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

The Korean Institute of Commucations and Information Sciences (한국통신학회)
권호 표지

Amplitude and Phase Variant SLM Scheme for PAPR Reduction in QAM Modulated OFDM Signals

직교 주파수 분할 다중화 신호의 최대전력 대 평균전력의 비 감소를 위한 크기 및 위상 변이 선택 사상 기법

  • 전현배 (서울대학교 전기.컴퓨터공학부 및 뉴미디어통신 연구소) ;
  • 김기훈 (서울대학교 전기.컴퓨터공학부 및 뉴미디어통신 연구소) ;
  • 노종선 (서울대학교 전기.컴퓨터공학부 및 뉴미디어통신 연구소) ;
  • 신동준 (한양대학교 전자통신컴퓨터공학부)
  • Published : 2010.02.28
Download PDF
⟨ Previous Next ⟩

Abstract

In this paper, we propose a new selected mapping (SLM) scheme for reducing peak to average power ratio (PAPR) of orthogonal frequency division multiplexing (OFDM) signals modulated with quadrature amplitude modulation (QAM), called amplitude and phase variant SLM (APSLM). Contrary to the conventional SLM which rotates the phases of QAM symbols in the frequency domain, the proposed scheme changes the magnitudes as well as the phases of QAM symbols by applying binary sequences to the binary data sequence before mapped to QAM symbols. Simulation results show that the proposed scheme has better PAPR reduction performance than the conventional SLM scheme for the QAM modulated OFDM signals, especially for the small number of subcarriers.

본 논문에서는 크기 및 위상 변이 선택사상 기법(amplitude and phase variant SLM)을 제안한다. 이 기법은 직교 진폭 변조(quadrature amplitude modulation; QAM)로 변조된 직교 주파수 분할 다중화(orthogonal frequency division multiplexing; OFDM)신호에서 최대전력 대 평균전력의 비(peak to average power ratio; PAPR)를 감소시킨다. 주파수 영역에서 QAM 심볼들의 위상만을 회전시키는 기존의 SLM과 비교하였을 때에 제안된 기법은 QAM 심볼들로 대응되기 전의 이진 데이터의 특정 위치에 이진 시퀀스를 곱해줌으로써 QAM 심볼에 대응 시에 위상은 물론 크기까지 변화시켜준다. 모의실험 결과는 제안된 기법이 QAM 변조된 OFDM 신호들에 대하여 기존의 SLM 보다 PAPR 감소 성능이 더 좋다는 것을 보여준다.

Keywords

References

  1. M. R. D. Rodrigues and I. J. Wassell, "IMD reduction with SLM and PTS to improve the error-probability performance of nonlinearly distorted OFDM signals," IEEE Trans. Veh. Technol., Vol.55, No.2, pp.537-548, Mar. 2006. https://doi.org/10.1109/TVT.2005.863417
  2. J. Armstrong, "Peak-to-average power reduction for OFDM by repeated clipping and frequency domain ltering," IEE Electron. Lett., Vol.38, pp. 246-247, Feb. 2002. https://doi.org/10.1049/el:20020175
  3. J. Tellado, "Peak to average power reduction for multicarrier modulation," Ph.D. dissertation, Stanford Univ., Stanford, CA, 2000.
  4. S. H. Muller and J. B. Huber, "OFDM with reduced peak-to-average power ratio by optimum combination of partial transmit sequences," IEE Electron. Lett., Vol.33, No.5, pp.368-369, Feb. 1997. https://doi.org/10.1049/el:19970266
  5. R. W. Bauml, R. F. H. Fischer, and J. B. Huber, "Reducing the peak-to-average power ratio of multicarrier modulation by selected mapping," IEE Electron. Lett., Vol.32, No.22, pp.2056-2057, Oct. 1996. https://doi.org/10.1049/el:19961384
  6. A. D. S. Jayalath and C. Tellambura, "Reducing the peak-to-average power ratio of orthogonal frequency division multiplexing signal throuhg bit or symbol interleaving," IEE Electron. Lett., Vol.36, No.13, pp.1161-1163, Jun. 2000. https://doi.org/10.1049/el:20000822
  7. M. Breiling, S. H.Muller, and J. B. Huber, "SLM peak-power reduction without explicit side information," IEEE Commun. Lett., Vol.5, No.6, pp.239-241, Jun. 2001. https://doi.org/10.1109/4234.929598
  8. D.-W. Lim, S.-J. Heo, and J.-S. No, "On the phase sequence set of SLM OFDM scheme for a crest factor reduction," IEEE Trans. Signal Process., Vol.54, No.5, pp.1931-1935, May 2006. https://doi.org/10.1109/TSP.2006.871979
  9. G. T. Zhou and L. Peng, "Optimality condition for selected mapping in OFDM," IEEE Trans. Signal Process., Vol.54, No.8, pp.3159-3165, Aug. 2006. https://doi.org/10.1109/TSP.2006.874774
  10. S.-L. J. Hu, "Probabilistic independence and joint cumulants," J. of Engin. Mech., Vol.17, No.3, pp.640-652, Mar. 1991.