A class of binary rate one-half convolutional codes that allows an improved stack decoder

T HIS INTRODUCTORY section applies to general binary rate k/n convolutional codes. In Section II we specialize to rate one-half to describe a class of codes that allows an interesting mod ification of the stack decoding algorithm [l]-[2]. Section III presents our simulation results. Let G be a conventional convolutional encoder [3] whose rows are the first k rows of a polynomial n X n matrix B with polynomial inverse B -‘. The generator matrix G has an instantaneous polynomial inverse G -’ and a syndrome former HT consisting of the first k columns and the last n k columns of B -*, respectively. The last n k rows of B are the transpose of the inverse of H. Summarizing,