Diversity analysis of OTFS over block time-varying channels

Amit Sravan Bora, Khoa T. Phan, Yi Hong

Research output: Contribution to journalArticleResearchpeer-review

Abstract

Orthogonal time frequency space (OTFS) modulation exhibits excellent performance in time-varying channels with severe Doppler shifts. Diversity analysis is an effective method in predicting error performance of an OTFS system. Recent works have studied OTFS diversity in a time-varying channel assuming constant delay-Doppler (DD) channel realization per frame. However, in practice, DD channel realizations may vary in a frame due to the rapid changes in channel geometry relative to a frame duration, leading to a block time-varying (BTV) channel. This paper analyzes the OTFS diversity in such BTV channels. Specifically, we derive the pairwise error probability of the system and analyze its diversity by finding the minimum rank of the pairwise error matrix and its associated multiplicity. We also compare it with other known schemes and demonstrate its improved diversity. Finally, simulations are performed to validate the analytical results.

Original languageEnglish
Number of pages6
JournalIEEE Transactions on Vehicular Technology
DOIs
Publication statusAccepted/In press - 3 May 2024

Keywords

  • Analytical models
  • block time-varying channel
  • Delays
  • Discrete Fourier transforms
  • diversity
  • OTFS
  • pairwise error probability
  • Symbols
  • Time-frequency analysis
  • Time-varying channels
  • Vectors

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