Search

This study provides necessary condition (lower bound) and sufficient condition (upper bound) for the existence of Solid Burst (SB) errors locating PCD’s codes within a sub-block where the length of the code is assumed that it is split up into a fix number of identically sized sub-blocks. An example of such a code is also provided. The codes obtained here have been compared with the previously existing codes that are capable to detect and locate the repeated burst errors. [ABSTRACT FROM AUTHOR]

Quantum error correction lies at the heart of building reliable quantum information processing systems. Stabilizer codes, a fundamental class of quantum errorcorrecting codes, play a pivotal role in mitigating the adverse effects of noise and decoherence in quantum systems. This paper introduces a novel construction of quantum stabilizer codes using Hadamard difference sets, an elegant mathematical concept derived from combinatorial design theory. In this paper, the construction of the quantum stabilizer codes over non- cyclic Hadamard difference sets with parameters (4m²,2m²-m, m²-m), where m is a positive integer is discussed. Firstly, the parity check matrices are constructed from the Circulant permutation matrices with the help of Hadamard difference sets and then, the Symplectic inner product condition for Hadamard difference sets over binary operation for parity check matrices are obtained to affirm the commutative condition for Stabilizer operators which is vital for the error detection. For application, we constructed a Hadamard difference sets with parameters (16,6,2) for m = 2 of ordered pair of the group Z2 Z8 × (non-cyclic group) and quantum stabilizer codes are obtained by parity-check matrix. [ABSTRACT FROM AUTHOR]

A column‐weight k$k$ LDPC code with the parity‐check matrix H$H$ is called decomposable if there exists a permutation π$\pi$ on the rows of H$H$, such that π(H)${\pi }(H)$ can be decomposed into k$k$ column‐weight one matrix. In this paper, some variations of edge coloring of graphs are used to construct some column‐weight three decomposable LDPC codes with girths at least six and eight. Applying the presented method on several known classes of bipartite graphs, some classes of column‐weight three decomposable LDPC codes are derived having flexibility in length and rate. Interestingly, the constructed parity‐check matrices based on the proper edge coloring of graphs can be considered as the base matrix of some high rate column‐weight three quasi‐cyclic (QC) LDPC codes with maximum‐achievable girth 20. The paper also leads to a simple characterization of elementary trapping sets of the decomposable codes based on the chromatic index of the corresponding normal graphs. This characterization corresponds to a simple search algorithm finds all possible existing elementary trapping sets in a girth‐6 or girth‐8 column‐weight 3 LDPC code which are layered super set of a short cycle in the Tanner graph of the code. Simulation results indicate that the QC‐LDPC codes with large girths lifted from the constructed base matrices have good performances over AWGN channel. [ABSTRACT FROM AUTHOR]

In this paper, we construct new types of codes, called Weighted Block-wise Burst Error Correcting Codes (Weighted BBEC Codes), which are an improvement on the previously known block wise burst error correcting codes in the sense of their weight, i.e., (n = n1 + n2, k) linear codes that correct all the bursts of length b1 (fixed) with the weight w1(w1 ≤ b1) or more (less) in the first sub-block of length n1 and all the bursts of length b2 (fixed) with the weight w2 or more (less) in the next sub-block of length n2. [ABSTRACT FROM AUTHOR]

A hardware architecture is presented to decode (N, K) polar codes based on a low‐density parity‐check code‐like decoding method. By applying suitable pruning techniques to the dense graph of the polar code, the decoder architectures are optimized using fewer check nodes (CN) and variable nodes (VN). Pipelining is introduced in the CN and VN architectures, reducing the critical path delay. Latency is reduced further by a fully parallelized, single‐stage architecture compared with the log N stages in the conventional belief propagation (BP) decoder. The designed decoder for short‐to‐intermediate code lengths was implemented using the Virtex‐7 field‐programmable gate array (FPGA). It achieved a throughput of 2.44 Gbps, which is four times and 1.4 times higher than those of the fast‐simplified successive cancellation and combinational decoders, respectively. The proposed decoder for the (1024, 512) polar code yielded a negligible bit error rate of 10−4 at 2.7 Eb/No (dB). It converged faster than the BP decoding scheme on a dense parity‐check matrix. Moreover, the proposed decoder is also implemented using the Xilinx ultra‐scale FPGA and verified with the fifth generation new radio physical downlink control channel specification. The superior error‐correcting performance and better hardware efficiency makes our decoder a suitable alternative to the successive cancellation list decoders used in 5G wireless communication. [ABSTRACT FROM AUTHOR]

Copyright of Informatics Control Measurement in Economy & Environment Protection / Informatyka, Automatyka, Pomiary w Gospodarce i Ochronie Środowiska is the property of Lublin University of Technology and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

A new decoding method for low-density parity-check (LDPC) codes is presented to lower the energy consumption of LDPC decoders for NAND flash-based storage systems. Since the channel condition of NAND flash memory is reliable for most of its lifetime, it is inefficient to apply the maximum-effort decoding with the full parity-check matrix (H-matrix) from the beginning of the lifespan. As the energy consumption and the decoding latency are proportional to the size of the H-matrix used in decoding, the proposed algorithm starts the decoding with a partial H-matrix selected by considering the channel condition. In addition, the proposed partial decoding provides various error-correcting capabilities by adjusting the partial H-matrix. Based on the proposed partial decoding algorithm, a prototype decoder is implemented in a 65 nm CMOS process to decode a 4 KB LDPC code. The proposed decoder reduces energy consumption by 93% compared to the conventional LDPC decoding architecture at maximum. [ABSTRACT FROM AUTHOR]

