A message update function specifically defined as part of the invention, is used to determine the outgoing message at the variable node, and {HEAD ~ the simple min operation} along with modulo 2 sum of signs is used at {TAIL ~ the check node} 
is used at
A message update function specifically defined as part of the invention , is used to determine the outgoing message at the variable node , and { HEAD ~ the simple min operation } along with modulo 2 sum of signs is used at { TAIL ~ the check node }
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH REL REL REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL