Optimization of Energy Consumptions in Sensor Networks

摘要

The purpose of this paper is to minimize the energy consumption for a single link communication in wireless sensor network. The quadrature amplitude modulation (QAM) and auto repeat request (ARQ) with finite retry limit and various packet size are considered in the system model. We formulate the optimization problem to be a nonlinear integer programming with modulation order and packet size as variables. To solve this problem, the continuous relaxation based branch and bound method and the successive quadratic programming (SQP) algorithm is used. Further, a variable transformation method is adopted to convexificate the problem and guarantee the global optimization. A numerical example is given to illustrate the solution, which suggests that the joint optimization of packet size and modulation order for various communication distance can make the sensor nodes work in a more energy efficient way.