Decoding Simulation On Irregular Accumulate Code In Deep Space

The exploration of deep space has been playing a more important role in the whole human strategic missions, which also means humans are confronted with the great period-Space Period. In order to implement exploring outer space, different kinds of spacecrafts with various purposes are needed to be launched to outer space, which requires to build several effective connections between spacecrafts and the earth, that is deep space communication. The exploration of deep space has been proved to be the important mainstay of deep space network, among which signals have to be transmitted between a very long distance. Thus, compared to other methods of communications, it is difficult to communicate of high quality.Decades of years have passed since the early channel coding ensemble- convolutional code was proposed, Later Turbo code which outperforms other channel coding was commended by the Consultative Committee for Space Data Systems (CCSDS). But the decoding method of Turbo code is so complicated that it is largely constrained its application while the encoding part of LDPC is also very hard, thus in this paper, irregular accumulate code is introduced to achieve Shannon limit with low complexity of encoding and decoding. It can be viewed as Turbo-like code or as LDPC-like code, also it has simple code structure and similar decoding performance with Turbo code and LDPC code.Firstly, the paper introduces the fundamental principle of IRA code, based on which, the encoding and decoding algorithm of IRA code are discussed in detail. On the implementation of decoding algorithm, the iterative decoding algorithm based on Tanner graph is introduced.Secondly, with concerns of the deep space channel is largely similar with the AWGN channel, 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 IRA code simulation flow is established.Finally, under different conditions the simulation and analysis of the performance of IRA code are carried out. In the AWGN channel, the effect of the IRA code's performance of some simulation parameters is considered, which includes code length, iteration number, decoding algorithms, different rate and so on, and the performance of the RA code and IRA code is compared.