Positioning Technology, Based On The Time Reversal Of The Wireless Sensor Network Node

As an excellent channel equalization method, TR(Time Reversal) can depress the multipath and improve the energy distribution in the space, and then make the signal focus both temporally and spatially. Temporal focus can depress the multipath effect and improve the signal noise rate (SNR) of the system. Spatial focus can enhance the speed, security and efficiency of the information transmission. Meanwhile it can make the EMC ability of the equipment better than before.The traditional localization schemes suffer from big errors in the complicated EM environment. In order to overcome this problem, the author made a survey about the development state of the traditional location scheme and studied the traditional localization schemes and the TR method overall, and then designed a novel node location scheme. In this thesis, firstly the performance of this scheme that it can enhance the accuracy of the node localization by large margin is validated. Then a set of simulations on this new scheme is utilized in the LOS (Line Of Sight) and NLOS (Not Line Of Sight) multipath environments using TR-UWB platform.The simulation result demonstrates that the TR localization's error is less than the traditional scheme in the complicated environment, and then a reason why there is no difference between the new scheme and the traditional TOA scheme under certain circumstances is explained in this thesis.The contents of the thesis are introduced as following:In the first chapter, the principle of Time Reversal method and its development state are introduced.In the second chapter, the classification and the principle of the traditional localization schemes are introduced firstly. Then the theory and implement of the Time Reversal based node localization method in wireless sensor network are described. At last, some important techniques on the application of this scheme are discussed.In the third chapter, the usage and the computing principle of the new special purpose software TR-UWB are described, and then the simulation purpose and the implementation of this scheme are introduced.In the forth chapter, a comparison about the location accuracies of the two schemes under the LOS and NLOS environment are made. The conclusion that the Time Reversal localization scheme has a higher precision than the traditional scheme in the complicated environment is drawn.In the last chapter, a brief summary on the whole thesis and the disadvantages of the Time Reversal localization scheme and the tasks in the future are given.