on the encrypted signal. In this embodiment, the FPGA component dynamically selects the modulation scheme based on channel quality detection results. Specifically, when the signal-to-noise ratio is better than 30dB, 4-PAM modulation is used to carry 2 bits of data per symbol, while in complex electromagnetic environments, it switches to QPSK-OFDM to improve anti-interference capabilities. The modulation output is converted into a baseband electrical signal after a DC bias is added by a digital-to-analog converter. Its voltage range is adapted to the laser driving requirements of this system. For example, -3V to +3V corresponds to the four symbol states of 4-PAM. This process converts the original 48Gbps HDMI data stream into an electrical signal form that can drive the laser, laying the foundation for high-speed optical communication.

[0032] Step S2: The transmitting module performs laser driving and beam shaping processing on the baseband electrical signal according to the acquired transmission distance to transmit light signals.

[0033] After obtaining the baseband electrical signal for laser driving, the transmitting module triggers the laser driving and beam shaping process. Specifically, the DAC within the optical module assembly converts the baseband electrical signal into an analog current to drive the 1550nm DML laser integrated into the transmitting module in this embodiment. Temperature control is performed synchronously during the driving process. When the temperature sensor detects that the laser substrate exceeds a preset temperature threshold (e.g., 45°C), a reverse current (e.g., 1.5A) is applied to the Peltier semiconductor in the transmitting module to implement active cooling, ensuring that the wavelength drift of the optical signal is less than 0.1nm. Beam shaping is achieved through an optomechanical adjustment device. This device uses a stepper motor to drive a threaded lens sleeve, dynamically adjusting the divergence angle according to the preset transmission distance. For example, when the preset transmission distance is 0.3m, the divergence angle is compressed from an initial 30° to 1.5°, causing the spot diameter to converge to 2mm. When the transmission distance increases to 1m, it is adjusted to 7.3mrad to maintain an 8mm spot diameter.

[0034] Before emitting the light signal, the transmitting module emits a cross-shaped guide light, which is projected onto the photoelectric receiving module. This guides the user to manually adjust the transmission angle of the transmitting module by visually observing the position of the light spot, ensuring that the distance error between the guide light and the center of the sensing area on the photoelectric receiving module is within ±5cm, thus ensuring an effective communication link can be established between the modules. After completing the manual calibration, the transmitting module receives a calibration completion message from the photoelectric receiving module, which triggers the transmission of the light signal. The light signal includes visible guide light (e.g., visible light with a wavelength of 532nm) used to monitor whether device offset occurs during communication, and signal light (e.g., near-infrared light with a wavelength of 1550nm) as the information carrier.

[0035] In an optional implementation, after the user completes the manual adjustment of the transmitting module (i.e., the distance error between the guide light and the center point of the sensing area on the photoelectric receiving module is within ±5cm), the photoelectric receiving module will trigger an autonomous fine calibration process before the transmitting module emits the light signal. Specifically, the photoelectric receiving module first sends back a preset autonomous calibration signal, causing the transmitting module to activate a preset test light control signal, driving the 532nm green laser to emit a crosshair positioning spot as a calibration test light. This light is coaxial with the subsequent communication beam but is only used for position calibration and does not carry data. The CMOS sensor of the photoelectric receiving module acquires images of the preset target area (i.e., the spot image) at a rate of 30 frames / second, and extracts the center coordinates of the spot using a hard-core image processor. For example, at a resolution of 1920×1080, the pixel coordinates of the crosshair intersection are identified and converted into physical positions (X). spot ,Y spot Using the preset target center coordinates (e.g., X=960 pixels, Y=540 pixels) in the optical receiving unit as a reference, the real-time offset between the two is calculated in real time (i.e., ΔX=X). spot -960, ΔY=Y spot -540).

