Iterative joint source-channel decoding using turbo codes for MPEG-4 video transmission

This paper presents a novel iterative joint source-channel decoding scheme for MPEG-4 video transmission over noisy channels. The proposed scheme, on one hand, utilizes the channel soft outputs generated by the turbo decoder to assist video decompression. On the other hand, the syntactic/semantic information from the video decompressor is used to modify the extrinsic information so as to improve the error correction capability of the turbo decoder. With the proposed video packet mixer, the scheme can correct most turbo coding blocks with a large number of errors. Simulation results show significant improvement in terms of PSNR, reconstructed video quality, as well as BER over turbo decoding only.