Analysis of a Burst-Trapping Error Correction Procedure

A burst-trapping error correction procedure for error control on compound channels such as the telephone channel has been described by S. Y. Tong. 1 An evaluation of the burst-trapping procedure by computer simulation of its performance on recorded telephone channel error data is presented in the companion paper. 2 An analysis technique for determining the performance of the burst-trapping procedure is presented here. The analysis technique permits determination of upper and lower bounds on the probability of block error. It is valid for random, burst, or compound channels provided that a block interleaving degree I ^ 1 can be found for the channel such that error patterns in blocks spaced i blocks apart occur (approximately) independently. Expressions for upper and lower bounds on the probability of block error for codes of rate and § are given in Table I. For higher rate codes, numerical determination of the stationary probabilities which yield the bounds seems preferable to determination of expressions for the bounds. The performance of a rate § code, the (39, 26) shortened BCH code, has been computed using the expressions for probability of block error of Table I for two sets of recorded telephone channel error data. For both sets of data the computed performance agrees well with the performance obtained by computer simulation. 493