An OFDM beamformer of a signal receiving system receives multiple frequency-domain sample signal vectors each transformed from arrival signals received by a corresponding antenna element of an antenna array, and includes: multiple signal splitters each splitting a corresponding frequency-domain sample signal vector into a data signal subvector and a pilot signal subvector based on predetermined position information; a weight generator generating an estimated auto-correlation matrix and an estimated cross-correlation vector based on the data signal subvectors, the pilot signal subvectors, and a reference pilot signal vector associated with a desired user, and generating an optimal weight vector based on the estimated auto-correlation matrix and the estimated cross-correlation vector; and a combining unit combining, based on the optimal weight vector, serial data signals converted from each data signal vector by a corresponding parallel-to-serial converter to generate an estimated data symbol output corresponding to the desired user.