Interference cancellation method for DS-CDMA multicode-packet transmission

Multicode transmission has been proposed for high-speed DS-CDMA packet-data transmission systems. Transmission performance of such systems is degraded by multipath propagation because the cross-correlation values between the multiple codes are not zero. Although interference cancellers are very effective in this situation, the conventional methods require a great deal of calculation. We propose a fast channel-estimation method and a low-calculation-effort interference cancellation method for the slotted ALOHA multicode-packet transmission system. Computer simulations are performed in the frequency-selective Rayleigh fading model. The channel-estimation ability, the interference cancellation effect, the sufficient cancellation-stage number, and the error correction effect are clarified.