During a calibration phase a training signal is injected digitally into the digital to analog {HEAD ~ converter} of {TAIL ~ the transmit path} 
of
During a calibration phase a training signal is injected digitally into the digital to analog { HEAD ~ converter } of { TAIL ~ the transmit path }
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL