Fast Time-Varying Channel Estimation Technique for LTE Uplink in HST Environment

A novel channel estimation technique is proposed for the time-division-duplex long-term evolution (TDD-LTE) single-carrier frequency-division multiple-access (SC-FDMA) system in the high-speed-train (HST) environment. In the new defined transform domain, the channel parameters of the two block pilots in the SC-FDMA subframe are first estimated, then the polynomial basis expansion model (P-BEM) is employed to estimate the channel parameters of the data symbols, and an autoregressive (AR) model is used to improve the estimation accuracy of the channel parameters of the data symbols out of the two block pilots. The symbol-by-symbol changes of the channel parameters can be effectively estimated by the proposed method. Simulation results show that the proposed method is robust to the fast time-varying channel in the HST scenario, and that the frame error rate (FER) performance of the system by using the proposed method can obtain a gain in the signal-to-noise ratio (SNR) of more than 10 dB compared with those of the available methods.