High speed trains communication systems in 5G cellular networks

Abstract

In this paper, a new transmitter-receiver structure for high speed train (HST) data transmission and detection in fifth generation (5G) communication systems is proposed. This structure employs a new Doppler shift frequency (DSF) estimation approach, projected in this paper, to calculate the channel taps' DSFs at the base station (BS) receiver. The estimated DSFs are used to calculate the channel taps' angle of departures (AoDs). Considering the estimated AoDs, the transmitter beamformer regulates its coefficients to suppress the non-line of sight channel taps (NLoSCTs) and a DSF compensation block is employed to alleviate the line of sight channel tap's (LoSCT's) DSF. The proposed DSF estimation approach is a two-phase scheme which obtains a coarse estimation of DSFs at the first phase and calculates DSFs more accurately at the second phase. While this two-phase DSF estimation approach is able to estimate DSFs in both multipath rich and Rician channel models, an alternative DSF estimation scheme for Rician channel models is proposed which can estimate the LoSCT's DSF with much lower computational complexity compared to the two-phase DSF estimation method. Simulation results indicate the fidelity of the proposed DSF estimation methods and the proposed transmitter-receiver structure.