This paper presents a joint source–channel image transmission model based on a modified trellis construction using variable-length and fixed-length codes. The model employs linear block trellis codes and a modified Bahl–Cocke–Jelinek–Raviv algorithm for decoding in the source channel. Additionally, this model utilizes a hierarchical tree and a parity-check matrix to combine the source and channel codes, reducing errors in the decoding process and enabling the decoding of longer sequences without substantial loss of quality. [ABSTRACT FROM AUTHOR]

...-ispotty-byte error correcting codes over Zq [7] are non-binary codes generalizing the binary irregular-spotty-byte codes [3] suitable for semiconductor memories in which a word is divided into irregular bytes not necessarily of the same length. The distance between distinct words is measured in terms of newly defined ... - metric function [7]. In this paper, we present the code construction methods of ...-ispotty-byte error correcting codes in terms of their parity check matrix. [ABSTRACT FROM AUTHOR]

In modern large-scale storage systems, locally repairable codes(LRCs) improve the repair efficiency when node failure occurs. This work discusses several new methods for constructing LRCs with small localities using the generator and parity-check matrices approach. Many new LRCs have been found, all distance-optimal (d-optimal) or best-known (BK). Based on the newly obtained LRCs and known results, a database presenting all d-optimal (or BK) binary LRCs with a relatively small locality where n ≤ 40 is given. The majority of them are r-optimal or near r-optimal. [ABSTRACT FROM AUTHOR]

Information reconciliation is an important step in quantum key distribution (QKD). As a good channel coding technology, LDPC (low-density parity-check) code perform well in information reconciliation. In this paper, we investigate a new approach, namely blind information reconciliation. In our approach, after the state distribution is carried out by Alice and the measurements are taken by Bob, Alice can select an appropriate LDPC encoder (parity-check matrix) from the predefined candidate pool according to the estimated QBER (quantum bit-error-rate). Bob can use the expectation–maximization (EM) estimator and the maximum average log-likelihood ratio (LLR) detector to blindly identify parity-check matrices associated with not only different code-rates but also different codeword-lengths Alice employed. Moreover, puncturing and shortening can also be invoked to adjust the code-rate slightly to improve the error-correction performance. Monte Carlo simulations have demonstrated that our proposed new blind information-reconciliation scheme can successfully identify the parity-check matrix even under high QBER conditions, reduce the interactive communication-rounds, and improve the reconciliation efficiency in comparison with the conventional rate-adaptive LDPC coding scheme without QBER estimation. [ABSTRACT FROM AUTHOR]

• An LDPC coded strategy to enhances the performance of CVB multiplexing communication over few-mode fiber was proposed. • A 4-channel CVB multiplexing communication was demonstrated, and 96 Gbit/s QPSK-OFDM signals were successfully transmitted over a 5 km FMF. • After equalization using LDPC coded, the bit error rate decreased by ∼ 2.5 orders of magnitude, and the communication sensitivity improved by ∼ 8 dB. Cylindrical vector beams (CVBs) have attracted significant research interest in mode-division multiplexing communication thanks to their capacity to carry orthogonal vector modes. Because CVB modes are the eigen-solutions of few-mode fiber (FMF), they are well-suited for long-distance transmission. Nevertheless, the application of CVB multiplexing communication is impeded by mode coupling in FMF, which leads to mode crosstalk and signal fading. Herein we propose an LDPC coded strategy to provide a channel equalization solution, which enhances the performance of CVB multiplexing communication. Digital signals are encoded using a sparse parity-check matrix that establishes a specific parity-check relationship between the original data bits and the check bits. This enables the correction of error bits for channel equalization. To demonstrate the concept, we built a 4-channel CVB multiplexing communication system that transmitted 24 × 4 Gbit/s QPSK-OFDM signals over 5 km FMF. After equalization, the bit error rate decreased by ∼ 2.5 orders of magnitude, and the communication sensitivity improved by ∼ 8 dB. This proof of concept demonstrates the potential of the proposed LDPC coded strategy to enhance the performance of CVB multiplexing communication systems. [ABSTRACT FROM AUTHOR]

In this paper, we give a parity check matrix of the (+) -extended twisted generalized Reed Solomon code, and then not only prove that it is MDS or NMDS, but also determine the weight distribution. Especially, based on Schur method, we show that the (+) -extended twisted generalized Reed Solomon code is neither the generalized Reed Solomon code nor extended generalized Reed Solomon code. Furthermore, we present necessary and sufficient conditions for the (+) -twisted generalized Reed Solomon code and the (+) -extended twisted generalized Reed Solomon code to be self-orthogonal, respectively. Finally, several classes of self-dual (+) -twisted generalized Reed Solomon code codes and almost self-dual (+) -extended twisted generalized Reed Solomon codes are constructed. [ABSTRACT FROM AUTHOR]