Optimal Power Scheduling for Data Fusion in Inhomogeneous Wireless Sensor Networks

We consider the problem of optimal power scheduling for the decentralized detection of a deterministic signal in an inhomogeneous wireless sensor network. The observation noise at local sensors is assumed to be independently and identically distributed (i.i.d.) and at the local sensors each node performs analog-relay amplifier processing for its observation independently. The communication between the local sensors and the fusion center is assumed to be through an inhomogeneous channel. The optimal power scheduling scheme suggests that the sensors with poor observation quality and channels should be inactive in order to save total power expenditure of the system. For the remaining active sensors the optimal transmit power is determined jointly by the individual channel gains, total number of active sensors, local observation signal to noise ratio (SNR) and the required probability of error at the fusion center. We show that the optimal scheme can provide significant system power savings compared to the uniform power allocation scheme when the number of sensors in the system is large.