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 Rapid Signal Acquisition Scheme for Noncoherent UWB Systems

비동기식 초광대역 시스템을 위한 고속 신호 동기획득 기법

  • 김재운 (숭실대학교 정보통신전자공학부) ;
  • 양석철 (숭실대학교 정보통신전자공학부) ;
  • 최성수 (한국전기연구원 전기정보망기술연구그룹) ;
  • 신요안 (숭실대학교 정보통신전자공학부)
  • Published : 2006.04.01
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Abstract

In this Paper, we propose to extend the TSS-LS(Two-Step Search scheme with Linear search based Second step) scheme which was already proposed by the authors for coherent UWB(Ultra Wide Band) systems, to rapid and reliable acquisition of noncoherent UWB systems in multipath channels. The proposed noncoherent TSS-LS employing simple energy window banks utilizes two different thresholds and search windows to achieve fast acquisition. Furthermore, the linear search is adopted for the second step in the proposed scheme to correctly find the starting point in the range of effective delay spread of the multipath channels, and to obtain reliable BER(Bit Error Rate) performance of the noncoherent UWB systems. Simulation results with multipath channel models by IEEE 802.15.3a show that the proposed two-step search scheme can achieve significant reduction of the required mean acquisition time as compared to general search schemes. ]n addition, the proposed scheme achieves quite good BER performance for large signal-to-noise ratios, which is favorably comparable to the case of ideal perfect timing.

이 논문에서는 다중경로 채널 환경에서 비동기식(Noncoherent) 초광대역(Ultra Wide Band) 무선통신 시스템의 고속 고신뢰 신호 동기획득을 위해, 저자들이 동기식(Coherent) 초광대역 시스템을 위해 제안하였던 TSS-LS (Two-Step Search scheme with Linear search based Second step). 기법을 비동기식 초광대역 시스템에 확장 적용하는 방안을 제안한다. 간단한 에너지 윈도우 뱅크를 사용하는 제안된 비동기식 TSS-LS 기법은 고속의 동기획득을 위해 두 단계의 서로 다른 문턱값과 탐색창을 적용하게 된다. 더욱이 다중경로 채널의 실효 지연 확산 범위에서의 시작 지점을 정확히 찾고 비동기식 초광대역 변복조와 연동했을 때 신뢰성 있는 비트오율(Bit Error Rate) 성능을 얻기 위해 두 번째 단계에서 선형 알고리즘을 적용한다. IEEE 802.15.3a의 다중경로 채널 모형을 이용한 모의실험 결과, 일반적인 탐색 기법보다 제안된 기법의 평균 동기획득 소요 시간이 큰 폭으로 단축됨을 확인할 수 있었다. 또한, 신호 동기획득 과정과 연동된 비트오율 성능 평가에서 신호대잡음비가 높을 때 이상적인 동기획득의 경우에 필적하는 매우 우수한 성능을 보임을 확인할 수 있었다.

Keywords

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