In this paper, we derive a simple expression to determine the optimum antenna number ratio for multi-input multi-output systems under low signalto-noise ratio (SNR) conditions. The parameters of the proposed expression are optimally determined by the
differential evolution algorithm. The accuracy of the new expression is evaluated at different low SNRs. Numerical results show that the expression introduced in this paper significantly outperforms the high SNR approximation, and the results exhibit very good agreement with the optimum antenna number ratios that maximize the noise-limited asymptotic capacity expression.
In this paper, we derive a simple expression to determine the optimum antenna number ratio for multi-input multi-output systems under low signal-to-noise ratio (SNR) conditions. The parameters of the proposed expression are optimally determined by the differential evolution algorithm. The accuracy of the new expression is evaluated at different low SNRs. Numerical results show that the expression introduced in this paper significantly outperforms the high SNR approximation, and the results exhibit very good agreement with the optimum antenna number ratios that maximize the noise-limited asymptotic capacity expression.