[0036] The signal processing unit encodes the offset into Manchester-formatted pulse commands, thereby driving the piezoelectric ceramic micro-displacement platform integrated into the photodetector base. Its voltage-displacement response characteristic is that it generates a 1-micrometer displacement for every 100V of voltage. For example, when ΔX = +120, the signal processing unit converts ΔX into a binary sequence 1100, which is then Manchester-encoded to generate a 10 1001 01 pulse chain. This applies a +1200V voltage to the piezoelectric ceramic micro-displacement platform, causing the lens group to shift 120 micrometers to the right. The dynamic adjustment process operates continuously in a closed loop. The CMOS sensor updates the spot position and recalculates the offset every 33mm until three consecutive times the real-time offset is detected to be less than a preset offset threshold (e.g., |ΔX| < 10 pixels (approximately 0.7mm), |ΔY| < 10 pixels). The photoelectric receiving module sends back calibration completion information, which triggers the transmission module to emit a light signal.

[0037] Step S3: The photoelectric receiving module performs photoelectric conversion, noise suppression, and signal compensation processing on the received light signal to obtain a digital signal.

[0038] After detecting the light signal, the photoelectric receiving module performs photoelectric conversion and signal optimization. First, the light signal is separated by a dichroic mirror in the optical receiving unit. For example, the reflective layer of the dichroic mirror reflects 532nm guide light with 99% efficiency to the CMOS sensor for spot tracking, while the transmission layer focuses the 1550nm signal light onto the InGaAs APD detector. The photoelectric conversion stage employs avalanche gain technology. Under a 200V bias, the APD amplifies the 0.1μW weak light signal by 1000 times through impact ionization, outputting a 1mA current. The gain value is dynamically adjusted according to the input light intensity. After the transimpedance amplifier converts the current into a voltage signal, a 40GHz low-pass filter removes radio frequency interference such as WiFi. However, the signal still suffers from nonlinear distortion caused by laser chirp. To address this, the signal processing unit is equipped with a 3rd-order Volterra equalizer. 100 pre-stored coefficients are used for inverse waveform compensation based on distortion characteristics at different temperatures. For example, in a 50°C environment, approximately 15% of inter-symbol interference is compensated. This operation improves the signal-to-noise ratio by more than 6dB, ensuring a bit error rate below 10% even in industrial electromagnetic interference environments. -4 .

[0039] Step S4: The photoelectric receiving module demodulates and decodes the digital signal according to the first protocol to restore the multimedia data.

[0040] Finally, the optoelectronic receiving module performs data restoration, and the analog-to-digital converter captures the analog voltage waveform at a sampling rate of 100GS / s, quantizing each sampling point into a 12-bit digital signal. The clock recovery unit uses the Gardner algorithm to extract the precise clock phase from the discrete samples, and its error detection formula reconstructs the timing reference through the amplitude relationship between adjacent sampling points. The demodulation process operates in reverse according to the modulation scheme of the transmitting end. Specifically, in 4-PAM modulation, the voltage range from -4V to +4V is divided into four symbol states, for example, -1.02V is judged as a 01 symbol; QPSK-OFDM resolves the phase of the orthogonal subcarriers. The LDPC decoder iteratively corrects data packets at a code rate of 5 / 6, which can repair 15% of random bit errors and 8% of burst bit errors, such as automatically reconstructing lost data packets when there is a momentary blockage in the transmission path. After the protocol parsing layer strips the HDCP 2.3 encryption header and timestamp, the original multimedia data is output to the display through the HDMI 2.1 interface.

[0041] In one optional implementation, after the multimedia data is restored and output to the display, the photoelectric receiving module feeds back the execution status of the control commands in the multimedia data (i.e., control command completion information) to the data source device through the sending module via a preset bidirectional control link, or feeds back the reconstruction control commands to the sending module to prompt the sending module to dynamically adjust the light signal.

[0042] First, the photoelectric receiving module parses the control commands in the multimedia data stream. These commands contain user operation information or link optimization requirements. For example, when the TV detects that the user has pressed the "volume +" button on the remote control, it extracts the 16-bit control code 0x0F01 (operation code 0x0F represents volume adjustment, and parameter 0x01 indicates an increment of 1 level). To improve anti-interference capability, the control commands are converted into uplink control data packets using Manchester encoding. This encoding rule converts the original bit stream into a level transition sequence, mapping logic "0" to a low-to-high transition and logic "1" to a high-to-low transition, giving the data built-in clock synchronization information and eliminating the timing jitter defects of traditional RF solutions in electromagnetically sensitive environments. In the nuclear power plant control room scenario, this design avoids delay fluctuations introduced by retransmission mechanisms, ensuring a command transmission success rate of over 99.9%.

