中文摘要

在無線通訊系統裡，當訊號發送之後會受到雜訊的干擾，造成接收端接收之後對於資料的誤判，增加位元錯誤率，所以對於雜訊的消除一直是接收端重要的課題。所以本論文將針對藍芽(Bluetooth)無線區域網路的接收端，以利用自調適濾波器─AOSC-LMS algorithm，來消除雜訊干擾並還原資料來討論。藍芽使用2.4GHz的ISM頻帶，採用FHSS (Frequency Hopping Spread Spectrum)方式及FSK調變系統，然而aosc- LMS演算法是對弦波訊號作處理的，配合一個窄頻帶通IIR濾波器，藉由係數的疊代來調整其濾波器中心頻率，以消除其他部分雜訊並強化訊號，讓AOSC-LMS演算法更容易對於訊號的頻率來估測，使得接收端可以很準確地判斷資料。可是這種方法只適用於有一個頻率存在時，但藍芽無線區域網路內必定還有其他使用者，這樣其他使用者宛如一個強大干擾者，此時以跳頻序列指定的頻率來當IIR濾波器中心頻率，如此就可隔絕其他使用者的干擾了。另一問題AOSC-LMS演算法面對的是2.4GHz的訊號，我們以成本及技術考量，必須以Down-Sample的原則下來處理2.4GHz的訊號。我們藉由電腦模擬來評估及改善自調適演算法─AOSC-LMS在接收端的能力。

Abstract
In the past decades, progress in microelectronics and VLSI technology has fostered the widespread use of computing and communication applications in portable electronic devices. Around late 90’s, the idea of the Bluetooth technology was brought out by Ericsson to replace cable connections between digital devices. This is a new universal radio interface enabling electronic devices to connect and communicate wirelessly via short-range connections.
The Gaussian Frequency Shift Keying (GFSK) modulation has been chosen as the modulation technique for the physical layer of Bluetooth. This paper proposes a novel adaptive algorithm (AOSC-LMS algorithm) to detect the frequency of a sinusoid in noisy environment and determine the data from the receiver signal. The adaptive algorithm is based on the working principle of active-oscillator. In order to reduce interference of the noise, the AOSC-LMS algorithm is associated with a narrow-band IIR band-pass filter and adjusts the central frequency by the coefficient updated. Therefore, make sure maintain BER is under 0.1% on the environment which SNR is 21dB .

目 錄

中文摘要 ……………………………………………………………i
英文摘要 …………………………………………………………ii
致謝 ………………………………………………………………iv
目錄 ………………………………………………………………v
圖目錄 ……………………………………………………………vii
表目錄 ………………………………………………………………x
第一章緒論 ………………………………………………………1
1.1研究動機 ………………………………………………1
1.2研究方向 ………………………………………………2
第二章Bluetooth …………………………………………………4
2.1Bluetooth的訂定與發展 ………………………………4
2.2Bluetooth的規格說明 …………………………………5
2.3Radio Specification ………………………………………7
2.4Baseband Specification …………………………………8
2.4.1Master and Slave ………………………………………8
2.4.2TDD ……………………………………………………10
2.4.3Physical Links …………………………………………11
2.4.4Packet ………………………………………………12
2.4.5Access Code …………………………………………13
2.4.6Header ………………………………………………15
2.4.7Payload ………………………………………………17
2.4.8Packet Type …………………………………………18
2.4.9Error Correction ……………………………………24
2.4.10 Data Whitening ……………………………………27
2.4.11 Hop Selection ……………………………………28
2.4.12 Transmit/Receive Routines ………………………32
2.4.13 Audio ………………………………………………33
2.4.14 Bluetooth Clock ……………………………………33
2.4.15 States ………………………………………………34
第三章AOSC-LMS Algorithm …………………………………36
3.1數位訊號處理(Digital Signal Process) ……………36
3.2自調式濾波器(adaptive filter) ……………………37
3.2.1自回歸(autoregressive) ……………………………39
3.2.2active-Oscillator Based演算法 ……………………40
3.2.3AOSC-LMS演算法 …………………………………40
3.2.4頻率偵測系統的架構 ……………………………44
3.3參數(parameter)的影響 …………………………47
第四章AOSC-LMS運用於Bluetooth接收端 ………………51
4.1FSK vs. GFSK ……………………………………51
4.2AOSC-LMS偵測訊號頻率之架構 ………………55
4.2.1帶通濾波器(BPF1) ……………………………57
4.2.1決策原則 …………………………………………58
4.3增加訊號處理頻率 …………………………………63
4.3.1不同的訊號處理頻率 …………………………63
4.3.2Up-Sample …………………………………………67
4.4頻率位移 …………………………………………68
4.4.1不同的訊號處理頻率 …………………………70
4.4.2Up-Sample …………………………………………71
4.5總結 ………………………………………………72
第五章結論 ……………………………………………………75
參考文獻 …………………………………………………………77
作者簡介 …………………………………………………………79

參考資料[1]Alan V. Oppenheim, Ronald W. Schafer. “Discrete-Time Signal Processing”. 2nd ed., Prentice-Hall, Inc., 1996.[2]S. Haykin, “Adaptive Filter Theory”, 3rd ed., Prentice-Hall, Inc., 1996.[3]Bluetooth SIG, “Specification of the Bluetooth system – core”, Technical Specification Version 1.1 Bluetooth SIG, February 2001.[4]Roger L. Peterson, Rodger E. Ziemer, and David E. Borth. ”Introduction To Spread-Spectrum Communications”, Prentice-Hall, Inc., 2000[5]Roel Schiphorst, Fokke Hoeksema and Kees Slump, “Channel selec- tion requirements for Bluetooth receivers using a simple demodulation algorithm”[6]Mohammed Nafie, Alan Gatherer and Aanand Dabak. “Decision Feedback Equalization for Bluetooth Systems”[7]N. P. Kontakos and J.K. Pollard. “Bluetooth RF Layer Performance Evaluation”.[8]Jaap C. Haartsen and Sven Mattisson, “Bluetooth_ A New Low- Power Radio Interface Providing Short-Range Connectivity”, vol. 88. NO. 10, October 2000.[9]Cheol-Hee Park, Young-Hwan You, Jong-Ho Paik, Min-Chul Ju, and Jin-Woong Cho. “Channel Estimation and DC-Offset Compensation Schemes for Frequency-Hopped Bluetooth Networks”. Vol. 5, NO. 1, January 2001. [10]Jennifer Bray and Charles F Sturman. ”Bluetooth Connection Without Cables”. [11]廖和恩 博士與兵聖潔 學姐, “利用自調適濾波器偵測多重弦波之頻率”, NO.13, June 2000.