频分复用原理及其应用研究重点.doc

2015届学士学位论文 频分复用原理及其应用研究  频分复用原理及其应用研究 摘要 频分复用(FDM)是通信系统中信号多路复用方式中的一种，本质上是依据频率来分隔信道的。频分复用技术在当今通信领域有着很重要的地位。根据性质和特点的不同频分复用还可以被细分为传统的频分复用(FDM)和正交频分复用(OFDM)。 本论文主要由以下几个部分组成。第一部分介绍频分复用基本原理，系统实现以及其应用特点；第二部分介绍正交频分复用的基本原理及DFT的实现；第三部分主要介绍在实际应用中当载波频率接近时，频谱会发生重叠，传统的频分复用解调效果容易出现失真，正交频分复用由于其载波的正交性特点,在频谱发生重叠时可以保证解调效果；最后通过MATLAB程序中的SIMULINK仿真图来表现正交频分复用的优越之处。 关键词 频分复用；正交频分复用；MATLAB仿真  Frequency division multiplexing principle and its application research Abstract Frequency division multiplexing (FDM) is a kind of signal multiplexing mode in communication system, which is divided by frequency channel?essentially. Frequency division multiplexing technology is very widely used in todays communication. Frequency division multiplexing can also be divided into the traditional frequency division multiple(FDM) and orthogonal frequency division multiplexing(OFDM) depending on the nature and characteristics. This paper consists of the following parts. The basic principle of frequency division multiplexing, system implementation and its application characteristics are introduced in the first part . The basic principle of orthogonal frequency division multiplexing and its realization of DFT are introduced in the second part .Due to its characteristics ,orthogonal frequency division multiplexing can guarantee the demodulation compare with the traditional frequency division multiplexing when the carrier frequency is close to in the practical application, spectrum overlap happens ,which is introduced in the third part .Finally by SIMULINK of MATLAB simulation diagram to show the superiority of the orthogonal frequency division multiplexing. Keywords Frequency division multiplexing; Orthogonal frequency division Multiplexing ;MATLAB simulation 目 录 1.引言 1 2频分复用基本原理及实现 2 2.1频分复用的基本原理 2 2.2 频分复用系统应用及其特点 2 3正交频分复用基本原理及实现 4 3.1正交频分复用原理 4 3.2 DFT的实现 6 3.3 正交频分复用的优缺点 8 4频分复用原理的应用 9 4.1系统仿真主要模块的介绍 9 4.2频分复用系统仿真的实际应用分析 9 4.3 仿真结果分析 14 结 论 15 参考文