• Title/Summary/Keyword: code complexity

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Literature and Genomic Narrative: Richard Powers' The Book of Life (문학과 유전체 내러티브 -리차드 파워스의 생명의 책)

  • Song, Taejeong
    • Journal of English Language & Literature
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    • v.53 no.2
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    • pp.243-260
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    • 2007
  • This article explores how Richard Powers' The Gold Bug Variations, an interdisciplinary novel through the new concepts of biocriticism and bioliterature is connected with literature/art and science/technology. Powers uses Edgar Allen Poe's "The Gold Bug" and Johann Sebastian Bach's "The Goldberg Variations" for decoding DNA in order to analogize a genomic metaphor. He imagines literature as "the book of life" genome, written by DNA code due to the complexity and multiplicity of the genome. His novel, as 'genomic narrative,' shows the articulation of the genomic reading, and expression in the life language through the discourses of the information technology and the rhetorical tropes in biology. New biological ideas are continually required to articulate these processes. In the present tendency of the Human Genome Project, such advanced devices as biocybernetics offer the potential to open up new possibilities to researching the complexity of the genome. This can only happen if the following two ideas are followed: One is to comply with advanced technologies for processing the rapidly increasing data of the genome sequence; The other is to admit the necessary paradigm shift in biology. As shown above, the complexity and multiplicity of the genomic reality is not so simple. We must go beyond determinism, even if representation of a biological reality reveals the possibility of expressing its constituent elements by the advanced biotechnology. Consequently, in the unstoppable advances of the art of decoding the genome, The Gold Bug Variations interrelates to the interdisciplinary approaches through the rhetorical tropes that unfold the complex discursive world of the genome. Powers shows that the complex mechanisms of the genome in the microworld of every cell as the plot of "the book of life" can be designed and written using DNA language. At the same time, his genomic reading and writing demonstrate the historical processes of the shifting center of new genomic development and polysemous interpretation.

An Accurate Estimation of Channel Loss Threshold Set for Optimal FEC Code Rate Decision (최적의 FEC 부호율 결정을 위한 정확한 채널손실 한계집합 추정기법)

  • Jung, Tae-Jun;Jeong, Yo-Won;Seo, Kwang-Deok
    • Journal of Broadcast Engineering
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    • v.19 no.2
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    • pp.268-271
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    • 2014
  • Conventional forward error correction (FEC) code rate decision schemes using analytical source coding distortion model and channel-induced distortion model are usually complex, and require the typical process of model parameter training which involves potentially high computational complexity and implementation cost. To avoid the complex modeling procedure, we propose a simple but accurate joint source-channel distortion model to estimate channel loss threshold set for optimal FEC code rate decision.

Error Performance of Serially Concatenated Space-Time Coding

  • Altunbas, Ibrahim;Yongacoglu, Abbas
    • Journal of Communications and Networks
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    • v.5 no.2
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    • pp.135-140
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    • 2003
  • In this paper, we investigate the error performance of a serially concatenated system using a nonrecursive convolutional code as the outer code and a recursive QPSK space-time trellis code as the inner code on quasi-static and rapid Rayleigh fading channels. At the receiver, we consider iterative decoding based on the maximum a posteriori (MAP) algorithm. The performance is evaluated by means of computer simulations and it is shown that better error performance can be obtained by using low complexity outer and/or inner codes and the Euclidean distance criterion based recursive space-time inner codes. We also obtain new systems with large number of trasmit and/or receive antennas providing good error performance.

On Optimal PN Code Acquisition (최적화된 PN Code Acquisition에 대한 연구)

  • Jang, U-Jin
    • Proceedings of the IEEK Conference
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    • 1998.06a
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    • pp.23-25
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    • 1998
  • Many of the currently used PN code acquisition algorithms detect the phase of the incoming PN signal on the basis of ML estimation principle and utilize statistics grounded in taking inner products. By showing that any set of 2n-1 PN sequences arising in SSRG or MSRG (those typically used in IS'95 implementations) configuration constitutes a linearly independent set and that the number of candidate PN sequences has to equal the dimension of the span of the candidate PN sequences, we prove that the lowerbounding computational complexity involved in any PN code acquistion, utilizing (only) inner product computations at each stage of acquisition, corresponds precisely to those, such as double dwell acquistion circuitries, currently used.

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An Efficient Vocoder for Digital Cellular System (디지틀 셀룰라 시스템을 위한 효율적인 음성부호화 기술)

  • 강상원;이인성;한경호
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.18 no.9
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    • pp.1348-1357
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    • 1993
  • In this paper, we present code-excited linear prediction coding using trellis coded vector excitation, termed trellis code-excited linear prediction coding (TCELP), for an efficient 8 kbps digital cellular vocoder. A training sequence-based algorithm is developed for designing an optimized codebook subject to the TCELP structure. Also, we discuss the encoding complexity of the TCELP system and trellis symbol release rules that avoid excessive encoding delay. finally, simulation results results for the TCELP coder are given at the bit rate of 8 kbps.

