Breakdown Point Analysis of a New M-Estimator for Robust Multiuser Detection in Non-Gaussian Channels

This paper presents a robust multiuser detector for combating multiple access interference and impulsive noise in direct-sequence code-division multiple-access (DS-CDMA) communication systems. A new M-estimator is proposed for robustifying the detector. The lower bounds for the explosion and implosion breakdown points of the proposed estimator are derived. For appropriate tuning constants, it is shown that the breakdown points attain the maximum possible value. The approach is also corroborated with simulation results to evaluate the performance of the proposed robust multiuser detector in comparison with the linear decorrelating detector, Huber and Hampel M-estimator based detectors. Simulation results show that, in highly impulsive noise, the proposed detector with the proposed M-estimator with significant performance gain outperforms the linear decorrelating detector, Huber and Hampel M-estimator based detectors in both synchronous and asynchronous non-Gaussian channels.