[0043] The uplink control data packet then undergoes pulse position mapping processing to generate an uplink drive electrical signal according to a preset OOK modulation rule. For example, the Manchester-coded "10" sequence is converted into a +3V / 10ns pulse, and the "01" sequence into a 0V level. The pulse is activated only during the video vertical blanking period (duty cycle 0.02%), significantly reducing power consumption. This electrical signal drives the 1310nm vertical-cavity surface-emitting laser integrated into the optoelectronic receiver module. The emitted uplink optical pulse sequence is isolated from the main communication link wavelength: the 1550nm downlink signal light carries audio and video data, while the 1310nm uplink pulse is dedicated to control commands; the two are physically separated by a dichroic mirror.

[0044] After the infrared receiving unit of the transmitting module captures the uplink optical pulse sequence, it demodulates and decodes the sequence according to the received time sequence—restoring the Manchester code through edge detection. Specifically, rising edges are identified as "1" and falling edges as "0", thus demodulating the uplink optical pulse sequence into a digital sequence composed of "1"s and "0"s. This digital sequence is then decoded by the decoder to reconstruct the original control command. When the command is a dynamic adjustment request (e.g., when link quality monitoring detects a bit error rate exceeding 10%)... -4 The transmitting module immediately responds to the reconstruction control command: if it is a 0xA301 code (requesting a lower code rate), the FPGA component switches the modulation scheme from 4-PAM to QPSK, reducing the data transmission rate from 50Gbps to 30Gbps to improve stability; if it is a 0x0F01 volume command, the audio processing unit increases the digital gain by 3dB. After adjustment, an HDCP 2.3 encrypted confirmation signal is sent to the optoelectronic receiving module via the main link.

[0045] It should be understood that the various variations and specific embodiments of the methods provided in the above embodiments are also applicable to the wireless optical communication method for high-definition audio and video transmission in this embodiment. Through the foregoing detailed description of the wireless optical communication system for high-definition audio and video transmission, those skilled in the art can clearly understand the implementation method of the wireless optical communication method for high-definition audio and video transmission in this embodiment. For the sake of brevity, it will not be described in detail here.

[0046] In the several embodiments provided in this application, it should be understood that the disclosed apparatus and methods can be implemented in other ways. For example, the apparatus embodiments described above are merely illustrative; for instance, the division of modules is only a logical functional division, and other division methods may be used in actual implementation.

[0047] The modules described as separate components may or may not be physically separate. The components shown as modules may or may not be physical units; they may be located in one place or distributed across multiple network units. Some or all of the modules can be selected to achieve the purpose of this embodiment according to actual needs.

[0048] The above are all preferred embodiments of this application, and are not intended to limit the scope of protection of this application. Therefore, all equivalent changes made in accordance with the structure, shape and principle of this application should be covered within the scope of protection of this application.

Claims

1. A wireless optical communication system for high-definition audio-visual transmission, the system comprising a transmitting module for connecting an audio-visual transmission line and an optoelectronic receiving module for connecting a display, characterized in that, The transmitting module includes a data transmission SFP component connected to the audio-visual transmission line, an optical module component disposed at the light emitting end, and an FPGA component disposed between the data transmission SFP component and the optical module component; The SFP component is used to convert input video / audio data into optical signals; The optical module assembly is used to convert the input transmission signal into an analog drive signal suitable for the built-in laser, so as to emit light signals into free space according to the analog drive signal; The FPGA component is used to perform protocol encapsulation, forward error correction, and signal modulation on the optical signal to generate the transmission signal. The photoelectric receiving module includes an optical receiving unit disposed at the light receiving end, an output interface connected to the display, and a signal processing unit disposed between the optical receiving unit and the output interface; The optical receiving unit is used to filter and compensate the received light signal to generate an analog signal; The signal processing unit is used to demodulate and decode the analog signal to restore the video / audio data.

