Design Of Wireless Sensor Network System Based On RSSI

Wireless sensor network localization technology is one of the main technologies of wireless sensor network, and it has been widely used in practice. In recent years,there are many positioning research algorithms in domestic and international, but the research on how to effectively apply in the actual project started late, and the algorithm is not mature enough. Affected by the actual complex environment, when the system is applied, the positioning accuracy is low, the positioning error is large and so on. Therefore, it is very meaningful to study the localization of wireless sensor network positioning system.The research content of this paper is the application of wireless sensor positioning algorithm in the actual project, mainly divided into two parts. The first part is to determine the positioning algorithm. Through the analysis of several classical localization algorithms, and through the comparison and selection, the classic three edge positioning algorithm is improved, and the weighted maximum likelihood estimation algorithm based on RSSI is introduced. Finally, combined with the APIT algorithm, the R-A hybrid positioning algorithm is introduced. The algorithm uses the APIT localization algorithm based on range of auxiliary positioning to compensate due to hardware limitations result based on the RSSI localization algorithm of congenital lack of precision, also can be utilized by the distance measurement based on RSSI positioning algorithm to reduce the APIT localization algorithm for the number of reference nodes, and simplified algorithm for the computation and communication overhead. MATLAB simulation results show that the R-A hybrid positioning algorithm can reduce the node localization error and get more accurate node coordinates. The algorithm can be used in the experimental platform.In the second part, the experiment platform of the positioning system is built and tested. The first step by the CC2530 module appropriate changes, composed of coordinator, reference node and blind node three types of nodes, and set up the hardware system of wireless sensor network; the second step design computer software, respectively to three node positioning system in transplantation of the ZigBee protocol stack, composed of tree topology. The third step, designing of the host computer software, its functions include data acquisition, algorithm implementation and GUI display. The fourth step, the entire wireless sensor network positioning system based on RSSI is tested and analysised.Through MATLAB simulation and experiment, the results shows that the R-A hybrid location algorithm can be used for experimental platform, realizes the function of positioning, high positioning accuracy, to achieve the desired effect. In addition to the low cost, easy expansion and maintenance, and other characteristics,it has a good application prospect in engineering.