Research Of Communication And Positioning System Based On Power Line And WiFi

In the era of rapid development of Internet technology,people are paying more and more attention to data access and sharing in buildings.In the aspect of communication,traditional indoor signal transmission system often has complex layout links and high installation cost,and such broadband access methods cannot meet people's modern needs.Using the existing power line supply network for indoor communication has aroused great concern.Meanwhile,how to carry out accurate real-time positioning in a complex indoor environment,has also gained great research interest.As a mature radio technology,Wi-Fi can be used as a technology for indoor positioning,which makes up for the lack of indoor positioning of outdoor satellite positioning system.Power Line Communication(PLC)technology combined with Wi-Fi wireless positioning technology will surely show good prospects for development in smart buildings.Firstly,we analyzed the great advantages and some unresolved problems of PLC combined with Wi-Fi positioning technology in communication and positioning,respectively.On the one hand,power line has great interference on the transmission performance due to the complexity of the channel.On the other hand,the Wi-Fi-based indoor positioning technology also has the problem of poor accuracy due to inaccuracy of the algorithm.In terms of communication,we introduced Discrete Wavelet Transform(DWT)of Orthogonal Frequency Division Multiplexing(OFDM)modulation technology,and found DWT-OFDM technology can significantly resist all kinds of interference caused by the PLC channel.The fingerprint matching technology based on Received Signal Strength(RSSI)and combined with K-Nearest Neighbor(KNN)algorithm was used on indoor positioning.Meanwhile,we used Kalman Filtering(KF)and Particle Filte(PF)to improve the positioning accuracy to within 1m(0.59m).Finally,we found that the PLC + Wi-Fi communication system and indoor positioning scheme based on Wi-Fi have a good communication and positioning performance,which provides a good theoretical basis for practical application,through MATLAB simulation.