A&M based fractional delay and Doppler channel estimation in OTFS
Abstract
Orthogonal time frequency space (OTFS) modulation is a candidate for low-density high-mobility communication (LDHMC) use case in sixth generation (6G) due to its robustness against Doppler effects. This paper presents a low-complexity channel estimation method based on the A&M frequency estimation algorithm, enabling precise recovery of fractional delay, Doppler, and gain. We show that conventional virtual tap-based methods are inadequate for detection, while sparse Bayesian learning (SBL)-based off-grid approaches, though precise, are computationally intensive. To bridge this gap, we propose a method that combines precision with efficiency, eliminating the trade-off between accuracy and complexity. Its effectiveness is validated through MATLAB simulations and real-time implementation on an Ettus USRP B210 SDR platform.
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Authors: Omid Abbassi Aghda, Oussama Ben Haj Belkacem, Nikolajs Tihomorskis, João Guerreiro, Nuno Souto, Michal Szczachor, Rui Dinis
Institutions: Riga Technical University, Universidade Nova de Lisboa, Instituto de Telecomunicações, University of Carthage, Université Tunis Carthage, Iscte – Instituto Universitário de Lisboa, University of Wrocław