Research On Improved Node Location Algorithm Based On RSSI In Wireless Sensor Networks

With the development of information technology,wireless sensor networks have gradually become an important research field.WSN is mainly used in environmental monitoring,industrial control,logistics management and other fields.In the application,the WSN not only needs to collect data but also needs to know the location of each node.Location information is particularly important for WSN.The arrangement of WSN nodes is characterized by randomness,so most nodes can only be located by a small number of nodes with known locations.The traditional node location algorithm has the problems of low efficiency and large positioning error.This paper proposes several improvements in the traditional node location technology based on ranging.In this paper,the performance of the improved algorithm is verified by MATLAB,and the practicality is verified in the WSN consisting of ZigBee CC2430.The main research content of this paper is based on RSSI node positioning algorithm.The entire positioning process is divided into three stages:ranging,positioning,and correction.This thesis focuses on the improvement of these three stages.In the ranging stage,the Gaussian model is first used to process the RSSI data,which reduces the effect of noise on the RSSI data.Then,the parameter setting method in the distance path loss model is improved.Using the environment-based parameter measurement method,the parameters in the distance path loss model are updated in real time to reduce the interference caused by the error and environmental factors.In the positioning and correction stage,we use a combination of distance-weighted least square method and Newton's method to improve the positioning accuracy.Because Newton's method has higher requirements for initial values,we use improved distance-weighted least-squares method to obtain more accurate initial positioning.Then,we use Newton's method to update the positioning,Finally,this paper uses MATLAB to simulate the improved positioning algorithm and other positioning algorithms.Through the analysis of the normalized average error at different known node numbers and the average positioning error at different communication radius,it is shown that the improved algorithm in this paper improves the positioning accuracy relative to other algorithms.The data required by the algorithm is obtained in the WSN composed of ZigBee CC2430.The improved algorithm is used to locate the data in MATLAB,which verifies the practicability of the algorithm.