KR970060862A - Fast adaptive channel equalizer - Google Patents

Fast adaptive channel equalizer Download PDF

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Publication number
KR970060862A
KR970060862A KR1019960001722A KR19960001722A KR970060862A KR 970060862 A KR970060862 A KR 970060862A KR 1019960001722 A KR1019960001722 A KR 1019960001722A KR 19960001722 A KR19960001722 A KR 19960001722A KR 970060862 A KR970060862 A KR 970060862A
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KR
South Korea
Prior art keywords
output
comparing
step size
unit
counting
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Application number
KR1019960001722A
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Korean (ko)
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KR0172928B1 (en
Inventor
이동훈
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구자홍
엘지전자 주식회사
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Priority to KR1019960001722A priority Critical patent/KR0172928B1/en
Publication of KR970060862A publication Critical patent/KR970060862A/en
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    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
    • H04L27/00—Modulated-carrier systems
    • H04L27/01—Equalisers
    • H—ELECTRICITY
    • H03—ELECTRONIC CIRCUITRY
    • H03K—PULSE TECHNIQUE
    • H03K19/00—Logic circuits, i.e. having at least two inputs acting on one output; Inverting circuits
    • H03K19/20—Logic circuits, i.e. having at least two inputs acting on one output; Inverting circuits characterised by logic function, e.g. AND, OR, NOR, NOT circuits
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04N—PICTORIAL COMMUNICATION, e.g. TELEVISION
    • H04N5/00—Details of television systems
    • H04N5/14—Picture signal circuitry for video frequency region
    • H04N5/21—Circuitry for suppressing or minimising disturbance, e.g. moiré or halo
    • H04N5/211—Ghost signal cancellation
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
    • H04L25/00—Baseband systems
    • H04L25/02—Details ; arrangements for supplying electrical power along data transmission lines
    • H04L25/03—Shaping networks in transmitter or receiver, e.g. adaptive shaping networks
    • H04L25/03006—Arrangements for removing intersymbol interference
    • H04L2025/03592—Adaptation methods
    • H04L2025/03598—Algorithms
    • H04L2025/03611—Iterative algorithms
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
    • H04L25/00—Baseband systems
    • H04L25/02—Details ; arrangements for supplying electrical power along data transmission lines
    • H04L25/03—Shaping networks in transmitter or receiver, e.g. adaptive shaping networks
    • H04L25/03006—Arrangements for removing intersymbol interference
    • H04L2025/03592—Adaptation methods
    • H04L2025/03726—Switching between algorithms
    • H04L2025/03732—Switching between algorithms according to the convergence state

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  • Engineering & Computer Science (AREA)
  • Signal Processing (AREA)
  • Multimedia (AREA)
  • Computer Networks & Wireless Communication (AREA)
  • Physics & Mathematics (AREA)
  • Computer Hardware Design (AREA)
  • Computing Systems (AREA)
  • General Engineering & Computer Science (AREA)
  • Mathematical Physics (AREA)
  • Filters That Use Time-Delay Elements (AREA)
  • Cable Transmission Systems, Equalization Of Radio And Reduction Of Echo (AREA)

Abstract

본 발명은 전송 채널상에서 발생되는 고스트신호로 인해 열화된 수신신호를 빠른 속도로 적응시켜 열화를 보상하는 고속 적응 채널 등화기에 관한 것으로. 본 발명은 종래의 채널 등화기는 스텝 사이즈 및 반복(Iteration)양이 일정하게 고정되어 있어서 채널 환경이 나쁠때나 고스트가 많이 생길 경우 적응속도가 늦은 단점이 있었던 점을 감안하여 입력신호와 에러신호에 의해 각 필드의 필드 싱크 라인의 SNR을 구하는 SNR계산부와, SNR계산부의 출력과 정해진 기준값과 비교하여 비교결과에 따라 업/다운 카운팅을 행하는 비교 및 카운팅부와, 비교 및 카운팅부의 출력에 따라 최적의 계수값으로 접근시키기 위한 최적의 반복횟수를 갖는 경로를 선택하는 반복 제어부와, 반복 제어부의 제어에 따라 선택된 반복횟수를 갖는 경로에 맞는 스텝 사이즈를 출력하는 스텝 사이즈 룩-업 테이블을 구비하여 조건에 따라 계수 갱신 스텝 사이즈를 변화시켜 고속으로 수렴할 수 있도록 함으로써 채널 환경이 좋지 않은 지역에서도 빠른 속도로 적응해 열화된 신호를 보상할 수 있도록 한 것이다. 그리고 본 발명은 빌딩이 많이 모여있는 대도시 및 항공기가 많이 지나가는 지역 등 채널환경이 좋지 않은 지역에 적용가능하다.The present invention relates to a fast adaptive channel equalizer that compensates for degradation by rapidly adapting a received signal degraded by a ghost signal generated on a transmission channel. The present invention is based on the fact that the conventional channel equalizer has a disadvantage in that the adaptation speed is slow when the channel environment is bad or the ghost is generated because the step size and the amount of iterations are fixed constantly. A comparing and counting unit for comparing the output of the SNR calculating unit with a predetermined reference value and performing up / down counting according to the comparison result, and a comparing / counting unit for comparing the output of the comparing unit and the counting unit And a step size look-up table for outputting a step size corresponding to the path having the repetition number selected according to the control of the repetition control section, The coefficient update step size can be changed in accordance with the channel size It will also have to be adapted to compensate the degraded signal at high speed. The present invention can be applied to an area where the channel environment is poor, such as a metropolitan area where a lot of buildings are gathered and an area where a lot of airplanes pass.

