Softbit-source decoding based on the turbo-principle

This contribution deals with a robust decoding approach of source codec parameters called softbit-source decoding. It can be considered as an error concealment technique which estimates codec parameters at the receiver utilizing the residual redundancy remaining after source coding and the channel decoder reliability information. We apply the turbo-principle to softbit-source decoding. We derive a formula that shows how different terms of residual redundancy can be transformed into independent extrinsic information utilizable in iterative processes. After introducing a new, iterative approach to softbit-source decoding, we analyze the influences of different bit mappings and of the number of iterations. Finally, the new approach is compared to conventional techniques with respect to performance and complexity.