Robust multiuser detection for wireless MC-CDMA systems under narrowband interference

In this paper, we present a robust decorrelating multiuser detector to suppress multiple access interference (MAI) and narrowband interference (NBI) in wireless multicarrier code-division multiple access (MC-CDMA) systems. The linear decorrelating multiuser detector is a simple and efficient method to mitigate the MAI. However, its performance degrades substantially in the presence of NBI. A robust weighted least M-estimate (WLM) algorithm based on the robust statistics and weighted least-squares (WLS) is therefore proposed for combating the NBI. Numerical results illustrate the significant improvement of the proposed robust decorrelating detection over the conventional linear decorrelator in the presence of NBI.