Bilayer Low-Density Parity-Check Codes for Decode-and-Forward in Relay Channels

This paper describes an efficient implementation of binning for Decode-and-Forward (DF) in relay channels using Low-Density Parity-Check (LDPC) codes. Bilayer LDPC codes are devised to approach the theoretically promised rate of the DF relaying strategy by incorporating relay-generated parity bits in specially designed bilayer graphical code structures. While conventional LDPC codes are sensitively tuned to operate efficiently at a certain channel parameter, the proposed bilayer LDPC codes are capable of working at two different channel parameters and two different rates: that at the relay and at the destination.