基于MATLAB的OFDM系统设计与仿真
摘要：随着通信产业的逐步发展，4G时代已经来临。作为第四代移动通信技术的核心，OFDM得到了前所未有的关注。它具有频谱利用率高、抗干扰能力强等优点。本文首先简要介绍了OFDM的发展状况以及优缺点，然后详细分析了OFDM的工作原理及其相应的各个模块，并介绍了它的关键技术。最后，分别利用M函数和Simulink做了OFDM系统的设计与仿真，并对误码率进行了分析，得到了BER性能曲线。
关键词：正交频分复用；MATLAB；仿真；BER
Design and Simulation of OFDM System Based on MATLAB
Abstract: With the gradual development of the communication industry, 4G era has come. As the key technology of the fourth generation mobile communications,OFDM has received unprecedented attention. It has a high spectrum utilization, strong ability of anti-interference and so on. This article describes the development of OFDM and it’s advantages and disadvantages briefly, analysis the working principles of OFDM and each module detailed,and describes it’s key technology.At last, design and simulate OFDM system with the M function and Simulink separately, analysis the error rate and obtain BER performance curve .
Keywords: OFDM; MATLAB; Simulation; BER
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目 录
1 引言 ................................................................................................................... 4 1.1 OFDM概述 ..................................................................................................... 4 1.1.1 OFDM技术发展历史 .................................................................................. 4 1.1.2 OFDM技术的优缺点 .................................................................................. 5 2 OFDM基本原理及关键技术 ............................................................................ 5 2.1 OFDM基本原理及系统构成 ......................................................................... 5 2.1.1 OFDM基本原理 .......................................................................................... 5 2.1.2 串并转换 ..................................................................................................... 6 2.1.3 调制与解调 ................................................................................................. 6 2.1.4 保护间隔与循环前缀 ................................................................................. 8 2.2 OFDM的关键技术 ....................................................................................... 10 2.2.1 信道估计概述 ........................................................................................... 10 2.2.2 基于导频的信道估计方法 ....................................................................... 10 2.2.3 信道的插值方法 ....................................................................................... 11 3 OFDM的系统设计与仿真 .............................................................................. 12 3.1 MATLAB概述 .............................................................................................. 12 3.2 OFDM系统设计与仿真 ............................................................................... 12 3.2.1 随机序列的产生 ....................................................................................... 12 3.2.2 串并转换 ................................................................................................... 14 3.2.3 QPSK调制 ................................................................................................. 14 3.2.4 QPSK调制星座图 ..................................................................................... 14 3.2.5 IFFT/FFT运算 ........................................................................................... 15 3.2.6 保护间隔和循环前缀 ............................................................................... 16 3.2.7 并串转换 ................................................................................................... 16 3.2.8 加入高斯白噪声 ....................................................................................... 17 3.2.9 QPSK解调 ................................................................................................. 17 3.2.10 接收信号 ................................................................................................. 18 3.3 系统误码率的分析 ...................................................................................... 18
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3.4 基于Simulink的系统仿真 .......................................................................... 19 4 总结 ................................................................................................................. 21 参考文献 ............................................................................................................. 21 附录 ..................................................................................................................... 22
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