Channel Spreading Function-Inspired Channel Transfer Function Estimation for OFDM Systems with High-Mobility

TL;DR

This paper introduces a novel CSF-based channel transfer function estimation method for OFDM systems in high-mobility scenarios, outperforming traditional methods by leveraging delay-Doppler domain properties.

Contribution

The paper develops a CSF estimation model using only pilot symbols and establishes the relationship between CSF compactness and pilot spacing for accurate estimation.

Findings

Outperforms traditional interpolation-based methods in high-mobility scenarios

Closely matches the optimal estimator in estimation accuracy

Enables CSF estimation in commercial OFDM systems

Abstract

In this letter, we propose a novel channel transfer function (CTF) estimation approach for orthogonal frequency division multiplexing (OFDM) systems in high-mobility scenarios, that leverages the stationary properties of the delay-Doppler domain channel spreading function (CSF). First, we develop a CSF estimation model for OFDM systems that relies solely on discrete pilot symbols in the time-frequency (TF) domain, positioned at predefined resource elements. We then present theorems to elucidate the relationship between CSF compactness and pilot spacing in the TF domain for accurate CSF acquisition. Based on the estimated CSF, we finally estimate the CTF for data symbols. Numerical results show that, in high-mobility scenarios, the proposed approach outperforms traditional interpolation-based methods and closely matches the optimal estimator in terms of estimation accuracy. This work may pave the way for CSF estimation in commercial OFDM systems, benefiting high-mobility communications, integrated sensing and communications, and related applications.