Channel Estimation for OFDM Systems in Rapidly Time-Variant Channels Using High Degree Channel Approximation

The orthogonality between the sub-carriers of orthogonal frequency division multiplexing (OFDM) systems is lost in case of time-variant channels, and thus, the system performance is degraded because of the resulting inter-carrier interference (ICI) phenomenon. In such case, a complete estimation of the channel matrix is required to cancel the effect of ICI. In this paper, an ICI cancellation method for digital radio mondiale (DRM) is introduced. The cancellation method is based on estimating the channel matrix by means of high degree approximation of the channel variations over few OFDM symbols.