過去的研究顯示廣播式自動回報系統的訊號抵達時間差觀測量使用在廣域多點定位系統的可行性，然而廣域多點定位系統的精確度會因為參考站幾何分布不佳而被嚴重降低，該研究提出增加訊號抵達角觀測量至定位演算法中能夠提昇參考站幾何分布不佳時的定位結果。
本論文主要的貢獻在於利用相位天線建立一套角度觀測量估測系統雛型來增強上述的廣域多點定位系統，本系統實現於通用軟體無線電平台，在多個接收機的系統中，儀器的同步是必須要完成的工作，此論文中使用一個外部時間震盪器來達成接收機之間的時間同步，本論文也提出一個方法消除接收機之間的初始相位，而軟體方面，透過修改免費的廣播式自動回報系統解碼軟體gr-air-modes的程式碼並應用於通用軟體無線電平台上實現訊號抵達角觀測系統，論文中提及兩種訊號方位估測演算法與其在不同參數設定下的模擬，實作上，利用本論文開發的角度估測系統執行跨城市規模的實驗，其結果展現本系統能夠提供服務的範圍遠達八十公里，而為了提升本系統的性能，在論文最後一部分提出了一個修正的演算法，最後，改善的結果顯示此角度估測系統雛型在半功率波束寬度的方均根誤差約為四度。

The previous researches illustrated the feasibility of wide area multilateration (WAM) using the differential time of arrival measurement in the ADS-B data link. However, the performance of the WAM system is degraded severely due to the insufficient ground station geometric distribution. To improve the performance of the WAM, the research presented a multi-measurement positioning simulation by adding angle of arrival measurement.
The contribution of this thesis is the development of a prototype of an angle of arrival (AOA) estimation system with a phased array for a 1090MHz ADS-B WAM augmentation system. The system is implemented on Universal Software Radio Peripherals (USRPs) platform. In a multi-receiver system, the device synchronization is an essential work to do. An external time source is used to synchronize the device time in this thesis. An approach for eliminating the initial phase of each receiver is also presented and conducted. In soft-ware, gr-air-modes, a free software to decode ADS-B data, is modified and implement on USPR platform to develop the AOA estimation system. There are two AOA estimation algorithms and their simulation results with different parameter settings are presented in this thesis. Practically, the experiment is carried out to present the performance of AOA estimation system. To promote the performance of this system, a modified algorithm is also pro-posed and subsequently carried out. Finally, the improved results show the root mean square error of this prototype system to be 4 degrees in half power beam width.

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