Thomas Zemen - Communication systems
Date: - Location: Eurecom
In this presentation we focus on iterative time-variant channel estimation for the IEEE 802.11p standard which is based on orthogonal frequency division multiplexing (OFDM). The IEEE 802.11p standard uses a pilot pattern that is identical to the one used in 802.11a which was initially designed for indoor wireless channel estimation. This pilot pattern violates the sampling theorem for channels with both large delay spread and large Doppler spread. We design a robust iterative channel estimator based on a two dimensional subspace spanned by generalized discrete prolate spheroidal sequences. Due to the tight subspace design the iterative receiver is able to converge to the bit error rate as with perfect channel knowledge. Furthermore, we propose a backward compatible modification of the IEEE 802.11p pilot pattern such that 2 iterations are sufficient for convergence, strongly reducing implementation complexity.
