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

The Korean Institute of Commucations and Information Sciences (한국통신학회)
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A Signal Detection Technique for OFDMA-based Wireless Mesh Networks with Different Time Delays

서로 다른 지연 시간을 갖는 OFDMA 기반의 Wireless Mesh Networks를 위한 신호 검출 기법

  • Park, Chang-Hwan (School of Electrical & Electronic Engineering, Chung-Ang University) ;
  • Yoo, Hyun-Il (School of Electrical & Electronic Engineering, Chung-Ang University) ;
  • Kim, Yeong-Jun (School of Electrical & Electronic Engineering, Chung-Ang University) ;
  • Kwon, Dong-Seung (Wireless System Research Department, Korea Electronics Technology Institute) ;
  • Cho, Yong-Soo (School of Electrical & Electronic Engineering, Chung-Ang University)
  • 박창환 (중앙대학교 전자전기공학부) ;
  • 유현일 (중앙대학교 전자전기공학부) ;
  • 김영준 (중앙대학교 전자전기공학부) ;
  • 권동승 (국전자통신연구원 인터넷연구부문 무선시스템연구부) ;
  • 조용수 (중앙대학교 전자전기공학부)
  • Received : 2010.04.30
  • Accepted : 2010.06.07
  • Published : 2010.06.30
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Abstract

In this paper, the effect of Near-Far Problem (NFP) among distributed nodes in OFDMA-based Wireless Mesh Networks (WMNs) is analyzed by investigating statistical characteristics of Time Difference of Arrival (TDoA) and Desired-to-Undesired power Ratio (DUR). In order to overcome the effects of Inter-Symbol Interference (ISI), Inter-Carrier Interference (ICI), and Inter Link Interference (ILI), caused by TDoA in WMNs, we derive effective SINR for each subcarrier, and then, propose the optimal starting point of FFT window which can minimize BER for each subcarrier. In addition, we propose a subcarrier-based Zero Forcing - 2 Dimensional Ordered Successive Interference Cancellation (ZF-2DOSIC) technique for signal detection in WMNs with TDoA. It is verified by simulation that the effective SINR and uncoded BER performances of the proposed signal detection technique for OFDMA-based WMNs are significantly improved, compared with those of conventional technique.

본 논문에서는 OFDMA(Orthogonal Frequency Division Multiple Access) 기반의 WMN(Wireless Mesh Network)에서 분산 노드(node)간에 NFP(Near-Far Problem)의 영향을 알아보기 위하여, TDoA(Time Difference of Arrival)와 DUR(Desired-to-Undesired power Ratio)의 통계적 특성을 분석한다. WMN에서 서로 다른 지연 시간에 따른 ISI(Inter-Symbol Interference)와 ICI(Inter-Carrier Interference) 및 ILI(Inter Link Interference)의 영향을 극복하기 위하여 각 부반송파 별로 FFT 윈도우 시작 위치에 따른 effective SINR을 유도하고, 이를 바탕으로 각 부반송파 위치에서 BER을 최소화 하는 FFT 윈도우 시작 위치 선정 기법을 제안한다. 또한, 서로 다른 지연 시간을 갖는WMN에서 신호검출을 위하여 ZF-2DOSIC(Zero Forcing - 2 Dimensional Ordered Successive Interference Cancellation) 기법을 제안한다. 제안된 FFT 윈도우 시작 위치 선정 기법과 신호 검출 기법은 기존의 기법과 비교하여 WMN에서 effective SINR과 uncoded BER 성능이 크게 향상되는 것을 모의실험을 통하여 확인한다.

Keywords

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