Image Transmission Systems for Wireless Channels

In the modern day, many novel information §technologies involve the transmission of imagery §over noisy channels such as satellite and§wireless mobile channels. In general, a low-bit-rate §image transmission system requires an outstanding §image encoder that provides both an excellent §quality for the reconstructed image and§a high compression ratio. However, the resulting §compressed bit stream becomes highly sensitive to §channel noise. There have been§several approaches to add error resiliency to an §image coder. For instance, the joint source-channel §technique (JSC) techniques are developed by §considering both source and channel codecs. This book§is focused on a kind of this technique known as §source-controlled channel decoding. In particular, §the residual redundancy in MPEG-4 compressed imagery §is considered. Here an embedded zerotree wavelet §(EZW) algorithm is used to generate a compressed bit §stream, which is then passed through a§ring convolutional encoder (CE) and a CPFSK §modulation system. Moreover, the design of trellis §codes using ring convolutional§codes and CPFSK for MAP decoding is also described.