Optimal Estimation in Wireless Sensor Networks With Energy Harvesting

In this paper, the source estimation problem is investigated in a wireless sensor network (WSN) with energy-harvesting (EH) nodes. We first consider a deterministic EH model where the amount of harvested energy at each node is known prior to transmissions. For such a model, we investigate the average mean-square-error (MSE) minimization problem over a finite horizon of multiple estimation periods and derive the optimal solution. Moreover, a more realistic stochastic EH model is considered, where only the current amount of harvested energy is known. The corresponding MSE minimization problem over an infinite horizon is formulated. The Lyapunov optimization technique is adopted to obtain a solution for the stochastic EH problem. Simulation results are conducted to validate the effectiveness of the proposed solutions for both the deterministic and stochastic EH models.