基于simulink的OFDM系统仿真和分析
毕业论文关键词 OFDM 衰落信道 simulink 多普勒频移 仿真分析
Title the simulation and analysis based on simulink of OFDM system
Abstract The development of science and technology led to an unprecedented demand forcomplex structure of high speed signal processing applications.In the 4 g wirelesscommunication system, the bandwidth is a precious commodity, and operators havebeen plagued by in the allocation of bandwidth limited can be placed more users.Inorder to improve the information more efficient transmission in the wirelessmedium, orthogonal frequency pision multiplexing (OFDM) technology can beused.This paper introduces the basic principle of OFDM system, details thesimulation and analysis of OFDM system. Simulink in MATLAB software platform, tobuild complete OFDM system, and learn to complete parameter Settings of each moduleand analysis functions of each module. Simulation of OFDM system under differentmodulation mode and performance analysis; Under white gaussian noise and Rayleighfading channel affect the performance of OFDM system, and the influence of dopplerfrequency shift on the system. In general, OFDM still has many superiorperformance, it is also important reason for it is widely used now. It is obtainedby simulation analysis, according to the different channels, different modulationOFDM effects in the environment of the present. This is also the experiment results.
Keywords OFDM fading channel simulink simulation analysis of doppler frequencyshift
目录
1 引言（或绪论）..1
2 OFDM的介绍 2
2.1 技术发展史 2
2.2 技术应用领域 2
2.3 技术的优缺点 3
2.4 本文研究内容..3
3.OFDM原理和内容.4
3.1 OFDM 的基本原理模型..4
3.2OFDM 的IFFT/FFT 实现..7
3.3 保护间隔和循环前缀.8
4.1 仿真软件简介及其现在应用领域..10
4.2 Matlab 仿真软件的特点. 10
4.2.2基本 simulink的操作 11
5 OFDM系统仿真13
5.1 不同调制方式下OFDM 系统性能分析. 13
5.1.1系统仿真框图13
5.1.2不同调制下性能分析.. 13
5.2 不同信道环境中OFDM 系统性能分析. 21
5.2.1多径衰落.. 21
5.2.2信道分类.. 23
5.2.3 Simulink仿真.23
5.2.4性能分析.. 25
结论.28
致谢.29
参考文献..30
1 引言（或绪论）未来通讯系统和通讯网络会从根本上改进人类交流方式。通讯服务其中之一的无线通讯有希望在未来产生重大影响，这回允许远距离通话和信息传输到达地球上任意角落。巨大且快速成长的商业市场对于产生和接收这些通讯服务;已经孕育出了在信号设计，调制，探测和信号处理方面的新科技。对于无线通讯系统，有限的带宽分配与潜在的大量用户相协调限制了用户带宽的可用性[2]。因此，一个成功的无线通讯系统很大程度上取决于带宽的高效信息传输方案。这样的一个高效传输方案调制就是 OFDM。复用的组合构成了正交分频复用技术（OFDM） 。主信号下的分支独立信号被复用在 OFDM 下，而且信号本身首次被分成独立的信道，被数据调制，进而再次被复用来建立 OFDM 载波。正交这些分支载波是 OFDM的核心概念。正交的特性使得附加的分支载波可以同时发射在一个小的频率空间内而且不会互相干扰。这是 OFDM 的一个卓越之处