A Doppler Shift Estimator for Millimeter-Wave Communication Systems on High-Speed Railways

Abstract

The millimeter-wave (mmWave) technology is one possible solution to addressing the explosive requirements for mobile data access on high-speed railways (HSRs). However, utilizing the mmWave technology on HSRs will result in large Doppler shift, which should be estimated and compensated. Traditional Doppler shift estimators including the cyclic prefix (CP) based estimator (CPBE), the two-training-symbol based estimator (TBE) and the best linear unbiased estimator (BLUE) have inferior estimation accuracy especially at low signal-to-noise ratio (SNR). In this paper, we propose the new Doppler shift estimator for mmWave communication systems on HSRs: an equally-divided structure based estimator (ESBE) that divides the effective orthogonal frequency-division multiplexing (OFDM) symbol into multiple equal fragments. Simulation results show that our new estimator outperforms several existing Doppler shift estimators in mmWave communication systems on HSR.