ON A TECHNIQUE TO CALCULATE THE EXACT PERFORMANCE OF A CONVOLUTIONAL CODE

A Markovian technique is described to calculate the exact performance of the Viterbi algorithm used as either a channel decoder or a source encoder for a convolutional code. The probability of information bit e rror and the expected Hamming distortion are computed for codes of var ious rates and constraint lengths. The concept of tie-breaking rules i s introduced and its influence on decoder performance is examined. Com puter simulation is used to verify the accuracy of the results. Finall y, we discuss the issue of when a coded system outperforms an uncoded system in Light of the new results.