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

The Korean Institute of Commucations and Information Sciences (한국통신학회)
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Efficient Usage of Secondary Scramble Code via Optical Repeater in W-CDMA System

W-CDMA 시스템에서 광중계기를 이용한 secondary-스크램블 코드의 효율적 활용방안에 대한 연구

  • 전은성 (연세대학교 전기전자공학과 이동통신 연구실) ;
  • 박준효 (연세대학교 전기전자공학과 이동통신 연구실) ;
  • 양장훈 (연세대학교 전기전자공학과 이동통신 연구실) ;
  • 김동구 (연세대학교 전기전자공학과 이동통신 연구실)
  • Published : 2009.08.31
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Abstract

Optical repeater is often installed at the isolated area. Spatial separation makes it possible to reduce the inter-code interference when secondary scrambling codes are used for traffic connected through repeater. In this paper, we propose five secondary scrambling code usage scenarios with the aids of optical repeater to maximize the user capacity. In order to evaluate the performance, dynamic system level simulation is performed. We also propose a base station-repeater switching where each active users can change access points by comparing the channel condition from base station and repeater thorough secondary common pilot channel (S-CPICH) signal to noise-interference ratio (SINR). Moreover, primary-secondary scramble code replacing scheme is proposed which replaces secondary scramble code with primary scramble code when a call using primary scramble code is ended and its corresponding OVSF code is available to users using the secondary scramble code

최근 셀 커버리지 증대와 음영지역 및 핫스팟(hot spot) 지역의 서비스 공급을 위해 추가적인 기지국 설치를 하지 않고 중계기를 활용하고 있다. 중계기는 기지국과 지형적으로 떨어져 있기 때문에 중계기와 기지국이 서로 다른 스크램블 코드를 사용할 때, 코드간 간섭이 줄어들 수 있다. 본 논문은 이와 같은 사실을 이용하여 중계기를 활용한 primary-secondary 스크램블 코드 활용 방안을 연구한다.. 이를 위해서 다섯 가지의 시나리오를 제시하고, 각 시나리오 별 성능을 시스템 레벨 시뮬레이션을 통해 비교한다. 이에 더하여, secondary 스크램블 코드의 미치는 간섭을 줄이고, 아웃티지(outage) 성능을 향상시키기 위해서 기지국-중계기간 스위칭(switching) 기법과 primary-secondary 스크램블 코드간 리플레이싱(replacing) 기법을 제안한다.

Keywords

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