A 1 Gb/s, 4-state, sliding block Viterbi decoder

In recent years there has been great interest in the implementation of high-speed Viterbi decoders. A potential application which has pushed decode rates into the Gb/s range is convolutional coding for optical channels. In this paper, an alternative sliding block Viterbi decoder is proposed that approaches ideal linear scaling (complexity proportional to speedup) without constraining the encoding process. Sliding block Viterbi decoder implementation of the Viterbi algorithm as a sliding block decoder (SBD) is based on the observation that the state at time n can be decoded using only the information from the interval n-L to n +L, where L is the survivor path length.