Time-Domain Channel Estimation for the LTE-V System Over High-Speed Mobile Channels

Developed from the LTE uplink, the LTE-V2X standard, widely used as LTE-V, increases the overhead of pilot symbols in order to acquire channel information robustly. In this paper, we propose to estimate time-varying pieces of channel rays for pilot symbols based on the basis expansion model (BEM), and subsequently to reconstruct time-domain channel response for data symbols by utilizing Slepian sequences based piece-wise interpolation (SS-PWI). To demonstrate the precision of channel estimation (CE), the Cramer Rao lower bound (CRLB) is derived. The simulations are implemented on the LTE-V platform, on which we consider the extended vehicular A model (EVA) channel with 2800 Hz maximum Doppler shift. The proposed time-domain CE schemes are well capable of tracking the channel state information (CSI), and the mean squared error (MSE) of CE nearly reaches the theoretically derived CRLB.