Adaptive Turbo-coded Modulation for Progressive Image Transmission on Flat-Fading Channels

In this paper, the adaptive turbo-coded modulation is used in a joint source and channel coding (JSCC) system on flat-fading channels. Assume perfect channel estimate and instantaneous feedback, the optimal power and rate adaptation strategy is determined to achieve the minimum average distortion for progressive image transmission under the bandwidth and average power constraints. The solution requires high-complexity computer search methods. However, by adopting a discrete-rate scheme and fixing the packet error rate in each channel region, the problem can be simplified into an optimal solution for maximum throughput. Simulation results show that the proposed scheme outperforms conventional nonadaptive JSCC schemes on varying channels.