Channel Estimation of the 802.11p Standard in High-Speed Mobile Environments

Wireless communication systems of the 802.11 p standard designed for direct communication between high-speed mobile users in the channels of the 5.9 Ghz band, subject to rapid fading. At the physical level, these systems are completely identical to the 802.11 a systems created for communication in the same range with very low speed objects, and the channel evaluation is performed by the “preamble” training symbols transmitted at the beginning of the frame. As a result, in longterm information packets (frames), the value of the channel estimation error reaches unacceptably large values. In this paper, it is proposed the change in the channel estimation in 802.11 p is based on the” cross-layered” approach, where the pilot symbols or pilot tones (PT) known on the receiving side are inserted at a high standard level as pilot ones to improve the channel estimation. The initial information for the channel parmeters is the estimates of these additional PT, and to improve this assessment, it is proposed to apply the inter-channel interference (ICI) self-suppression approach. The resulting reduction in the mean-square error of the channel estimation is given on the example of a channel with Rayleigh fading caused by Doppler spreading of the Jake.s type.