Efficient channel equalization and symbol detection for MIMO OTFS systems

Qu, H., Liu, G., Wen, S., Imran, M. A. and Zhang, L. (2022) Efficient channel equalization and symbol detection for MIMO OTFS systems. IEEE Transactions on Wireless Communications, 21(8), pp. 6672-6686. (doi: 10.1109/TWC.2022.3151821)

Abstract

The application of multiple-input multiple-output (MIMO) over orthogonal time frequency space (OTFS) modulation is envisioned to provide high-data-rate wireless transmission in high-mobility environments. However, in these communication scenarios, the multiple-dimensional interference, which can generate from space, delay and Doppler domains, challenges the channel equalization and symbol detection at the MIMO-OTFS receiver. To tackle this issue, we propose a time-space domain channel equalizer, relying on the mathematical least squares minimum residual algorithm, to remove the channel distortion on data symbols. The proposed channel equalizer adopts a recursion method to achieve symbol estimates, which can realize fast convergence by leveraging the sparsity of MIMO-OTFS channel matrix. Instead of directly remapping the equalized OTFS symbols into data bits, we develop an enhanced data detection (EDD) scheme to iteratively demodulate the superposed multi-antenna signal. The EDD can not only realize the linear-complexity interference cancellation, but also efficiently reap the spatial and multi-path diversities of MIMO-OTFS channel. The simulations show the proposed channel equalization and EDD algorithms enable the MIMO-OTFS receiver to robustly demodulate multi-stream 256-ary quadrature amplitude modulation symbols, under a maximum velocity of 550 km/h at 5.9 GHz carrier frequency.

• Item Type: Articles
• Status: Published
• Refereed: Yes
• Glasgow Author(s) Enlighten ID: Zhang, Professor Lei and Imran, Professor Muhammad
• Authors: Qu, H., Liu, G., Wen, S., Imran, M. A., and Zhang, L.
• College/School: College of Science and Engineering > School of Engineering > Autonomous Systems and Connectivity
• Journal Name: IEEE Transactions on Wireless Communications
• Publisher: IEEE
• ISSN: 1536-1276
• ISSN (Online): 1558-2248
• Published Online: 23 February 2022
• Copyright Holders: Copyright © 2022 IEEE
• First Published: First published in IEEE Transactions on Wireless Communications 21(8): 6672-6686
• Publisher Policy: Reproduced in accordance with the publisher copyright policy