A Novel Delay-Doppler-Based Channel Estimation Method in Doubly-Dispersive OCDM Systems

Zegrar S. E., ARSLAN H.

IEEE Wireless Communications Letters, vol.13, no.3, pp.801-804, 2024 (SCI-Expanded) identifier

  • Publication Type: Article / Article
  • Volume: 13 Issue: 3
  • Publication Date: 2024
  • Doi Number: 10.1109/lwc.2023.3344231
  • Journal Name: IEEE Wireless Communications Letters
  • Journal Indexes: Science Citation Index Expanded (SCI-EXPANDED), Scopus, Compendex, INSPEC
  • Page Numbers: pp.801-804
  • Keywords: channel estimation, delay-Doppler domain, doubly-dispersive channel, Frenel domain, OCDM
  • Istanbul Medipol University Affiliated: Yes

Abstract

Orthogonal chirp division multiplexing (OCDM) has recently emerged as a new candidate for the 6G waveform. In high-mobility wireless channels, the inseparability of the data symbols in both time and frequency domains makes channel estimation in OCDM-based wireless communication quite challenging. In this letter, we address this issue by investigating the representation of the OCDM waveform in the delay-Doppler domain in which we reveal that OCDM carriers exhibit a sparse representation. Building upon this observation, we propose a low-complexity channel estimation technique for OCDM systems. This technique involves designing pilots in the Fresnel domain and estimating the channel in the delay-Doppler domain. We evaluate the performance of the proposed channel estimation and demonstrate the superior performance of our approach, showcasing both high accuracy and low computational complexity.