Low-density parity-check (LDPC) codes on symmetric memoryless channels have been analyzed using statistical physics by several authors. In this paper, statistical mechanical analysis of LDPC codes is performed for asymmetric memoryless channels and general Markov channels. It is shown that the saddle point equations of the replica symmetric solution for a Markov channel is equivalent to the den...

We suggest a new protocol for the information reconciliation stage of quantum key distribution based on polar codes. The suggested approach is blind technique, which proved to be useful low-density parity-check (LDPC) show that outperforms with LDPC codes, especially when there are high fluctuations in bit error rate (QBER).

In this paper, an efficient partial incremental redundancy (P-IR) scheme is proposed for an H-ARQ using block type low density parity check (B-LDPC) codes. The performance of the proposed P-IR scheme is evaluated in an HSDPA system using IEEE 802.16e B-LDPC codes. Simulation results show that the proposed H-ARQ using IEEE 802.16e BLDPC codes outperforms the H-ARQ using 3GPP turbo codes. key wor...

Source coding with correlated decoder side information is considered. We impose the practical constraint that the encoder be unaware of even the statistical dependencies between source and side information. Two classes of rate-adaptive distributed source codes, both based on Low-Density Parity-Check (LDPC) codes, are developed and their design is studied. Specific realizations are shown to be b...

-Error correction provides reliable information free from errors. BCH codes are widely used to perform error correction. However, in order to improve the reliability of error correction BCH codes have been replaced by Low Density Parity Check (LDPC) codes. LDPC codes are special class of error correcting codes widely used in communication and memory systems, due to its Shannon limit approaching...

This article presents a method for constructing large girth column-weight 2 QC-LDPC codes. A distance graph is first constructed using an existing method. The distance graph is then converted into a Tanner graph. The proposed method could easily construct codes with girths large than 12 and is more flexible compared to previous methods. Obtained codes show good bit error rate performance compar...

This paper presents the construction of large girth Quasi-Cyclic low density parity check (QC-LDPC) codes. The row groups are paired two times the row weight which has cut down hardware implementation cost and complexity as compared to the connection of individual columns and rows. The construction of newly obtained codes gives a class of efficiently encodable quasi-cyclic LDPC codes.

LDPC convolutional codes, also known as spatially coupled LDPC codes, have attracted considerable attention due to their promising properties. By coupling the protographs from different positions into a chain and terminating the chain properly, the resulting convolutional-like LDPC code ensemble is able to produce capacityachieving performance in the limit of large parameters. In addition, opti...

— We present a class of concatenated codes called Parallel Concatenated Gallager Codes (PCGC) using Low-Density Parity-Check (LDPC) component codes. We report simulation results for PCGC that outperform those for comparable LDPC codes both in Additive White Gaussian Noise (AWGN) and ßat Rayleigh fading channels. The good performance of PCGC increases the capacity of CDMA systems while the reduc...

In this paper we give lower bounds on the size of (a, b) elementary trapping sets (ETSs) belonging to variable-regular LDPC codes with any girth, g, and irregular ones with girth 8, where a is the size, b is the number of degree-one check nodes and satisfy the inequality b a < 1. Our proposed lower bounds are analytical, rather than exhaustive search-based, and based on graph theories. The nume...