中文摘要：

脉冲位置相位翻转键控（3PRK）是一种超窄带（UNB）调制技术，其已调信号是循环平稳信号。该已调信号通过相位跳变翻转来表征携带的信息。针对传统傅里叶分析不能确定3PRK已调信号信息所在的位置和频率与时间的关系，因此引入短时傅氏变换（STFT）和伪Wigner-Ville分布（PWVD）时频分析的方法。分析结果表明，STFT和PWVD能够很好分析信号的信息所在位置和表示信号频率与时间的关系。

英文摘要：

Pulse Position Phase Reversal Keying （3PRK） is a kind of UNB modulation method and the modulated signal has the cyelostationary property. And its modulated signal carries information through reversing the phase. Because traditional Fourier transform analysis can not show where the exact information of the 3PRK signal lies and the relationship between time and frequency,this paper introduces Short Time Fourier Transform （STFT） and pseudo Wigner-Ville distribution （PWVD） to analysis the signal.The result shows that STFT and PWVD methods can tell where the exact information lies and the relationship between time and frequency of the 3PRK signal.