Simplified implementation of a soft decision threshold decoder

New fully digital hardware designs for soft-decision threshold decoders are introduced to significantly reduce the complexity and increase the coding gain as compared to previously proposed architectures. These designs are useful for high-rate self-orthogonal convolutional codes with a long constraint length. The study case considered in this paper is for a rate 23/24, constraint length 4056 code used in a typical microwave digital radio. The new decoder architecture provides a four-fold decrease in complexity and an additional 0.3 dB coding gain as compared to previous designs. The simplification of the decoding architectures is possible through the use of three techniques: a different processing of feedback, the separation of information bit and reliability bit processing and the use of partial reencoding