鐘嘉德臺灣大學：電機工程學研究所黃士彰Huang, Shih-ChangShih-ChangHuang2007-11-262018-07-062007-11-262018-07-062006http://ntur.lib.ntu.edu.tw//handle/246246/53451在此篇論文當中，我們將討論差分振幅相位移鍵調變(Differentially Amplitude Phase Shift Keying,簡稱DAPSK)訊號在經過雷力衰減通道(Rayleigh fading channels)後，使用切換停留結合接收方式的接收器來解調訊號之研究。 本篇論文的研究方向著重於在接收端該如何接收並解調信號，尤其是針對接收訊號的訊噪比(signal to noise ratio,簡稱SNR)，在接收端根據不同的訊噪比來調整切換門檻(switching threshold)以得到最小的錯誤率。In this thesis, we will study the performance of DAPSK signals when transmitting over Rayleigh fading channels with switch and stay combining reception. The key point of this thesis is how to receive and demodulate the received signals. For different signal to noise ratio, especially, the receiver how to adjust the switching threshold to achieve minimum bit error rate.Contents 1. Introduction…………………………………………1 2. Differentially Amplitude Phase Shift Keying Signals…………………………………………………..2 2.1 Introduction………………………………………………2 2.2 Mathematical Form of (N,M)DAPSK signals…………...4 2.3 Channel Model…………………………………………...7 2.4 DAPSK Receiver……………………………………….11 2.5 BEP Characteristics of DAPSK Signals………………..14 3. Switch and Stay Combining Reception…………..21 3.1 Introduction…………………………………………….21 3.2 Modified SSC for DAPSK……………………………..24 4. Simulation Results…………………………………29 4.1 The effects of different threshold value on the BEP performance……………………………………………29 4.2 Simulation results for applying both SSC and EDGC over non-identical channels………………………………….43 5. Conclusions………………………………………...46 6. References………………………………………….47 List of Figures: Fig 2-1 Signal constellation of (4,16)DAPSK……………………………5 Fig 2-2 Signal constellation of (2,8)DAPSK……………………………..5 Fig 2-3 Transmitter Block diagram of (4,16)DAPSK……………………6 Fig 2.4 Jake’s channel model…………………………………………….9 Fig (2.5) BEP versus Ring Ratio characteristics for 2,8) DAPSK with =0.9995……………………………………………………………….15 Fig (2.6) BEP versus Ring Ratio characteristics for (4,16)DAPSK with =0.9995……………………………………………………………….16 Fig (2.7) BEP versus ring ratio characteristics for (2,8)DAPSK with =0.99………………………………………………………………….18 Fig (2.8) BEP versus Ring Ratio characteristics for (4,16)DAPSK with =0.9995……………………………………………………………….19 Fig (2.9) BEP versus SNR for different channel conditions ( =0.99 and 0.9995) with (4,16)DAPSK and (2,8)DAPSK………………………….20 Fig (3.1) Block diagram of noncoherent BFSK with postdetection SSC……………………………………………………………………...24 Fig (3.2) Receiver Block Diagram for DAPSK signals with modified SSC reception…………………………………...……………………………26 Fig (4.1) BEP versus Normalized Switching Threshold characteristics with (2,8)DAPSK and SSC reception when…………………………….30 Fig (4.2) BEP versus Normalized Switching Threshold characteristics with (4,16)DAPSK and SSC reception when ………………...31 Fig (4.3) BEP versus Normalized Switching Threshold characteristics with (2,8)DAPSK and SSC reception when ………………..33 Fig (4.4) BEP versus Normalized Switching Threshold characteristics with (4,16)DAPSK and SSC reception when ………………34 Fig (4.5) BEP versus SNR characteristics with switching threshold optimized, and (2,8)DAPSK……………………………….36 Fig (4.6) BEP versus SNR characteristics with switching threshold optimized, and (4,16)DAPSK……………….……………..37 Fig (4.7) BEP versus SNR characteristics with switching threshold optimized, and (2,8)DAPSK…………………………………38 Fig (4.8) BEP versus SNR characteristics with switching threshold optimized, and (4,16)DAPSK………………………………..39 Fig (4.9) BEP versus ring ratio and normalized switching threshold value when SNR=30, =0.9995 and (2,8) DAPSK………………………..…41 Fig (4.10) The optimum switching threshold versus SNR characteristics for both (2,8)DAPSK and (4,16)DAPSK……………………………….42 Fig (4.11) BEP characteristics with SSC and EDGC reception over non-identical channels (2,8)DAPSK is used……………………………44 Fig (4.12) BEP characteristics with SSC and EDGC reception over non-identical channels (4,16)DAPSK is used…………………………..45en-US差分振幅相位移鍵調變衰減通道切換結合Differentially Amplitude Phase Shift Keying(DAPSK)Rayleigh FadingSwitch Combiningthesis