This survey paper provides fundamentals in the design of LDPC codes. To provide a target for the code designer, we first summarize the EXIT chart technique for determining (near-)optimal degree distributions for LDPC code ensembles. We also demonstrate the simplicity of representing codes by protographs and how this naturally leads to quasi-cyclic LDPC codes. The EXIT chart technique is then ex...

This work focuses on the decoding algorithm of the LDPC large block FEC codes for the packet erasure channel, also called AL-FEC (Application-Level Forward Error Correction). More specifically this work details the design and the performance of a hybrid decoding scheme, that starts with the Zyablov iterative decoding algorithm, a rapid but suboptimal algorithm in terms of erasure recovery capab...

We first consider the design of generalized LPDC (G-LDPC) codes with recursive systematic convolutional (RSC) constraint nodes in place of the standard single parity-check constraint nodes. Because rate-1/2 RSC nodes lead to low-rate G-LDPC codes, we consider high-rate tail-biting RSC nodes for which Riedel’s APP-decoder based on the reciprocal-dual code trellis becomes necessary. We then consi...

This study analyzed the use of LDPC codes as error control coding in energy-efficiency of wireless sensor network nodes. Meanwhile, it provided the application scheme of LDPC codes in wireless sensor networks, which adopts regular LDPC codes with various code length and code rate of 0.5. The result shows that LDPC codes, as the error control coding, is quite suitable for energy-constrained wire...

We introduce multi-edge type LDPC codes, a generalization of the concept of irregular LDPC codes that yields improvements in performance, range of applications, adaptability and error floor. The multiedge type LDPC codes formalism includes various constructions that have been proposed in the literature including, among others, concatenated tree (CT) codes [1], (generalized irregular) repeat acc...

42 JANUARY 2004 1053-5888/04/$20.00©2004IEEE e consider the problem of designing unoriented bipartite graphs with large girth. These graphs are the Tanner graphs associated with the parity-check matrix H of low density parity-check (LDPC) codes or Gallager codes. Larger girth improves the computational and bit error rate (BER) performance of these codes. The article overviews several existing m...

The literature survey has been carried out in 3 phases. The first phase focussed on LDPC Codes .The 2 nd Phase on Projective Geometry and Majority Logic decoding and the 3 rd phase on p-adic extension of PG LDPC Codes. In the first phase, the introduction to LDPC Codes, their construction,comparision is done in the references from [1],[9]-[21].The decoding methodologies and various techniques a...

Low density parity checking codes (LDPC) are one of the most important issues in coding theory at present. LDPC-code a type linear-block LDPC-codes. Channel might be considered as finest conversant and potent components cellular communications systems, that was employed for transmitting errors corrections imposed by noise, fading interfering. LDPC-codes advanced gain, i.e., new area coding. per...

In this paper, we propose a new design method of irregular spatially-coupled low-density paritycheck (SC-LDPC) codes with non-uniform degree distributions by linear programming (LP). In general, irregular SC-LDPC codes with non-uniform degree distributions is difficult to design with low complexity because their density evolution equations are multi-dimensional. To solve the problem, the propos...

Sparse graph-based codes such as low-density parity-check (LDPC) codes have revolutionized coding theory and have been proposed for many emerging communication and storage systems due to their excellent performance. A substantial amount of research has been devoted to the study of binary LDPC codes. In contrast, non-binary LDPC codes had been deemed too complex and consequently have not been st...