On the effect of imperfect interleaving for the Gilbert-Elliott channel

By using the Gilbert-Elliott model to study the performance of block-coded transmission over the land mobile channel, a new analytical expression illu strating the effect of various parameters, e.g., mobile speed, delay constr aint, and parameters for the error correcting code, is found. Comparisons b etween the results obtained by this analytical expression and results obtai ned by computer simulations show that the analytical results are accurate f or a broad range of channel parameters. The Gilbert-Elliott model is then u sed to compare the performance of different binary BCH codes when the delay constraint does not allow the assumption of infinite interleaving. In cont rast to the memoryless case, where the performance typically is improved wi th increased block length, short codes are found to be as good, or even sup erior, due to the fact that the interleaver works better for shorter codes.