公开(公告)号：JPH07147646A

公开(公告)日：1995-06-06

申请号：JP12279994

申请日：1994-06-03

Applicant: ST MICROELECTRONICS SRL

Inventor： D ALTO VIVIANA ,  AIROLDI FABRIZIO ,  SCALISE FABIO ,  PODESTA MARIA GRAZIA

IPC: H04B7/015 ,  H04N5/21

Abstract: PURPOSE: To suppress video signal echoes in a television equalizer. CONSTITUTION: A first digital filter 2 in television equalizer 1 supplies an output upon receiving a video signal x(k) and a first adding node 3 in the equalizer 1 supplies an equalizer output signal y(k) upon receiving the output of the filter 2. A digital filter 5 in the equalizer 1 supplies an output to the node 3 upon receiving the equalizer output signal y(k) and a second adding node in the equalizer 1 supplies an error signal e(k) which is equal to the difference between the equalizer output signal y(k) and a reference signal d(k). An echo suppressing circuit 4 supplies a filter coefficient updated upon receiving the error signal e(k) to the first and second digital filters 2 and 5.

公开(公告)号：DE69327900D1

公开(公告)日：2000-03-30

申请号：DE69327900

申请日：1993-06-09

Applicant: ST MICROELECTRONICS SRL

Inventor： D ALTO VIVIANA ,  AIROLDI FABRIZIO ,  SCALISE FABIO ,  PODESTA MARIA GRAZIA

IPC: H04B7/015 ,  H04N5/21

Abstract: An adaptive method for suppressing video signal x(k) echoes in equalizers of TV sets including digital filters whose coefficients are updated in an adaptive and iterative manner using an LMS (Least Mean Square) algorithm until the difference, or output error, between a target output signal d(k), called the reference signal, and an outgoing signal y(k) from the equalizer is gradually reduced, comprises the steps of: applying a "combing" technique to an original filter having K*N coefficients in order to select K comb filters having N coefficients each; applying said LMS algorithm, with a variable convergence factor ( mu ) to each individual comb filter for a predetermined number of iterations; gathering the resultant configurations of the comb filter coefficients and selecting a subfilter with N largest modulo coefficients therefrom; updating the values of said N coefficients again by reiterating the LMS algorithm to said subfilter for a limited number of iterations; zeroing all the coefficients with a lower modulo than a predetermined threshold; selecting a group of F coefficients by a slotting operation across those of said coefficients which have a cluster value: and updating the value of said group of F coefficients, by reiterating the LMS algorithm, until the output error e(k) becomes smaller than a predetermined value.

公开(公告)号：DE69327900T2

公开(公告)日：2000-07-06

申请号：DE69327900

申请日：1993-06-09

Applicant: ST MICROELECTRONICS SRL

Inventor： D ALTO VIVIANA ,  AIROLDI FABRIZIO ,  SCALISE FABIO ,  PODESTA MARIA GRAZIA

IPC: H04B7/015 ,  H04N5/21

Abstract: An adaptive method for suppressing video signal x(k) echoes in equalizers of TV sets including digital filters whose coefficients are updated in an adaptive and iterative manner using an LMS (Least Mean Square) algorithm until the difference, or output error, between a target output signal d(k), called the reference signal, and an outgoing signal y(k) from the equalizer is gradually reduced, comprises the steps of: applying a "combing" technique to an original filter having K*N coefficients in order to select K comb filters having N coefficients each; applying said LMS algorithm, with a variable convergence factor ( mu ) to each individual comb filter for a predetermined number of iterations; gathering the resultant configurations of the comb filter coefficients and selecting a subfilter with N largest modulo coefficients therefrom; updating the values of said N coefficients again by reiterating the LMS algorithm to said subfilter for a limited number of iterations; zeroing all the coefficients with a lower modulo than a predetermined threshold; selecting a group of F coefficients by a slotting operation across those of said coefficients which have a cluster value: and updating the value of said group of F coefficients, by reiterating the LMS algorithm, until the output error e(k) becomes smaller than a predetermined value.