Near–Far Resistant ICA based Detector for DS-CDMA Systems in the Downlink

The performance of a conventional single user DS-CDMA receiver is severely limited by multiple access interference (MAI) and near–far effects. This severity has motivated research into adaptive filtering, near–far resistant detectors and power control strategies for DS-CDMA systems. In this paper, we propose a near–far resistant detector based on independent component analysis (ICA) of the received signal. Since ICA is a blind technique, the proposed ICA based detector has the potential to combat the near–far problem. The ICA is a higher order statistical technique based on the assumption of independence of source signals. The assumptions in ICA algorithm are the realistic conditions in a DS-CDMA system and therefore ICA algorithm can be applied successfully to detect the signal of the desired user. The focus of this paper is to illustrate the near–far resistance capability of the ICA based detector. Simulation studies performed on the proposed detector show that it is resistant to the near-far problem and has low bit error rate.