Week 4 - Digital-To-Digital conversion

Question 1

What is line coding?

Answer 1

Converting digital data to a digital signal.

Question 2

What is a data element?

Answer 2

A bit, the smallest entity of information.

Question 3

What is a signal element?

Answer 3

Carries data elements, the shortest unit (timewise) of a digital signal.

Question 4

What is the difference between data rate and signal rate?

Answer 4

Data rate is the number of bits you can send (bps).
An increase means an increase in speed of transmission

Signal rate is the number of signal elements sent in 1s (baud)

Question 5

What is the relationship between signal rate and bandwidth?

Answer 5

They are proportional to one another.

Question 6

What is a DC component and why is it bad?

Answer 6

When you have a constant voltage level which creates a zero frequency. Usually a long running trail of 1s.

Systems have trouble passing very very low frequencies

Makes the signal’s average amplitude not equal to zero and shifts the signal away from zero.

Question 7

What is a bipolar scheme?

Answer 7

Alternating values for 1s
Has a neutral voltage

Question 8

What are two examples of polar schemes?

Answer 8

Manchestor
Differential Manchestor

Question 9

What is a unipolar scheme?

Answer 9

All signal levels above time axis (On-off keying)