1.1 Signals and Transmissions

Question 1

What is a baseband signal? When is it useful and why?

Answer 1

Does not use a carrier frequency. Only useful for internal signals because it is low power. It can be voice powered.

Question 2

What is a Modulated signal?

Answer 2

A baseband signal combined with a carrier frequency.

Information is embedded in the carrier signal by modulating the amplitude, frequency, or phase.

Question 3

What is Band Limiting?

Answer 3

Restrict the frequency range of a signal to prevent interference and optimize transmission efficiency.

Question 4

What are the advantages of Digital Signals? (5)

Answer 4

Data Integrity
Data Rate
Encryption
Error Detection and Correction
Multiplexing

Question 5

Why do Digital Signals have Data Integrity?

Answer 5

Digital signals are more resistant to noise and interference because they involve threshold comparison rather than an exact reading of the amplitude.

Question 6

How do digital signals use multiplexing?

Answer 6

Multiple signals are sent in a single transmission because the signals may not use the entire bandwidth.

Question 7

What is the advantage of analogue signals?

Answer 7

Greater dynamic range.