Robust image transmission over CDMA channels

The transmission of real-time images and video over wireless communication channels is a challenging problem. Digital compressed images are sensitive to bit errors which are typical in wireless communications. Moreover, the b andwidth at the air interface is currently a limiting factor because the fi rst and second generation of mobile phone standards mainly support voice co mmunications. In this paper, we present a study of real-time image traffic over a radio link - the aim of this research is for videophone applications . In this study, we use the Discrete Wavelet Transform (DWT) to compress im ages and a Code Division Multiple Access (CDMA) link to transfer images ove r wireless communications network. The experiment results indicate that it is possible to transfer 9-12 QCIF gray scale images per second over a CDMA link with graceful degradation in image quality.