Orthogonal source adaptive modulation for image transmission over noisy channels

Abstract

This paper presents a low-complexity method of transmitting digitally compressed imagery through AWCN and fading channels. The proposed method combines a wavelet-based image coder that employs phase scrambling and trellis-coded quantization (TCQ), and orthogonal source adaptive modulation (OSAM), which is implemented using time diversity and orthogonal modulation. We compare the performance of the OSAM-TCQ system to that of a system that utilizes unequal error protection (UEP). We show that for the AWCN channel, the OSAM-TCQ system performs nearly 4 dB better than UEP-TCQ at high bit error rates (BERs), and the same as the UEP-TCQ system at low bit error rates, with much lower complexity than the UEP-based system.