On the Performance of Spatial Modulation Schemes in Large-Scale MIMO under Correlated Nakagami Fading

Abstract

Many variants of spatial modulation (SM), aiming to enhance data rate and bit error rate (BER) performance, have been proposed, however, their performance has not been compared for large-scale multiple-input multiple-output (MIMO) systems. This paper looks at various such schemes, namely spatial modulation (SM), generalized spatial modulation (GSM), quadrature spatial modulation (QSM) and enhanced spatial modulation (ESM) to study their performance for large-scale MIMO systems under generalized fading conditions. Our results indicate that for the same spectral efficiency and transmit power, QSM and ESM perform better than GSM and SM schemes. For lower order modulation, QSM outperforms all other schemes under various fading conditions, whereas ESM takes over for higher order modulation. The BERs for QSM and ESM under various transmit configurations have been evaluated via extensive Monte Carlo simulations. The results reveal that in QSM, a higher number of total transmit antennas, N <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">t</sub> , with a lower order modulation scheme provides a much better BER than a lower number of N <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">t</sub> with a higher order modulation scheme, for the same data rate. This performance difference, however, becomes smaller in ESM, which can provide comparable performance using a higher order modulation and half the transmit antennas.