Compressing construction of QC-LDPC codes

Two compressing construction methods of quasi-cyclic LDPC (QC-LDPC) codes are proposed, which can be called recursive-compressing and single-compressing respectively. Selecting a good QC-LDPC code as the Mother, the son codes constructed through the compressing methods are still good codes, i.e., have high girth and few short cycles, moreover, they have continuous code length and require smaller memory space. Analysis and simulation results show they can perform well over the AWGN channel.