Noncoherent Orthogonal Time Frequency Space Modulation

Xu C, Xiang L, Sugiura S, Maunder RG, Yang LL, Niyato D, Li GY, Schober R, Hanzo L (2024)

Publication Type: Journal article

Publication year: 2024

Journal

IEEE Transactions on Wireless Communications Institute of Electrical and Electronics Engineers (IEEE)

Pages Range: 1-1

DOI: 10.1109/TWC.2024.3368406

Abstract

The recently-developed orthogonal time frequency space (OTFS) modulation is capable of transforming the time-varying fading of the time-frequency (TF) domain into the time-invariant fading representations of the delay-Doppler (DD) domain. The OTFS system using orthogonal frequency-division multiplexing (OFDM) as inner core naturally requires the subcarrier spacing (SCS) Δf to be larger than the maximum Doppler frequency ϑmax, i.e. Δf > ϑmax, when perfect channel state information (CSI) knowledge is assumed. However, for the first time in literature, we explicitly demonstrate that the practical OFDM-based OTFS systems have to double their SCS in order to facilitate CSI estimation, requiring Δf′ = 2Δf > 2ϑmax. In order to mitigate this loss, we propose a novel noncoherent OTFS system, which is capable of operating at Δf > ϑmax. The major challenge in this context is the mitigation of the DD-domain interference without CSI. Against this background, we draw an analogy between the input-output model of OTFS and that of V-BLAST, where V-BLAST’s blind inter-antenna interference mitigation technique is invoked. Moreover, we propose to partition the DD-domain modulated symbols into groups, where space-time block coding is invoked in order to eliminate the DD-domain interference within each group. Our simulation results demonstrate that the proposed noncoherent OTFS is capable of substantially outperforming its coherent counterparts relying on CSI estimation.

Authors with CRIS profile

Robert Schober Lehrstuhl für Digitale Übertragung

Involved external institutions

University of Southampton GB United Kingdom (GB) University of Electronic Science and Technology of China (UESTC) / 电子科技大学 CN China (CN) University of Tokyo JP Japan (JP) Nanyang Technological University (NTU) SG Singapore (SG) Imperial College London / The Imperial College of Science, Technology and Medicine GB United Kingdom (GB)

How to cite

APA:

Xu, C., Xiang, L., Sugiura, S., Maunder, R.G., Yang, L.L., Niyato, D.,... Hanzo, L. (2024). Noncoherent Orthogonal Time Frequency Space Modulation. IEEE Transactions on Wireless Communications, 1-1. https://doi.org/10.1109/TWC.2024.3368406

MLA:

Xu, Chao, et al. "Noncoherent Orthogonal Time Frequency Space Modulation." IEEE Transactions on Wireless Communications (2024): 1-1.

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