1. Electromagnetic Wave

2. Wireless Communication
Cellular Phone
Radio
Television .

3. Analog Modulation http://en.wikipedia.org/wiki/Modulation
Amplitude modulation
Double-sideband modulation DSB
+ Double-sideband modulation with unsuppressed carrier (DSB- WC)(used on the radio AM band)
+ Double-sideband suppressed-carrier transmission (DSB-SC)
+ Double-sideband reduced carrier transmission (DSB-RC)
Single-sideband modulation
+ Single-sideband modulation (SSB, or SSB-AM), very similar to
+ single-sideband suppressed carrier modulation (SSB-SC)
Vestigial sideband modulation (VSB, or VSB-AM)
Quadrature amplitude modulation (QAM)
Angle modulation
Frequency modulation (FM)
Phase modulation (PM)

4.
Amplitude Modulation

5. Amplitude Modulation

6. Envelope and Modulation Percentage
Transmitted signal:
Envelope:
Percentage of Modulation:
For any message satisfies -1≤ Bm(t) ≤ +1:
Over Modulation:

7. Envelope and Modulation Percentage
Transmitted signal:
Envelope:
Percentage of Modulation:
For a message:

8.
Over Modulation

9. Envelope Detector
Envelope:

10. Example for Square Wave