Research On Underwater Single Photon Video Transmission Technology Based On Distributed Compressed Sensing

To achieve long-distance Underwater Wireless Optical Communication(UWOC),the receiving terminal uses a highly sensitive photon counting detector to detect the optical signal,and extracts effective information from the discrete pulses output by the detector.Due to the attenuation of the underwater channel and the optical quantum effect,there are bit errors in the transmission of optical signals.In order to reduce the amount of data transmitted,the long-distance underwater wireless optical video communication needs to compress and encode the video file.The traditional video coding method uses a hybrid coding method combining prediction and transformation for compression,and there is a large dependence between video frames.If one frame of data is lost,the other frames cannot be decoded,which will cause great difficulties in recovering continuous video streams.Therefore,traditional coding methods are not suitable for underwater single-photon video communication systems that are prone to bit errors.Distributed Compressive Video Sensing(DCVS)combines the advantages of Compressive Sensing(CS)and Distributed Video Coding(DVC).It transfers the complexity of the encoder to the decoder,with the advantages of low encoder complexity and good robustness.In view of the above analysis,this paper focuses on the underwater video transmission technology based on distributed compressed sensing.The main research contents and results obtained are summarized as follows:(1)In order to analyze the factors that affect the quality of underwater single photon communication,we synthesize the underwater communication channel characteristics,the Poisson random process of photon emission and detection,and use Monte Carlo(MC)simulation to establish a long-distance weak link UWOC model.The effects of demodulation threshold,signal and noise optical power on system performance are studied,and the calculation formula of system Bit Error Rate(BER)is derived.(2)To achieve reliable video transmission,a joint source-channel coding scheme based on residual distributed compressive video sensing is proposed for the underwater photon counting communication system.Signal extraction from single photon pulses,data frame and data verification are specifically designed.The effects of sampling rate and channel BER on the quality of reconstructed video frames are analyzed experimentally.The experimental results show that,when the BER is high,as long as the measurement rate is large enough,the video frames can still be clearly restored.(3)In order to further reduce the amount of data transmitted by the encoder and ensure the reconstruction quality of the decoder,this paper makes full use of the spatio temporal correlativity of the video,and proposes a DCVS scheme for adaptive measurement values transmission and secondary reconstruction.Simulation results show that the adaptive transmission scheme can appropriately reduce the amount of transmitted data according to the complexity of the video signal,and the secondary reconstruction scheme can further improve the reconstruction quality based on the first reconstruction.