Optimal power allocation for the maximization of energy efficiency in wireless sensor networks

Energy efficiency (EE) is an important factor for the deployment of wireless sensor networks. Cooperative communication can help to reduce energy consumption for long distance data transmission. This paper mainly presents the optimal power allocation scheme for cooperative communication in wireless sensor networks. We formulate the EE maximization problem with power constraint, and show that this problem, albeit being non-convex, possesses an interesting quasi-convex property in the reformulated form. By exploiting this property, the optimal problem is shown to be solvable availably via Lagrangian function and bisection method, and the optimal power allocation is presented as a closed-form solution. Finally, numerical results show that the proposed power allocation can improve the system performance compared to the conventional equal power allocation through MATLAB simulation.