為了在CDMA系統中更好地應用QDPSK數字調制方式，在分析四相相對移相（QDPSK)信號調制解調原理的基礎上，設計了一種QDPSK調制解調電路，它包括串并轉換、差分編碼、四相載波產生和選相、相干解調、差分譯碼和并串轉換電路。在MAX+PLUSⅡ軟件平臺上，進行了編譯和波形仿真。綜合后下載到復雜可編程邏輯器件EPM7128SLC84-15中，測試結果表明，調制電路能正確選相，解調電路輸出數據與QDPSK調制輸入數據完全一致，達到了預期的設計要求。 Abstract: In order to realize the better application of digital modulation mode QDPSK in the CDMA system， a sort of QDPSK modulation-demodulation circuit was designed based on the analysis of QDPSK signal modulation-demodulation principles. It included serial/parallel conversion circuit, differential encoding circuit, four-phase carrier wave produced and phase chosen circuit, coherent demodulation circuit, difference decoding circuit and parallel/serial conversion circuit. And it was compiled and simulated on the MAX+PLUSⅡ software platform,and downloaded into the CPLD of EPM7128SLC84-15.The test result shows that the modulation circuit can exactly choose the phase，and the output data of the demodulator circuit is the same as the input data of the QDPSK modulate. The circuit achieves the prospective requirement of the design.
上傳時間： 2013-10-28
上傳用戶：jyycc
在Multisim 10軟件環境下，設計一種由運算放大器構成的精確可控矩形波信號發生器，結合系統電路原理圖重點闡述了各參數指標的實現與測試方法。通過改變RC電路的電容充、放電路徑和時間常數實現了占空比和頻率的調節，通過多路開關投入不同數值的電容實現了頻段的調節，通過電壓取樣和同相放大電路實現了輸出電壓幅值的調節并提高了電路的帶負載能力，可作為頻率和幅值可調的方波信號發生器。Multisim 10仿真分析及應用電路測試結果表明，電路性能指標達到了設計要求。 Abstract: Based on Multisim 10， this paper designed a kind of rectangular-wave signal generator which could be controlled exactly composed of operational amplifier， the key point was how to implement and test the parameter indicators based on the circuit diagram. The duty and the frequency were adjusted by changing the time constant and the way of charging and discharging of the capacitor， the width of frequency was adjusted by using different capacitors provided with multiple switch， the amplitude of output voltage was adjusted by sampling voltage and using in-phase amplifier circuit，the ability of driving loads was raised， the circuit can be used as squarewave signal generator whose frequency and amplitude can be adjusted. The final simulation results of Multisim 10 and the tests of applicable circuit show that the performance indicators of the circuit meets the design requirements.
上傳時間： 2014-01-21
上傳用戶：shen007yue
簡單混合衰落信道 This mfile inputs an unmodulated sinewave through a simple Rayleigh two path fading channel and shows the output with phase, gain, and attenuation characteristics via animation.
標簽： unmodulated Rayleigh sinewave through
上傳時間： 2015-05-17
上傳用戶：CSUSheep
C++ Demystified: A Self-Teaching Guide by Jeff Kent ISBN:0072253703 McGraw-Hill/Osborne © 2004 This hands-on, step-by-step resource will guide you through each phase of C++ programming, providing you with the foundation to discover how computer programs and programming languages work.
標簽： Self-Teaching Demystified McGraw-Hill 0072253703
上傳時間： 2013-12-13
上傳用戶：1427796291
The Hopfield model is a distributed model of an associative memory. Neurons are pixels and can take the values of -1 (off) or +1 (on). The network has stored a certain number of pixel patterns. During a retrieval phase, the network is started with some initial configuration and the network dynamics evolves towards the stored pattern which is closest to the initial configuration.
標簽： model distributed associative Hopfield
上傳時間： 2015-06-17
上傳用戶：l254587896
The same two-stage decoder as above. However, when transforming the symbols prior to Viterbi decoding, the amplitude information is ignored and only the phase of the received symbol is employed in the metric computation stage.
標簽： transforming two-stage However decoder
上傳時間： 2015-07-05
上傳用戶：sevenbestfei
This mfile illustrates a simple two path Rayleigh multipath fading channel This mfile inputs an unmodulated sinewave through a simple Rayleigh two path fading channel and shows the output with phase, gain, and attenuation characteristics via animation
標簽： mfile This illustrates multipath
上傳時間： 2014-08-30
上傳用戶：lindor
Blind Equalizer 的演算法主要是利用CMA及 LMS 的配合，當CMA將EYE打開，使訊號趨近于正確值，就切換到LMS，利用Slicer的輸出當作training sequence來調整Equalizer的系數，而Carrier Recovery 的部份，則是將phase error track出來
上傳時間： 2013-12-28
上傳用戶：it男一枚
假近鄰法(False Nearest Neighbor, FNN)計算嵌入維的Matlab程序 文件夾說明： Main_FNN.m - 程序主函數，直接運行此文件即可 LorenzData.dll - 產生Lorenz時間序列 PhaSpaRecon.m - 相空間重構 fnn_luzhenbo.dll - 假近鄰計算主函數 SearchNN.dll - 近鄰點搜索 buffer_SearchNN_1.dll - 近鄰點搜索緩存1 buffer_SearchNN_2.dll - 近鄰點搜索緩存2 參考文獻： M.B.Kennel, R.Brown, H.D.I.Abarbanel. Determining embedding dimension for phase-space reconstruction using a geometrical construction[J]. Phys. Rev. A 1992,45:3403.
標簽： Main_FNN Neighbor Nearest Matlab
上傳時間： 2013-12-10
上傳用戶：songnanhua
鎖相回路可視為一個輸出相位和輸入相位的回授系統用以同步輸入參考訊號和回授后輸出信號。并讓其操作同樣的頻率。如(圖一)所示，簡單鎖相回路[3,4]是由三個電路構成，分別為相位偵測器（Phase Detector）、回路濾波器（Loop Filter）、壓控蕩器（VCO）
上傳時間： 2015-08-16
上傳用戶：franktu
