Upper Bound of Ergodic Capacity for MIMO Channels with Ricean-Fading using Majorization Theory

Abstract

This paper presents a closed-form upper bound for the ergodic capacity of spatially uncorrelated Ricean flat-fading channels with multiple-input multiple-output (MIMO) antennas. By considering an arbitrary number of antennas at both the transmitter and receiver sides and assuming that the channel state information (CSI) is completely unknown at the transmitter, the Majorization theory is used as a powerful mathematical tool, which allows us to derive an upper bound on the channel capacity for this class of channels. The upper bound obtained does not depend on the Ricean-K factor. Moreover, in the high signal-to-noise-ratio (SNR) regimes, we give another approximation for Ricean-fading channel capacity. Finally, we present some numerical results that illustrate the validity of our approach.