FDM系统调制与解调.docx

FDM技术及其Matlab仿真摘要随着数据业务的爆炸增长，数据信道带宽需求不断增加，由于信道资源有限，要想在有限的信道中尽可能多的传送数据，信道复用是目前最好的解决方法。频分复用（Frequency-division multiplexing，FDM）技术，特点是所有子信道传输的信号以并行的方式工作，每一路信号传输时可不考虑传输时延，因而取得了非常广泛的应用。本论文根据频分复用的通信原理，建立了频分复用通信系统模型，运用Matlab软件采集三路语音信号，选择合适的高频载波进行调制，得到复用信号；然后设计带通滤波器、低通滤波器，从复用信号中恢复所采集的语音信号；模拟了调制、信道传输、解调等通信过程，实现了多路语音信号的传输。关键字：FDM；高频调制；滤波器设计；信号恢复FDM技术及其Matlab仿真AbstractWith the explosive growth in data services, the demand of channel bandwidth continues increasing. Due to the limited channel resources, in order to transport information as much as possible in the limited channel, channel multiplexing is the best solution. Frequency-division multiplexing technology, which transports signals in all sub-channels in a parallel manner, and the transmission delay of each sub-channel can take no consideration, has become widely used. In this paper, according to the frequency-division multiplexing principles, establish a frequency-division multiplexing communication system, use Matlab software to capture three-way voice signals, select the appropriate high-frequency carrier modulation, get the multiplexed signal, and then design three different kinds of bandpass filters and a kind of lowpass filter to recover the voice signal from the multiplexed. What’s more, simulate signal modulation, channel transmission and signal demodulation of communication process. Finally, achieve the goal of multi-channel transmission of voice signals.Key Words：FDM；High Frequency Modulation；Filter Design；Signal Recovery 目录第一章 前言41.1FDM技术简介41.2 FDM技术的发展及应用41.3 本论文主要研究内容与工作安排5第二章 FDM系统研究62.1 频分复用原理62.2系统设计82.2.1 语音信号采样82.2.2 语音信号的调制92.2.3 系统的滤波器设计102.2.4 信道噪声12第三章 MATLAB仿真143.1 Matlab软件介绍143.2 语音信号的时域和频域仿真143.3 调制信号的仿真163.4 复用信号仿真173.5信号传输仿真183.6 解调信号仿真194 本章总结22第四章 总结23致谢24参考文献25第一章 前言1.1FDM技术简介随着数据业务的爆炸增长，数据信道带宽需求不断增加，由于信道资源有限，要想在有限的信道中尽可能多的传送数据，信道复用是目前最好的解决方法。信道复用，就是利用一条信道同时传输多路信号的一种技术，目前常用的复用技术有：时分复用（TDM）、频分复用（FDM）、码分复用（CDMA）、以及波分复用（WDM）。对于频分复用（Frequency-division multiplexing，FDM）技术，但多路信号带宽小于信道带宽时，可以将信道分割成