Spatial diversity gained through different beamforming techniques in antenna array is one of the main advantages over the single antenna. Antenna complexity and beamwidth broadening at the scanning angles other than broadside are downsides of antenna arrays that prevent its practical implementation from some applications. In this letter, we propose an efficient beamforming method based on the sparse multiple-input-multiple-output (MIMO) array and spatial filter bank (SFB). The sparse MIMO array produces narrow beams while significantly reduces the number of array elements without compromising system performance. Multiple main beams are chosen from grating lobes by SFB. By combining sparse array geometry and SFB, we can achieve a narrower beamwidth with less antenna elements, multiple beams, and constant beamwidth. The burden of system will be transferred from the frontend hardware to the signal processing back end.
- Digital beamforming
- multiple-input-multiple-output (MIMO) array
- sparse antenna array
- spatial filter bank (SFB)
- virtual array