Doppler Effect Reduction in an OFDM System Thanks to Massive MIMO

Among many challenges, 5G should improve the quality of service for moving users. In such a mobility context, the Doppler effect creates interference which can severely damage the performance of the systems. The effect of very large number of uncorrelated receive antennas on the Doppler effect is studied in this paper with a simple maximum ratio combining receiver and the orthogonal frequency division multiplexing modulation. This paper relies on an analytical analysis of the signal-to-interference ratio (SIR) and on a statistical analysis of the propagation channel. Therefore, the contribution of this paper is twofold. First, the asymptotic SIR is analytically expressed when the number of receive antennas tends toward infinity. Second, the decrease of the impact of the Doppler effect with the increase of the number of receive antennas is demonstrated, proving that a massive multiple-input multiple-output system with a low-complexity maximum ratio combining receiver can be used to improve the quality of service in mobility scenarios. Finally, the simulation results highlight the impact of such a massive multiple-input multiple-output system in practice.