• Title/Summary/Keyword: modified step-by-step decoding

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Low-Complexity Triple-Error-Correcting Parallel BCH Decoder

  • Yeon, Jaewoong;Yang, Seung-Jun;Kim, Cheolho;Lee, Hanho
    • JSTS:Journal of Semiconductor Technology and Science
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    • v.13 no.5
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    • pp.465-472
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    • 2013
  • This paper presents a low-complexity triple-error-correcting parallel Bose-Chaudhuri-Hocquenghem (BCH) decoder architecture and its efficient design techniques. A novel modified step-by-step (m-SBS) decoding algorithm, which significantly reduces computational complexity, is proposed for the parallel BCH decoder. In addition, a determinant calculator and a error locator are proposed to reduce hardware complexity. Specifically, a sharing syndrome factor calculator and a self-error detection scheme are proposed. The multi-channel multi-parallel BCH decoder using the proposed m-SBS algorithm and design techniques have considerably less hardware complexity and latency than those using a conventional algorithms. For a 16-channel 4-parallel (1020, 990) BCH decoder over GF($2^{12}$), the proposed design can lead to a reduction in complexity of at least 23 % compared to conventional architecttures.

A Versatile Reed-Solomon Decoder for Continuous Decoding of Variable Block-Length Codewords (가변 블록 길이 부호어의 연속 복호를 위한 가변형 Reed-Solomon 복호기)

  • 송문규;공민한
    • Journal of the Institute of Electronics Engineers of Korea TC
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    • v.41 no.3
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    • pp.187-187
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    • 2004
  • In this paper, we present an efficient architecture of a versatile Reed-Solomon (RS) decoder which can be programmed to decode RS codes continuously with my message length k as well as any block length n. This unique feature eliminates the need of inserting zeros for decoding shortened RS codes. Also, the values of the parameters n and k, hence the error-correcting capability t can be altered at every codeword block. The decoder permits 3-step pipelined processing based on the modified Euclid's algorithm (MEA). Since each step can be driven by a separate clock, the decoder can operate just as 2-step pipeline processing by employing the faster clock in step 2 and/or step 3. Also, the decoder can be used even in the case that the input clock is different from the output clock. Each step is designed to have a structure suitable for decoding RS codes with varying block length. A new architecture for the MEA is designed for variable values of the t. The operating length of the shift registers in the MEA block is shortened by one, and it can be varied according to the different values of the t. To maintain the throughput rate with less circuitry, the MEA block uses both the recursive technique and the over-clocking technique. The decoder can decodes codeword received not only in a burst mode, but also in a continuous mode. It can be used in a wide range of applications because of its versatility. The adaptive RS decoder over GF($2^8$) having the error-correcting capability of upto 10 has been designed in VHDL, and successfully synthesized in an FPGA chip.

A Versatile Reed-Solomon Decoder for Continuous Decoding of Variable Block-Length Codewords (가변 블록 길이 부호어의 연속 복호를 위한 가변형 Reed-Solomon 복호기)

  • 송문규;공민한
    • Journal of the Institute of Electronics Engineers of Korea TC
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    • v.41 no.3
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    • pp.29-38
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    • 2004
  • In this paper, we present an efficient architecture of a versatile Reed-Solomon (RS) decoder which can be programmed to decode RS codes continuously with my message length k as well as any block length n. This unique feature eliminates the need of inserting zeros for decoding shortened RS codes. Also, the values of the parameters n and k, hence the error-correcting capability t can be altered at every codeword block. The decoder permits 3-step pipelined processing based on the modified Euclid's algorithm (MEA). Since each step can be driven by a separate clock, the decoder can operate just as 2-step pipeline processing by employing the faster clock in step 2 and/or step 3. Also, the decoder can be used even in the case that the input clock is different from the output clock. Each step is designed to have a structure suitable for decoding RS codes with varying block length. A new architecture for the MEA is designed for variable values of the t. The operating length of the shift registers in the MEA block is shortened by one, and it can be varied according to the different values of the t. To maintain the throughput rate with less circuitry, the MEA block uses both the recursive technique and the over-clocking technique. The decoder can decodes codeword received not only in a burst mode, but also in a continuous mode. It can be used in a wide range of applications because of its versatility. The adaptive RS decoder over GF(2$^{8}$ ) having the error-correcting capability of upto 10 has been designed in VHDL, and successfully synthesized in an FPGA chip.

