Robust image transmission using variable QoS joint source-modulation coding

In this paper, we present an optimal, low-complexity method of transmitting digitally compressed imagery through interference-dominated and frequency-selective fading channels. The proposed method combines a wavelet-based image coder that employs phase scrambling and variable quality-of-service (VQoS) trellis-coded quantization (TCQ), and VQoS multi carrier (MC) power allocation across the channel. Optimal image quality is achieved through a joint iterative process between the image coder and MC allocation algorithm. Using our VQoS allocation method, we show that the image quality can be improved significantly, as compared to an approach that uses an arbitrary fixed joint QoS-modulation allocation across the channel. Further, this improvement extends to a variety of channels, including those that exhibit jamming interference and frequency-selective fading. The method is also shown to be computationally efficient.