Combined source-channel coding for the transmission of still images over a code division multiple access (CDMA) channel

This work considers a combined source-channel coding scheme for image transmission over the uplink of a wireless IS-95 CDMA channel using discrete cosine transform. By adjusting the dimension of the orthogonal signaling scheme, we trade the system error-correction capability for a faster bit rate. The increase in channel error is relieved by employing a set of quantizers which are designed using a joint source-channel optimization algorithm. The bit allocation problem of the quantizer array is solved by using a new approach based on the integer programming technique. Without bandwidth expansion, our proposed scheme results in a substantial improvement in the reconstructed image quality, especially for good channel condition.