The Theory Research Of Iterative Turbo Decoding Process

Turbo code demonstrates excellent performance of nearing the Shannon limit, mainly because it has adopted the thought of iterative decoding. The thought of iterative decoding offers the new thinking for solving the problem of different field of communication. A theory analysis of the iterative turbo decoding process has been given in this paper.This paper introduces a method of analyzing the performance of Turbo code in theory and of analyzing Turbo code from the perspective of the nonlinear dynamics, then discusses the fixed point, bifurcations and chaos during the iterative turbo decoding process. Firstly, the backgrounds and the recent development are introduced. And the fundamental knowledge of Turbo code is indicated. Secondly, from the angle of the nonlinear dynamics, the existence and convergence of fixed point and the bifurcation and chaos during the iterative turbo decoding process are discussed. Thirdly, a new stopping criterion is proposed from the perspective that the turbo iterative decoding process as a nonlinear dynamic system. The simulation experiment shows that the new criterion can reduce the number of decoding iteration while the BER performance is not degraded. Finally, because Turbo code and LDPC code are two-research focus on the coding community at present, we talk about the performance of the LDPC decoding. And then, the BER performance of Turbo code and LDPC code are compared in different code parameter.