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

The Korean Institute of Commucations and Information Sciences (한국통신학회)
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Interference Mitigation Technique for OFDMA-based Mesh Networks in Doubly Selective Channels

시간/주파수 선택적 채널환경에서 OFDMA 기반의 메쉬 네트워크를 위한 간섭 완화 기법

  • Park, Chang-Hwan (School of Electrical & Electronic Engineering, Chung-Ang University) ;
  • Kong, Mi-Kyung (School of Electrical & Electronic Engineering, Chung-Ang University) ;
  • Cho, Yong-Soo (School of Electrical & Electronic Engineering, Chung-Ang University)
  • Received : 2011.05.24
  • Accepted : 2011.10.10
  • Published : 2012.01.31
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Abstract

In this paper, we described a received signal model in terms of the starting point of FFT window and derive a post-detection SINR for the receiver with MMSE filter and the corresponding filter coefficients in order to mitigate the effects of interferences caused by time and frequency selective fading channels and time difference of arrival (TDoA) in OFDMA-based Mesh Networks. In addition, we proposed an MMSE Bidirectional Successive Detection (BSD) technique which can suppress the effects of interferences among multi-nodes without any redundant FFT operations. It was shown by simulation that the proposed interference suppression technique has not an error floor at higher average SNR than 30dB in terms of 64QAM uncoded BER contrary to the conventional techniques.

본 논문에서는 OFDMA(Orthogonal Frequency Division Multiple Access) 기반 메쉬 네트워크에서 시간/주파수 선택적 페이딩 채널과 TDoA(Time Difference of Arrival)에 의한 간섭의 영향을 완화하기 위하여, FFT 윈도우 시작 위치에 따른 수신 신호 모델을 기술하고, MMSE 필터를 사용하는 수신기를 위한 사후 검출 SINR과 필터 계수를 유도하였다. 또한, 이를 바탕으로 중복된 FFT 연산을 회피하면서 다중 노드간에 발생하는 간섭을 효과적으로 완화할 수 있는 MMSE-BSD(Bidirectional Successive Detection) 기법을 제안하였다. 제안하는 기법은 기존의 기법과 달리 30dB 이상의 평균 SNR에서도 64QAM uncoded BER 성능에 오차 마루 현상이 없음을 모의실험을 통하여 확인하였다.

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