Doppler Spread Estimation by Tracking the Delay-Subspace for OFDM Systems in Doubly Selective Fading Channels

TL;DR

This paper introduces a new algorithm for estimating the maximum Doppler spread in OFDM systems by tracking the delay subspace, transforming the problem into a polynomial equation solved via Newton's method, with demonstrated simulation performance.

Contribution

It proposes a novel Doppler spread estimation method based on delay subspace tracking and polynomial solving, improving accuracy in doubly selective fading channels.

Findings

Accurate Doppler spread estimation demonstrated in simulations

Effective tracking of delay subspace in time-varying channels

Enhanced performance over existing methods

Abstract

A novel maximum Doppler spread estimation algorithm for OFDM systems with comb-type pilot pattern is presented in this paper. By tracking the drifting delay subspace of time-varying multipath channels, a Doppler dependent parameter can be accurately measured and further expanded and transformed into a non-linear high-order polynomial equation, from which the maximum Doppler spread is readily solved by resorting to the Newton's method. Its performance is demonstrated by simulations.