Study on mismatched source transition probability matrix using in MAP source-controlled channel decoding for MPEG-4 video sequence wireless transmission systems

摘要

In this work, the MAP source-controlled channel decoder with matched and mismatched source transition probability matrix (STPM) is intensively examined for a MPEG-4 video sequence. We attempt to answer whether or not one can use the MAP decoding with a mismatched STPM instead of the MAP decoding with the matched STPM. The matched STPM requires the transmission for every frame images. Here, the commonly "foreman" video input is extracted into 300 frame images. Each image is inserted into the MPEG-4 image transmission system over the Nakagami-m block-fading channels with m = 1.5 2.0 and 2.5. The system performance in in term of the peak signal to noise ratio (PSNR) and word error rate (WER) are summarized at 7b = 3.75 and 5 dB. The results from both MAP decoding with matched STMP and mismatched STMP show the similarity of the system performance. Moreover, the slight improvement is obtained when MAP decoder is compared with ML decoder.