Research On Indoor Localization Technology Of Wireless Sensor Networks Based On CSS

WSN(Wireless Sensor Networks) Node localization is one of the basic and key technology of the Wireless Sensor Network applications. Indoor localization as a wireless sensor network localization application occasions, is very significant to people's life and production. CSS(Chirp Spread Spectrum) technology has high anti-interference ability, and long transmission distance, so it is suitable for the wireless sensor node localization technology in indoor environment. This paper mainly studies the indoor node localization technology based on CSS, aiming at the interference of various complex conditions existing in the indoor localization environment, we researches and optimizes the CSS localization technology.CSS based node localization technology is a kind of ranging based localization technology, using the TOA(Time of Arrival) for ranging. This paper discusses the problem of CSS based ranging technology in the indoor environment and the source of the error, and optimize the technology for the problems of the CSS ranging technology by improved Kalman filter and the measurement redundancy RSSI(Received Signal Strength Indicator) value. The experimental results show that the accuracy of the method in this paper can effectively improve CSS ranging, inhibit the ranging error under the indoor environment.There're a lot of ranging based localization algorithm for wireless sensor networks, this paper studies several common ranging based node localization algorithm. Based on the traditional LSE(Least Square Estimation) localization algorithm, this paper joined the Kalman filter to smooth the localization results, and the Kalman filter estimation algorithm of state noise variance matrix and measurement noise covariance matrix update is improved, and finally applied to indoor localization. The experimental results show the algorithm has a high localization accuracy in the indoor localization environment.Aiming at wireless node localization in indoor environment, this paper designs a set of indoor localization system based on CSS, by means of TOA measurement value as the fingerprint data, through calculation to obtain the localization fingerprint database, and uses the improved algorithm for the LSE to achieve precise coordinate localization, finally improves the efficiency of the localization precision and localization. Finally, the feasibility of the algorithm is verified by experiments.