Beamforming apparatus and method for multi-antenna system

A beamforming method which is applied to a multi-antenna system comprising a phase control unit comprising a plurality of phase shifters which respectively control the phases of signals received from a plurality of antennas according to a preset phase weight vector;

• a signal combination unit combining the signals outputted from the plurality of phase shifters;
• a frequency down converter down-converting the combined signal outputted from the signal combination unit into a baseband signal;
• and an A/D converter converting the baseband signal outputted from the frequency down converter into a digital signal, the beamforming method comprising:
• performing an SNR detection operation of providing a plurality of phase weight vectors contained in a preset phase weight vector codebook to the phase control unit according to a preset application sequence, and detecting a plurality of SNRs corresponding to the applied phase weight vectors by using the digital signal outputted from the A/D converter;
• performing an SNR comparison operation of comparing the magnitudes of the plurality of SNRs;
• performing a maximum SNR decision operation of deciding a maximum SNR according to the comparison result among the plurality of SNRs;
• and
• performing a beamforming operation of controlling beamforming of the phase control unit by using the maximum SNR.