• Title/Summary/Keyword: block iterative algorithm

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LLR Based Generalization of Soft Decision Iterative Decoding Algorithms for Block Turbo Codes (LLR 기반 블록 터보 부호의 연판정 복호 알고리즘 일반화)

  • Im, Hyun-Ho;Kwon, Kyung-Hoon;Heo, Jun
    • Journal of Broadcast Engineering
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    • v.16 no.6
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    • pp.1026-1035
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    • 2011
  • This paper presents generalization and application for the conventional SISO decoding algorithm of Block Turbo Codes. R. M. Pyndiah suggested an iterative SISO decoding algorithm for Product Codes, two-dimensionally combined linear block codes, on AWGN channel. It wascalled Block Turbo Codes. Based on decision of Chase algorithm which is SIHO decoding method, SISO decoder for BTC computes soft decision information and transfers the information to next decoder for iterative decoding. Block Turbo Codes show Shannon limit approaching performance with a little iteration at high code rate on AWGN channel. In this paper we generalize the conventional decoding algorithm of Block Turbo Codes, under BPSK modulation and AWGN channel transmission assumption, to the LLR value based algorithm and suggest an application example such as concatenated structure of LDPC codes and Block Turbo Codes.

Modal control algorithm on optimal control of intelligent structure shape

  • Yao, Guo Feng;Chen, Su Huan;Wang, Wei
    • Structural Engineering and Mechanics
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    • v.15 no.4
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    • pp.451-462
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    • 2003
  • In this paper, a new block iterative algorithm is presented by using the special feature of the continuous Riccati equation in the optimal shape control. Because the real-time control require that the CPU time should be as short as possible, an appropriate modal control algorithm is sought. The computing cost is less than the one of the all state feedback control. A numerical example is given to illustrate the algorithm.

Application of Block Turbo Code for Improving the Performance of 5 ㎓ IEEE 802,11a WLAN System (5 ㎓대 IEEE 802.11a WLAN 시스템의 성능향상을 위한 블록터보코드(Block Turbo Code)의 응용)

  • 김한종;이병남
    • The Journal of Korean Institute of Electromagnetic Engineering and Science
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    • v.15 no.1
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    • pp.21-28
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    • 2004
  • In this paper we apply block turbo coding at the transmitter and iterative decoding algorithm at the receiver for different operating modes, based on the 5 ㎓ IEEE 802.1 la WLAN system, instead of convolutional coding and soft decision viterbi algorithm to improve forward error correcting performance. Experimental results showed that each coding scheme outperforms coding gains of up to 3.5 ㏈ at the BER of 10$\^$-3/.

Improvement of Iterative Algorithm for Live Variable Analysis based on Computation Reordering (사용할 변수의 예측에 사용되는 반복적 알고리즘의 계산순서 재정렬을 통한 수행 속도 개선)

  • Yun Jeong-Han;Han Taisook
    • Journal of KIISE:Software and Applications
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    • v.32 no.8
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    • pp.795-807
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    • 2005
  • The classical approaches for computing Live Variable Analysis(LVA) use iterative algorithms across the entire programs based on the Data Flow Analysis framework. In case of Zephyr compiler, average execution time of LVA takes $7\%$ of the compilation time for the benchmark programs. The classical LVA algorithm has many aspects for improvement. The iterative algorithm for LVA scans useless basic blocks and calculates large sets of variables repeatedly. We propose the improvement of Iterative algorithm for LVA based on used variables' upward movement. Our algorithm produces the same result as the previous iterative algorithm. It is based on use-def chain. Reordering of applying the flow equation in DFA reduces the number of visiting basic blocks and redundant flow equation executions, which improves overall processing time. Experimental results say that our algorithm ran reduce $36.4\%\;of\;LVA\;execution\;time\;and\;2.6\%$ of overall computation time in Zephyr compiler with benchmark programs.

Piecewise Phase Recovery Algorithm Using Block Turbo Codes for Next Generation Mobile Communications

  • Ryoo, Sun-Heui;Kim, Soo-Young;Ahn, Do-Seob
    • ETRI Journal
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    • v.28 no.4
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    • pp.435-443
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    • 2006
  • This paper presents an efficient carrier recovery algorithm combined with a turbo-coding technique in a mobile communication system. By using a block turbo code made up of independently decodable block codes, we can efficiently recover the fast time-varying carrier phase as well as correct channel errors. Our simulation results reveal that the proposed scheme can accommodate mobiles with high speed, and at the same time can reduce the number of iterations to lock the phase.

