Uplink channel estimation with basis expansion model and expectation maximization for wireless communication systems on high speed railways

This paper proposes a blind channel estimator based on expectation maximization (EM) algorithm and historical information based basis expansion model (HiBEM) for uplink wireless communication systems on high speed railways (HSRs). The information of basis matrices is obtained from the uplink data of the past trains at the base station (BS). With the known basis matrices at the BS, our suggested estimator can estimate the basis coefficients and recover the channel parameters without requiring training symbols. Numerical results are provided to corroborate that the proposed estimator outperforms existing data-aided estimators, including least square (LS) and linear minimum mean square error (LMMSE).