高码率Turbo码的结构及特性

构成高码率Ｔｕｒｂｏ码有删除法与多维法两种，讨论了删除法构成Ｔｏｒｂｏ码的交织器设计及删除短阵结构。通过分析两种方法构成Ｔｕｒｂｏ码的自由码距，得到了它们的误码率限，发现多维法构成的Ｔｕｒｂｏ码的性能上优于删除法构成的Ｔｕｒｂｏ码，但译码复杂度高、时延大。经比较发现，删除法构成Ｔｕｒｂｏ码能在性能与实现复杂度上取得较好折衷，是一种理论的高码率Ｔｕｒｂｏ码构成方案。

The Structure and Performance of High Rate Turbo-Codes

There are multidimension and punctured methods for constructing Turbocodes. The interleave design and punctured matrix structure in constructing Turbocodes with the punctured method are discussed. Through the analysis of the free distances and decoding of high rate Turbocodes constructed by the above two methods, their bit error limits are obtained, from which the Turbocodes constructed by multidimension method are found to have better performance than those by punctured method, but with more complex decoding and bigger time delay. Comparison shows that with better compromise in performance and implementation complexity, the punctured method is an ideal scheme to construct high rate Turbocodes.