在感測網路的環境中,定位服務是很重要的基礎應用,目前在室內環境中,指紋定位技術是最常被採用的技術之一,因其成本較低、架設容易,只要透過架設幾台無線基地台即可完成室內定位環境的建置,但無線訊號容易受到實體環境的各種因素所干擾影響,讓訊號強度時常不穩定。而在指紋定位的技術中,參考點的佈置方式與數量,將會影響到定位的準確度,若參考點的越多越密,固然可以提高定位的準確性,但提昇的幅度並不大,卻大大的增加了建置成本。故本篇論文中,將會提出兩個方法,分別為參考點配置方式和參考點群組化,參考點配置方式是希望在不增加參考點數量的建置成本下,透過改變參考點佈點方式,讓參考點之間距離變大,來加強參考點彼此之間的特徵性,使密度較高的參考點容易辨識。而參考點群組化是將訊號相似的參考點分為一群,使挑出的參考點的實際座標是連續的,來解決挑出的多個鄰近參考點中,會有少數的鄰近參考點過遠的問題,來降低誤差距離,以提高定位的準確度。最後再透過實驗將本論文提出的方法與其他方法比較來驗證,經過多次的實驗測試,將參考點群組化可改善定位的準確度。
Location-based services(LBS) is very important in the Wireless Sensor Network. In LBS, fingerprint positioning is one of the most commonly used techniques in indoors, because it can be easily established with a low cost. It only takes a few wireless access points to complete the construction of the indoor localization. In fingerprint positioning, the distribution and the number of reference points determine the accuracy of positioning. The more reference points, the higher the accuracy; however, the degree of the accuracy that this technique has helped increased does not worth the cost gained in constructing the points. Therefore, the study aims to propose reference points allocation and grouping to solve the problem. To make the positioning more accurate, the present study distributes few reference points on a certain scale within the same amount of cost, and then grouping the reference points in order to eliminate some of the points that are too far away among a more number of chosen reference points. Finally, other experiments and comparative approaches will be conducted to prove whether the solution proposed in the study is feasible or not.