Question

What is PAM PWM PPM?

Answer 1

1. Modulation is the process in which the transmitter modifies the message signal into a form that is suitable for transmission over the channel.
2. Modulation is of two types -
   2.1 Continuous Wave Modulation in which carrier wave is continuous and
   2.2 Pulse Modulation in which carrier wave is in the form series of pulses. A pulse wave is a non-sinusoidal wave that is very similar to a square wave. It is also termed Rectangular.
3. Pulse Modulation is of two types Analog Modulation and Digital Modulation.
4. Analog Modulation is further divided into three types-
   5.1 PAM(Pulse Amplitude Modulation) -
   
   5.1.1 It is the modulation, in which the instantaneous amplitude of the pulse carrier is varied according to the message signal.
   5.1.2 PAM is mostly applied in non-based modulating transmission of digital data and applications replaced by pulse-code modulation and pulse-position modulation.
   5.2 PWM(Pulse Width Modulation) -
   5.2.1 It is the modulation, in which the width of the pulses of the carrier is varied according to the message signal.
   5.2.2 The pulse width modulation technique is used in telecommunication for encoding purposes.
   5.2.3 The PWM technique controls the fan inside a CPU of the computer, thereby successfully dissipating the heat.
   5.3 PPM(Pulse Position Modulation) -
   

1. 
   5.3.1 It is the modulation, in which the position of the pulse carrier wave is varied according to the message signal.
   5.3.2 It is used in the air traffic control system and telecommunication systems.
   5.3.3 It is used to compress data and hence it is used for storage.