| Summary: | 碩士 === 國立虎尾科技大學 === 光電與材料科技研究所 === 102 === With the development of communication technology, radio position is combined with a number of emerging technologies, which is widely applied in many fields, such as civilian facilities, wireless network management, interference location, transportation systems and seismic exploration.
Generally speaking, Radio Direction Finder System mainly includes four components, direction-finding antenna, processing unit, receiver(s), and a positioning display. A node receiver plays an important role for the accuracy of positioning. If the system can provide reliably and accurately received data, the accuracy of positioning can be improved significantly. However, it needs some changes in physical levels and it may impact the structure of the current system and increase cost. Thus, for most of positing systems, to process signals after receive data is very essential. Utilizing positioning algorithms to increase the accuracy of positing is currently main research directions.
The principle of wireless positioning utilizes received signal features to calculate transmission time, transmission distance and orientation of signals, followed by acquiring the location of target by means of computation. Compared to AOA (Angle of Arrival) and TOA (Time-Of-Arrival) techniques, the request for synchronization with receiving station is lower, the implementation is easier and the accuracy is higher for TDOA (Time Difference of Arrival). In the study, a TDOA positioning calculation method based on genetic algorithm is proposed. Based on positioning, the arrival time differences of the signals received by multiple sensors are defined, and the possible range of transmission source is reduced in combination with the renovation mechanism of the genetic algorithm to search for the most possible location of the target. As for experimental setting, MATLAB is used to simulate correlated functions, such that the expansibility of positioning is increased and the calculation complexity of the algorithm is reduced. In addition to the test for positioning range, and comparison for numbers of stations and traditional positioning algorithms, the applicability in real environments is also studied. From the results, it is evident that the positioning accuracy of this method is good, which may be used to adjust appropriate positioning condition in terms of environments and is easy in computation. Finally, the researcher makes a conclusion based on the results of the study and makes some suggestions for further research.
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