Research on Doppler-resisting differential decoding in underwater acoustic time pattern delay shift coding communication system

Among various demodulation techniques of CPFSK,multiple differential detection(MDD) strategy exhibits even better BER performance than coherent detection,however,its hardware complexity is very high.

32 standard are discussed in the paper,including the differential encoding,convolution encoding and Viterbi decoding,and the simulation results,which shows TCM Coding can improve the performance of the system.

32,including convolutional encoding,differential encoding and Viterbi decoding.

For the SOAP request, it realizes differential encoding by adding SOAP message skeleton, for the SOAP response, it compresses long message or realizes differential encoding of the short SOAP message.

Then,the contour extraction of the port is fulfilled and the difference chain code is used to represent the port contour.

The differential coding is performed in the time domain,while the space-frequency coding is processed in the frequency domain to achieve the diversity ga.

Relationship is established in the transmitter using differential coding between the difference in SOPs of the optical signals in consecutive symbol periods and the input symbol of the differential encoder.

Firstly,it is easy to predict the pixel s value;secondly,it reduces the relativity of the coded data by the differential coding technique that is beneficial to improving the compression capability.

Based on the 16QAM Satellite Burst signal, this paper introduces the application of differential code to 16QAM communication system, and performs the computer simulation of 16QAM communication system by using Matlab to testfy it.