Name : Rowshanara ID : 1834902165

1. Assignment
On
Class Lecture-04
Course code : CSE – 313
Course name : Data communication
Submitted to
Pronab Bandhu Nath
Senior Lecturer
Department of CSE
City university
Submitted by
Name : Rowshanara
ID : 1834902165
Batch : 49th
(B)
Department of CSE
Submission date : 29/08/2021

2. Data modulation : Data modulation is a process that
converts analog signals into digital signals and digital
signals into analog signals. Computers store and process
data in digital format. Data modulation allows computers to
store and process analog signals.
• When data is sent over physical medium.it means to
first convert into electromagnetic signal.Data itself
can be converted into signal.
• Signal : 1.Analog signal :- Human voice.
2.Digital signal :- Document on a Disk.
Data signal : A pulse or frequency of electricity or
light that represents data as it travels over a network, a
computer channel or wireless. Contrast with control signal.
Digital modulation : Digital modulation is the
process of encoding a digital information signal into the
amplitude, phase, or frequency of the transmitted signal.
Types of Digital modulation :
1. ASK ( Aplititude shift keying).
2. FSK (Frequency shift keying).
3. PSK (Phase shift keying).

3. ASK :
• Use optical fiber.
• If signal on it’s provide 1
• If signal off ityprovide 0
FSK :
• Use Coaxial cable.
• In High frequency it’s provide 1

4. • In low frequency it’s provide 0.
PSK :
• Use Router or Brouter.
• BPSK :- Two phase binary shift keying.
• QPSK :- Four phase Quadrature shift keying.