Pilot-aided beamforming for OFDM detection over severe multipath fading

In broadband OFDM wireless communications, data symbol detection commonly requires a pilot-aided frequency channel estimation. A partial estimate is first computed from known symbols (pilots), frequencially multiplexed into the data. Estimation over the full bandwidth is then performed by frequency interpolation. In a multipath context, a strong fading effect may seriously degrade the channel estimation and error correcting codes are then necessary to improve the detection at the cost of a lower data transmission rate. In this paper, we propose to use a receiving array-antenna and to implement a pilot-aided beamformer in order to get an important fading effect mitigation. Unlike conventional array processing, our approach does not require the knowledge of the antenna/wavefront geometry nor any angle sweeping scheme. The proposed method is successfully tested on DVB-T real data in a SFN configuration.