A simple and efficient approach for post-FFT beamforming in OFDM communications

A simple method is proposed for space-frequency channel estimation in an orthogonal frequency division multiplexing (OFDM) system with an antenna array. The conventional Least Square algorithm for channel estimation in the frequency-domain is applied to each antenna. Furthermore, spatial filtering vectors are directly extracted from the estimated channel matrix for beamforming in the frequency-domain, and the channel compensation is implemented in the spatial filtering. Compared with the existing systems where independent beamforming and channel compensation in frequency domain are conducted, respectively, the proposed method can significantly reduce the complexity of the system without loss of performance.