‎s‎. ‎kim et al‎. ‎have been analyzed the girth of some algebraically‎ ‎structured quasi-cyclic (qc) low-density parity-check (ldpc)‎ ‎codes‎, ‎i.e‎. ‎tanner $(3,5)$ of length $5p$‎, ‎where $p$ is a prime of‎ ‎the form $15m+1$‎. ‎in this paper‎, ‎by extension this method to‎ ‎tanner $(3,7)$ codes of length $7p$‎, ‎where $p$ is a prime of the‎ ‎form $21m‎+ ‎1$‎, ‎the girth values of tanner $(3,7...

in this paper, we consider a class of column-weight two quasi-cyclic low-density paritycheck codes in which the girth can be large enough, as an arbitrary multiple of 8. then we devote a convolutional form to these codes, such that their generator matrix can be obtained by elementary row and column operations on the parity-check matrix. finally, we show that the free distance of the convolution...

Low-density parity-check (LDPC) codes are one of the most powerful error correcting codes and are attracting much attention these days. LDPC codes are promising for communications and broadcasting as well where the use of error correcting codes are essential. LDPC codes have been standardized in some communication standards, such as, IEEE802.16e, DVB-S2, IEEE802.3an (10BASE-T), and so on. The p...

This paper corresponds to a brief survey of LDPC codes. Many error detection and correction codes have been studied. There are vast classes of such codes; some of them are hamming codes, turbo codes, BCH codes and LDPC codes. But among these codes LDPC codes achieve better performance and lower decoding complexity. LDPC codes were originally discovered by Robert G. Gallager. But after the redis...

Low-density parity-check (LDPC) codes, invented by Gallager [2], who described and analyzed a block variant of the codes, arouse great interest of researchers. These codes are widely used in practice since they can be decoded by using relatively simple iterative decoding algorithms. Several modifications of these codes are known, in particular, generalized LDPC codes [3]. In contrast to Gallage...

LDPC codes provide good random error performance nearer to Shannon limit. The LDPC codes have some residue errors which cannot be corrected even after large number of iterations such errors can be corrected by concatenating LDPC codes with RS codes. This paper describes the development of an iterative decoder scheme for LDPC-RS product codes which made LDPC codes and Turbo codes popular. The it...

In this work, we propose structured Root-LowDensity Parity-Check (LDPC) codes and design techniques for block-fading channels. In particular, Quasi-Cyclic Root-LDPC codes, Irregular repeat-accumulate Root-LDPC codes and Controlled Doping Root-LDPC codes based on Progressive Edge Growth (PEG) techniques for block-fading channels are proposed. The proposed Root-LDPC codes are both suitable for ch...

In this work, we propose structured root-low-density parity-check (LDPC) codes and design techniques for block-fading channels. In particular, quasi-cyclic root-LDPC codes, irregular repeat-accumulate root-LDPC codes and controlled doping root-LDPC codes based on progressive edge growth (PEG) techniques for block-fading channels are proposed. The proposed root-LDPC codes are both suitable for c...

Low Density Parity Check (LDPC) codes over GF(2) are an extension of binary LDPC codes that have not been studied extensively. Performances of GF(2) LDPC codes have been shown to be higher than binary LDPC codes, but the complexity of the encoders/decoders increases. Hence there is a substantial lack of hardware implementations for LDPC over GF(2) codes. This paper presents a FPGA serial implem...