Joint source-channel coding using simplified block-based segmentation and content-based rate-control for wireless video transport

The scenario of using Automatic Repeat reQuest (ARQ) retransmission for two-way low bit-rate video communications over wireless Rayleigh fading channels is studied. In this kind of channel, the packets inevitably experience errors during deep fades. The retransmissions can be used to re-send such packets. During retransmissions, the video encoder buffer fills up quickly and may cause the rate-control algorithm to skip frames or allocate less number of bits to encode the video frame. To reduce the number of frames skipped and improve bit allocation, we propose a content-based rate-control scheme using simplified block-based segmentation to intelligently allocate more bits to the foreground region. In addition, our proposed scheme also takes into consideration the effects of the video buffer fill-up, an a priori channel model, channel feedback information. The simulation results indicate that our proposed scheme encodes the video sequences with higher quality on the foreground region and much fewer frame skipping as compared to H.263 TMN8.