1. Sep 27, 2005CS477: Analog and Digital Communications1 Amplitude Modulation Analog and Digital Communications Autumn 2005-2006

2. Sep 27, 2005CS477: Analog and Digital Communications2 Amplitude Modulation Double-sideband (DSB)

3. Sep 27, 2005CS477: Analog and Digital Communications3 Amplitude Modulation Double-sideband+carrier (DSB+C) or simple AM

4. Sep 27, 2005CS477: Analog and Digital Communications4 Amplitude Modulation We can “easily” demodulate the signal if Envelope Detection Envelope Distortion Phase Reversal

5. Sep 27, 2005CS477: Analog and Digital Communications5 AM in Frequency domain Key Points: 1. Power wasted in carrier 2. Requires twice the baseband bandwidth USB LSB

6. Sep 27, 2005CS477: Analog and Digital Communications6 AM – Power Calculations Lets calculate power in carrier and sidebands: (in one sideband)

7. Sep 27, 2005CS477: Analog and Digital Communications7 AM – Power Calculations At least 50% power is wasted in carrier

8. Sep 27, 2005CS477: Analog and Digital Communications8 DSB-SC or Simple DSB USB LSB