定位是適地性服務(Location-Based Service, LBS)裡最重要的步驟。由於最常用來定位的全球定位系統(Global Positioning System, GPS)所發出的訊號被牆壁所阻礙，使得在室內的使用者沒辦法透過GPS得知他們所在的位置。大多數的室內定位(Indoor Positioning)系統都依據從室內無線發射裝置所接收到的接收訊號強度(Received Signal Strength, RSS)來當作定位的參考。藉由整合室內定位的資訊到現今智慧型手機的應用程式裡，可以更容易得到室內位置的資訊。在這篇論文中，我們提出一個新的室內定位設計方式藉由接收訊號強度指紋(RSS Fingerprint)和訊號足跡(Footprint)的輔助，並接收從周圍環境中的Wi-Fi存取點(Wi-Fi APs)所發出來的無線訊號強度，藉由這種方式智慧型手機(Smartphone)的使用者可以得到他們的室內位置。有了周圍所收集到的Wi-Fi 接收訊號強度的幫助，以及限制並區分不同方位與方向所接收到的訊號強度，並且緩和訊號的跳動，我們所提出來的設計可以克服在室內訊號極度不穩定的問題和提升定位的準確度。同時，所提出來的接收訊號強度指紋和訊號足跡比對方法可以加快定位的速度。在實驗結果裡證明我們所提出來的設計在室內環境裡可以達到一定程度的定位準確度，並且勝過其它的方法。

Positioning is the foremost procedure in the location based service (LBS). With the GPS signal strength obstructed by the wall, indoor users cannot obtain their positions through the global positioning satellites. Most of the indoor positioning systems have relied on received signal strengths (RSSs) from indoor wireless emitting devices. Integrating indoor position information into the APP in the modern smartphone can facilitate the precision of in-building location information. In this paper, we propose a novel indoor positioning scheme assisted by the RSS fingerprint and footprint. Smartphone users can get their indoor position based on RSSs from the surrounding Wi-Fi access points (APs). With the assistance of collecting ambient Wi-Fi RSSs, confining RSSs by directions/orientations, and mitigating signal fluctuation, our proposed scheme can overcome the severe signal instability problem in the building and raise the positioning accuracy. Meanwhile, the proposed RSS fingerprint and footprint matching mechanism can speed up the positioning procedure. The experiment results show that our proposed scheme can achieve a certain level of accuracy in the indoor environments and outperform other solutions.

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