On robust multiuser detection

We study the design of multiuser detectors from an H∞ point of view. The H∞ approach is most appropriate in the situations where the statistical properties of the disturbances are not known or are too hard to model and analyze. The design of the H∞ optimal FIR multiuser detectors can be efficiently performed using numerical methods. Exploiting the inherent non-uniqueness of the H∞ solution, we additionally optimize for an average performance thus obtaining mixed H^2/H∞ optimal multiuser detector. Recursive solutions, allowing for computationally efficient implementation of the decision-feedback detectors, is briefly discussed.