On the statistics of block errors in bursty channels

In the development of encoding algorithms for image, video, and other mixed media transmissions, it is important to note that the channel `seen' by the applications is the physical channel as modified by the error-correcting mechanisms used at the physical level. Therefore, the statistics of the residual error process is relevant to the design of encoding algorithms. In this paper, we study the second- and third-order statistics of the residual error process when block transmissions are performed over a bursty channel. The effect of interleaving is explicitly studied. The conditions under which a Markovian model for the block errors is adequate are identified. Derivations of the parameters of the block error process are then presented in terms of the parameters of the bit/symbol error process. At higher data speeds an effective interleaving strategy is found to require a very large buffer.