Low-complexity symbol detection and interference cancellation for OTFS system

Qu, H., Liu, G., Zhang, L. , Wen, S. and Imran, M. A. (2021) Low-complexity symbol detection and interference cancellation for OTFS system. IEEE Transactions on Communications, 69(3), pp. 1524-1537. (doi: 10.1109/TCOMM.2020.3043007)

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Orthogonal time frequency space (OTFS) is a two-dimensional modulation scheme realized in the delay-Doppler domain, which targets the robust wireless transmissions in high-mobility environments. In such scenarios, OTFS signal suffers from multipath channel with continuous Doppler spread, which results in significant inter-symbol interference and inter-Doppler interference (IDI). In this paper, we analyze the interference generation mechanism, and compare statistical distributions of the IDI in two typical cases, i.e., limited-Doppler-shift channel and continuous-Doppler-spread channel (CoDSC). Focusing on the OTFS signal transmission over the CoDSC, our study firstly indicates that the widespread IDI incurs a computational burden for the element-wise detector like the message passing in the state-of-the-art works. Addressing this challenge, we propose a block-wise OTFS receiver by exploiting the structure and characteristics of the OTFS transmission matrix. In the receiver, we deliberately design an iteration strategy among the least squares minimum residual based channel equalizer, reliability-based symbol detector and interference eliminator, which can realize fast convergence by leveraging the sparsity of channel matrix. The simulations demonstrate that, in the CoDSC, the proposed scheme achieves much less detection error, and meanwhile reduces the computational complexity by an order of magnitude, compared with the state-of-the-art OTFS receivers.

Item Type:Articles
Additional Information:This work was supported in part by the National Natural Science Foundation of China under Grant 62071097, and in part by the 111 Project under Grant B17008.
Glasgow Author(s) Enlighten ID:Imran, Professor Muhammad and Zhang, Professor Lei
Authors: Qu, H., Liu, G., Zhang, L., Wen, S., and Imran, M. A.
College/School:College of Science and Engineering > School of Engineering > Systems Power and Energy
Journal Name:IEEE Transactions on Communications
ISSN (Online):1558-0857
Published Online:07 December 2020
Copyright Holders:Copyright © 2020 IEEE
First Published:First published in IEEE Transactions on Communications 69(3): 1524-1537
Publisher Policy:Reproduced in accordance with the publisher copyright policy

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