Nowadays, adaptive modulation and coding (AMC) techniques can facilitate flexible strategies subject to dynamic channel quality. The AMC transceivers select the most suitable coding and modulation mechanisms subject to the acquired channel information. Meanwhile, a control channel or a preamble is usually required to synchronously coordinate such changes between transmitters and receivers. On t...

This paper presents a novel parallel quasi-cyclic low-density parity-check (QC-LDPC) encoding algorithm with low complexity, which is compatible the 5th generation (5G) new radio (NR). Basing on algorithm, we propose high area-efficient encoder architecture. The proposed has advantages of and pipelined operations. Furthermore, it designed as configurable structure, fully different base graphs 5...

3D flash memories have been widely developed to further increase the storage capacity of SSDs by vertically stacking multiple layers. However, this special physical structure brings new error characteristics. Existing studies discovered that there exist significant Raw Bit Error Rates (RBERs) variations among different layers and RBERs similarity inside same layer due manufacturing process. The...

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 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...

We present a systematic construction of a class of highrate, well-structured low density parity check (LDPC) codes based on combinatorial designs. We show that the proposed -design results in a class of -regular LDPC codes, which are systematic, quasicyclic, free of length-4 and length-6 cycles, linear-time encodable and decodable, and which have high code rates of . Analysis from the maximum l...

Aiming at seeking a low complexity decoder of the low-density parity-check (LDPC) codes, we present one modified multi-bit flipping (MMBF) algorithm. For those LDPC codes whose parity check matrices have light column weight, both the bootstrap step and a novel delay-handling step are included in MMBF, based on one framework which is the combination of conventional PWBF and IWBF. On the other ha...

Adding the ability of LDPC to an OFDM system gives rise to a robust and suitable technique for broadband PLC. However, despite LDPC codes performing admirably for large block sizes, real time operation and low computational effort require small and medium sized codes, which tend to be affected by channel SNR and errors in channel equalization. This paper deals with improvements made to an OFDM ...

We present a methodology to search for harmful subgraphs in the Tanner graph of a regular column-weightthree low-density parity-check (LDPC) code. These harmful subgraphs, which are more commonly known under the name “trapping sets,” cause a degradation in the error correcting performance of LDPC codes in the high signal-to-noise ratio (SNR) region. Our method of searching for trapping sets uti...

This paper is concerned with construction and structural analysis of both cyclic and quasi-cyclic codes, particularly LDPC codes. It consists of three parts. The first part shows that a cyclic code given by a parity-check matrix in circulant form can be decomposed into descendant cyclic and quasi-cyclic codes of various lengths and rates. Some fundamental structural properties of these descenda...