Viterbi Trellis Generator

Creates the trellis struct needed by convenc & vitdec, for use with viterbi encoding and decoding.

This function creates the trellis struct needed by the Matlab Communication Toolbox functions convenc and vitdec (convolutional encoder, viterbi decoder), for use with Viterbi encoding and decoding. The user provides the constraint length, g1 taps, and g2 taps, and the function returns the trellis struct.