Inverse Methods for Reconstruction of Channel Taps in OFDM Systems

We describe a novel pilot-aided method for estimation of doubly selective wireless channels in OFDM systems. We compute the first few Fourier coefficients of each channel tap from the pilot information. We then estimate the BEM coefficients of the channel taps from their respective Fourier coefficients using a recently developed inverse reconstruction method. For a system with L channel taps, the proposed method uses O(L log L) operations and O(L) memory per OFDM symbol. We validate our method by simulating a system conforming to the IEEE 802.16e standard.