In order to improve the transmission performance of Orthogonal Frequency Division Multiplexing(OFDM) systems in fast time-varying channels,a novel time-domain channel estimation scheme based on the superimposed training sequence is proposed.In this scheme,according to the exponential interpolation model of the channel tap coefficient,a linear model is established by using the periodic superimposed training sequence of a symbol,and the parameters of the interpolation model are estimated by means of the least...