Abstract:

In order to reduce computational complexity of selecting beamforming vectors and feedback in multiple input multiple output orthogonal frequency division multiplexing (MIMO-OFDM) systems, a nonlinear interpolation based beamforming scheme is proposed, the principle of which is to interpolate beamforming vectors of the non-pilot subcarriers via that of the pilot subcarriers. Analysis and simulation results illustrate that the proposed scheme outperforms the optimal beamforming with quantization as well as significant feedback and computational complexity reduction in the case of small size of codebook, while provides better performance than the existing linear interpolation and geodesic interpolation based beamforming methods with the same feedback.

Key words: Beamforming, limited feedback, multi-input multi-output, nonlinear interpolation, orthogonal frequency division multiplexing