Performance of turbo codes in 3rd generation cdma2000 mobile system

The performance of turbo codes in the 3^rd generation cdma2000 mobile system is evaluated in this paper. cdma2000 is a wideband, IS-95 compatible CDMA technology for the next generation of wireless communication systems, which is aimed at supporting a wide range of operating environments, data rates, and advanced services. Turbo codes are recommended as a channel coding scheme for higher data rates due to the superior performance over conventional convolutional codes. In this paper, we study the performance of turbo codes applied in cdma2000 direct spread forward link (from BS to MS). Different channel environments, including indoor to outdoor/pedestrian and vehicular, are studied. The effect of fast (800 Hz) closed loop power control in the forward link is also addressed. Compared with the convolutional codes specified in IS-95, in most cases turbo codes enjoy 1.3-1.5 dB gain at 10^-2 frame error rate (FER)