Exact Analysis of Bit Error and Burst Error Probability for 2-State Soft Decision Viterbi Decoding

摘要

Although convolutional codes with soft decision Viterbi decoding are widely used in practical systems, only a few studies have been made for exact analysis of error probability. Most results are based on the bound of error probability of on the computer simulation. In this paper, we propose a new method for the exact analysis of bit error probability of 2-state convolutional code which is applicable to soft decision Viterbi decoding. The method employs an iterative calculation of probability density function (pdf) of path metric per one transition. Numerical results of bit error probability show that 4 or 5 iteration gives the bit error probability with sufficient accuracy, and that the proposed method is effective even in the region of low signal-to-noise power ratio (SNR). The extension to burst error probability analysis is also presented.