A direction of arrival estimation algorithm designed under the maximum power collection criterion

Beamforming has been used in wireless sensor networks (WSNs) to increase the communication range of sensor nodes. These works investigate the beamforming performance using the theory of random arrays, and aims to achieve maximum transmitting power. Since the relative positions of sensor nodes and frequency/spatial response are generally unknown, it's also referred to as blind beamforming. In this paper, we propose a new method to design the weighting vector of the blind beamformer. By decoupling the processing in the spatial domain and the time domain, it is shown that in a certain situation, the previous blind beamformer is equivalent to the multiplication of two mutually independent classical beamformers. Designing the two beamforming components according to some well-known beamforming techniques, the spatial directivity of the new beamformer can be predesigned, and then it can be used to solve the direction of arrival estimation problem. Because of the additional temporal gain, the new beamformer achieves higher array output signal to noise ratio (SNR) compared with classical beamformers. Theoretical justification of this approach is presented to prove the fulfillment of the maximum power collecting criterion.