The squared signal is integrated over {TAIL ~ a period} related to the frequency fm to provide {HEAD ~ a dc signal} 
The squared signal is integrated over { TAIL ~ a period } related to the frequency fm to provide { HEAD ~ a dc signal }
OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD