Robust power allocation techniques for MIMO systems under modulus channel knowledge at the transmitter

In this paper, we study a family of robust power allocation techniques for multi-input multi-output communication systems with incomplete channel state information at the transmitter side. Precisely, we focus our attention to the case where the transmitter has access only to the modulus of the channel coefficients. We present the robust techniques under two main approaches: the Bayesian (or stochastic) point of view, and the maximin (or worst-case) criterion. The formulation developed in this paper holds for flat fading channels, and also for frequency selective channels; in this latter case, through a multicarrier perspective.