This method has been proposed by Viterbi et al. [VIT 97]. We will describe this method using an example. Let us consider the case of a systematic recursive convolutional encoder (7,5). The state transition matrix for this encoder is as follows:
and the weight enumerator function is given by:
The transition equations are then:
and:
with the following initial conditions: , and else. We just have to apply equations [B.3] for i = 1,…, K.