基于Matlab的OFDM系统仿真及分析毕业设计

基于Matlab的OFDM系统仿真及分析毕业设计

基于Matlab的OFDM系统仿真及分析

Simulation and Performance Analysis of OFDM System Based on Matlab

基于Matlab的OFDM系统仿真及分析毕业设计毕业设计成绩单

基于Matlab的OFDM系统仿真及分析毕业设计毕业论文任务书

毕业设计开题报告

摘要

在无线通信系统中，存在着各种严重的衰落，例如频率选择性衰落、快衰落和慢衰落，以及由于各种物体对传输信号的反射引起的多径传播，而由此引起的符号间干扰是无线通信系统设计中必须考虑的问题，特别是在高速传输的环境中。而正交频分复用（OFDM）正是为了解决这些问题提出的，它是第四代移动通信的核心技术之一。

OFDM是一种特殊的多载波传输方案，它将数字调制、数字信号处理、多载波传输等技术有机结合在一起，是目前已知的频谱利用率最高的一种通信系统，具有传输速度快、抗多径干扰能力强的优点。目前，OFDM技术在数字音频广播、地面数字视频广播、无线局域网等领域得到广泛应用。

本文论述了OFDM的基本原理以及信号调制技术，给出了OFDM系统模型，并从频域的角度分析OFDM信号的性质及DFT实现，最后用MATLAB语言实现了整个系统的计算机仿真并给出参考设计程序，对OFDM调制系统中主要传输技术、基本参数的选择、同步及关键技术和仿真实现进行了相关的讨论。

关键词：OFDM多载波系统仿真MATLAB

Abstract

There are some severe problems in wireless communication systems, such as frequency selective fading, fast fading and slow fading, and various objects of reflection led to the transmitted signal multipath propagation. The resulting inter-symbol interference (ISI) is a wireless communication system design issues that must be considered, especially in the high-speed transmission environment. Orthogonal frequency division multiplexing (OFDM) is proposed to solve these problems, it is the core technology of the fourth generation mobile communication.

OFDM is a special multi-carrier transmission scheme, it combines some technologies such as figure modulation, digital signal processing, multi-carrier transmission. It is the maximum utilization of the spectrum communication system, with the advantages of faster transfer rates, anti-multipath interference. Currently known at present, OFDM technology is widely used in the digital audio broadcasting, terrestrial digital video broadcasting and wireless LAN.

This paper introduce the orthogonal frequency division multiplexing basic principle and discusses signal modulation technology, then, given OFDM system model, and analysis the nature and DFT realization of OFDM signals from the point of view of frequency domain. Finally, based on the given system model, OFDM system is computer simulated with MATLAB language and the referential design procedure is given. Discussing in the system of OFDM modulation transmission technology, basic parameter selection, system of synchronous, key technology and OFDM system simulation.

Key words：OFDM Multi-carrier System Simulation MATLAB

目录

第1章绪论 (1)

1.1课题研究目的及意义 (1)

1.2国内外研究现状 (1)

1.3课题研究的主要内容 (4)

第2章OFDM系统基本原理 (5)

2.1原理 (5)

2.1.1OFDM基本原理 (5)

2.1.2串并转换 (5)

2.1.3子载波调制 (6)

2.1.4DFT变换 (9)

2.1.5傅里叶变换过采样 (10)

2.2调制方式 (11)

2.3本章小结 (12)

第3章软件介绍及应用 (13)

3.1MA TLAB简介 (13)

3.2QPSK信号的产生 (14)

第4章OFDM系统仿真的实现 (18)

4.1OFDM系统收发机 (18)

4.2OFDM系统仿真 (18)

4.2.1基本参数的选择 (18)

4.2.2串行数据的产生 (20)

4.2.3串并转换过程 (20)

4.2.4IFFT/FFT运算 (20)

4.2.5保护间隔和循环前缀 (21)

4.2.6加入高斯噪声 (21)

4.2.7接受信号 (22)

4.3系统误码率的分析 (22)

4.4实验仿真结果 (23)

4.5OFDM的性能比较 (26)

4.6本章小结 (27)

第5章结论与展望 (28)

5.1结论 (28)

5.2展望 (28)

参考文献 (29)

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