Leakage Suppression in Pulse-Shaped OTFS Delay-Doppler-Pilot Channel Estimation

Abstract

In this letter, we propose a novel channel estimation scheme with leakage suppression for orthogonal time frequency and space (OTFS) modulation. In OTFS, data and pilot symbols are placed in the delay-Doppler (DD) domain and spread over the time-frequency (TF) domain. This increases the achievable accuracy in estimating linear time-varying (LTV) channels. Unfortunately, leakage effects reduce the measurement precision significantly. Therefore, we propose a scheme that exploits smoothness regularization in TF to suppress the leakage observed in the DD domain. It allows us to improve the channel estimation accuracy while reducing signaling overhead.