A Versatile Pilot Design Scheme for FDD Systems Utilizing Gaussian Mixture Models
<|reference_start|>A Versatile Pilot Design Scheme for FDD Systems Utilizing Gaussian Mixture Models: 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 during 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.<|reference_end|>
@article{turan2024a,
    title={A Versatile Pilot Design Scheme for FDD Systems Utilizing Gaussian
  Mixture Models},
    author={Nurettin Turan, Benedikt B"ock, Benedikt Fesl, Michael Joham, Deniz
  G"und"uz, Wolfgang Utschick},
    journal={arXiv preprint arXiv:2408.03756},
    year={2024},
    archivePrefix={arXiv},
    eprint={2408.03756},
    primaryClass={cs.IT eess.SP math.IT}
}