- 學位論文
無線感測器網路之定位晶片研製及系統開發
Development of Location Identification ASIC and system in Wireless Sensor Network
摘要
本論文主要目的在於開發適用於無線感測器網路的定位晶片和分析定位功能於現有硬體架構下之可行性，首先本論文中將介紹各種定位方法如TDOA、TOA和AOA等等，最終以量測無線電訊號於空氣中傳播之時間間隔作為定位架構的基本參數，並試著針對本實驗室無線感測器網路的架構尋找適合的定位方式，並進行初步的測試。 於量測訊號的傳播時間方面，為了未來可讓本實驗室無線感測器網路能邁入System On Chip(SOC)的階段，本論文實作定位晶片並利用傳統的Nutt method的概念以數位方式設計測時電路，並利用台積電(TSMC)的.35製程製作晶片，相較於類比方式的設計具有更小的面積，並擁有3ns以內的量測誤差，操作時脈最低為50MHz，可望日後能整合RF收發器及微控制器，達到SOC化的效果。 最後本論文亦嘗試進行定位架構驗證，先利用現有的微控制器和RF收發器搭配測時晶片作系統化的定位設計，並為微控制器撰寫控制程式來控制測時晶片，將測時結果透過RS232介面傳送給後端電腦作分析。由於應用於本文中的定位方式可克服大部份由硬體所產生的訊號延遲時間，因此可將定位誤差值降低。
並列摘要
The main thrust of this dissertation is to develop the Application Specific Integrated Circuit (ASIC) of location identification for Wireless Sensor Network (WSN) and to analyze the capability of location identification in existing hardware. Beside, this thesis will discuss a number of the location identification methods, such as TDOA, TOA and AOA, etc. By utilizing the time interval of propagating signal as my basic location identification parameter, this thesis examines the suitable location identification methodology based on the Wireless Sensor Network configuration developed within NTU. Some preliminary tests were performed to verify the performance of the newly developed system. To implement Wireless Sensor Network in a System On Chip configuration, this thesis utilizes the digital concept of the classical Nutt method to measure the time interval of propagating signal. This newly designed ASIC was then fabricated by the .35um CMOS process of TSMC. The location identification ASIC has smaller size than that of the design based on analog method and was found to have resolution better than 1 meter when operating the clock at minimum 50MHz. The location identification ASIC is expected to be integrated further with the RF transceiver and micro-controller on a chip in the future. Finally, the performance of the newly developed location identification ASIC was verified by integrating it with existing RF transceiver and micro-controller to serve as the testbed. Control code for the micro-controller was developed to access the measurement result obtained, which was transmitted to the control center by using serial RS232 interface. Because the location identification method developed within the Wireless Sensor Network can overcome most of the hardware delay, the error of time interval was significantly reduced.