These decoders are much lower in {HEAD ~ complexity} compared to {TAIL ~ the standard belief propagation decoder} 
These decoders are much lower in { HEAD ~ complexity } compared to { TAIL ~ the standard belief propagation decoder }
OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD REL REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL