Sidelobe Control by Node Selection Algorithm Based on Virtual Linear Array for Collaborative Beamforming in WSNs

To communicate directly with the base station without multi-hops, this paper presents a sidelobe control by node selection algorithm (SCNSA) based on a virtual linear antenna array for collaborative beamforming (CB) in wireless sensor networks. SCNSA first presents a method to calculate the energy-optimal number of the array nodes and the accuracy of the method is verified by experiments. Then a CB array node selection algorithm is proposed to determine how to select the array nodes. In the end, a calculation strategy of the optimal excitation current for each array nodes via cuckoo search algorithm is presented. Simulation results demonstrate that the sidelobe level of SCNSA is much lower than that of PSO-LSNA whereas the mainlobe of the two algorithms are basically the same. Moreover, the average energy consumption of nodes obtained by SCNSA is decreased by 38.08, 48.77, and 48.54 % compared with those by LEACH, CUCRA and UCR, respectively. The communication delay of SCNSA is significantly lower compared with those of LEACH and CUCRA. Therefore, SCNSA can effectively prolong the lifetime of the networks.