Channel capacity and beamforming issues in MIMO channels subject to tolerances

Abstract

In this paper multiple input multiple output (MIMO) channels are considered that are subject to tolerances. The deviations in amplitude and phase that occur at the transmitter and at the receiver are investigated. The resulting MIMO systems with different calibrations are evaluated in terms of the corresponding MIMO channel capacities and their suitability for beamforming-based evaluations as they are applied in e.g. communication over spatial multiplexing (SM) or direction of arrival (DOA) or direction of departure (DOD) estimation. The results reveal that some of the deviations have an impact on the evaluation of the channel capacity and on the beamforming (BF) but others are negligible because they are canceled during the processing. The negligible ones allow for savings in effort and computation both in MIMO channel determination systems like channel measurement systems and channel simulators and in communication systems.