On Channel Estimation for 802.11p in Highly Time-Varying Vehicular Channels

TL;DR

This paper proposes a cross-layer method to enhance channel estimation in 802.11p vehicular systems, significantly reducing frame errors in highly time-varying channels by using known data bits for improved estimation.

Contribution

It introduces a novel cross-layer approach with a modified receiver that leverages known data bits for better channel estimation in 802.11p, addressing issues caused by rapid channel variations.

Findings

Frame error rates close to perfect channel knowledge achieved

Improved channel estimation with noniterative receiver configuration

Enhanced robustness in highly time-varying vehicular channels

Abstract

Vehicular wireless channels are highly time-varying and the pilot pattern in the 802.11p orthogonal frequency-division multiplexing frame has been shown to be ill suited for long data packets. The high frame error rate in off-the-shelf chipsets with noniterative receiver configurations is mostly due to the use of outdated channel estimates for equalization. This paper deals with improving the channel estimation in 802.11p systems using a cross layered approach, where known data bits are inserted in the higher layers and a modified receiver makes use of these bits as training data for improved channel estimation. We also describe a noniterative receiver configuration for utilizing the additional training bits and show through simulations that frame error rates close to the case with perfect channel knowledge can be achieved.