For each received symbol, the receiver determines which of a plurality of {HEAD ~ phase} sectors {TAIL ~ the phase angle} lies in 
For each received symbol , the receiver determines which of a plurality of { HEAD ~ phase } sectors { TAIL ~ the phase angle } lies in
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 OTH OTH