The Error Correcting Codes Simulation And Research For Deep Space Communications

As the coming of Space Age, the exploration of deep space is becoming a great Human strategic mission. Before implementing exploring outer space, some spacecrafts with different purpose should be launched to outer space. And because of this, effective contacts are required to be constructed between spacecraft and the earth, and among the spacecrafts, namely we should perform deep space communication. The fact of exploring outer space has proved deep space network is the vital mainstay of exploring space. Very long distance of transmission is its fundamental characteristic; it is more difficult to communicate comparing with other communication mode.Concerning channel coding, it's for tens of years from the first convolutional code to Turbo code recommended by the Consultative Committee for Space Data Systems (CCSDS). But for the high complexity, it's difficult to implementation. This thesis introduces the repeat accumulate (RA) code and accumulate repeat accumulate (ARA) code. They can be viewed as Turbo-like code or as LDPC-like code, also they have simple code structure and similar decoding performance with Turbo code and LDPC code.Firstly, the paper introduces the fundamental principle of RA code and ARA code, based on this, the encoding and decoding algorithm of RA code and ARA code are discussed in detail. On the implementation of decoding algorithm, the iterative decoding algorithm based on Tanner graph is introduced.Secondly, the paper introduces the AWGN channel model and the implementation of this channel model, for the deep space communication channel is AWGN channel. Based on the encoding part, decoding part and the channel model, the RA code and ARA code simulation flow is established.Finally, under different conditions the simulation and analysis of the performance of RA code and ARA code are carried out. In the AWGN channel, the effect to the RA code and ARA code's performance of some simulation parameters is considered, which include code length, iteration number, decoding algorithms, different rate and so on, and the performance of the RA code and ARA code is compared.