CROSS LAYER OPTIMIZATION FOR VIDEO TRANSMISSION OVER MULTI RATE GMC-CDMA WIRELESS LINKS
CDMA, CMDA, GSM, Video processing, Mat lab
In this paper we consider the problem of video transmission over wireless generalized multicarrier code division multiple access (GMC-CDMA) systems. Such systems offer deterministic elimination of multiple access interfaces. A scalable video source code is used and a multi rate setup is assumed each video user is allowed to occupy more than on GMC-CDMA channels. Furthermore, each of these channels can utilize a different number of sub carriers. We propose a cross-layer optimization method to select the source coding rate, channel coding rate, number of sub carriers per GMC-CDMA channel and transmission power per GMC-CDMA channel given a maximum transmission power for each video user and an available chip rate. Universal rate distortion characteristics (URDC) are used to approximate the expected distortion at the receiver. The proposed algorithm is optimal in the operational rate distortion sense subject to specific setup used and the approximation caused by the used of the URDC. Experimental results are presented and conclusions are drawn.