Page 63 - DCAP311_DCAP607_WIRELESS_NETWORKS

Unit 3: Radio Frequency and Light Signal Fundamentals

Phase-shift keying (PSK): is a digital modulation scheme that conveys data by changing, or Notes
modulating, the phase of a reference signal (the carrier wave).
Orthogonal frequency-division multiplexing (OFDM): is a method of encoding digital data on
multiple carrier frequencies.
Ultra-wideband (UWB) signals: are generally defined as signals with fractional bandwidth
greater then twenty percent of their central frequency or as signals with bandwidth more than
500MHz, whichever is less.

3.8 Review Questions

1. Describe the process of communicating using fiber-optics
2. What are wireless transceivers?
3. Discuss the properties of RF waves
4. Discuss the RF signal pros and cons
5. Describe RF signal impairments

6. Explain the working of light signals
7. What do you mean by modulation?
8. Discuss phase shift-keying.
9. Describe quadrature amplitude modulation.

10. Explain orthogonal frequency division multiplexing.
Answers: Self-Assessment

1. Fiber-optic 2. Light
3. IR 4. 300
5. Wavelength 6. Phase
7. RFID 8. Tag
9. Reader 10. Equalisers

11. amplitude (“volume”) 12. baseband
13. Phase-shift keying (PSK) 14. Cellular Digital Packet Data
15. QAM

3.9 Further Readings

Books 802.11 Wireless Networks: The Definitive Guide, Second Edition, Matthew Gast
Introduction to wireless networks, John Ross
Wireless Communications & Networking, Vijay Garg
Wireless Communications: Principles and Practice, Theodore S. Rappaport

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