Description

고속 적응 채널 등화기Fast adaptive channel equalizer

본 내용은 요부공개 건이므로 전문내용을 수록하지 않았음Since this is a trivial issue, I did not include the contents of the text.

제2도는 본 발명에 따른 고속 적응 채널 등화기의 구성도.FIG. 2 is a block diagram of a fast adaptive channel equalizer according to the present invention; FIG.

제3도는 본 발명에 따른 고속 적응 채널 등화기의 동작 플로우 챠트.FIG. 3 is a flowchart of an operation of a fast adaptive channel equalizer according to the present invention; FIG.

Claims (1)

포워드 필터와 피드백 필터의 출력을 감하여 등화된 채널 출력을 행하며, 필터 계수 계산부에서는 디시젼된 데이터 정보 출력이나 필드 싱크에 들어있는 트레이닝 시퀀스의 출력중의 어느 하나와 상기 등화된 채널 출력간의 차이값이 에러신호와 입력신호와의 상관에 따라 상기 포워드 필터 및 피드백 필터의 계수값을 갱신시키는 채널 등화기에 있어서, 상기 필터 계수 계산부는 입력 신호와 상기 에러신호의 상관값을 구하는 상관기와, 상기 상관기의 출력이 일시 저장되는 FIFO와, 입력신호와 상기 에러신호에 의해 각 필드의 필드 싱크 라인의 SNR을 구하는 SNR계산부와, 상기 SNR계산부의 출력과 정해진 기준값과 비교하여 비교결과에 따라 없/다운 카운팅을 행하는 비교 및 카운팅부와, 상기 비교 및 카운팅부의 출력에 따라 최적의 계수값으로 접근시키기 위한 최적을 반복횟수를 갖는 경로를 선택하는 반복 제어부와, 상기 반복 제어부의 제어에 따라 상기 선택된 반복횟수를 갖는 경로에 맞는 스텝사이즈를 출력하는 스텝 사이즈 룩-업 테이블과, 상기 FIFO를 통해 출력되는 상관값과 상기 스텝 사이즈 룩-없 테이블의 출력을 곱하는 곱셈기와, 상기 반복 제어부의 출력에 따라 현재 탭과 새로운 탭의 계수값의 입출력이 제어되는 듀얼 포트 램과, 상기 곱셈기의 출력과 상기 듀얼 포트 램으로부터의 현재 탭의 계수값을 감하여 갱신된 계수값을 얻어 상기 포워드 및 피드백 필터 로딩하며, 상기 듀얼 포트 램에 새로운 탭의 계수값으로 저장하는 감산기로 구성됨을 특징으로 하는 고속 적응 채널 등화기.The output of the forward filter and the feedback filter is subtracted to perform an equalized channel output. In the filter coefficient calculation unit, a difference value between any one of the output of the data information outputted, or the output of the training sequence included in the field sync, And a filter coefficient calculator for calculating a correlation value between the input signal and the input signal, wherein the filter coefficient calculator comprises: a correlator for obtaining a correlation value between the input signal and the error signal; An SNR calculation unit for obtaining an SNR of a field sync line of each field by an input signal and the error signal; a FIFO comparing unit for comparing the output of the SNR calculating unit with a predetermined reference value, A comparison and counting unit for performing a comparison and counting on the output of the comparison and counting unit, A step size look-up table for outputting a step size corresponding to a path having the selected repetition number under the control of the repetition control unit; A multiplier for multiplying the output of the multiplier and the output of the step size look-up table, and a dual port RAM in which input and output of current tap and new tap coefficients are controlled according to the output of the repetition control unit, And a subtractor for subtracting the count value of the current tap from the port RAM to obtain the updated count value, to load the forward and feedback filters, and to store the count value as a new tap count value in the dual port RAM. . ※ 참고사항 : 최초출원 내용에 의하여 공개하는 것임.※ Note: It is disclosed by the contents of the first application.
KR1019960001722A 1996-01-26 1996-01-26 High speed adaptive channel equalizer KR0172928B1 (en)

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KR0172928B1 KR0172928B1 (en) 1999-03-20

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Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
KR20010055964A (en) * 1999-12-13 2001-07-04 박종섭 Equalizer having coefficient input and output function
KR100718078B1 (en) * 1998-12-22 2007-05-16 톰슨 콘슈머 일렉트로닉스, 인코포레이티드 Adaptive channel equalizer having a training mode
KR100789833B1 (en) * 2006-01-16 2008-01-02 엘지전자 주식회사 Equalizer

Families Citing this family (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
KR100705006B1 (en) * 2001-06-30 2007-04-09 매그나칩 반도체 유한회사 Adaptive equalizing device for removing dynamic ghost and thereof method
KR100762135B1 (en) * 2005-11-28 2007-10-02 엘지전자 주식회사 Apparatus and method for channel equalizing in digital broadcasting receiving system

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
KR100718078B1 (en) * 1998-12-22 2007-05-16 톰슨 콘슈머 일렉트로닉스, 인코포레이티드 Adaptive channel equalizer having a training mode
KR20010055964A (en) * 1999-12-13 2001-07-04 박종섭 Equalizer having coefficient input and output function
KR100789833B1 (en) * 2006-01-16 2008-01-02 엘지전자 주식회사 Equalizer

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