Channel estimation and data detection schemes for Orthogonal Time Frequency Space massive MIMO systems

Abstract

Orthogonal Time Frequency Space (OTFS) massive Multiple Input Multiple Output (MIMO) system combines the benefits of massive MIMO and OTFS modulation to improve performance in high-Doppler scenarios. In this paper, Compressive Sampling Matching Pursuit (CoSaMP) channel estimation is proposed for the downlink OTFS massive MIMO system to improve signal reconstruction in high-Doppler scenarios. Furthermore, this paper implements Gauss-Seidel (GS)-based minimum mean square error (MMSE) data detection in uplink OTFS massive MIMO to lower the complexity of matrix inversion in MMSE data detection and match the MMSE data detection performance in the delay-Doppler domain. The computer simulations performed suggest that the performance of the proposed CoSaMP-based channel estimation with interleaving outperforms the previously proposed channel estimator for the system with negligible computational complexity. The simulation results also suggest that the proposed GS-based MMSE data detection technique almost matches the traditional MMSE-based data detection technique's performance at significantly reduced computational complexity cost.