Windowed Iterative Source-Channel Decoding With Delay Constraints

Iterative source-channel decoding (ISCD) exploits the residual redundancy of source codec parameters by using the Turbo principle. In most practical implementations of ISCD, a delay constraint prohibits the utilization of future frames required for optimal soft decision source decoding if correlation between successive frames is exploited. In this paper, we propose a novel windowed receiver concept that attempts to partly overcome the receiver sub-optimality by refining the extrinsic information of past frames in order to improve the estimation of the parameters of the current frame. Simulation results show consistent performance improvements, which can be visualized by an information flow analysis.