This document discusses different types of modulation techniques used in electronics and telecommunications. It begins by defining modulation as the process of varying a carrier signal in accordance with a message signal in order to reduce antenna size and interference. It then describes analog modulation techniques including amplitude modulation, frequency modulation, and phase modulation. The document also covers digital modulation techniques like amplitude shift keying, phase shift keying, frequency shift keying, and quadrature amplitude modulation. It highlights how quadrature amplitude modulation is commonly used in radio communication due to its ability to carry high data rates.

1. By:HAJIRA
Vemana Institute of technology

2.  In electronics and telecommunication,
Modulation is the process in which
the carrier signal varies in
accordance with the message signal
 Modulation is done to reduce the size
of the antenna and to reduce the
interference

3.  Analog modulation
 Digital modulation

4.  In analog modulation, analog signal is
used as a carrier signal that modulates
the message signal .
 TYPES
 Amplitude Modulation (AM)
 Frequency Modulation (FM)
 Phase Modulation (PM)

5.  In this modulation, the amplitude of the
carrier signal varies in accordance with the
message signal, and other factors like phase
and frequency remain constant.
 It consists of lower frequency band, upper-
frequency band, and carrier frequency
components. This type of modulation
requires greater bandwidth, more power.

6.  In this modulation the frequency of the
carrier signal varies in accordance with the
message signal and the other factors like
amplitude and phase remain constant.
 It is used in applications like radio, radar etc.
The efficiency and bandwidths depend on the
modulation index and maximum modulating
frequency.

7.  In phase modulation, the carrier phase is
varied in accordance with the data signal. In
this type of modulation, when the phase is
changed it also affects the frequency, so this
modulation also comes under frequency
modulation
 This type of modulation is used for signal
generation in synthesizers.

9.  For a better quality and efficient
communication, digital modulation technique
is employed. The main advantages of the
digital modulation over analog modulation
include available bandwidth , high noise
immunity and permissible power. In digital
modulation, a message signal is converted
from analog to digital message, and then
modulated by using a carrier wave.

10.  Amplitude Shift Keying (ASK)
 Phase Shift Keying (PSK)
 Frequency Shift Keying(FSK)
 Quadrature Amplitude Modulation(QAM)

11. ASK
FSK
PSK

12.  QAM which is widely used in radio communication
especially in LTE.
 QAM is used in radio communication as it is able to
carry higher data rates when compared to other
modulation techniques.
 The most common forms of QAM are 16-QAM, 64-
QAM and 256-QAM. By using higher order
modulation formats. The advantage of moving to
the higher order formats is that it is possible to
transmit more bits per symbol. However the
disadvantage is that it is more sensitive to noise.
As a result, higher versions of QAM are used only
when there is a sufficiently high signal to noise
ratio(S/N).

13. THANK YOU