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A Weighted Block-by-Block Decoding Algorithm for CPM-QC-LDPC Code Using Neural Network

  • Xu, Zuohong;Zhu, Jiang;Zhang, Zixuan;Cheng, Qian
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • v.12 no.8
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    • pp.3749-3768
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    • 2018
  • As one of the most potential types of low-density parity-check (LDPC) codes, CPM-QC-LDPC code has considerable advantages but there still exist some limitations in practical application, for example, the existing decoding algorithm has a low convergence rate and a high decoding complexity. According to the structural property of this code, we propose a new method based on a CPM-RID decoding algorithm that decodes block-by-block with weights, which are obtained by neural network training. From the simulation results, we can conclude that our proposed method not only improves the bit error rate and frame error rate performance but also increases the convergence rate, when compared with the original CPM-RID decoding algorithm and scaled MSA algorithm.

Adaptive Channel-Matched Extended Alamouti Space-Time Code Exploiting Partial Feedback

  • Badic, Biljana;Rupp, Markus;Weinrichter, Hans
    • ETRI Journal
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    • v.26 no.5
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    • pp.443-451
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    • 2004
  • Since the publication of Alamouti's famous space-time block code, various quasi-orthogonal space-time block codes (QSTBC) for multi-input multi-output (MIMO) fading channels for more than two transmit antennas have been proposed. It has been shown that these codes cannot achieve full diversity at full rate. In this paper, we present a simple feedback scheme for rich scattering (flat Rayleigh fading) MIMO channels that improves the coding gain and diversity of a QSTBC for 2$^n$ (n=3, 4, ${\cdots}$) transmit antennas. The relevant channel state information is sent back from the receiver to the transmitter quantized to one or two bits per code block. In this way, signal transmission with an improved coding gain and diversity near to the maximum diversity order is achieved. Such high diversity can be exploited with either a maximum-likelihood receiver or low-complexity zero-forcing receiver.

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Performance of LDPC with Message-Passing Channel Detector for Perpendicular Magnetic Recording Channel (수직자기기록 채널에서 LDPC를 이용한 메시지 전달 방식의 채널 검출 성능비교)

  • Park, Dong-Hyuk;Lee, Jae-Jin
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.33 no.4C
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    • pp.299-304
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    • 2008
  • For perpendicular magnetic recording channels, it is hard to expect improving the performance by using the PRML or NPML. Hence, we exploit LDPC code to improve the performance. In this paper, we examine a single message-passing detector/decoder matched to the combination of a perpendicular magnetic recording channel detector and an LDPC code decoder. We examine the performance of channel iteration with joint LDPC code on perpendicular magnetic recording channel, and simplify the complexity of the message-passing detector algorithm.

Space-Time Block Coding Techniques for MIMO 2×2 System using Walsh-Hadamard Codes

  • Djemamar, Younes;Ibnyaich, Saida;Zeroual, Abdelouhab
    • Journal of information and communication convergence engineering
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    • v.20 no.1
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    • pp.1-7
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    • 2022
  • Herein, a new space-time block coding technique is proposed for a MIMO 2 × 2 multiple-input multiple output (MIMO) system to minimize the bit error rate (BER) in Rayleigh fading channels with reduced decoding complexity using ZF and MMSE linear detection techniques. The main objective is to improve the service quality of wireless communication systems and optimize the number of antennas used in base stations and terminals. The idea is to exploit the correlation product technique between both information symbols to transmit per space-time block code and their own orthogonal Walsh-Hadamard sequences to ensure orthogonality between both symbol vectors and create a full-rate orthogonal STBC code. Using 16 quadrature amplitude modulation and the quasi-static Rayleigh channel model in the MATLAB environment, the simulation results show that the proposed space-time block code performs better than the Alamouti code in terms of BER performance in the 2 × 2 MIMO system for both cases of linear decoding ZF and MMSE.

A New Parity Preserving Run-length Limited Code for Optical Recording System (광 기록 저장 장치를 위한 새로운 패리티 보존형 런-길이 제한 코드)

  • Hong, Hyun-Sun;Lee, Jae-Jin
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.29 no.1C
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    • pp.59-64
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    • 2004
  • We propose a new RLL(run length limited) (2,7) PP(parity preserving) code with 4 RMTR(repeated minimum transition run) for optical recording. The proposed code has better characteristics in terms of density ratio, RMTR, DC(direct current) component suppression, BER(bit error rate) and system complexity than (2,1O) code that currently applied in storage systems and (1,7) PP code that highly recommended as the next generation optical recording system. Some characteristics of the code are described with several simulations. And the proposed code's superiorites in performance is illustrated as compared with the other codes.