Wyniki wyszukiwania - BazTech

1

Dekoder LDPC implementowany w mikrokontrolerze dla systemów Internetu Rzeczy

Hyla Jakub, Sułek Wojciech

Przegląd Elektrotechniczny

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2023

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R. 99, nr 4

133--139

PL

Artykuł dotyczy projektowania systemów kodowania korekcyjnego dla protokołów komunikacyjnych w Internecie Rzeczy, które są implementowane na platformach o mocno ograniczonych zasobach obliczeniowych. W artykule zaproponowano wykorzystanie nowoczesnych kodów LDPC (Low Density Parity Check), zaprezentowano algorytm dekodujący oraz przedstawiono wyniki eksperymentalne implementacji w układzie mikrokontrolera. Przeprowadzono testy dla różnych wielkości słów kodowych oraz zebrano wyniki związane z czasem dekodowania, przepustowością jak również liczbą iteracji potrzebną do zdekodowania jednego bloku.

EN

The article concerns the design of correction coding systems for communication protocols in the Internet of Things, which are implemented on platforms with very limited computing resources. The article proposes the use of modern LDPC (Low Density Parity Check) codes, presents the decoding algorithm and presents the experimental results of the implementation in a microcontroller device. Experiments were performed for different codeword sizes and the results were collected concerning the decoding time, throughput as well as the number of iterations needed to decode one block.

2

Optimizing the Bit-flipping Method for Decoding Low-density Parity-check Codes in Wireless Networks by Using the Artificial Spider Algorithm

Ghaffoori Ali Jasim, Abdul-Adheem Wameedh Riyadh

International Journal of Electronics and Telecommunications

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2022

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Vol. 68, No. 1

109--114

EN

In this paper, the performance of Low-Density Parity-Check (LDPC) codes is improved, which leads to reduce the complexity of hard-decision Bit-Flipping (BF) decoding by utilizing the Artificial Spider Algorithm (ASA). The ASA is used to solve the optimization problem of decoding thresholds. Two decoding thresholds are used to flip multiple bits in each round of iteration to reduce the probability of errors and accelerate decoding convergence speed while improving decoding performance. These errors occur every time the bits are flipped. Then, the BF algorithm with a low-complexity optimizer only requires real number operations before iteration and logical operations in each iteration. The ASA is better than the optimized decoding scheme that uses the Particle Swarm Optimization (PSO) algorithm. The proposed scheme can improve the performance of wireless network applications with good proficiency and results. Simulation results show that the ASA-based algorithm for solving highly nonlinear unconstrained problems exhibits fast decoding convergence speed and excellent decoding performance. Thus, it is suitable for applications in broadband wireless networks.

3

The design of structured LDPC codes with algorithmic graph construction

Sułek Wojciech

Bulletin of the Polish Academy of Sciences. Technical Sciences

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2022

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Vol. 70, nr 4

art. no. e141592

EN

Low-Density Parity-Check (LDPC) codes are among the most effective modern error-correcting codes due to their excellent correction performance and highly parallel decoding scheme. Moreover, the nonbinary extension of such codes further increases performance in the short-block regime. In this paper, we review the key elements for the construction of implementation-oriented binary and nonbinary codes. These Quasi-Cyclic LDPC (QC-LDPC) codes additionally feature efficient encoder and decoder implementation frameworks. We then present a versatile algorithm for the construction of both binary and nonbinary QC-LDPC codes that have low encoding complexity and an optimized corresponding graph structure. Our algorithm uses a progressive edge growth algorithm, modified for QC-LDPC graph construction, and then performs an iterative global search for optimized cyclic shift values within the QC-LDPC circulants. Strong error correction performance is achieved by minimizing the number of short cycles, and cycles with low external connectivity, within the code graph. We validate this approach via error rate simulations of a transmission system model featuring an LDPC coder-decoder, digital modulation, and additive white Gaussian noise channels. The obtained numerical results validate the effectiveness of the proposed construction algorithm, with a number of constructed codes exhibiting either similar or superior performance to industry standard binary codes and selected nonbinary codes from the literature.

4

Porównanie wybranych sposobów kodowania na potrzeby transmisji URC

Sybis M., Langowski A., Wesołowski K., Lenarska K.

Przegląd Telekomunikacyjny + Wiadomości Telekomunikacyjne

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2016

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nr 6

605--608, CD

PL

W artykule przedstawiono porównanie jako ści dekodowania, jaka można uzyskać dla trzech typów kodów zastosowanych w systemach o wysokiej niezawodno sci (URC). W artykule przebadano działanie kodów PEG LDPC i kodów kaskadowych (CC-RS), których wyniki nastepnie porównano z wynikami dla turbo kodów. skane wyniki pokazały, że zastosowanie algorytmu PEG LDPC pozwoliło na osiagniecie lepszej jakości dekodowania w porównaniu do popularnych turbo kodów.

EN

The article presents a comparison of the decod ing performance of the turbo code with two competing coding schemes that could be also considered as transmis sion schemes for the URL transmission. Obtained results have proven that application of PEG-LDPC allows to achieve a better decoding performance compared to the commonly used turbo codes.

5

Implementacja algorytmu kodowania i dekodowania LDCP dla zastosowań kosmicznych

Truszczyński T., Kurek K.

Przegląd Telekomunikacyjny + Wiadomości Telekomunikacyjne

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2016

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nr 6

205—208, CD

PL

Referat opisuje programową, opartą o procesor ogólnego przeznaczenia, implementację kodera i dekodera kodu LDPC w wersji do zastosowań kosmicznych, zgodnej ze standardami CCSDS (Consultative Committee for Space Data Systems). Program optymalnie wykorzystuje możliwości współczesnych procesorów - wielordzeniowość i instrukcje wektorowe (SIMD). Uzyskane przepływności wskazują na równoprawność proponowanego rozwiązania z implementacjami opartymi o karty graficzne.

EN

The paper describes software implementation of LDPC codec for codes from CCSDS standards based on CPU. The codec takes advantage of possibilities provided by modern processors – multiple cores and vector instructions (SIMD). Achieved throughput shows that proposed approach is comparable with implementations based on graphics processing units.

6

Robust Audio Watermarks in Frequency Domain

Dymarski P., Markiewicz R.

Journal of Telecommunications and Information Technology

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2014

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nr 2

12--21

EN

In this paper an audio watermarking technique is presented, using log-spectrum, dirty paper codes and LDPC for watermark embedding. This technique may be used as a digital communication channel, transmitting data at about 40 b/s. It may be also applied for hiding a digital signature, e.g., for copyright protection purposes. Robustness of the watermarks against audio signal compression, resampling and transmitting through an acoustic channel is tested.

7

Performance of Non-Binary LDPC Codes for Next Generation Mobile Systems

Gierszal H., Hołubowicz W., Kiedrowski Ł., Flizikowski A.

International Journal of Electronics and Telecommunications

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2010

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Vol. 56, No. 2

111-116

EN

A new family of non-binary LDPC is presented that are based on a finite field GF(64). They may be successfully implemented in single-carrier and OFDM transmission system. Results prove that DAVINCI codes allow for improving the system performance and may be considered to be applied in the future mobile system.