Sparse Channel Estimation for High-Mobility OFDM Systems in Downlink

In this paper, the time-varying channel estimation for high-mobility orthogonal frequency division multiplexing (OFDM) systems is investigated. The communication link between the static base station (BS) and the mobile relay station (MRS) on top of the high-speed train is considered, where the train is traveling in the open areas, such as rural, suburban and viaduct scenarios. In these scenarios, the channel has the sparse characteristic which means that there are only limited multipaths with different Doppler frequency offsets (DFOs) from the BS to the MRS. Then, the basis pursuit based method can be used to recover the time-domain channel response. Both the theoretical analysis and simulation results are provided to verify the effectiveness of the proposed method.