define frequency modulation ? write the advantages of frequency modulation over amplitude modulation ?
Frequency Modulation: Frequency of carrier signal wave varies in accordance with modulating signal.
In AM, information is carried in the form of amplitude variations. The electric fields in the channel may affect the amplitude of the signal which are called noise
In FM transmission, message is in the form of frequency variation of carriers waves. During modulation, noise gets amplitude modulated, changing the amplitude of carrier waves. Obviously, the message signals, in the form of frequency, is not affected, That is why FM signal is less susceptible to noise than an AM signal.
In AM, information is carried in the form of amplitude variations. The electric fields in the channel may affect the amplitude of the signal which are called noise
In FM transmission, message is in the form of frequency variation of carriers waves. During modulation, noise gets amplitude modulated, changing the amplitude of carrier waves. Obviously, the message signals, in the form of frequency, is not affected, That is why FM signal is less susceptible to noise than an AM signal.