Design of a Variable Shortened and Punctured RS Decoder (단축 및 펑처링 기반의 가변형 RS 복호기 설계)

  • Song Moon-Kyou;Kong Min-Han;Lim Myoung-Seob
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.31 no.8C
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    • pp.763-770
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    • 2006
  • In this paper, a variable Reed-Solomon(RS) decoder with erasure decoding functionality is designed based on the modified Euclid's algorithm(MEA). The variability of the decoder is implemented through shortening and puncturing based on the RS(124, 108, 8) code, other than the primitive RS(255, 239, 8) code. This leads to shortening the decoding latency. The decoder performs 4-step pipelined operation, where each step is designed to be clocked by an independent clock. Thus by using a faster clock for the MEA block, the complexity and the decoding latency can be reduced. It can support both continuous- and burst-mode decoding. It has been designed in VHDL and synthesized in an FPGA chip, consuming 3,717 logic cells and 2,048-bit memories. The maximum decoding throughput is 33 MByte/sec.

Iterative Reliability-Based Modified Majority-Logic Decoding for Structured Binary LDPC Codes

  • Chen, Haiqiang;Luo, Lingshan;Sun, Youming;Li, Xiangcheng;Wan, Haibin;Luo, Liping;Qin, Tuanfa
    • Journal of Communications and Networks
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    • v.17 no.4
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    • pp.339-345
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    • 2015
  • In this paper, we present an iterative reliability-based modified majority-logic decoding algorithm for two classes of structured low-density parity-check codes. Different from the conventional modified one-step majority-logic decoding algorithms, we design a turbo-like iterative strategy to recover the performance degradation caused by the simply flipping operation. The main computational loads of the presented algorithm include only binary logic and integer operations, resulting in low decoding complexity. Furthermore, by introducing the iterative set, a very small proportion (less than 6%) of variable nodes are involved in the reliability updating process, which can further reduce the computational complexity. Simulation results show that, combined with the factor correction technique and a well-designed non-uniform quantization scheme, the presented algorithm can achieve a significant performance improvement and a fast decoding speed, even with very small quantization levels (3-4 bits resolution). The presented algorithm provides a candidate for trade-offs between performance and complexity.

Self-Adaptive Termination Check of Min-Sum Algorithm for LDPC Decoders Using the First Two Minima

  • Cho, Keol;Chung, Ki-Seok
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • v.11 no.4
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    • pp.1987-2001
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    • 2017
  • Low-density parity-check (LDPC) codes have attracted a great attention because of their excellent error correction capability with reasonably low decoding complexity. Among decoding algorithms for LDPC codes, the min-sum (MS) algorithm and its modified versions have been widely adopted due to their high efficiency in hardware implementation. In this paper, a self-adaptive MS algorithm using the difference of the first two minima is proposed for faster decoding speed and lower power consumption. Finding the first two minima is an important operation when MS-based LDPC decoders are implemented in hardware, and the found minima are often compressed using the difference of the two values to reduce interconnection complexity and memory usage. It is found that, when these difference values are bounded, decoding is not successfully terminated. Thus, the proposed method dynamically decides whether the termination-checking step will be carried out based on the difference in the two found minima. The simulation results show that the decoding speed is improved by 7%, and the power consumption is reduced by 16.34% by skipping unnecessary steps in the unsuccessful iteration without any loss in error correction performance. In addition, the synthesis results show that the hardware overhead for the proposed method is negligible.