Wireless JPEG Image Transmission Using Multiple Diversity Combining and Unequal Error Protection

In this paper we investigate the performance of JPEG image transmission over the IEEE 802.11a WLAN, using Multiple Diversity Combining (MDC) and Unequal Error Protection (UEP). An MDC scheme is obtained by simultaneously employing transmitter diversity, receiver diversity and retransmission diversity. UEP is performed by first optimizing the number of headers allocated to the subbands of a JPEG image to prevent error propagation, and secondly by optimizing the number of retransmissions with a view to minimize the channel induced distortion. The MDC-UEP strategy has been employed with both Convolutional and Turbo codes. Simulation results show that a gain of 8 dB in PSNR can be obtained with MDC-UEP in the range 0 dB a parts per thousand currency sign Eb/No a parts per thousand currency sign 3 dB, over a scheme which uses MDC with Equal Error Protection (EEP). Moreover MDC-UEP with Turbo codes provides a gain of 0.5 dB in PSNR and 5 percent in throughput over an MDC-UEP scheme with Convolutional codes.