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An Efficient Overlapped LDPC Decoder with a Upper Dual-diagonal Structure

  • Byun, Yong Ki (School of Information and Communication Engineering, Sungkyunkwan University) ;
  • Park, Jong Kang (School of Information and Communication Engineering, Sungkyunkwan University) ;
  • Kwon, Soongyu (School of Information and Communication Engineering, Sungkyunkwan University) ;
  • Kim, Jong Tae (School of Information and Communication Engineering, Sungkyunkwan University)
  • Received : 2012.04.27
  • Published : 2013.02.28

Abstract

A low density parity check (LDPC) decoder provides a most powerful error control capability for mobile communication devices and storage systems, due to its performance being close to Shannon's limit. In this paper, we introduce an efficient overlapped LDPC decoding algorithm using a upper dual-diagonal parity check matrix structure. By means of this algorithm, the LDPC decoder can concurrently execute parts of the check node update and variable node update in the sum-product algorithm. In this way, we can reduce the number of clock cycles per iteration as well as reduce the total latency. The proposed decoding structure offers a very simple control and is very flexible in terms of the variable bit length and variable code rate. The experiment results show that the proposed decoder can complete the decoding of codewords within 70% of the number of clock cycles required for a conventional non-overlapped decoder. The proposed design also reduces the power consumption by 33% when compared to the non-overlapped design.

Keywords

References

  1. S. Jeon and B. V. K. V. Kumar, "Performance and Complexity of 32 k-bit Binary LDPC Codes for Magnetic Recording Channels," IEEE Trans. Magnetics, vol. 46, pp. 2244-2247, Jun, 2010. https://doi.org/10.1109/TMAG.2010.2043067
  2. H. Zhong, T. Zhong, and E. F. Haratsch, "Quasi- Cyclic LDPC Codes for the Magnetic Recording Channel: Code Design and VLSI Implementation," IEEE Trans. Magnetics, vol. 43, pp. 1118-1123, Mar, 2007. https://doi.org/10.1109/TMAG.2006.888607
  3. M. P. C. Fossorier, "Quasi-Cyclic Low-Density Parity-Check Codes From Circulant Permutation Matrices," IEEE Trans. Info. Theory, vol. 50, pp. 1788-1793, Aug, 2004. https://doi.org/10.1109/TIT.2004.831841
  4. M. Jiang, C. Wang, Y. Zhang, and C. Zhao, "An improved variable length coding scheme using structured LDPC codes," IEEE Int. Conf. on WCSP, Oct, 2010.
  5. Z. Wang, Z. Cui, and J. Sha, "VLSI Design for Low-Density Parity-Check Code Decoding," IEEE Circuit and System Mag., vol. 11, pp. 52-69, Feb, 2011.
  6. Y. Chen and K. K. Parhi, "Overlapped message passing for quasi-cyclic low-density parity check codes," IEEE Trans. Circuits and Syst., vol. 51, pp. 1106-1113, June, 2004. https://doi.org/10.1109/TCSI.2004.826194
  7. Y. Dai and Z. Yan, "Optimal Overlapped Message Passing Decoding of Quasi-Cyclic LDPC Codes," IEEE Trans on VLSI, Vol. 16, pp.565-578, May, 2008. https://doi.org/10.1109/TVLSI.2008.917540
  8. L. Liu and C.-J.R. Shi, "Sliced Message Passing: High Throughput Overlapped Decoding of High- Rate Low-Density Parity-Check Codes," IEEE Trans. Circuits and Syst., Vol. 55, pp.3697-3710, 2008. https://doi.org/10.1109/TCSI.2008.926995
  9. S. Myung, K. Yang, and J. Kim, "Quasi-cyclic LDPC codes for fast encoding," IEEE Trans Inform. Theory, vol. 51, pp. 2894-2901, Aug. 2005. https://doi.org/10.1109/TIT.2005.851753
  10. T. Richardson and R. Urbanke, "Efficient encoding of low-density parity-check codes," IEEE Trans. Inform. Theory, vol. 47, pp. 638-656, Feb.2001. https://doi.org/10.1109/18.910579
  11. Wenming Liu, Guangxi Zhu, Yongqiang Deng, and Yejun He, "Deterministic quasi-regular LDPC codes," VTC-2005-Fall, vol. 1, pp 512- 516, 2005.
  12. M. Yang, W. Ryan, and Y. Li, "Design of efficiently encodable moderate-length high-rate irregular LDPC codes," IEEE Trans. Comm., vol. 52, pp. 564-571, April, 2004. https://doi.org/10.1109/TCOMM.2004.826367
  13. "Part 16: air interface for fixed and mobile broadband wireless access systems amendment for physical and medium access control layers for combined fixed and mobile operation in licensed bands", IEEE P802.16e-2005, Oct. 2005.
  14. X. Shih, C. Zhan, C. Lin, and A. Wu, "A 19-mode 8.29 mm2 52-mW LDPC decoder chip for IEEE 802.16e system," Proc. of Symp. on VLSI Circuits, pp. 16-17, 2007.
  15. T.-C. Kuo and J. A. N. Willson, "A flexible decoder IC for WiMAX QC-LDPC codes," Proc. of Custom Integrated Circuits Conf., pp.527-530, 2008.
  16. A. Blad and O. Gustafsson, "FPGA implementation of rate-compatible QC-LDPC code decoder," proc. of 20-th ECCTD, pp.277.280, 2011.
  17. K. Gunnam, G. Choi, M. Yeary, and M. Atiquzzaman, "VLSI architectures for layered decoding for irregular LDPC codes of WiMax," Proc. of IEEE Int. Conf. Commun., pp. 4542-4547, 2007.
  18. K. Zhang and X. Huang, "A low-complexity ratecompatible LDPC decoder," Proc. of Signals, Systems and Computers Conf. Record of the Forty- Third Asilomar, pp.749-753, 2009.
  19. C. Yoon, E. Choi, M. Cheong and S. Lee, "Arbitrary Bit Generation and Correction Technique for Encoding QC-LDPC Codes with Dual-Diagonal Parity Structure", Proc. of IEEE conf. WCNC, pp.662-666, 2007.
  20. Z. He, S. Roy, and P. Fortier, "Encoder Architecture with Throughput Over 10 Gbit/sec for Quasi-cyclic LDPC Codes," Proc. of ISCAS, pp.3269-3272, 2006.