1. A low density parity check decoder comprising: a variable node processor operable to generate variable node to check node messages and to calculate perceived values based on normalized check node to variable node messages and on normalized decoder inputs, and to output normalized decoded values; and a check node processor operable to generate the check node to variable node messages based on normalized variable node to check node messages, wherein the variable node processor and check node processor are operable to perform layered multi-level decoding.