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

  • 제35권2A호
  • /
  • Pages.202-208
  • /
  • 2010
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  • 1226-4717(pISSN)
  • /
  • 2287-3880(eISSN)
한국통신학회 (The Korean Institute of Commucations and Information Sciences)
권호 표지

WDM/SCM-PON의 상향 전송에서 헤테로다인 방식을 이용한 광간섭잡음 문제 극복방안 연구

Overcoming OBI Problem by Means of Heterodyne Detection in Upstream Transmission of WDM/SCM-PON

  • 전유찬 (고려대학교 전기전자전파공학과 통신네트워크 연구실) ;
  • 신홍석 (삼성전자 DMC연구소) ;
  • 박진우 (고려대학교 전기전자전파공학과 통신네트워크 연구실)
  • 발행 : 2010.02.28
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⟨ 이전 논문 다음 논문 ⟩

초록

WDM/SCM-PON에서 상향 전송을 할 때 다수의 ONU가 단일 광 채널을 공유하여 다수의 신호를 전송할 경우에 수신부에서 잡음으로 작용하는 OBI가 발생하게 되어 전체 시스템의 성능을 악화시키기 때문에 OBI에 대한 문제 해결이 필수적인 과제이다. 본 논문은 SCM-PON에서 상향 전송을 할 때 발생하는 OBI를 헤테로다인 검출 방식으로 극복하는 새로운 방안을 제시하였다. 제안된 방식은 수신 광검출기 앞부분에 별도의 LD를 사용하여 heterodyne detection을 가능케 함으로써, OBI 성분을 검출신호와 구분되도록 하여 OBI로 인한 문제를 해결하는데 근거를 두고 있다. 또한, 가입자단에서 R-SOA를 사용함으로써 경제적인 저가형 ONU 구현을 가능케 하는 장점을 갖는다.

The performance of upstream transmission in SCM-PON is generally limited by the presence of OBI which is caused by the beating of two or more lasers. In this paper, we propose a novel approach for reducing OBI problem by using heterodyne detection with an additional LD as a local oscillator, resulting that the RF signal is shifted to the other spectal band. In addition, it is possible that the proposed method can provide the cost-effective solution thanks to the loop-back mechanism using R-SOA in ONUs. The performance is superior when the spectral width of LD is smaller and the power difference between the transmission LD and the oscillation LD is bigger. System configuration and design consideration are discussed. Performance of the systems is evaluated by simulator called OptSim. It is expected to provide WDM/SCM-PON system not only cost-effective but also efficient in increasing the number of subscribers.

키워드

참고문헌

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