The Improved WSN Routing Protocol Based On LEACH

In the WSN(Wireless Sensor Network), The essential feature of traditional routing protocols such as Flooding、DD、SPIN is that information collected by the nodes in the monitoring area is directly transmitted to the base station, the environmental interference, long transmission distance and the node’s residual energy and other factors is ignored in the data transmission process, causing many problems such as energy wasting, the loss of information during transmission and channel blockage.As a typical hierarchical routing protocol, LEACH (Low Energy Adaptive Clustering Hierarchy) puts forward the hierarchical model with simple stable structure for the first time,but it can not effectively reduce the redundant data and the external interference in the data transmission process. The random election of cluster heads may result in the premature death of some cluster heads with lower energy.In this dissertation, the LEACH-DH (LEACH-Double Heads) routing protocol is designed on the basis of the LEACH. In order to save energy, improve the reliability of information, prolong the network lifetime and reduce the amount of data communication, the hierarchical clustering, the election of double cluster heads and the introduction of hierarchical data fusion technology are adopted in this new protocol.Through the comparison of several typical routing protocols, the hierarchical data fusion is proposed in LEACH-DH on the basis of LEACH protocol. LEACH-DH protocol is divided into bottom layer, middle layer and the top layer from the structure and function, and for the characteristics of each layer, the corresponding data fusion technology is introduced. Nodes in the bottom layer are mainly responsible for the data acquisition and the mean processing of the collected data 。 In order to improve the reliability of data information, the data should be sent to the nodes of middle layer after passing the inspection of the confidence interval. Nodes in the middle layer are mainly responsible for the Kalman filtering of the received information. The purpose of this step is to reduce the noise interference in the data transmission. After Kalman filter, the data information is transmitted to the nodes of top layer. Taking into account the factor that the credibility of information from different nodes is not identical, the fuzzy theory data fusion technology is adopted into the top layer to process the received data information. In order to reduce the amount of data communication,the nodes in the top layer merge several data into a single data information. Through the data fusion of three layer, the redundant information in the network and the reliability of information are effectively improved, and the energy consumption of network is saved.In the same simulation environment,the LEACH-DH protocol, LEACH-C protocol and LEACH protocol are simulated on the basis of MATLAB platform.The result shows that the network lifetime is prolonged 700 rounds, the speed of data-transmission is increased 3.7 times by LEACH-DH routing protocol compared with LEACH.The interference of noise in the data transmission and the error between the result and the real information are effectively reduced through the adopted hierarchical data fusion technology.