干扰条件下正弦类Haar小波MPSK信号识别分析
2014-12-13王铁铸
王铁铸
摘 要: 为提高MPSK信号的类内识别率,分析了MPSK信号正弦类Haar小波变换信号的相位信息,通过提取脊线拟合函数相位的方法对MPSK信号进行类内识别。对提出的方法进行了数值分析和仿真实验,得到8PSK信号的相位提取图,并对不同MPSK信号在无噪和有噪两种情况下进行识别分析,最后得到调制方式识别率曲线。分析和实验结果表明,提出的识别方法正确识别率在90%以上,并且具有一定的抵抗通信干扰能力。
关键词: 调制方式识别; Haar小波分析; 相移键控; 通信干扰
中图分类号: TN911.7?34 文献标识码: A 文章编号: 1004?373X(2014)23?0054?04
Abstract: The phase information of the sinusoidal Haar wavelet transform of MPSK signals is analyzed to improve the within?class recognition rate of MPSK signals. The within?class recognition of MPSK signals is achieved by means of extracting the fitting function phases of regression line. The mathematical analysis and simulation experiments were performed for the proposed phase extracting method. The phase extracting diagram of an 8PSK signal was derived, the recognition analysis for different MPSK signals under two situations of both non?noise and noise was conducted, and then the recognition rate curves of the derived modulation mode were obtained. The analysis and simulation results show that the recognition rate of the proposed method is above 90%, and the method has a certain capability of anti?jamming.
Keywords: modulation mode recognition; Haar wavelet analysis; phase shift keying; communication jamming
0 引 言
通信信号调制方式识别主要是通过信号变换来提取信号体制、相位、频率等特征参数,为雷达、导航等无线电信号的分析提供技术手段[1?2]。信号调制方式识别一般包括类间识别和类内识别两种,类间识别相对容易,而类内识别由于信号的调制方式相同或相近,因此难度较大,特别是在通信干扰条件下,信号波形发生畸变,有时甚至接收不到信号,类内识别更加困难。
哈尔小波(Haar)[3?4]既具有小波分析的变焦距性质,又具有计算量小、简单实用的优点,采用Haar小波分析MPSK信号识别,可有效提取信号特征参数和调制参量,提高信号调制方式识别准确度。
1 MPSK信号正弦类Haar小波变换
正弦信号具有振幅、频率、相位3个参量可供携带信息,是数字通信系统载波的理想选择,将MPSK信号信息加载于正弦载波相位上,并设置该载波相位[φc∈0,2π],则MPSK信号相位满足的条件为:
[?m∈2πMm-1Mm=1] (1)
对于BPSK信号,则[?1=0,?2=π;……
