摘要
为了得到伪码调相和锯齿调频复合调制探测系统中频信号的能量时频分布,根据理论推导得到复合调制中频信号是伪随机码与锯齿调频波的差频信号相乘的结果,使用相位分析法和傅里叶变换对复合调制中频信号的锯齿调频波差频信号项进行了详细分析,得到其精确时频域表达式,结合时频重排方法并借助Matlab得到了中频信号的时频分布,继而得到伪码调相对中频信号的影响,结论表明中频信号的能量谱分布由锯齿调频波差频信号的低频分量决定,伪码调相则造成中频信号在时频平面上的大量脉冲。
The intermediate-frequency signal（IF signal） of a new hybrid modulation detector,which combined Sawtooth-wave frequency modulation with pseudo-random binary phase modulation（PRBP） is studied.The IF signal is the product of the difference frequency signal of sawtooth frequency modulation signal and pseudo-random code.The time-frequency expression of the difference frequency is gotten with the methods of phase analysis and Fourier transform.The time-frequency rearrangement method is used to analysis the time-frequency energy distribution of IF signal by Matlab.The result shows that,the spectral energy distribution of the IF signal is decided by the low frequency component of the difference frequency signal of sawtooth frequency modulation signal,and the large number of pulses along the IF signal in the time-frequency plane is caused by PRBP.
出处
《国外电子测量技术》
2011年第11期22-26,共5页
Foreign Electronic Measurement Technology
关键词
复合调制
时频分析
时频重排
中频信号
hybire modulation
time-frequency analysis
time-frequency rearrangement
intermediate-frequency signal
