The Journal of Korean Institute of Communications and Information Sciences (한국통신학회논문지)

The Korean Institute of Commucations and Information Sciences (한국통신학회)
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Design of the Normalization Unit for a Low-Power and Area-Efficient Turbo Decoders

저전력 및 면적 효율적인 터보 복호기를 위한 정규화 유닛 설계

  • 문제우 (서강대학교 전자공학과 CAD & Computer System 연구실) ;
  • 김식 (서강대학교 전자공학과 CAD & Computer System 연구실) ;
  • 황선영 (서강대학교 전자공학과 CAD & Computer System 연구실)
  • Published : 2003.11.01
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Abstract

This paper proposes a novel normalization scheme in the state metric calculation unit for the Block-wise MAP Turbo decoder. The proposed scheme subtracts one of four metrics from the state metrics in a trellis stage and shifts, if necessary, those metrics for normalization. The proposed architecture can reduce power consumption and memory requirement by reducing the number of the state metrics by one in a trellis stage in the Block-wise MAP decoder which requires an intensive state metric calculations. Simulation results show that dynamic power has been reduced by 17.9% and area has been reduced by 6.6% in the Turbo decoder employing the proposed normalization scheme, when compared to the conventional Block-wise MAP Turbo decoders.

본 논문은 블록 MAP 터보 복호기의 상태 메트릭 계산 유닛을 위한 정규화 방식을 제안한다. 제안된 방식은 정규화를 위해 격자단(trellis stage)에서 하나의 상태 메트릭 값을 모든 상태 메트릭에 빼주고 쉬프트 시키는 구조를 갖게 되어, 상태 메트릭 계산이 많은 블록 MAP 복호기의 격자단에서 하나의 상태 메트릭을 줄여 파워 소모와 메모리 요구량을 줄일 수 있다. 시뮬레이션 결과 제안된 정규화 구조를 적용한 터보 복호기는 기존의 블록 MAP 터보 복호기에 비해 동적 파워 소모는 17.9%까지 감소하고 면적은 6.6%까지 감소함을 확인하였다.

Keywords

References

  1. C. Berrou, A. Glavieux, and P. Thitimajshima,'Near Shannon Limit Error-correcting Coding andDecoding: Turbo-Codes(l),' in Proc. ICC,Geneva, Switzerland, pp. 1064-1070, May 1993
  2. C. Shannon, 'A Mathematical Theory of Information,' Bell System Technical Journal,Vol. 27, pp. 379-423, July 1948 https://doi.org/10.1002/j.1538-7305.1948.tb01338.x
  3. S. Barabulescu and S. Piebrobon, 'Turbo Codes: A Tutorial on a New Class of Powerful Error Correcting Coding Schems, Part2 : DecdoerDesign and Performance,' IEEE Journal ofElectrical and Electronics Engineering, Vol. 19,No. 3, pp. 143-152, Sept. 1999
  4. Y. Wu and J. Ebel, 'A Simple Stopping Criterion for Turbo Decoding', IEEE Comm.Letter, Vol. 4, pp. 258-260, Aug. 2000 https://doi.org/10.1109/4234.864187
  5. A. Viterbi, 'An Intuitive Justification and a Simplified Implementation of the MAP Decoder for Convolutional Codes,' IEEE Journal on Selected Areas in Communications,Vol. 16, No. 2, pp. 260-264, Feb. 1998 https://doi.org/10.1109/49.661114
  6. G. Park, S. Yoon, I. Jin, and C. Kang, 'A Block-wise MAP Decoder Using a Probability Ratio for Branch Metric' in Proc. VTC, Amsterdam, Netherlands, pp. 1610-1614, Sept.1999
  7. G. Masera and G. Piccinini, 'VLSIArchitectures for Turbo Codes,' in IEEE Trans. on VLSI Systems, VOL. 7, No 3, pp.369-379, Sept. 1999 https://doi.org/10.1109/92.784098
  8. Z. Wang, H. Suzuki, and K. Parhi, 'VLSIImplementation Issues of Turbo DecoderDesign for Wireless Applications', in Proc.IEEE Workshop on Signal ProcessingSystems, Taipei, Taiwan, pp. 503-512, Oct.1999
  9. S. Hong and W. Stark, 'Design andImplementation of a Low Complexity VLSITurbo-Code Decoder Architecture for LowEnergy Mobile Wireless Communication,'Jounal of VLSI Signal Processing Systems,Vol. 24, pp. 43-57, Feb. 2000 https://doi.org/10.1023/A:1008114510995
  10. G. Lee and S. Park, 'Turbo Decoder Designfor IS-2000 System,' in Proc. VTC, pp.412-415, Sept. 2000
  11. J. Cheng and T. Ottosson, 'Linearly Approximated Log-MAP AIgorithm for Turbocoding,' in Proc. VTC, pp. 2252- 2256, May2000
  12. G. Park and S. Yoon, 'An Implementation Method of a Turbo-code Decoder using aBlock wise MAP Algorithm,' in Proc. VTC,pp. 2956-2961, May 2000
  13. Y. Wu and B. Woerner, 'The Influence of Quantization and Fixed Point Arithmetic uponthe BER Performance of Turbo Codes,' inProc. VTC, Houston, TX, pp. 1683-1687, May1999
  14. Jeong and D. Hsia, 'Optimal Quantizationfor Soft-decision Turbo Decoder,' in Proc.VTC., Amsterdam, Netherlands, pp. 1620-1624,Sept. 1999
  15. Y. Wu and D. Brian, 'Data Width Requirements in SISO Decoding with Modulo Normalization,' IEEE Trans. Comm., Vol. 49, No. 11, pp. 1861-1868, Nov. 2001 https://doi.org/10.1109/26.966047
  16. Z. Wang and H. Suzuki, 'Finite Wordlength Analysis and Adaptive Decoding for Turbo/MAP Decoder,' in Journal of VLSI Signal Processing 29, 209-221, Nov. 2001 https://doi.org/10.1023/A:1012283413624
  17. Z. Wang and H. Suzuki, 'VLSI Implementation Issues of Turbo Decoder Design for Wireless Applications,' in Proc.IEEE Workshop on Signal Processing Systems, pp. 503-512, 1999
  18. J. Harrison, 'Implementation of a 3GPP Turbo Decoder on a Programmable DSP Core,' Communication Design Conference, San Jose, CA, Oct. 2001
  19. A. Worm and H. Michel, 'Advanced Implementation Issues of Turbo-Decoders,' inProc. 2nd International Symp. on Turbo Codes& Related Topics, pp. 351-354, Sept. 2000
  20. M. Valenti and J. Sun, 'UMTS Turbo Codeand an Efficient Decoder Implementation Suitable for Software-Defined-Radios,'International Journal of Wireless Information Networks, Vol. 8, No. 4, pp. 203-215, Oct.2001 https://doi.org/10.1023/A:1017925603986