Adaptive Joint Source-Channel Coding Using Multilevel codes for Unequal Error Protection and Hierarchical Modulation for SPIHT Image Transmission

摘要

A highly reliable and efficient wireless communication system for compressed images delivery is required in emerging multimedia applications. However, the transmission of the image can be attenuated by different factors mainly involved by the wireless communication multimedia systems. In the past decades, various source and channel coding schemes have been developed separately. In this paper, we investigate a joint source-channel coding scheme to improve the image transmission performance. Our main target is to reach a good tradeoff in terms of rate-distortion for Set Partitioning in Hierarchical Trees (SPIHT) image transmission. For the wireless communication part, we consider the Audio Visual PHY Ultra Wide Band IEEE 802.15.3c system. The proposed strategies rely on adaptive process applied for error protection and the modulation operations. Thus, error correcting codes for unequal error protection (UEP) of the compressed bit streams is included. Then, Hierarchical Modulation (HM) is applied to the different bits according to their importance levels. Full of simulations are performed and our results show image quality improvements at the receiver using multilevel UEP and Hierarchical Modulation compared to the ordinary joint source-channel coding system without introducing any extra bandwidth usage.