臺灣博碩士論文加值系統

Code Division Multiple Access (CDMA)是一個新穎的通訊技術，這種技術允許系統可以在同一個頻帶上，讓多個不同使用者的資料同時傳送[1], [2], [14]。CDMA技術對於頻帶的使用率來說，比起FDMA與TDMA來的更為有效率，因為它允許多個使用者同時在同一個頻帶上面傳送資料，再由接收端根據不同的展頻碼來解讀資料。而在無線行動通訊網路中，許多的傳輸通訊會產生干擾與碰撞，甚至產生沒有效率的傳送[4], [5], [11], [13]。在這篇論文中，我們提出一個在無線行動網路下的高重複使用的碼分散式管理機制，以此機制嘗試改善碼的利用率與舒緩Exposed Node的問題。根據實驗結果顯示我們所提出的方法可以舒緩Exposed Node的問題並且同時提升CDMA碼的重複利用率。

Code Division Multiple Access (CDMA) is a new concept in field of communications which allows multiple users to transmit at the same time in the same frequency band [1], [2], [14]. The advantage of using CDMA over FDMA and TDMA is that it enables a greater number of users to be supported. Many wireless communications have interference and destruction in the mobile ad hoc networks [4], [5], [11], [13]. In this thesis, we propose a highly reused CDMA code scheme to improving utilization and try to mitigate the exposed node problem in mobile ad hoc networks. We combine mechanisms of RTS/CTS dialogue, busy tone, and power control. Simulation results show that our scheme has lower overhead and higher CDMA code reused.

Chapter 1 Introduction....................................1
Chapter 2 Related work....................................3
2.1 Introduction to CDMA...................................3
2.2 Introduction to Mobile Ad Hoc Networks.................4
Chapter 3 Preliminaries...................................9
3.1 Issues in CDMA based MAC...............................9
Chapter 4 Our Protocol...................................12
4.1 Operation principle of our protocol...................15
4.2 A dynamic CDMA code assignment scheme example.........15
4.3 The mobile networks interfering and destroying........19
Chapter 5 Simulation Results.............................23
Chapter 6 Conclusion.....................................35
Reference .................................................36

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