FEXT cancellation for high-speed local transmission over twisted pair wiring

동축 선로에서의 초고속 근거리 전송을 위한 FEXT 제거기

  • 우정수 (포항공과대학교 전자전기공학과 통신연구실) ;
  • 강규민 (포항공과대학교 전자전기공학과 통신연구실) ;
  • 임기홍 (포항공과대학교 전자전기공학과 통신연구실)
  • Published : 2002.08.01

Abstract

This paper discusses a far-end crosstalk (FEXT) canceller for twisted-pair transmission. Many twisted-pair systems such as fiber-to-the-curb (FTTC), very high-speed digital subscriber line (VDSL), and high-speed LAN systems, use frequency-division duplexing (FDD) for duplex transmission. It is shown that the maximum reach of FDD twisted-pair system is limited by the performance of its upstream channel, which is located at higher frequencies than the downstream channel. In order to improve the performance of such FDD transceiver, FEXT cancellation is introduced for the channel at higher frequencies. A system arrangement and its blind start-up procedure are studied when the FEXT canceller and equalizer are jointly adapted to combat channel intersymbol interference (ISI), FEXT, and other additive noise. The initial convergence and the steady-state behavior of the proposed twisted-pair system without requiring transmission of an ideal training sequence are investigated. Measured characteristics as well as analytical model of the FEXT channel are used to estimate the time span needed for the FEXT canceller. It is also shown that the memory span for the FEXT canceller is almost independent of the channel, thus making our results useful for the twisted-pair system over all different channels.

본 논문은 FEXT (far-end crosstalk) canceller에 관한 연구이다. Fiber to the curb (FTTC), very high speed digital subscriber와 같은 많은 동축선로 시스템에서 양방향 전송을 위해 frequency-division duplexing (FDD)를 사용한다. FDD 동축전송 시스템의 최고의 도달 거리는 하향채널보다는 높은 주파수에 위치한 상향 채널에 의해서 제한된다. 그런 FDD 송수신의 성능을 개선하기 위해서 높은 주파수에 있는 채널은 FEXT 제거를 적용하게 된다. 시스템을 배열과 그것은 blind startup 은 채널의 intersymbol interference (ISI), FEXT와 다른 잡음을 막기 위해 FEXT 제거기와 등화기를 함께 적용함으로써 연구한다. 이상적 훈련 신호를 전송하지 않고, 제안된 동축선로상에서 초기 수렴과 수렴된 후의 상태를 알아본다. 또한 FEXT 채널의 분석한 모델뿐만 아니라, 측정된 특성은 FEXT 제거기를 위해 필요한 기간을 측정하기 위해 사용되어진다. 또한 FEXT 제거기를 위한 메모리 수가 채널에 독립적이기 때문에, 제안된 시스템은 모든 독립적인 채널 상에서 동축 시스템에 대해 유용하게 적용할 수 있다.

Keywords

References

  1. IEEE J.Select.Areas in Commun v.9 no.6 The HDSL environment J.J.Werner
  2. AT&T/Bellcore Contribution ANSI T1E1.4/92-149 Desing of digital carrierless AM/PM transceivers W.Y.Chen;G.H.Im;J.J.Werner
  3. IEEE Commun. Magazine v.36 no.11 Comparison of single-carrier and multitone digital modulation for ADSL applications B.R.Saltzberg
  4. IEEE J. Select. Area in Commun v.13 no.9 Bandwidth-efficient digital transmission over unshielded twisted pair wiring G.H.Im;J.J.Werner
  5. IEEE J.Select.Areas in Commun. v.13 no.4 51.84 Mb/s 16-CAP ATM LAN standard G.H.Im;D.D.Harman;G.Huang;A.V.Mandzik;M H Nguyen;J.J.Werner
  6. IEEE J. Select. Areas in Commum v.13 no.9 A quaternary partial-response class-IV transceiver for 125 Mbit/s data transmission over unshielded twisted-pair cable: principles of operation and VLSI realization G.Cherubini;Sedat Olcer;G.Ungerboeck
  7. IEEE Trans. on Signal Processing v.46 no.8 A pipelined adaptive NEXT canceller G.H.Im;N.R.Shanbhag
  8. IEEE Commun. Letters v.4 no.8 Convergence behavior of a phase-splitting fractionally spaced equalizer in the presence of a cyclostationary crosstalk interference G.H.Im;H.C.Won;C.J.Park
  9. DAVIC 1.4 Specification Part 8; Lower Layer Protocols and Physical Interfaces
  10. IEEE Commun. Magazine, v.37 no.4 Blind equalization for broadband access J.J.Wemer(et al.)
  11. IEEE Commun. Letters v.5 no.2 A blind equalization with the sign algorithm for broadband access G.H.Im;C.J.Park;H.C.Won
  12. ANSI T1E1.4/96-194 Performance of single-carrier and multicarrier systems in the presence of broadband noise and narrowband interference J.J.Werner;G.H.Im;N.A.Zervos
  13. submitted for publication in IEEE J. Select.Areas in Commun All Digital timing recovery and programmable gain amplifier controller for VDSL transmission G.H.Im;D.H.Kim
  14. IEEE Trans. on Acoust., Speech, Signal Processing v.37 no.9 The LMS algorithm with delayed coefficient adaptation G.Long;F.Ling;J.G.Proakis