A Study on Turbo Soft-Decision Decoding for Hard-Detected Optical Communication Signals

摘要

We propose a method to realize soft-decision decoding for hard-detected signals. In this paper, a novel concept is introduced as "error-detected reliability." The method is very useful for optical fiber communications (OFC) as hard detection is the only detection method for the OFC systems. We demonstrate our proposed method using the turbo code in which soft information is required for decoding. As a result, the simulation shows slight difference in the range of moderate to high signal-to-noise ratio between the proposed decoding scheme and the conventional turbo decoding scheme. Moreover, the bit error rate of 10~(-11) can be achieved by serial concatenation of a Reed-Solomon code and a turbo code for Q-factor lower than 8.0dB with a bandwidth expansion ratio of 33.3%.