)7.1调频信号和调相信号 u。=Um cos(at+p) AM:Amplitude Modulation △Uam=Kua(t) △o。=Ku(t) FM:Frequency Modulation △p=Kuo(t) PM:Phase Modulation o()=d@1+o) dt 7.1 调频信号和调相信号 AM：Amplitude Modulation FM：Frequency Modulation PM：Phase Modulation Ucm  Ku t    Ku t uc Ucm cosC t    c  Ku t   d  0 t  t dt     