QoS- based JPEG images transmission protocol for wireless CDMA communication systems

Abstract

In recent years, wireless communication systems have become increasingly popular as an inexpensive and promising means for ubiquitous and wireless multimedia communications. However, before wireless multimedia appliances become a common commodity several challenging issues need to be resolved. Wireless communication channels are characterized by long bursts of data errors, and ambient noise, propagation losses, multipath, interference, and properties arising from the use of multiple antennas pose a serious problem to information transmission over wireless networks. In this paper, we propose a QoS-based modified scheme to transmit JPEG-coded images over wireless channels for CDMA communication systems, based upon a combination of a modified MAP (Maximum Aposteriori Probability) decoding to eliminate error transmissions and a fast decorrelating multiuser detection mechanism as a post-processing task to eliminate the MAI (Multiple Access Interference) interference. We describe our transmission protocol, and report on its performance evaluation using a simulation testbed we have designed for this purpose. Our results clearly indicate that our protocol improves significantly the quality of transmitted JPEG images over wireless CDMA systems and the transmission errors are significantly reduced when compared to regular transmissions.