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