The Research And Analysis Of Energy Efficiency Of Wireless Sensor Networks

With continuous progress of science and technology and increasing dependence on electronic products, small-size, low-cost and robust wireless sensor networks acquire extensive applications in all areas of production and life, and possess obvious advantage, especially in the harsh environment. However, the sensor nodes are powered by batteries not to be replaced secondary by environmental and cost constraints, which limits the further development of the wireless sensor network. Therefore, it has been a hot topic that how to effectively reduce the energy consumption of nodes and maximize the network lifetime in wireless sensor networks.The thesis firstly introduces the basic content of the wireless sensor networks, including its definition, structure, characteristics, application and energy consumption. Secondly, the thesis discusses node cooperative transmission scheme on the basis of spatial diversity techniques for wireless sensor networks, models the energy consumption of sensor network as a nonlinear function of node selection and power allocation according to the resources allocation of cooperative transmission scheme, and presents the brute force approach whose power allocation is based on solving Lagrangian function. In order to reduce the computational complexity, it also proposes a low complexity resource allocation scheme based on the channel state information called the greedy algorithm according to the theory of fractional programs, and confirms validity using simulation of Matlab software. Then, the paper analyzes and discusses the transmission energy and residual energy has impact on the network lifecycle from the perspective of the overall energy consumption of the network, and proposes a dynamic node selection and power allocation scheme. Finally, it describes the future development trends of wireless sensor networks and future research directions in the summary.