Name-nishant kumar

Roll-213ec5246

AIM:

Design of Amplitude Modulator and Demodulator using TMS Processor

THEORY:

Amplitude Modulation

Introduction

Amplitude Modulation is a technique used in electronics communication for

transmitting information via a carrier wave. It works by varying the strength of the

transmitted signal in relation to the information being sent.

Modulation

Modulation is the process whereby some characteristics of one wave is varied in

accordance with characteristics of another wave. In other words we can say that

modulation is the process of mixing or addition of information signal with an electronic or

optical carrier.

Carrier

The sinusoidal signal that is used in the modulation is known as carrier signal or carrier.

A carrier wave or carrier is a waveform that is modulated with an input signal for the

purpose of conveying information. This carrier wave is usually a much higher

frequency.

Signal

A signal is a real or complex valued function of one or more real variables. A signal is

an electric current or electromagnetic field used to convey data, gesture, action or

sound from one place to another place. The signal is said to be one dimensional.

Here the mathematical model that defines the AM signal is

AM = ( DC + Message ) * the carrier Classification of AM modulated signals: 1) DSB-FC (Double side band Full Carrier) 2) DSB-SC(Double side band suppressed Carrier) 3) SSB(Single side band ) 4)VSB(Vestigial sideband)

Amplitude Demodulation

If we've completed AM Modulation then we've seen what happens when a

sinewave is used to amplitude modulate a carrier to produce an AM signal.

Importantly, we would have seen a key characteristic of an AM signal - its

envelopes are the same shape as the message ( though the lower envelope is

inverted ).

Recovering the original message from a modulated carrier is

called demodulation . We use envelope detector and synchronous detector for

demodulation.

Simulink

Results:-

Demod