Challenges to Subcarrier MIMO Precoding and Equalisation with Smooth Phase Responses

Bakhit MA, Khattak FA, Schlecht S, Rice GW, Weiss S (2025)

Publication Type: Conference contribution

Publication year: 2025

Publisher: Institute of Electrical and Electronics Engineers Inc.

Pages Range: 32-38

Conference Proceedings Title: WSA 2025 - Proceedings of the 28th International Workshop on Smart Antennas

Event location: Erlangen, DEU

ISBN: 9798350392685

DOI: 10.1109/WSA65299.2025.11202801

Abstract

Precoding for multiple-input multiple-output orthogonal frequency division multiplexing systems is often based on a per-subcarrier singular value decomposition, where phase smoothing is applied to the singular vectors that form the transmit beamformers. We show that such a smooth solution can ideally be based on an analytic singular value decomposition, but for estimated channel matrices is beset by challenges that deny a smooth or even continuous evolution of singular vectors with frequency. We show how such problems can be bypassed by admitting complex-valued singular values or fractional delays, and by exploiting a method analogous to the analytic eigenvalue decomposition to approximate ground truth analytic singular vectors from estimated channel matrices. We present examples and demonstrate some of the capabilities of a proposed algorithm through simulations.

Authors with CRIS profile

Sebastian Schlecht Lehrstuhl für Audiocodierung (AudioLabs)

Involved external institutions

University of Strathclyde GB United Kingdom (GB) University of Leeds GB United Kingdom (GB) MathWorks US United States (USA) (US)

How to cite

APA:

Bakhit, M.A., Khattak, F.A., Schlecht, S., Rice, G.W., & Weiss, S. (2025). Challenges to Subcarrier MIMO Precoding and Equalisation with Smooth Phase Responses. In Angelika S. Thalmayer, Maximilian Lubke (Eds.), WSA 2025 - Proceedings of the 28th International Workshop on Smart Antennas (pp. 32-38). Erlangen, DEU: Institute of Electrical and Electronics Engineers Inc..

MLA:

Bakhit, M. A., et al. "Challenges to Subcarrier MIMO Precoding and Equalisation with Smooth Phase Responses." Proceedings of the 28th International Workshop on Smart Antennas, WSA 2025, Erlangen, DEU Ed. Angelika S. Thalmayer, Maximilian Lubke, Institute of Electrical and Electronics Engineers Inc., 2025. 32-38.

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