Construction of QC-LDPC Codes from Sidon Sequence Using Permutation and Segmentation

By utilizing a Sidon sequence, two new methods are proposed to construct quasi-cyclic (QC) low-density parity-check (LDPC) codes. The first method yields a QC-LDPC code without 4-cycles and the second method gives a QC-LDPC code without 4-cycles and 6-cycles. In the literature there are two methods which employ mathematical objects somewhat resembling a Sidon sequence to remove 4-cycles, and there are two explicit constructions which guarantee the absence of 4-cycles and 6-cycles. Compared with the former, our first method is much more flexible in selecting parameters while providing identical or better performance. Compared with the latter, our second method provides much better performance.