Capacity analysis of an ARQ scheme for multimedia DS-CDMA systems

A multimedia DS-CDMA system using an ARQ reverse link for data transmission is proposed and analysed. The system capacity is evaluated for several err or-detecting codes (EDCs) such as the Hamming codes, the Golay code, the ex tended Golay code and two kinds of BCH codes. A simple new model based on t he asymptotic gain for block and convolutional codes is proposed. Using thi s asymptotic gain model, analytical expressions for the system capacity are derived, which makes the system capacity evaluation easier and faster. The proposed system allows a greater number of data users by using mon powerfu l block EDCs, instead of the Hamming class. The convolutional code efficien cy in this system is also discussed.