Robust Channel Estimation via FFT Interpolation for Multicarrier Systems

The problem of channel estimation in multicarrier systems is considered. In the present work, we propose a robust implementation of the channel estimation via fast Fourier transform (FFT) interpolation for multicarrier systems whenever null carriers exist in the transmitted spectrum. In such a case, the existing approach presents the "border effect" phenomenon, which degrades significantly the overall performance and leads to the appearance of an error floor. The proposed solution resolves this serious handicap by incorporating correctly during the channel estimation process the existence of null carriers. In fact, the resulting method constitutes a generalization of the already existing scheme. Finally, with several simulations we demonstrate the significant performance improvements offered by our approach compared to the existing one.