Angle Modulation Technology

  • Apurba Das
Part of the Signals and Communication Technology book series (SCT)


From the understanding of the primary properties of an electrical signal, we understood that, we can either modulate amplitude or the phase of the signal. In phase again we have two tunable parts namely frequency and initial phase. The algorithm of modulation in this case may be of two types. We may modulate the frequency of carrier with respect to the modulating signal, or we may directly modulate the entire phase of the carrier depending upon the modulating signal. In both the cases, the resultant signal will form an appreciable amount of angle with the raw carrier component. Whichever may be the case, ultimately the angle will be modulated. Therefore, frequency modulation (FM) and phase modulation (PM) are the indispensable part of angle modulation. Two major disturbances, occurred in communication or signal transfer technology, are noise and distortions. It would be easier for even an impulsive noise to distort instantaneous amplitude of any signal but not so easy to distort frequency, as definition of frequency does not permit the term “instantaneous”.


Frequency Modulation Phase Modulation Modulate Signal Instantaneous Frequency Modulation Index 
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Copyright information

© Springer-Verlag Berlin Heidelberg 2012

Authors and Affiliations

  1. 1.Image Processing Lab CDAC, KolkattaMinistry of Communication and ITKolkattaIndia
  2. 2.Imaging Tech Lab, Engineering and R&DHCL Technologies Ltd.ChennaiIndia

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