Journal of the Institute of Electronics Engineers of Korea TC (대한전자공학회논문지TC)

The Institute of Electronics and Information Engineers (대한전자공학회)
권호 표지

PTS Technique with Low Computational Complexity for PAPR Reduction of OFDM Signals

OFDM 신호의 PAPR 감소를 위한 낮은 계산 복잡도를 갖는 PTS 기법

  • Kong, Min-Han (Dept. of Electrical Electronic and Information Engineering, Wonkwang University) ;
  • Song, Moon-Kyou (Dept. of Electrical Electronic and Information Engineering, Wonkwang University)
  • 공민한 (원광대학교 전기전자및정보공학부) ;
  • 송문규 (원광대학교 전기전자및정보공학부)
  • Published : 2008.01.25
Download PDF
⟨ Previous Next ⟩

Abstract

The high peak-to-average power ratio(PAPR) of the transmitted signals is one of the major drawbacks of the orthogonal frequency division multiplexing(OFDM). The partial transmit sequences(PTS) technique can improve the PAPR statistics of the OFDM signals. However, in the PTS technique, the computational complexity to select phase weighting factors increases exponentially with the number of sub-blocks. In this paper, a search algorithm that has no limit on the values of phase weighting factors and requires no additional operations for the search is presented. To evaluate the performance, the proposed search algorithm is compared with the full search algorithm in terms of the complementary cumulative distribution function(CCDF) of the PAPR and the computational complexity. It is shown through simulations that the proposed technique can achieve significant reductions in the computational complexity with little performance degradation compared with the full search algorithm.

전송 신호의 높은 PAPR(Peak-to-Average Power Ratio)은 OFDM(Orthogonal Frequency Division Multiplexing)의 주된 문제점중의 하나이다. PTS(Partial Transmit Sequences) 기법은 OFDM 신호의 PAPR의 통계를 개선하는 기법이다. 그러나 PTS 기법에서 위상 가중치의 선택을 위한 계산 복잡도는 서브블록의 수에 따라 지수적으로 증가한다. 본 논문에서는 위상 가중치 값의 제한이 없고 탐색을 위해 부가적인 연산이 불필요한 탐색 알고리즘을 제안한다. 제안하는 탐색 알고리즘의 성능을 평가하기 위해 PAPR의 CCDF(Complementary Cumulative Distribution Function)와 계산 복잡도를 완전 탐색과 비교한다. 시뮬레이션을 통하여 제안한 탐색 알고리즘은 완전 탐색과 비교할 때 약간의 성능 저하를 가지고 계산 복잡도를 상당히 낮출 수 있음을 보였다.

Keywords

References

  1. R. Van Nee and R. Prasad, OFDM for Wireless Multimedia Communications, Boston, MA: Artech House, 2000
  2. J. Heiskala and J. Terry, OFDM Wireless LANs: A Theoretical and Practical Guide, Sams, 2002
  3. S. H. Muller and J. B. Huber, 'OFDM with Reduced Peak-to-Average Power Ratio by Optimum Combination of Partial Transmit Sequences,' Electronic Letters, vol. 33, no. 5, Feb. 1997, pp. 368-69 https://doi.org/10.1049/el:19970266
  4. Leonard J. Cimini, Jr. and Nelson R. Sollenberger, 'Peak-to-average power ratio reduction of an OFDM signal using partial transmit sequences,' IEEE Communications Letters, vol. 4, no. 3, pp. 86-88, Mar. 2000 https://doi.org/10.1109/4234.831033
  5. A. D. S. Jayalath and C. Tellambura, 'Adaptive PTS Approach for Reduction of Peak-to- Average Power Ratio of OFDM Signal,' Electronic Letters, vol. 36, no. 14, pp. 1226-28. July 2000 https://doi.org/10.1049/el:20000881
  6. Wong Sai Ho, A. S. Madhukumar, and Francois Chin, 'Peak-to-average power reduction using partial transmit sequences: a suboptimal approach based on dual layered phase sequencing,'IEEETransactions on Broadcasting, vol. 49, no. 2, pp. 225-231, Jun. 2003 https://doi.org/10.1109/TBC.2003.813440
  7. L. Yang, R. S. Chen, and K. K. Soo, 'PAPR reduction of an OFDM signal by use of PTS with low computational complexity,' IEEE Transactions on Broadcasting, vol. 52, no. 1, pp. 83-86, Mar. 2006 https://doi.org/10.1109/TBC.2005.856727
  8. C. Tellambura, 'Computation of the Continuous- Time PAR of an OFDM Signal with BPSK Subcarriers,' IEEE Communications Letters, vol. 5, no. 5, pp. 185-187, May 2001 https://doi.org/10.1109/4234.922754