Study On Improving The Transmission Reliability Of Deep-sea Disposal Profiler By RS-CC Concatenated Code

XCTD is the abbreviation of the Expendable Conductivity-Temperature-Depth profiler.As one of typical products of the deep-sea abandoned profiler,it had been developed successfully and rapidly in recent years.At present,the United States and Japan are a leader in the XCTD technical aspects of the research in the world,but the development of XCTD technology in china is mainly in the initial stage.Considering the influence of cost,work environment or other factors,the transmission line uses a double-stranded enameled wire to transmit data signal in XCTD measurement system.Because of the constraint of the real-time change of channel impedance parameters and the interference of complex ocean noise,the measured data can not transfer to receiving terminal reliablyand effectively.So how can we make sure that the data signal reliably transfers in the channel at high transmission frequency is one of the key problems of the development of XCTD technology in china.Firstly,the paper analyzes the transmission characteristic of XCTD channel by establishing the optimized circuit model of XCTD channel,and then analyzed the types of error code may have in the process of signal transmission according to the characteristic of complex noise existing in the channel environment.We hereby propose the channel coding scheme of Reed-Solomon code+ Interleaver +Convolutional code concatenated code(RS-CC)based on ASK frequency band transmission.Secondly,according to the characteristic of different channel coding types and actual working environment of XCTD,we designed the specific project of RS-CC encoding and decoding of(255,223)RS code +(8,255)Interleaver +(7,1/2)Convolutional code.Thirdly,we build the channel simulation model of RS-CC concatenated code by means of SIMULINK in MATLAB software,then we analyze what influence the random noise have on ASK transmission mode at certain investigation depth and transmission frequency,and compare with RS-CC + ASK transmission mode and different coding schemes based on ASK frequency transmission to verify the designed scheme.Because random noise is always here,and yet burst noise could appear,we finally analyze what influence the burst noise have on RS-CC + ASK transmission mode on the basis of the certain random noise,and confirm the application condition of RS-CC + ASK transmission mode in XCTD communication system.