Robust CDMA Multiuser Detectors: Probability-Constrained Versus the Worst-Case-Based Design

In this letter, a robust code-division multiple-access (CDMA) multiuser detection technique which is based on the probability-constrained optimization approach is developed, and its relationship to the popular worst-case-based robust CDMA multiuser detection technique is established. The important advantage of the proposed probability-constrained optimization-based approach with respect to the worst-case-based design is that in the former approach, the parameter of the uncertainty region of the worst-case-based design is quantified in terms of the outage probability and second-order statistics of the user signature estimation error. A simulation example demonstrates the advantages of such statistically motivated choice of the parameter of the uncertainty region.