To recover the amplitude information, {HEAD ~ the receiver section} includes an amplitude detector such as an envelope detector, {TAIL ~ a low pass filter}, etc 
To recover the amplitude information , { HEAD ~ the receiver section } includes an amplitude detector such as an envelope detector , { TAIL ~ a low pass filter } , etc
OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH