{TAIL ~ This increased similarity} between the constellation symbols of a digital system that uses a denser constellation turns into {HEAD ~ a serious problem} for the system performance when the channel is dispersive 
{ TAIL ~ This increased similarity } between the constellation symbols of a digital system that uses a denser constellation turns into { HEAD ~ a serious problem } for the system performance when the channel is dispersive
TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH OTH OTH