We propose a technique to design finite-length irregular low-density parity-check (LDPC) codes over the binary-input additive white Gaussian noise (AWGN) channel with good performance in both the waterfall and the error floor region. The design process starts from a protograph which embodies a desirable degree distribution. This protograph is then lifted cyclically to a certain block length of interest. The lift is designed carefully to satisfy a certain approximate cycle extrinsic message degree (ACE) spectrum. The target ACE spectrum is one with extremal properties, implying a good error floor performance for the designed code. The proposed construction results in quasi-cyclic codes which are attractive in practice due to simple encoder and decoder implementation. Simulation results are provided to demonstrate the effectiveness of the proposed construction in comparison with similar existing constructions.

Additional Metadata
Persistent URL dx.doi.org/10.1109/ISIT.2011.6034270
Conference 2011 IEEE International Symposium on Information Theory Proceedings, ISIT 2011
Citation
Asvadi, R. (Reza), Banihashemi, A, & Ahmadian-Attari, M. (Mahmoud). (2011). Design of irregular quasi-cyclic protograph codes with low error floors. In IEEE International Symposium on Information Theory - Proceedings (pp. 908–912). doi:10.1109/ISIT.2011.6034270