1. Chapter 3. Amplitude Modulation

2. Start with the sinusoidal modulating wave. Single-Sideband Modulation 2

3. Generalize (3.17) to periodic message signals Single-Sideband Modulation 3

4. 4

5. 5

6. SSB Modulation 6 Frequency discrimination method

7. SSB Modulation 7 Phase discrimination method

8. SSB Modulation 8 Frequency translation

9. Vestigial Sideband Modulation 9 Motivation –SSB works well for a message signal with an energy gap centered around zero frequency. –However, the spectra of wideband signals contain significant low frequencies. –DSB-SC requires a transmission bandwidth equal to twice the message bandwidth. Vestigial sideband (VSB) modulation –Instead of completely removing a sideband, a trace of vestige of that sideband is transmitted, the name vestigial sideband. –Instead of transmitting the other sideband in full, almost the whole of this second band is also transmitted.

10. VSB Filter 10 DSB-SC SSB VSB

11. VSB Modulator 11

12. Example: Sinusoidal VSB 12

13. Coherent Detection of VSB 13

14. Baseband Representation of Modulated Waves 14

15. Baseband Representation of Modulated Waves 15

16. Baseband Representation of Modulated Waves 16

17. Baseband Representation of Bandpass Filters 17

18. Baseband Representation of Bandpass Filters 18