A reference delay unit delays the first delayed signal by {HEAD ~ a predetermined reference time period} to generate {TAIL ~ a reference signal} 
to generate
A reference delay unit delays the first delayed signal by { HEAD ~ a predetermined reference time period } to generate { TAIL ~ a reference signal }
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD REL REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL