Time variant channel estimation using a modified complex exponential basis expansion model in LTE-OFDM systems

Abstract

In future wireless communication systems like LTE, wide bandwidths for the transmission of high data rates result in frequency selective mobile radio channels. If data transmission takes place at high mobile speeds the mobile radio channel becomes also time selective. In this paper we propose for the estimation of such double selective channels a modification to the well known complex exponential basis expansion model, which is based on the assumed knowledge of the maximum Doppler frequency at the mobile user. We are able to reduce the estimation error by an order of magnitude up to very high mobile speeds for the OFDMA-based LTE downlink.