Pilot-Aided Joint Time Synchronization and Channel Estimation for OTFS

TL;DR

This paper introduces a pilot-aided joint time synchronization and channel estimation algorithm for OTFS systems that leverages MLS autocorrelation properties, improving BER performance close to ideal conditions.

Contribution

It presents a novel JTSCE algorithm using MLS pilots for OTFS, enabling more accurate synchronization and channel estimation than existing methods.

Findings

Achieves better BER performance than existing algorithms.

Uses MLS autocorrelation for precise timing and channel delay estimation.

Performs close to perfect synchronization in simulations.

Abstract

This letter proposes a pilot-aided joint time synchronization and channel estimation (JTSCE) algorithm for orthogonal time frequency space (OTFS) systems. Unlike existing algorithms, JTSCE employs a maximum length sequence (MLS) rather than an isolated signal as the pilot. Distinctively, JTSCE explores MLS's autocorrelation properties to estimate timing offset and channel delay taps. After obtaining delay taps, closed-form expressions of Doppler and channel gain for each propagation path are derived. Simulation results indicate that, compared to its counterpart, JTSCE achieves better bit error rate performance, close to that with perfect time synchronization and channel state information.