Adaptive decision feedback orthogonality restoration filter for windowed OFDM

OFDM is a promising multi-carrier modulation technique that can effectively mitigate impairments caused by wireless communication channels. In some OFDM standards (eg, IEEE 802.11a), windowing is employed to reduce sensitivity to frequency offset and phase noise, and at the same time conserve bandwidth. However, windowing causes the loss of orthogonality between subcarriers. We propose a decision feedback orthogonality restoration filter for minimizing orthogonality loss due to both windowing and inter-block interference. Simulation results using IEEE 802.11a parameters show that the proposed scheme achieves significant performance improvement