在1993年所提出的同調渦輪解碼，因其優異的錯誤效能受到高度的重視，在許多通訊協定中也被採用。另一方面，渦輪碼在加成性高斯白雜訊通道上的非同調最大後置機率解碼演算法已被提出，但其複雜度甚高，在本論文中，我們考慮渦輪碼在加成性高斯白雜訊通道上的非同調解碼，提出兩類作法。第一類作法是在接收端先用解調器計算對數可能性，再送入同調渦輪解碼器解碼。第二類作法是在每一次遞迴都估測通道相移，再將消除通道相移後的訊號送到同調解碼器做解碼。電腦模擬結果顯示第二類作法擁有不錯的效能。 Turbo code was proposed in 1993 and has raised great attention for its good effectiveness, and thus it has been used widely in many communication protocols. Otherwise, noncoherent maximum a posteriori decoding for the AWGN channel has been already proposed, and it is too complex. Therefore, in this thesis, we proposed two algorithms of noncoherent decoding to Turbo code for the AWGN channel. In order to fine tune the likelihoods to the Turbo decoding, the first algorithm re-computes the log-likelihood of transmitted bits in every iterative. The second algorithm re-estimates the phase shift in every iterative, and the signal which recovered phase sent to Turbo decoder. The positive results got from computer simulation showed that the second algorithms have good effectiveness.
