Real world effects such as {HEAD ~ filtering}, multipath time spread, and time base error destroy orthogonality and introduce {TAIL ~ a degree} of cross coupling between supposedly orthogonal channels 
Real world effects such as { HEAD ~ filtering } , multipath time spread , and time base error destroy orthogonality and introduce { TAIL ~ a degree } of cross coupling between supposedly orthogonal channels
OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH