This paper presents a study on the VHDL implementation of a class of binary irregular structured LDPC codes (IS-LDPC) applied to 100 Gbps optical networks. A comparison between two iterative decoding algorithms for irregular structured LDPC codes, sum-product based on loglikelihood ratio and min-sum, is used to define the best choice for implementation. The performances of IS-LDPC codes are eva...

This paper is the second part of a series of two papers on the investigation of the connection between two methods for constructing LDPC codes, namely the superposition and the protograph-based methods. In the first part, by taking the graph point of view, we established a strong connection between these two construction methods and showed that, in the binary case, the protograph-based construc...

We address the problem of constructing of coding schemes for the channels with high-order modulations. It is known, that non-binary LDPC codes are especially good for such channels and significantly outperform their binary counterparts. Unfortunately, their decoding complexity is still large. In order to reduce the decoding complexity we consider multilevel coding schemes based on non-binary LD...

The convergence rate of LDPC decoding is comparatively slower than turbo code decoding: 25 LDPC iterations versus 8-10 iterations for turbo codes. Recently, Mansour proposed a ‘turbo-schedule’ to improve the convergence rate of LDPC decoders. In this letter, we first extend the turbo-scheduling principle to the check messages. Second, we show analytically that the convergence rate of both turbo...

Powerful rate-compatible codes are essential for achieving high throughput in hybrid automatic repeat request (ARQ) systems for networks utilising packet data transmission. The paper focuses on the construction of efficient rate-compatible low-density parity-check (RC-LDPC) codes over a wide range of rates. Two LDPC code families are considered; namely, regular LDPC codes which are known for go...

Low-density parity-check (LDPC) codes and convolutional Turbo codes are two of the most powerful error correcting codes that are widely used in modern communication systems. In a multi-mode baseband receiver, both LDPC and Turbo decoders may be required. However, the different decoding approaches for LDPC and Turbo codes usually lead to different hardware architectures. In this paper we propose...

In this paper, we present a construction method of terminated non-binary low-density parity-check (LDPC) convolutional codes. Our construction method is an expansion of Felstrom and Zigangirov construction [1] for non-binary LDPC convolutional codes. The rate-compatibility of the non-binary LDPC convolutional codes is also discussed. The proposed ratecompatible code is designed from one single ...

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...

AhtractOrthogonal Frequency Division Multiplexing (OFDM) is a very attractive technique for high-hit-rate data transmission in multipath environments. Many error-correcting codes have been applied to OFDM, convolutional codes, Reed-Solomon codes, Turbo codes, and so on. Recently, low-density parity-check (LDPC) codes have attracted much attention particularly in the tield of coding theory. LDPC...