正交振幅调制解调QAM系统实验研究与仿真.doc

摘 要 论述了适用于数字微波系统的正交幅度调制解调方式，并根据星座图的形状指出了16QAM, 64QAM32QAM,128QAM（星座图为十字形）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，简要介绍了用于误码测试的伪随机序列的相关知识。最后利用通信系统仿真软件System View对16QAM, 32QAM, 64QAM,128QAM全数字调制与解调过程进行了仿真，并给出了16QAM在加性高斯白噪声条件下的误码率。实验及仿真的结果证明，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。 关键词：QAM；调制解调；星座图；误码率 。  Abstract This is the modern digital modulation techniques, from the first modern communications technology the key modulation and demodulation. leads to the concept of modulation and demodulation of the notes before the modern digital modulation techniques are briefly described. Then focuses on the application of digital microwave system QAM quadrature amplitude modulation and demodulation, Through experiments on Quadrature Amplitude modulation and demodulation process, principles and performance of the verification, analysis, According to Constellation and the shape of the map that a 16QAM, 64QAM (rectangular constellation map) and 32QAM. 128QAM (cross-shaped constellation map) modulation and demodulation of distinction, Theoretically discussion and description of the digital modulation and demodulation technology imaging system performance conditions and factors, and through eye diagrams of simple observation, briefed the BER testing for the pseudo-random sequence of related knowledge.Finally Communication System Simulation Software System View of 16QAM, 32QAM, 64QAM,128QAM digital modulation and demodulation process of simulation, 16QAM given the additive white Gaussian noise conditions BER. Experimental and simulation results proved that the digital quadrature amplitude modulation and demodulation easy to implement, and good performance, ICT is the future of one of the main direction of research, and broad application prospects. Key words : QAM; modulation and demodulation; Constellation plans; BER; 目 录 摘 要 1 Abstract 2 目 录 1 第一章 引言 1 第二章 正交振幅调制解调原理 5 2.1 正交振幅调制技术简介 5 2.2 QAM调制解调原理 6 2.2.1 QAM调制 6 2.2.2 QAM的解调和判决 7 2.3 QAM