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