Channel estimation and equalization for multi-carrier system in doubly selective channels

Multi-carrier modulation, Orthogonal Frequency Division Multiplexing (OFDM) particularly, has been successfully applied to a wide variety of digital communication application over the past several years. In the paper, we attempt to introduce a new method of channel estimation and equalization for OFDM system over a doubly selective channel. The core idea behind our method is to use a Taylor series expansion for the time-varying (TV) channel impulse response (CIR), along with the known statistical properties of mobile radio channels. In order that multi-carrier transmissions through frequency selective channel can be recovered even when deep fades are present, the ZP-OFDM is considered. We propose a low-complexity zero-forcing block linear equalizer by using of the band and lower triangular structure of the channel transfer matrix. Moreover, the proposed method allows a flexible tradeoff between complexity and performance.