Optimal Power Allocation for Scalable Video Transmission over Multirate GMC-CDMA Wireless Links

Generalized multi carrier code division multiple access (GMC-CDMA) is a promising technique for achieving high data rate transmission capacity in interference-limited cellular systems. A key challenge in a multirate GMC-CDMA system for video transmission is the optimal power allocation between the sub-channels that maximizes the received video quality subject to a data rate budget. In this paper, we propose a method for joint source and channel coding with optimal power allocation for scalable video transmission over multirate GMC-CDMA wireless links. A GMC-CDMA system offers deterministic elimination of multiple user interference (MUI). A scalable video source codec is used and a multirate setup is assumed i.e., each video user is allowed to occupy more than one GMC-CDMA channels. Each of the GMC-CDMA channels can utilize a different number of subcarriers. The optimal solution selects the set of source and channel coding rates for the user of interest along with the number of sub-carriers and power allocated to each GMC-CDMA channel that minimizes the end to end distortion subject to the rate budget. Universal rate distortion characteristics (URDC) are used along with the channel characteristic plots to obtain the optimal solution. Experimental results are presented and conclusions are drawn.