Interference Management upon Collaborative Beamforming in a Wireless Sensor Network Monitoring System featuring Multiple Unmanned Aerial Vehicles

Collaborative beamforming (CBF) has been proposed as a viable tool towards increasing node transmission range in Wireless Sensor Networks (WSNs). This is highly essential in scenarios featuring highly elevated airborne sinks (Unmanned Aerial Vehicles (UAVs)) where multi-hop transmission is inconceivable. CBF yields radiation in unintended directions (sidelobes). A high sidelobe is bound to lead to interference at an UAV in the sidelobe’s direction (taking into consideration a case of multiple and mobile UAV sinks). A direct consequence of increased interference is reduction in communication capacity at the affected UAV. This paper presents a generalized sidelobe minimization scheme using Gravitational Search Algorithm (GSA). The effect of sidelobe minimization on the communication capacity at unintended UAVs is analyzed. Appreciable capacity increase is observed in comparison to a scheme featuring peak sidelobe minimization only.