전자공학회논문지 (Journal of the Institute of Electronics and Information Engineers)

  • 제50권8호
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  • Pages.67-75
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  • 2013
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  • 2287-5026(pISSN)
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  • 2288-159X(eISSN)
대한전자공학회 (The Institute of Electronics and Information Engineers)
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OFDM 시스템의 비트 및 부채널 할당을 위한 선형계획법 기반 휴리스틱

A Linear Program Based Heuristic for the Bit and Subchannel Allocation in an OFDM System

  • 문우식 (숭실대학교, 정보통신전자공학부) ;
  • 김선호 (숭실대학교, 정보통신전자공학부) ;
  • 박태형 (숭실대학교, 산업정보시스템공학과) ;
  • 임성빈 (숭실대학교, 정보통신전자공학부)
  • Moon, Woosik (School of Electronic Engineering, Soongsil University) ;
  • Kim, Sunho (School of Electronic Engineering, Soongsil University) ;
  • Park, Taehyung (Department of Industrial and Information Systems Engineering, Soongsil University) ;
  • Im, Sungbin (School of Electronic Engineering, Soongsil University)
  • 투고 : 2013.05.14
  • 발행 : 2013.08.15
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초록

OFDM (Orthogonal Frequency Division Multiplexing) 전송방식의 장점은 높은 주파수 효율, RF 간섭에 대한 강인성, 낮은 다중경로 왜곡 등을 들 수 있다. 다중 사용자 OFDM의 채널용량을 확대하기 위해서는 사용자간의 부채널과 비트할당을 위한 효율적인 알고리즘을 개발하여야 한다. 본 연구에서는 다중 사용자 OFDM 시스템에서 총전송전력을 최소화하는 부채널 및 비트 할당을 위한 0-1 정수계획법문제의 선형계획법 dual 문제의 특성을 기존의 볼록최적화기법 접근법과 비교하고 선형계획법 dual 해를 이용한 primal 휴리스틱 알고리즘을 제안한다. MQAM (M-ary Quadrature Amplitude Modulation)을 사용하고 3개의 독립적인 Rayleigh 다중 경로로 구성된 주파수 선택적 채널을 가정한 경우 MATLAB을 사용한 모의실험에서 제안된 휴리스틱 해의 성능을 기존의 MAO, ESA 휴리스틱 해 및 정수계획법 최적해와 성능을 비교하였다.

The advantages of the orthogonal frequency division multiplexing (OFDM) are high spectral efficiency, resiliency to RF interference, and lower multi-path distortion. To further utilize vast channel capacity of the multiuser OFDM, one has to find the efficient adaptive subchannel and bit allocation among users. In this paper, we compare the performance of the linear programming dual of the 0-1 integer programming formulation with the existing convex optimization approach for the optimal subchannel and bit allocation problem of the multiuser OFDM. Utilizing tight lower bound provided by the LP dual formulation, we develop a primal heurisitc algorithm based on the LP dual solution. The performance of the primal heuristic is compared with MAO, ESA heuristic solutions, and integer programming solution on MATLAB simulation on a system employing M-ary quadrature amplitude modulation (MQAM) assuming a frequency-selective channel consisting of three independent Rayleigh multi-paths.

키워드

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