Multi-user interference cancellation technique for coded OFDM-CDMA system

In a mobile communication channel, the multi-user interference is one of the major performance degradation factors, and restoring the signal-to-signal orthogonality among users is the challenging problem. As a solution to the problem, we proposed a method of combining OFDM and CDMA into a coded OFDM-CDMA system. The proposed system is equipped with a multi-user interference suppression capability based on chip-based interference cancellation and adaptive DFE equalization in series with a low-density parity checker. The performance of the proposed system is verified in a reverse-link multipath Rayleigh fading channel using computer simulation. The overall system performance has improved over a single-carrier CDMA in terms of BER vs SNR.