一种新的软输出译码算法

A NEW SOFT-OUTPUT ALGORITHM OF DECODING

本文在Bahl算法的基础上给出了一种新的软输出译码的矩阵算法。此算法把Bahl算法中求后验概率和转移概率的复杂计算转化成一系列简单的适合于大规模集成电路实现的矩阵运算,把比特错误概率量化成n_δ比特的二进制值与信息比特或分枝码一起输出,从而使运算速度得到提高,并得到适合多级级联译码器中内译码器的软输出算法。

A new soft-output algorithm of decoding is derived from the Bahl algorithm. The complex operations of estimating posterior probabilities and difference metric in the Bahl algorithm are paralleled and well formulated into a set of simple matrix operations which are fit to design efficient VLSI circuits. The probability of uk ≠ uk is quantized with nδ bits and is output together with uk branch code Xk. Thus, the algorithm not only increases the decoding speed, but also provides a soft-output algorithm for multi-level concatenated code.