基于MATLAB的单边带调幅系统的建模仿真.doc

目 录 0 前言 1 1 单边带调制与解调的基本概念 2 1.1 单边带调制 2 1.2 单边带解调 2 1.3 希尔波特(Hilbert)变化 2 2 单边带调制的特点及应用 3 3 单边带调制与解调原理 3 3.1 单边带调制原理 3 3.2 单边带解调原理 5 4 调制编程仿真及结果 6 4.1 调制仿真程序 6 4.2 仿真图形 7 5 解调编程仿真及结果 7 5.1 解调仿真程序 7 5.2 仿真图形 9 6 存在误差时的仿真及结果 9 6.1仿真程序 9 6.2 仿真图形 11 7 结论 11 参考文献 12 基于MATLAB的单边带调幅系统的建模仿真 华 伟 （河南大学民生学院，河南 开封，475004） 摘 要： 本文主要介绍了单边带调制与解调的基本原理，以及在对基本原理理解的基础上进行建模仿真，使之能够在计算机中实现各种条件下的调制与解调结果，直观易懂且节约成本。双边带调幅所产生的上下两个边带包含的信息相同，所以只需要传输其中任意一个边带就可以了。将DSB信号中的某一个边带去除，所得的就是单边带调制信号。单边带调制的方法有滤波法和相移法。解调用相干解调。由仿真可以看出调制后的信号与原基带信号的频谱形状没有改变，仅是位置发生变化。相干解调后输出时域波形与基带信号波形近似，若本地载波与发送调制载波之间存在频差和相位差，则解调输出的时域波形将产生严重失真，但幅度谱失真不大。 关键词： 单边带调制与解调；希尔波特变换；仿真 Matlab-based Modeling And Simulation Of Single-sideband Amplitude Modulation System Hua Wei (School of Minsheng, Henan University, Henan Kaifeng 475004, China) Abstract: This paper introduces the single-sideband modulation and demodulation of the basic principles, and understanding of basic principles based on modeling and simulation, to enable the computer to achieve a variety of conditions, the result of modulation and demodulation, intuitive easy to understand and cost savings. Produced by bilateral upper and lower with the two AM sidebands contain the same information, so only need to transfer any of them with an edge on it. The DSB signal in one sideband removed from the signal is single-sideband modulation. SSB modulation methods are filtering method and the phase shift method. Solution called coherent demodulation. Simulation can be seen from the modulated signal and the shape of primordial spectrum with a signal has not changed, only the location changed. Coherent demodulation of the output time domain waveform and the baseband signal waveform approximation, if the local carrier and send a modulated carrier frequency offset and phase difference between, then the demodulated output waveform in time domain will have a serious distortion, but not the amplitude spectrum distortion . Key words: SSB Mdulation And Dmodulation, Hilbert Change,