Robust Multiuser Detection for Multi-Carrier CDMA

In this paper, we propose a class of robust multiuser detection (MUD) techniques for multi-carrier (MC) code-division multiple-access (CDMA) by explicitly taking into account prior estimation errors in the initial channel estimates and the sample covariance matrix. Specifically, robust MUD detectors are developed by optimizing the worst-case performance over two separate bounded uncertainty sets pertaining to the aforementioned estimation errors. We have shown that, although the prior estimation errors are generally not bounded, it is beneficial to optimize the worst-case performance over properly chosen bounded uncertainty sets determined by a bounding probability of user choice. Numerical results show that the proposed robust schemes yield improved performance over those that ignore the prior estimation errors