Cross-Layer Iterative Decoding of Irregular LDPC using Cyclic Redundancy Check Codes

This paper presents a cross layer iterative decoder for irregular Low-Density Parity-Check (LDPC) coded system by using Cyclic Redundancy Check (CRC) codes. The key idea of the decoder is to use the correctly decoded frame to help correcting the left erroneous ones. To accomplish this, the decoder digs the useful information between layers by using the cross layer design method and an iterative decoding architecture. Moreover, the Unequal-Error Protection (UEP) of irregular LDPC is exploited and both multiple-error detection and single-error correction capability of CRC code are used. Simulation results show that the proposed decoder outperforms the pure Sum-Product Algorithm (SPA) decoder by a considerable gain while the complexity increase is moderate. Furthermore, the error floor of irregular LDPC in high Eb/N0 can be lowered effectively. The proposed cross layer iterative decoder can be used for any irregular LDPC coded wireless system to boost the performance and lower the error floor.