题目基于MATLAB的数字频带通信系统仿真摘要本论文研究了数字频带传输的性能。围绕基本结构发送滤波器、调制器、信道、解调器、接收滤波器等部分进行仿真。在分析数字频带传输基本原理的基础上从两方面理论分析其传输系统的基本性能。第一个方面使用MATLAB中M语言完成QPSK的仿真，得出在加性高斯白噪声的信道下，传输比特错误率，得出关系曲线，并将比特错误率与理论值相比较，分析其传输性能。第二个方面是通过仿真得到QPSK和OQPSK信号经过带通后的波形。对比两个信号的功率谱密度图，理论分析其传输性能。关键词仿真MATLABQPSKOQPSKTitleBasedontheMATLABSimulationoftheDigitalBandCommunicationSystemAbstractThispaperstudiestheperformanceofthedigitalbandtransmission.Focusonthebasicstructureofthetransmitfilter,themodulator,channel,demodulator,receiverfiltersandotherpartsofthesimulation.OnthebasicprincipleofthedigitalbandCommunicationtoanalysisperformanceofthetransmissionsystem.ThefirstaspectoftheuseofMATLABMlanguagetocompleteQPSKsimulation,ObtainedintheadditivewhiteGaussiannoisechannel,thetransmissionbiterrorrate,todrawthecurve.Comparedtothebiterrorratewiththetheoreticalvalue,analyzethetransmissionperformance.ThesecondaspectisthesimulationwaveformofQPSKandOQPSKsignalsaftertheband-pass.Contrastthetwosignalsthepowerspectraldensityfigure,thetheoreticalanalysisthetransmissionproperties.Powerspectraldensitymapcomparisonofthetwosignals,thetheorytoanalyzethetransmissionperformance.KeywordsSimulationMATLABQPSKOQPSK目录1.前言..............................................................11.1数字频带传输系统的简介........................................11.2本论文的选题意义..............................................22.MATLAB简介........................................................42.1MATLAB的主要功能..............................................42.2MATLAB的优势..................................................42.3MATLAB工具箱..................................................62.4MATLAB语言....................................................73.通信系统..........................................................84.数字信号的基带传输................................................114.1数字基带传输系统..............................................114.2加性高斯白噪声AWGN............................................124.3升余弦滚降系统................................................125.数字信号的频带传输................................................155.1数字频带传输系统..............................................155.2四相移相键控（QPSK）..........................................165.2.1QPSK信号的产生............................................165.2.2QPSK信号的平均功率谱密度..................................185.2.3QPSK信号的接收及其平均误比特率............................195.2.4程序仿真..................................................225.3偏移四相移相键控（OQPSK）....................................235.3.1OQPSK调制................................................245.3.2OQPSK信号的最佳接收及误比特率............................265.3.3程序仿真..................................................276.结论..............................................................28致谢................................................................29参考文献............................................................30附录................................................................311.前言在现代信息化的社会里，通信是很重要的，尤其是移动通信，它在现...
