{TAIL ~ An adding unit} adds the reference signal to {HEAD ~ the filtered signal} to generate an output signal 
{ TAIL ~ An adding unit } adds the reference signal to { HEAD ~ the filtered signal } to generate an output signal
TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH