A Robust Channel Estimation for Broadband OFDM Systems with Virtual Tones

In broadband orthogonal frequency division multiplexing (OFDM) systems, accurate channel state information (CSI) is required to support coherent detection and diversity combining. However, it is indeed challenging for channel estimation in real systems since some tones are nulled to ease the implementation of spectral masking filters. We propose a novel channel estimation scheme which can solve the leakage caused by virtual tones (VTs) via effective energy compensation and partial refinement with no extra computational complexity. Additionally, the proposed scheme works well with different allocations of various VTs, and hence applicable for hardware realization. Simulation results validate that the proposed method is efficient to combat the leakage, and also robust to the existence of VTs.