A new digital beamforming approach for SDMA using spreading sequence array weights

A novel space division multiple access (SDMA) digital beamformer (DBF) is proposed which can replace traditional approaches to DBF. This new approach does not perform digital phase shifting nor does it rely on adaptive methods; however, multiple beams are produced in directions of interest. An array correlation matrix is not needed, array weights are not adapted, and an a priori knowledge of the signal environment is not required. Rather, a spreading technique is utilized that uniquely defines all received directions of interest. This receiver can create virtual contiguous beams or it can selectively look in any specific directions of interest.This approach blends the virtues of switched beam and adaptive array technologies. The new receiver has the same spatial resolution as traditional arrays while simultaneously looking in all desired directions of interest.