2. The wireless optical communication system for high-definition audio and video transmission according to claim 1, characterized in that, The optical module assembly includes an optomechanical adjustment device, which is used to dynamically adjust the spot size and divergence angle of the light signal according to different transmission distances.

3. The wireless optical communication system for high-definition audio-visual transmission according to claim 1, wherein the optical signal includes guide light and signal light, characterized in that, The optical receiving unit also includes a dichroic mirror for separating the light signal and filtering the guide light.

4. The wireless optical communication system for high-definition audio and video transmission according to claim 3, characterized in that, The optical receiving unit includes a photodetector and a focusing module disposed above the photodetector; The focusing module is used to focus the signal light onto the photodetector; The photodetector is used to convert the signal light into an analog electrical signal, and to amplify and filter the analog electrical signal to obtain an analog signal.

5. The wireless optical communication system for high-definition audio and video transmission according to claim 4, characterized in that, The optical receiving unit includes an image sensor, which is used to detect the position of the light spot of the guide light; The optical receiving unit is also used to dynamically adjust the photodetector according to the position of the light spot, so that the center point of the guiding light is aligned with the sensing area of ​​the photodetector.

6. The wireless optical communication system for high-definition audio / video transmission according to claim 1, wherein the video / audio data includes electrical signals, characterized in that, The SFP component includes a power line carrier communication interface for receiving video / audio data input via power lines.

7. A wireless optical communication method for high-definition audio and video transmission, applied to the wireless optical communication system for high-definition audio and video transmission as described in claim 1, characterized in that, The method includes: The transmitting module performs protocol encapsulation and high-order modulation on the received multimedia data according to a preset first protocol to obtain the baseband electrical signal driving the laser. The transmitting module performs laser driving and beam shaping processing on the baseband electrical signal according to the acquired transmission distance in order to transmit light signals; The photoelectric receiving module performs photoelectric conversion, noise suppression, and signal compensation processing on the received light signal to obtain a digital signal; The photoelectric receiving module demodulates and decodes the digital signal according to the first protocol to restore the multimedia data.

8. The wireless optical communication method for high-definition audio and video transmission according to claim 7, characterized in that, Before the transmitting module transmits the optical signal, the method further includes: Step S81: The transmitting module transmits calibration test light to the photoelectric receiving module according to the preset test light control signal; Step S82: The photoelectric receiving module acquires the spot image of the calibration test light in real time, and performs spot center identification and coordinate extraction on the spot image to obtain the real-time spot center coordinates; Step S83: The photoelectric receiving module performs offset calculation based on the preset target center coordinates in the optical receiving unit and the real-time light spot center coordinates to obtain the real-time offset amount. Step S84: The photoelectric receiving module generates a pulse command according to a preset command generation method and the real-time offset, and dynamically adjusts the optical receiving unit according to the pulse command; The photoelectric receiving module repeatedly executes steps S82 to S84 until the real-time offset is less than a preset offset threshold.

9. The wireless optical communication method for high-definition audio-visual transmission according to claim 7, wherein the multimedia data includes audio-visual data and control commands, characterized in that, After the photoelectric receiving module parses the multimedia data to obtain the control command, the method further includes: The photoelectric receiving module performs Manchester encoding on the control commands to obtain uplink control data packets; The photoelectric receiving module performs pulse position mapping processing on the uplink control data packet according to the preset OOK modulation rule to obtain the uplink drive electrical signal; The photoelectric receiving module drives the built-in transmitting laser unit according to the uplink driving electrical signal to transmit an uplink optical pulse sequence to the transmitting module; After the transmitting module acquires the uplink optical pulse sequence through the optical receiver, it demodulates and decodes the uplink optical pulse sequence according to the received time sequence to obtain reconstruction control command / control command completion information. When the transmitting module receives the reconstruction control command, the transmitting module dynamically adjusts the optical signal according to the reconstruction control command.

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