Using a UAV to collect data from low-power wireless sensors

In this work we propose an energy-efficient cooperative transmission scheme for wireless sensor networks (WSNs) where data gathered by sensor nodes need to be transmitted toward a far receiver. The scenario consists of sensor nodes that share a common message that has to be transmitted asynchronously toward a fusion center positioned onboard an unmanned aerial vehicle (UAV). We assume the communication channel between the sensors and the fusion center subject to fading and noise. Therefore, the fusion center must be able to receive the weak and noisy signals and combine them in coherent way to obtain a reliable communication. In our approach the fusion center is represented by a Rake receiver. The results of simulations show that such approach allows to obtain a throughput and an energy efficiency directly proportional to the number of nodes.