What is:(a)frequency modulation(b)pulse modulation(c)amplitude modulation.explain the process involved in each

Question

I want to know the procedure , functionig and details about the above three topics on class 12th basis

Answer 1

Hi.. I can anser this in general.. Carrier frequency can be modulated in no of ways to carry information. These are Amplitude modulation, Frequency modulation and Pulse Code modulation



In Frequency modulation, the FREQUENCY of the carrier is changed according to modulating signal, (keeping the amplitude constant). In Amplitude Modulation, the AMPLITUDE of the carrier wave is changed according to the moduating signal. Pulse code modulation is bit complex. The Modulating signal is digitized throuogh a Analog to Digital convertor and a train of digital words is constructed, which is used to Phase modulate the carrier. Phase modulation is nothing but changing PHASE of carrier wave as per the digital signal.

You should also note down the advantages and disadvantges of each for exam purpose

Answer 2

Frequency mod. requires a carrier wave of a set frequency,say 88 meg.

The information is injected at audio frequency onto the carrier,transmitted and retrieved through some type of low pass filter.

Amp. mod.requires a carrier of varying amplitude[not fixed].

Again the audio is injected varying the amplitude,demodulation retrieves the information.

Pulse mod. is used in digital transmission.

The information is chopped into bits or pulses

It still requires a carrier,and it can be transmitted as AM or FM

Cable companies use it in digital cable systems

Answer 3

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