Analogue and Digital Signals

Engineering Studies – H4 Telecommunication Engineering – Electricity

This topic compares the features and applications of analogue and digital signals.
Definitions and an understanding of communication options are the key concepts.

Key Concepts

• Definition of an analogue signal
• Definition of a digital signal
• Communication links

Discussion Questions

1. Describe the two main differences between analogue and digital signals.
2. Why does digital signalling usually perform better than analogue signalling in a noisy communications channel?
3. Give four reasons why telecommunications systems are increasingly becoming digital rather than analogue.
4. Explain why you would either (a) double the bandwidth, or (b) double the signal amplitude if you had money to spend to improve the channel capacity of a telecommunications link.
5. Give a reason why Amplitude Modulation is preferable to Frequency Modulation for radio broadcasting?
6. What is ‘noise’ in a communication link?
7. Give a reason why Frequency Modulation is preferable to Amplitude Modulation for radio broadcasting?
8. Describe three ways in which digital information can be represented as an analogue signal.
9. Describe the significant feature of a binary digital signal.
10. What is the common unit used to measure amplitude of a telecommunication signal?
11. What is the definition of wavelength period and wavelength frequency?
12. What are three characteristics that determine the maximum capacity of a communication link?