Orthogonal successive interference canceller for the downlink communications in a DS-CDMA mobile system

This paper proposes an interference cancellation technique for DS-CDMA downlink mobile communication systems. The proposed scheme, referred to as Orthogonal Successive Interference Canceller (OSIC), is a low complexity version of the Decorrelating Decision-Feedback Detector (DDFD) proposed in [4], which is achieved by using an orthogonal filter bank. A lower complexity scheme that takes into consideration only the subset of strongest active users at the OSIC is also proposed. For coherent detection of the OSIC under fading channels, the fixed AR model predictive and the higher order predictive channel estimation are employed. Computer simulations show that the proposed schemes with these two channel estimation techniques can achieve excellent BER performances under both AWGN and flat Rayleigh fading channels.