2. Introduction to the Encoding Techniques
Digital-To-Digital Encoding
Types of Digital-To-Digital Encoding
3. Information must be transformed into
signals before it can be transformed
across the communication media
How this information is transformed
depends upon its original format and
on the format of the communication
hardware
4.
5. Digital-to-Digital conversion/encoding is the
representation of digital information by digital
signal
For Example:
When you transmit data from Computer to
the Printer, both original and transmitted
data have to be digital
8. Simple and Primitive
Almost Obsolete Today
Study provides introduction to concepts
and problems involved with more
complex encoding systems
9.
10. PROS
Straight Forward and Simple
Inexpensive to Implement
CONS
DC Component
Lack of Synchronization
11. The average amplitude of a unipolar encoded
signal is non zero.
This creates a DC component.
12. Bit Rate = 1000 bps
1000 bits ---------- 1 second
1 bit ---------- = 0.001 sec
Positive voltage of 0.005 sec means five 1’s
Sometimes it stretches to 0.006 seconds
and an extra 1 bit is read by the Receiver
1000
1
13. Polar encoding uses two voltage levels
One positive and one negative
Average voltage level on the line is reduced
DC Component problem of Unipolar
encoding is alleviated
14.
15. The level of signal is either positive or negative
Two popular forms of NRZ
NRZ-L(Non Return to Zero-Level)
NRZ-I(NRZ-Invert)
NRZ
NRZ-L NRZ-I
16. In NRZ-L the level of the signal depends on the type of
bit that it represent.
The positive voltage usually means a 0 while a negative
voltage means the bit is a 1.
17.
18. NRZ-Invert
In NRZ-I ,an inversion of the voltage level represents a
1 bit.
It is the transition between a positive and negative
voltage, not the voltage itself, that represents a 1 bit.
A 0 bit is represented by no change.
19.
20. Introduction to the Encoding Techniques
Digital-To-Digital Encoding
Types of Digital-To-Digital Encoding
UniPolar Encoding
Polar Encoding
NRZ
