Non-Data-Aided Joint Multi-DFO Estimation for High-Mobility OFDM Communication Systems

In high-mobility communication systems, the relative motion between the transceivers will cause severe Doppler shifts, resulting in the doubly-selective fading channel. In this correspondence, a non-data-aided joint multiple Doppler frequency offsets (DFOs) estimator is proposed for high-mobility communication with orthogonal frequency division multiplexing (OFDM). Both the receive beamforming and multi-beamformer redundancy are employed to estimate and compensate multiple DFOs, thereby effectively mitigating the channel time-variation. Moreover, the inter-channel interference (ICI) has been derived to further analyze the impact of residual DFOs due to the estimation error on the system performance. Numerical results verify that the proposed non-data-aided estimator substantially outperforms existing ones.