Performance analysis and simulation results for a high-rate sequential decoder

A new sequential decoding technique has been implemented which is appropriate for high rate R = (n-1)/n decoding of convolutional codes. The decoding method employs a modified stack algorithm. A stack algorithm approach was chosen over the Fano approach because of advances in both computer and solid state technologies. The R = (n-1)/n sequential decoder developed herein employs many techniques which were previously unique to Viterbi decoders. Viterbi decoders are useful only for short constraint length code constructions, which ultimately limit their performance. In contrast, the sequential decoder is especially useful for large constraint length code constructions. Design issues regarding the implementation of the sequential decoder are discussed. Performance characteristics are studied and simulation results provided to justify the analysis. The decoder is expected to have many applications in satellite and space communications where channel error protection is desired and bandwidth conservation is important.