MATLAB基于循环谱的通信信号识别技术研究
毕业论文关键词 周期性 调制方式识别 循环谱 MATLAB 仿真
Title Modulation Recognition of Communication Signals Based on Cyclic Spectrum
Abstract
Automatic modulation recognition of communication signals is an important issue
for both military and civil use. Potential periodicity shows in most
communication signals. And cyclic spectrum extracts the periodicity. Thus,
modulation types can be recognized by cyclic spectrum. In this paper, we briefly
introduced the cyclostationary theory and its calculation. Firstly, we
generated common modulated signals (BPSK, QPSK, 2FSK and MSK) and calculated
their cyclic spectral respectively. Then we study these spectral and compare
the difference. As a result, we got a recognition algorithm base on distinct
characteristics of the spectral. This algorithm works when sample rate and
symbol rate are obtained. Finally, we computed the recognition rate by Mont
Carlo simulation.
Keywords periodicity Modulation Recognition Cyclic Spectrum MATLAB Simulation
目 次
1 绪论 1
1.1 课题背景 · 1
1.2 研究现状 · 1
1.3 研究方法 · 2
2 调制信号产生 4
2.1 BPSK信号产生 · 4
2.2 QPSK信号产生 · 5
2.3 2FSK信号产生 · 6
2.4 MSK信号产生 7
3 循环谱介绍 · 10
3.1 循环谱的定义 · 10
3.2 循环谱的性质 · 12
4 调制信号的循环谱计算 13
4.1 BPSK、2ASK信号的循环谱 13
4.2 QPSK信号的循环谱 · 16
4.3 2FSK信号的循环谱 · 18
4.4 MSK信号的循环谱 19
5 识别算法及识别性能仿真 · 22
5.1 循环谱差异比较 22
5.2 构造识别算法 · 22
5.3 识别性能仿真 · 23
结 论 25
致 谢 26
参考文献 · 27
1 绪论
1.1 课题背景
近年来，认知无线电逐渐成为一个热门研究方向。调制方式的自动识别是认知无线电中
一个非常重要的模块，是信号检测与解调之间不可或缺的步骤。
信号调制方式自动识别在军用和民用通信领域都是一个重要的研究课题，尤其是在频谱
动态管理和干扰识别方面。在军事上，它可以用于电子侦察，电子战和威胁分析等情形；战