基於基因演算法的到達時間差(TDOA)定位技術之研究

隨著通訊技術的發展，無線電定位結合許多新興技術，被廣泛的應用在民用設施、無線網路管理、干擾源定位、交通系統與地震探測等領域。一般來說，無線電測向系統主要包括四個部分，測向天線、輸入匹配單元、接收機和方位信息處理顯示，其中對於定位精確度最重要的部分是節點的接收器，若能即時提供可靠與準確的接收數據，定位精確度便可大大提升，但這需要依靠物理層面上的改變，如此可能會影響現有系統的結構，也會增加成本，因此對於大多數定位系統而言，在接收數據後的處理信息方面是非常重要的，利用定位算法來提高定位精確度是目前許多定位研究中主要的方向。無線定位的原理是利用接收到的信號特徵來計算信號的傳輸時間、傳輸距離與方位，再通過運算得知目標位置。與其他目前較多研究的到達角定位技術(Angle of Arrival, AOA)和到達時間定位技術(Time-Of- Arrival, TOA)相比，到達時間差定位技術(Time Difference of Arrival, TDOA)對接收站台的同步要求低、容易實現且精確度高。本文提出一種基於基因演算的TDOA定位算法，在定位的基礎上定義多個感測器接收到的信號到達時間差，結合基因演算法的汰換機制縮小發射源的可能範圍，尋找最有可能的目標位置。實驗設置使用MATLAB軟體對互相關函數進行模擬，提高了定位的擴展性也降低算法的計算複雜度。除了測試定位範圍、站台數量與傳統定位算法相比外，也探討在實際環境中應用的可行性，透過結果表明此方法的定位精確度良好、可以依照環境調整適合定位條件且容易運算。最後，以現有結果進行總結並對未來研究方向作出展望。

關鍵字

信號到達時間差；信號到達角度；基因演算法；信號到達時間；接收信號強度

並列摘要

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.

並列關鍵字

Time Difference of Arrival ； Angle of Arrival ； Genetic algorithm ； Time of Arrival ； Received Signal Strength Indicator

參考文獻

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基於基因演算法的到達時間差(TDOA)定位技術之研究

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