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  1. #1
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    am fm pm modulation

    Hi,

    Concerning RF.

    It's my understanding that the amplitude of the modulating signal is always used to modulate the carrier signal regardless if itís AM, FM or PM

    Is this true ?

    If so, Can someone help me to understand whats different between the modulating signal for all three.

    Or correct me if Iím wrong.

    Thanks,
    -Areal

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    comparison between am,fm & pm

    U CAN SEE THE BOOK "principles of communication systems" by TAUB & SCHILILNG



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    how pm is closely relate to fm




    •   Alt19th March 2008, 21:24

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    am fm pm modulation

    u should read the "ANALOG AND DIGITAL COMMUNICATION BY B.P LATHI"CH#4,5



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    am fm pm modulation which is best

    That is incorrect.
    FM uses the frequency to transmit information so your Amp can be completely
    saturated and still change freq. Phase mod is closely related to FM.

    You might be thinking of QAM. Where you do have Phase and Amplitude
    being used to send data.

    Cheers



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    am,fm,pm difference

    no, for example FM is a constant envelope modulation, the amplitude doesn't contain any information



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    difference in am ,fm ,pm

    Well you're right. The modulating signal is the same in all cases. The difference is how the carrier is modulated by the information signal



    •   Alt20th March 2008, 00:19

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    different between am,fm,pm

    Hy
    i think u r confused!!!
    simple way to understand :
    modulating signal=input signal (signal to be sent)
    for modulating signal,
    use appropriate modulation technique to send data over any channel.
    for more
    study
    carlson
    frenzel
    lathi (good for novice)
    Regards



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    am,fm,pm

    LATHI book will help you more to understand the diff between them



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    understand am fm modulation

    Hi,
    Your statement is correct, that is, Whatever be the type of modulation, it is the amplitude of the modulating signal that is used to modulate the carrier.
    Regards,
    Laktronics



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    comparison of am,fm and pm modulation

    hi,

    as laktronics said, your statement is correct..

    since we need to transmit the message signal we use it to modulate the carrier, hence the name 'modulating signal'... to transmit the message signal we need to know its amplitude at each time instant at the receiver. so the amplitude of the message (modulating) signal will be used to change:

    1. the amplitude of the carrier in case of amplitude modulation,
    2. the frequency of the carrier in case of frequency modulation,
    3. the phase of the carrier in case of phase modulation...

    these figures explain the difference. the book of lathi will help you to understand the concept better.






    best regards



  12. #12
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    am fm pm vs

    Hi Friend,

    Refer "Principles of Electronic Communication Systems" By Kennedy



    Regards,
    Avinash.S.



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    am fm pm wiki

    if you have a signal a high frequency one, the you can send information of a slow frequency signal on within it,
    if you vary the amplitude of the hf signal you have am, if you slightly modify the frequneyc i se less than 5% you have fm, and if you change its phase with respecto to a reference signal you have pm , see lathi for a mathematical covering, a lite one.



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    am fm pm questions

    MODULATING SIGNAL (VOICE) + CARIER SIGNAL MODULATED SIGANAL

    if we use varying amplitude of modulating signal to modulate its AM

    if we use varying FREQUENCY of modulating signal to modulate its FM

    PCM IS OTHER THING .IT USED PULSES TO GET IDEA OF MODUALTING SIGNAL AND THAT DATA WILL TRANSMIT BASICALLY.THIS ROUGH IDEA TO YOU



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    compare am,fm and pm

    It is completely wrong. because only in AM amplitude will used for modulation. For FM and PM signals amplitude has a constant value and frequency and phase changes.



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