Summary ANALOG COMMUNICATION

Source of Information and
Transmission Signal
In the context of communication systems, the source of
information refers to the place or device where the
message or data to be transmitted is initially generated.
This could be a person speaking into a microphone, a
computer sending data over the internet, or any other
device or system that generates information for
transmission.

The transmission signal, on the other hand, is the physical
signal that is used to carry the information from the
source to the destination. This signal is typically a
variation in some physical property, such as voltage,
amplitude, frequency, or phase, that can be detected and
interpreted by the receiver.

The transmission signal is created by modulating the
information from the source onto a carrier signal, which is
a signal that can be easily transmitted and detected.
There are several different modulation techniques that can
be used, including:

 Amplitude modulation (AM): In AM, the amplitude of
the carrier signal is varied in proportion to the
information signal.
 Frequency modulation (FM): In FM, the frequency of
the carrier signal is varied in proportion to the
information signal.
 Phase modulation (PM): In PM, the phase of the
carrier signal is varied in proportion to the
information signal.
Once the transmission signal has been created, it is sent
over a transmission channel to the receiver. The

,transmission channel can be a physical medium, such as a
wire or an optical fiber, or it can be a wireless medium,
such as air or space. The transmission channel has certain
characteristics, such as attenuation, noise, and distortion,
that can affect the quality of the transmission signal.

At the receiver, the transmission signal
is decoded and demodulated to extract the original
information. This process involves reversing the
modulation that was applied at the transmitter and
extracting the information from the transmission signal.

In summary, the source of information and transmission
signal are important concepts in communication systems.
The source of information is the origin of the message or
data to be transmitted, and the transmission signal is the
physical signal that carries the information from the
source to the destination. The transmission signal is
created by modulating the information onto a carrier
signal, and it is sent over a transmission channel to the
receiver, where it is decoded and demodulated to extract
the original information.



Communication Concepts and Definition Notes:

Modulation and Encoding in Transmitters

 Modulation is the process of adding information to
an electronic or optical signal.
 Two main types of modulation: analog and digital.
 Encoding is the process of converting information
into a format that can be transmitted.
Modulation Techniques in Communication

,  Amplitude modulation (AM) varies the amplitude of
the carrier signal.
 Frequency modulation (FM) varies the frequency of
the carrier signal.
 Phase modulation (PM) varies the phase of the
carrier signal.
Communication Systems: Overview and Basics

 Communication system consists of three main parts:
transmitter, channel, and receiver.
 Transmitter prepares the message for transmission.
 Channel is the medium through which the message
travels.
 Receiver interprets the message.
Decoding and Demodulation in Receivers

 Decoding is the process of converting the received
signal back into its original form.
 Demodulation is the process of extracting the
original message from the modulated carrier wave.
Transducers, Transmission Channels, and Encoding

 Transducers convert one form of energy into
another.
 Transmission channels are the medium through
which the message is transmitted.
 Encoding converts the message into a format that
can be transmitted.
Decoding and Receiving Signal in Communication

 Decoding converts the received signal back into its
original form.

,  Receiving signal involves extracting the message
from the received signal.
Transmission Channels: Characteristics and
Importance

 Transmission channels have characteristics such as
bandwidth, noise, and attenuation.
 Bandwidth is the range of frequencies that a
channel can transmit.
 Noise is any unwanted signal that interferes with
the message.
 Attenuation is the reduction in signal strength as it
travels through the channel.
Types of Communication: Point-to-Point vs
Broadcasting

 Point-to-point communication is between two
devices.
 Broadcasting is communication from one device to
many devices.
Source of Information and Transmission Signal

 Source of information is the origin of the message.
 Transmission signal is the form in which the
message is transmitted.