Amplitude shift keying (ASK) is a form of amplitude modulation that represents digital data as variations in the amplitude of a carrier wave. It uses a finite number of discrete amplitude levels, each assigned to a unique binary pattern. ASK modulation is implemented by band-limiting a carrier signal to impose two or more amplitude levels. There are two main types: binary ASK uses two levels for on-off keying, while multilevel ASK uses more than two levels and bits. ASK has applications in optical fiber data transmission and transmitting Morse code via LED transmitters.

1. AMPLITUDE SHIFT KEYING
DATA COMMUNICATION
SEMINAR ON

2.  A form of amplitude modulation process.
 Represents digital data as variations in the amplitude of a carrier wave.
 Imparts to a sinusoid, two or more discrete amplitude levels.
 Uses a finite number of amplitudes, each assigned a unique pattern
of binary digits.
What is Amplitude Shift Keying ?

3. A Simple ASK Wave

4. ASK GENERATION AND MODULATION
From a sinusoidal wave signal, ASK output is generated by BAND LIMITING method.
By applying BAND LIMITING method, sharp discontinuities would be rounded-off,
before transmission.

5. Conversion Of Original Message To ASK Through
Band Limit Method

6. Amplitude Shift Keying is of Two types-
1. Binary ASK
2. Multilevel ASK
Binary ASK is implemented using only 2 levels.
It is known as ON-OFF keying.
Multilevel ASK is implemented with more than two level.
Different Amplitude used are – 4,8,16…
Different Bits used are- 2,3,4…
TYPES OF AMPLITUDE SHIFT KEYING

7. Binary amplitude shift keying

8. DEMODULATION process consists of two stages-
 Recovery of band limited bit stream.
 Regeneration of binary bit stream.
DEMODULATION

9. ASK SYSTEM DIVISION
ASK System
Transmitter
Linear model of
effects of
channel
Reciever

10. Linear and Sensitive to atmospheric noise, distortions.
Inexpensive.
PROPERTIES

11. IN OUR DAILY USE
 Commonly used to transmit digital data
over optical fibre.
 Transmit Morse code.
For example, in LED transmitter.

12. THANK YOU