The invention relates to {TAIL ~ communication systems} in general, and particularly to {HEAD ~ MIMO communication systems} 
The invention relates to { TAIL ~ communication systems } in general , and particularly to { HEAD ~ MIMO communication systems }
OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD