{HEAD ~ The message} passing decoder 8, wherein the LDPC codes have {TAIL ~ a fixed column weight} 
{ HEAD ~ The message } passing decoder 8 , wherein the LDPC codes have { TAIL ~ a fixed column weight }
HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH OTH OTH OTH TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL