What are the differences between analog modulation and digital modulation?

Question

What the advantages of analog modulation over digital modulation, and what are the disadvantages of anlog modulation?

Answer 1

Pulse Code, Pulse position, and Pulse width modulation are forms of digital modulation. By turning the carrier off and on in a pattern (a numerical code, the position of pulse within a certain time-frame, or the width of a pulse within a certain time-frame) one may convey information over the carrier. Advantages:
- the modulation method is simple: switch the carrier on and off.
- one can achieve close to the theoretical limit of information transfer within a given band.
Disadvantages:
- square waves and sharp "on"/"off" edges of the carrier produce harmonics which must be filtered out or interference with adjacent bands will result.
- the receiver must have some form of synchronization with the transmitter to decode the digital information (synchronization wastes bandwidth because it is not 'information').

Analog modulation uses the analog information to modulate a carrier: either it's amplitude, frequency, phase, or a combination of the 3.
Advantages:
- Very simple demodulation techniques for AM and FM (1 or 2 diodes, capacitors, and a transformer (for FM))
- Linear amplifiers and modulators are used -- no digital circuits.
Disadvantages:
- Modulation methods require lots of power -- comparable with the carrier power.
- Generally the information is not a dense as in digital modulation

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Answer 2

Analog Modulation And Digital Modulation

Answer 3

Digital modulation allows for much more information to be packed in to the same bandwidth because you can start to use codes that wouldn't be possible with an analog circuit.

Answer 4

we are live in an "analog world" , what that mean is everything you can see or hear are the analog stuff. However, the computer lives is digital world. Computer only knows two numbers 0 and 1, when computer talk to each other, ;they are in digital communication. You and other person talk to each other that is analog communication. These days, we can convert digital to analog or analog to digital, this way you can communicate to computer or computer can communicate you.