Title: High-Mobility OFDM Downlink Transmission with Large-Scale Antenna Array,
Abstract: In this correspondence, we propose a new receiver design for high-mobility
orthogonal frequency division multiplexing (OFDM) downlink transmissions with a
large-scale antenna array. The downlink signal experiences the challenging fast
time-varying propagation channel. The time-varying nature originates from the
multiple carrier frequency offsets (CFOs) due to the transceiver oscillator
frequency offset (OFO) and multiple Doppler shifts. Let the received signal
first go through a carefully designed beamforming network, which could separate
multiple CFOs in the spatial domain with sufficient number of receive antennas.
A joint estimation method for the Doppler shifts and the OFO is further
developed. Then the conventional single-CFO compensation and channel estimation
method can be carried out for each beamforming branch. The proposed receiver
design avoids the complicated time-varying channel estimation, which differs a
lot from the conventional methods. More importantly, the proposed scheme can be
applied to the commonly used time-varying channel models, such as the Jakes'
channel model.