A versatile pilot design scheme for FDD systems utilizing Gaussian mixture models
File(s)
Published online version
Author(s)
Type
Journal Article
Abstract
In this work, we propose a Gaussian mixture model (GMM)-based pilot design scheme for downlink (DL) channel estimation in single- and multi-user multiple-input multiple-output (MIMO) frequency division duplex (FDD) systems. In an initial offline phase, the GMM captures prior information on the channel statistics through training, which is then utilized for pilot design. In the single-user case, the GMM is utilized to construct a codebook of pilot matrices and, once shared with the mobile terminal (MT), can be employed to determine a feedback index at the MT. This index selects a pilot matrix from the constructed codebook, eliminating the need for online pilot optimization. We further establish a sum conditional mutual information (CMI)-based pilot optimization framework for multi-user MIMO (MU-MIMO) systems. Based on the established framework, we utilize the GMM for pilot matrix design in MU-MIMO systems. The analytic representation of the GMM enables the adaptation to any signal-to-noise ratio (SNR) level and pilot configuration without re-training. Additionally, an adaption to any number of MTs is facilitated. Extensive simulations demonstrate the superior performance of the proposed pilot design scheme compared to state-of-the-art approaches. The performance gains can be exploited, e.g., to deploy systems with fewer pilots.
Date Issued
2025-05-01
Date Acceptance
2025-02-01
Citation
IEEE Transactions on Wireless Communications, 2025, 24 (5), pp.4115-4130
ISSN
1536-1276
Publisher
Institute of Electrical and Electronics Engineers (IEEE)
Start Page
4115
End Page
4130
Journal / Book Title
IEEE Transactions on Wireless Communications
Volume
24
Issue
5
Copyright Statement
© 2025 The Author(s). This work is licensed under a Creative Commons Attribution 4.0 License. For more information, see https://creativecommons.org/licenses/by/4.0/
License URL
Identifier
10.1109/TWC.2025.3537496
Subjects
Pilot design
Gaussian mixture models
machine learning
MU-MIMO
FDD systems
Publication Status
Published
Date Publish Online
2025-02-07