Shahrood University of TechnologyJournal of Algebraic Systems2345-51287220200101A REDUCTION IN THE SEARCH SPACE OF QC-LDPC CODES WITH GIRTH 8271280159510.22044/jas.2019.8086.1397ENF.AmirzadeFaculty of Mathematical Sciences, Shahrood University of Technology, Shahrood,
Iran.M.AlishahiFaculty of Mathematical Sciences, Shahrood University of Technology, Shahrood,
Iran.M.R.Rafsanjani-SadeghiDepartment of Mathematics and Computer Science, Amirkabir University of Technology,
Tehran, Iran.Journal Article20190216In this paper, we define a structure to obtain exponent matrices of girth-8 QC-LDPC codes with column weight 3. Using the difference matrices introduced by Amirzade et al., we investigate necessary and sufficient conditions which result in a Tanner graph with girth 8. Our proposed method contributes to reduce the search space in recognizing the elements of an exponent matrix. In fact, in this method we only search to obtain one row of an exponent matrix. The other rows are multiplications of that row.http://jas.shahroodut.ac.ir/article_1595_a7ac6815ccabe0982d7a0162bf5de1b0.pdf