A Decision-Directed Channel Estimator for OFDM-Based Bursty Vehicular Communication

Abstract

We consider bursty orthogonal frequency-division multiplexing (OFDM) signal transmission, where each signal burst (or packet) consists of a preamble followed by data symbols which may contain few pilots. Channel estimation in vehicular environments for such signals is a challenging issue, as evidenced by related studies for the IEEE 802.11p standard. Existing channel estimation methods often yield deficient performance or require relatively high latency to achieve better performance, unless additional pilots are introduced. We propose a technique that addresses this problem. The primary aspect of the design is to exploit the temporal correlation in channel responses over close-by OFDM symbols in a decision-oriented manner. A secondary aspect is to take advantage of any available pilots in the data symbols in a frequency-domain filtering built on the temporal processing results. Regarding the performance of the proposed method, we first analyze the proposed temporal processing technique under some simplistic channel conditions both for insight and for verification. Further simulation results based on the IEEE 802.11p specifications under a measurement-based fading multipath vehicle-to-vehicle (V2V) channel model show the superiority of the proposed method.