摘 要：多进制正交幅度调制(MQAM)是一种频谱利用率和功率密度较高的数字调制技术，在通信领域有着广泛的运用。论文着重论述了MQAM正交幅度调制解调方式，通过系统实验对正交幅度调制解调的过程、原理及性能进行了论证、分析，并根据星座图的形状指出了MQAM在调制与解调方法上的区别，理论上讨论和说明了数字调制解调技术中影响系统性能的条件和因素，并通过眼图进行了简单观察。最后利用仿真软件MATLAB对MQAM全数字调制与解调过程进行了仿真，并给出了MQAM在加性高斯白噪声条件下的误码率实验及仿真，结果证明全数字正交幅度调制解调易于实现，且性能良好，是未来通信技术的主要研究方向之一，并有广阔的应用前景。 64417

毕业论文关键词：QAM，调制解调，MATLAB，误码率

Abstract: Multiple Quadrature Amplitude Modulation (MQAM) is a kind of spectrum utilization efficiency and higher power density digital modulation technology, has been widely used in the field of communications.Paper emphatically discusses the MQAM quadrature amplitude modulation demodulation way, through the system experiments of quadrature amplitude modulation demodulation process, analyses and demonstrates the principle and performance, and according to the shape of the constellation diagram MQAM are pointed out in the difference between the modulation and demodulation method, theoretical discussion and illustrates the digital modulation demodulation technology of the conditions and factors influencing the performance of the system, and through the eye diagram has carried on the simple observation. Finally using the simulation software MATLAB for MQAM digital modulation and demodulation process are simulated, and presents a MQAM in additive gaussian white noise error rate under the condition of experiment and simulation, the results prove that the digital quadrature amplitude modulation demodulation is easy to implement, and good performance, is one of the main research direction of future communication technology, and has a broad application prospect.

Keywords: QAM, Modulator and Demodulator, MATLAB, BER

1  绪论 4

1.1  课题的背景及意义 4

1.2  QAM的研究现状 5

1.3  课题研究的主要内容 5

2  正交幅度调制解调原理 5

2.1  引言 5

2.2  QAM调制解调原理 5

2.2.1  QAM调制原理 5

2.2.2  QAM解调原理 6

2.3  MQAM调制解调原理 7

2.3.1  MQAM调制原理 7

2.3.2  MQAM解调原理 7

2.4  结语 8

3  MATLAB/SIMULINK的简介 8

4  仿真及实现说明 8

4.1  SIMULINK仿真框图 8

4.2  眼图 9

4.2.1  眼图简介 9

4.2.2  眼图分析 10

4.3  星座图及其波形的分析 10

4.4  误码率及噪声分析 13

结  论 18

参考文献 19

致  谢