基于MATLAB的QAM调制解调技术分析..doc

基于MATLAB的QAM调制解调技术分析 【摘要】当今频谱资源很大一部分已经被利用，随着用户数量的不断增加，对业务需求量不断地提高，在所剩无几的频谱资源如何才能够承载用户的需求，QAM凭借着自身高频谱利用率，低误码率。QAM，MATLAB，调制与解调，星座图，眼图，误码率  QAM Modulation and Demodulation Analysis Base on MATLAB 【 Abstract 】Today, a large part of the spectrum resources has already been used, as the number of users and the demand for business constantly increasing, QAM relying on its high spectrum utilization ratio and low error rate, strong anti-interference advantages catch numerous mobile experts concern and do research on it. The graduation design research topic is QAM modulation and demodulation technology base on MATLAB, this paper studies and analysis of QAM modulation and demodulation process involved each module, including the binary transmitting terminal input module, level conversion module, string and conversion module, signal modulation module, signal demodulation module, every module is established through MATLAB to realize, this process included a constellation diagram, eye diagram, the frequency spectrum graph, bit error rate curve to analysis different level modulation system of QAM performance, at the same time, add gaussian white noise on the previous signal , and do the same analysis like preceding [1]. 【keywords】QAM,MATLAB, modulation and demodulation, constellation diagram, bit error rate 【目录】 第一章：绪论 1 1.1QAM背景、研究目的及意义 1 1.2 QAM的最新研究状况 2 1.3本文研究的内容及结构 3 第二章：MATLAB的简介 4 2.1MATLAB的简述和基本功能 4 2.2MATLAB应用平台结构 4 2.3MATLAB的优势 4 2.4MATLAB的应用领域 5 第三章：正交振幅系统 6 3.1调制与解调 6 3.1.1调制简介 6 3.1.2解调简介 6 3.1.3数字通信系统构成及各模块的说明 7 3.2QAM系统的简介 8 3.2.1QAM调制和星座图简介 8 3.2.2串/并简介 10 3.2.3形成载波 10 3.2.4 QAM调制信号的形成 11 3.2.5正交调幅的解调和判决 11 3.3QAM的优缺点 12 3.4QAM的主要应用领域 13 3.5QAM的误码率性能分析 14 3.6QAM眼图 15 第四章：16QAM仿真 17 4.1基于MATLAB的16QAM仿真 17 4.1.1信号源 17 4.1.2电平转换 17 4.1.3QAM调制 19 4.1.4 16QAM星座图 19 4.1.5 16QAM频谱 21 4.2对16QAM加入高斯白噪声系统仿真 22 4.2.116QAM系统加入高斯白噪声后的星座图 22 4.2.21