In this correspondence, the construction of low-density parity-check (LDPC) codes from
circulant permutation matrices is investigated. It is shown that such codes cannot have a …

A quasi-cyclic (QC) low-density parity-check (LDPC) code can be viewed as the protograph
code with circulant permutation matrices (or circulants). In this correspondence, we find all …

This paper is concerned with construction and structural analysis of both cyclic and quasi-
cyclic codes, particularly low-density parity-check (LDPC) codes. It consists of three parts …

Quasi-cyclic low-density parity-check (QC-LDPC) codes based on protographs are of great
interest to code designers because analysis and implementation are facilitated by the …

This paper presents a simple and very flexible method for constructing quasi-cyclic (QC) low
density paritycheck (LDPC) codes based on finite fields. The code construction is based on …

In this paper, we study the relationships between the girth of the Tanner graph of a quasi-
cyclic (QC) protograph low-density parity-check (LDPC) code, the lifting degree, and the size …

This correspondence presents three algebraic methods for constructing low-density parity-
check (LDPC) codes. These methods are based on the structural properties of finite …

Gallager introduced low-density parity-check (LDPC) codes in 1962, presenting a
construction method to randomly allocate bits in the parity-check matrix subject to certain …

Analytically constructed LDPC codes comprise only a very small subset of possible codes
and as a result LDPC codes are still, for the most part, constructed randomly. This paper …

One approach to designing structured low-density parity-check (LDPC) codes with large
girth is to shorten codes with small girth in such a manner that the deleted columns of the …