A novel iterative approach for Doppler spread estimation in LOS environment

In this paper, a novel iterative algorithm for maximum Doppler frequency estimation is proposed. In line-of-sight (LOS) environments, it is known that the performance of the conventional maximum Doppler frequency estimator obtained by the Rayleigh fading assumption will degrade severely. Thus we propose an estimator that estimates the Rician K factor first, then iteratively estimate the Doppler spread and the angle of arrival (AOA) of the LOS component through the autocorrelation function. In addition, the Cramer-Rao bounds (CRB) for the K factor and maximum Doppler frequency estimations are also derived for comparison. Simulation results indicate that the proposed estimator is not only superior to the conventional estimator but also robust to the channel parameters variation.