Channel estimation for pilot-aided OFDM systems in single frequency network

In single frequency network (SFN), there exist some special long delay spread channels as well as conventional multi-path channels. For pilot-aided orthogonal frequency division multiplex (OFDM) systems, channel estimation is usually accomplished by interpolation with pilots. However, few pilot subcarriers exist within coherent bandwidth under the long delay spread channels in SFN. In this case, conventional interpolation methods cannot work properly. This paper proposes a sine-wave based frequency domain interpolation method for channel estimation of pilot-aided OFDM systems in SFN. As simulation results show, the proposed method gives accurate channel estimation under the long delay spread channels, whereas the mismatched Wiener interpolation filter (WIF) estimates channel response inaccurately. Moreover, the proposed method performs well under conventional multi-path channels, especially for systems which adopt high order modulations.