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Block Sparse Signals Recovery Algorithm for Distributed Compressed Sensing Reconstruction

  • Chen, Xingyi;Zhang, Yujie;Qi, Rui
    • Journal of Information Processing Systems
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    • v.15 no.2
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    • pp.410-421
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    • 2019
  • Distributed compressed sensing (DCS) states that we can recover the sparse signals from very few linear measurements. Various studies about DCS have been carried out recently. In many practical applications, there is no prior information except for standard sparsity on signals. The typical example is the sparse signals have block-sparse structures whose non-zero coefficients occurring in clusters, while the cluster pattern is usually unavailable as the prior information. To discuss this issue, a new algorithm, called backtracking-based adaptive orthogonal matching pursuit for block distributed compressed sensing (DCSBBAOMP), is proposed. In contrast to existing block methods which consider the single-channel signal reconstruction, the DCSBBAOMP resorts to the multi-channel signals reconstruction. Moreover, this algorithm is an iterative approach, which consists of forward selection and backward removal stages in each iteration. An advantage of this method is that perfect reconstruction performance can be achieved without prior information on the block-sparsity structure. Numerical experiments are provided to illustrate the desirable performance of the proposed method.

A study of a motion estimation with the block-based method (Block-Based Method를 이용한 Motion Estimation에 관한 연구)

  • 김상기;이원희;김재영;변재응;이범로;정진현
    • 제어로봇시스템학회:학술대회논문집
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    • 1996.10b
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    • pp.1-4
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    • 1996
  • It is difficult that a non-translational motion in a block is estimated by the block matching algorithm (BMA). In this paper, a nodal-displacement-based deformation model is used for this reason. This model assumes that a selected number of control nodes move freely in a block and that displacement of any interior point can be interpolated from nodal displacements. As a special case with a single node this model is equivalent to a translational model. And this model can represent more complex deformation using more nodes. We used an iterative gradient based search algorithm to estimate nodal displacement. Each iteration involves the solution of a simple linear equation. This method is called the deformable block matching algorithm (DBMA).

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A New BISON-like Construction Block Cipher: DBISON

  • Zhao, Haixia;Wei, Yongzhuang;Liu, Zhenghong
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • v.16 no.5
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    • pp.1611-1633
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    • 2022
  • At EUROCRYPT 2019, a new block cipher algorithm called BISON was proposed by Canteaut et al. which uses a novel structure named as Whitened Swap-Or-Not (WSN). Unlike the traditional wide trail strategy, the differential and linear properties of this algorithm can be easily determined. However, the encryption speed of the BISON algorithm is quite low due to a large number of iterative rounds needed to ensure certain security margins. Commonly, denoting by n is the data block length, this design requires 3n encryption rounds. Moreover, the block size n of BISON is always odd, which is not convenient for operations performed on a byte level. In order to overcome these issues, we propose a new block cipher, named DBISON, which more efficiently employs the ideas of double layers typical to the BISON-like construction. More precisely, DBISON divides the input into two parts of size n/2 bits and performs the round computations in parallel, which leads to an increased encryption speed. In particular, the data block length n of DBISON can be even, which gives certain additional implementation benefits over BISON. Furthermore, the resistance of DBISON against differential and linear attacks is also investigated. It is shown the maximal differential probability (MDP) is 1/2n-1 for n encryption rounds and that the maximal linear probability (MLP) is strictly less than 1/2n-1 when (n/2+3) iterative encryption rounds are used. These estimates are very close to the ideal values when n is close to 256.

Block Sparse Signals Recovery via Block Backtracking-Based Matching Pursuit Method

  • Qi, Rui;Zhang, Yujie;Li, Hongwei
    • Journal of Information Processing Systems
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    • v.13 no.2
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    • pp.360-369
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    • 2017
  • In this paper, a new iterative algorithm for reconstructing block sparse signals, called block backtracking-based adaptive orthogonal matching pursuit (BBAOMP) method, is proposed. Compared with existing methods, the BBAOMP method can bring some flexibility between computational complexity and reconstruction property by using the backtracking step. Another outstanding advantage of BBAOMP algorithm is that it can be done without another information of signal sparsity. Several experiments illustrate that the BBAOMP algorithm occupies certain superiority in terms of probability of exact reconstruction and running time.

A Proposal of Combined Iterative Algorithm for Optimal Design of Binary Phase Computer Generated Hologram (최적의 BPCGH 설계를 위한 합성 반복 알고리듬 제안)

  • Kim Cheol-Su
    • Journal of Korea Society of Industrial Information Systems
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    • v.10 no.4
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    • pp.16-25
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    • 2005
  • In this paper, we proposed a novel algorithm combined simulated annealing and genetic algorithms for designing optimal binary phase computer generated hologram. In the process of genetic algorithm searching by block units, after the crossover and mutation operations, simulated annealing algorithm searching by pixel units is inserted. So, the performance of BPCGH was improved. Computer simulations show that the proposed combined iterative algorithm has better performance than the simulated annealing algorithm in terms of diffraction efficiency

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