摘要
为了增强学生对通信原理的感性认识,以常用的四进制相位键控(QPSK)数字通信系统为例,设计了基于Matlab图形界面的交互式QPSK传输仿真系统。内容涵盖调制、信道、解调,各部分结构、功能按模块讲解,各功能通过仿真波形展示,亦可选择信号实测结果进行观测,增强系统的真实性。同时系统参数可以交互配置,通过图形直观地显示不同参数对系统的影响。分析成形滤波对调制波形的影响,并给出了相应的功率谱密度;研究了载波估计中频率偏差、相位偏差对解调结果的影响,并通过星座图的变化进行演示,同时给出频偏、相偏仿真的等效基带表示。
In order to increase students＇ comprehension to principles of communications,the common Quaternary Phase Shift Keying （QPSK） digital communication system is taken into consideration and an interactive QPSK transmission demonstration system based on the graphical user interface of Matlab is designed.Modulation,channel and demodulation parts are all included,and each one＇ s structures and functions are listed as modules,while the functions are illustrated using simulation waves.The measure results attained by testing real signal are displayed,so as to add the reality of platform.At the same time,the system can be configured interactively,and the influence of different parameters is shown by images intuitively.The effects of shaping filter are analyzed,and the power spectrum density figure is shown.Also frequency offset and phase offset are analyzed,and the alteration of constellation is presented,while equivalent baseband expression of frequency offset and phase offset is given.
出处
《实验室研究与探索》
CAS
北大核心
2014年第7期29-34,共6页
Research and Exploration In Laboratory
基金
国家自然科学基金项目(61072049)
