Introduction to Communication Systems (CNET - 222) Dr. Mohammed Abdul Gaffar Ali Department of Computer Networks College of CS&IS Jazan University, Jazan.

Chapter 2 Amplitude Modulation Introduction To Amplitude Modulation (AM) Equation for Message Carrier & Modulated Wave Types of Amplitude Modulation Advantages of AM Disadvantages AM.

Introduction To Amplitude Modulation (AM). Definition:- The amplitude of the carrier is made proportional to the instantaneous amplitude of the modulating voltage

Wave Forms For Message ,Carrier & AM Signals.

Equations. Modulating Signal:- Carrier Signal :- AM Signal :-

Modulation Index. Definition:-The ratio between the amplitudes of message signal and carrier signal is called Modulation Index.

M < 1 Under Modulation M = 1 Perfect Modulation. Modulation Index M > 1 Over Modulation M < 1 Under Modulation M = 1 Perfect Modulation.

Types of AM.

DSBFC :- Double Side Band Full Carrier. Power = PAM Band Width (BW)= 2Fm

DSBSC :- Double Side Band Suppressed Carrier. Power = PAM 3 Band Width (BW)= 2Fm

SSB :- Single Side Band Power = PAM 6 Band Width (BW)= Fm

VSB:- Vestigial Side Band. It is between SSB & DSBSC.

It is easy to receive and demodulate. Advantages of AM. It is easy to generate. It is easy to receive and demodulate. It is used worldwide.

It is more likely to be affected by Noise The power of AM is low. Disadvantages of AM. It is more likely to be affected by Noise The power of AM is low.

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