Pilots Aided Channel Estimation for Doubly Selective Fading Channel in Vehicular Environment

Abstract

Abstract. In vehicle communications, channel characteristic experiences time and frequency selective fading due to high velocity of vehicle and rapid changes of surrounding scatters. The packet format for IEEE 802.11p standard limits the choice of channel estimation algorithms. Conventional channel estimation algorithms perform the channel estimation based on the long preamble training sequence, then applies the estimated channel response to compensate for the entire packet. These algorithms are not optimal for a doubly selective channel in vehicle communications. In this paper, to overcome the effect of doubly selective channel, we propose a novel pilot insertion scheme that covers all subcarriers in both the time and frequency domains simultaneously. Adaptive channel estimation and equalization algorithms are then developed based on the new system architecture. Simulations show significant improvements comparing to other exiting methods.