SPC04-5: Practical Channel Estimation for OFDM in time-varying channels

In fast mobile environments, the reception of orthogonal frequency domain modulation (OFDM) signals with tight sub-carrier spacing is challenged by the inter-carrier interference (ICI). This ICI must be compensated for by a suitable equalizer design, which requires the estimation of a larger number of parameters than for static environments. In addition, ICI also degrades the quality of the channel estimation. We propose an analytical approach to estimate the frequency domain channel matrix that relies on its nearly banded structure and a first order Taylor approximation of the channel variation. An additional constraint of this work is to accommodate OFDM systems with large number of sub-carriers and scattered pilots, such as used in DVB-T and DVB-H broadcast. We provide simulation results to demonstrate the performance of the proposed channel estimation method.