Optimal limited feedback technique for small size and low rate MIMO systems

TLDR: The proposed antenna selection method performs better than unitary precoding schemes (even optimal precoding) for systems with small number of transmitter and receiver antennas, although precoding techniques exploit more bits of feedback information and computational complexity than the proposed method.

Abstract: In recent investigations, several methods for limited feedback multiple-input multiple-output (MIMO) systems have been proposed. Antenna selection at the transmitter and(or) receiver side is one of the approaches to minimize the average probability of error by using a limited bits of feedback information. In this paper, by using a novel approach, we calculate the optimal signal-to-noise ratio (SNR) for each received symbol for a general space-time block code. We propose an antenna selection method at the transmitter to maximize the average SNR for each symbol. Since we propose the optimal selection, our antenna selection method outperforms antenna selection methods available in the literature for space-time codes with rate⪕ 1 symbol per channel use, derived either based on SNR or capacity maximization. The proposed selection performs better than unitary precoding schemes (even optimal precoding) for systems with small number of transmitter and receiver antennas (particularly for mobile systems), although precoding techniques exploit more bits of feedback information and computational complexity than the proposed method.