Adaptive source-channel subband video coding for wireless channels

This paper proposes an adaptive source-channel subband coding scheme for the transmission of video over fading wireless channels. A three-dimensional subband decomposition followed by vector quantization of the subband coefficients forms the source coding strategy. For transmission over the channel, the individual subbands are offered different amounts of protection depending on their importance in reconstruction at the receiver. For each subband, the source coding rate as well as the level of protection (quantified by the channel coding rate) are jointly chosen to minimize the total mean-squared distortion suffered by the video coder. The choice of source and channel coding rates depends on the state of the physical channel. We use a finite state model for the fading channel, where every state corresponds to an AWGN channel. This results in a joint source-channel coding scheme that adapts in an optimal way to the current state of a fading channel.