The Journal of Korean Institute of Electromagnetic Engineering and Science (한국전자파학회논문지)

The Korean Institute of Electromagnetic Engineering and Science (한국전자파학회)
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A New Method of PAPR Reduction in OFDM Systems Using Modified GA-SPW

변형된 GA-SPW에 의한 OFDM의 새로운 PAPR 감소 기법

  • Kim, Sung-Soo (Department of Electrical Engineering, Chungbuk National University) ;
  • Kim, Myoung-Je (Department of Electrical Engineering, Chungbuk National University)
  • Published : 2006.11.30
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Abstract

An OFDM(Orthogonal Frequency Division Multiplexing) system has the problem of the PAPR(Peak-to-Average Power Ratio) due to the overlapping phenomena of many sub-carriers. The previously proposed GA-SPW(Genetic Sub-block Phase Weighting) method not only improved the reduction of PAPR as the number of sub-blocks increases in an OFDM symbol but also decreased the number of calculations involved in the iterative phase searching yields to depend on the number of population and generation by using genetic algorithm not on the number of sub-blocks and phase elements. In this paper, we propose the modified GA-SPW method in order to improve the performance and to decrease the complexity. It is shown that the proposed modified GA-SPW method achieves the significant performance and the reduction of search complexity comparing to the ordinary technique, iterative flipping and previously proposed GA-SPW by the experimental results and analysis.

OFDM(Orthogonal Frequency Division Multiplexing) 시스템은 다수 부반송파들의 중첩 현상으로 인해 PAPR (Peak-to-Average Power Ratio) 문제를 가진다. 기존의 제안된 GA-SPW(Genentic-Sub-block Phase Weighting) 기법은 하나의 OFDM 심볼에서 부 블록 수를 증가시켜 PAPR 감소 성능을 향상시키고, 부 블록 수에 따라 지수적으로 증가하는 위상 탐색량을 유전자 알고리즘을 이용하여 개체군과 세대수에 고정시켜 감소시켰다. 본 논문에서는 더 적은 탐색량으로 주어진 부 블록에서 최적에 가까운 PAPR 감소 성능을 얻기 위해 기존의 GA-SPW 기법에 새로이 변형된 유전자 알고리즘을 적용한다. 제안된 기법의 성능과 계산량의 우수성을 모든 부 블록과 위상수에 따른 모든 탐색을 하는 일반적인 탐색 방법, iterative flipping그리고 기존의 GA-SPW와 시뮬레이션과 결과의 분석을 통하여 나타내었다.

Keywords

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