EP1540820A4

Method and apparatus for channel equalization

Abstract

A method and apparatus is disclosed to overcome the effects of intersymbol interference during data transmission. Overcoming the effects of intersymbol interference makes possible higher data transmission rates for a given error rate. In one embodiment a receiver-transmitter pair is configured with a precode filter at the transmit side and a feed forward filter and a feedback filter at the receive side. Filter coefficients are calculated to reduce the undesirable effects of the channel, such as intersymbol interference. In one embodiment a training process occurs with the feedforward filter and a feedback filter, such that the first N coefficients of the feedback filter are set to zero. Thereafter, the coefficients of the feedforward filter are subject to spectral factorization and separated into minimum phase roots and maximum phase roots. The minimum phase roots comprise the precode filter coefficients and the maximum phase roots are established as feedforward filter coefficients.

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Projected expiry passed 27 June 2023, 3.2 years ago.

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Citations
Reference	Relation	Cited during
GI-HONG IM ET AL: "Performance of a Hybrid Decision Feedback Equalizer Structure for CAP-Based DSL Systems", IEEE TRANSACTIONS ON SIGNAL PROCESSING, IEEE SERVICE CENTER, NEW YORK, NY, US, vol. 49, no. 8, August 2001 (2001-08-01), XP011059368, ISSN: 1053-587X	Non-patent	Search report
EYUBOGLU M V: "Flexible precoding for V.fast (modem)", DATA TRANSMISSION - ADVANCES IN MODEM AND ISDN TECHNOLOGY AND APPLICATIONS, 1992., INTERNATIONAL CONFERENCE ON LONDON, UK, LONDON, UK,IEE, UK, 1992, pages 13 - 18, XP006514885, ISBN: 0-85296-552-4	Non-patent	Search report

19 members in 8 offices

This recordMember, by publication datePriority claim

Priority claims3

Priority claims
Document	Office	Kind	Date
188274	United States of America	–	2002-07-01
18827402	United States of America	A	2002-07-01
0320255	United States of America	W	2003-06-27

Members19

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Document	Office	Kind
US2004001540A1	United States of America	A1	2004-01-01
WO2004004192A2	World Intellectual Property Organization (WIPO)	A2	2004-01-08
AU2003253733A1	Australia	A1	2004-01-19
AU2003253733A8	Australia	A8	2004-01-19
WO2004004192A3	World Intellectual Property Organization (WIPO)	A3	2004-04-08
US2005025229A1	United States of America	A1	2005-02-03
EP1540820A2	European Patent Office (EPO)	A2	2005-06-15
CN1675837A	China	A	2005-09-28
JP2005531989A	Japan	A	2005-10-20
US6961373B2	United States of America	B2	2005-11-01
US2006007997A1	United States of America	A1	2006-01-12
US7257181B2	United States of America	B2	2007-08-14
CN100342645C	China	C	2007-10-10
EP1540820A4This record	European Patent Office (EPO)	A4	2007-12-12
US7400677B2	United States of America	B2	2008-07-15
EP1540820B1	European Patent Office (EPO)	B1	2010-01-20
AT456188T	Austria	T	2010-02-15
ATE456188T1	Austria	T1	2010-02-15
DE60331082D1	Germany	D1	2010-03-11

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	Event	Code	Office
2023-06-27	Expiry of rightR071	R071	DE
2023-06-14	Opt-out of the competence of the unified patent court (upc) registeredP01	P01	EP
2022-10-31	Annual fee paid to national office [announced via postgrant information from national office to epo]GrantedPGFP	PGFP	EP
2021-04-30	Lapsed in a contracting state [announced via postgrant information from national office to epo]LapsedPG25	PG25	EP
2021-04-30	Lapsed in a contracting state [announced via postgrant information from national office to epo]LapsedPG25	PG25	EP
2021-03-31	Gb: european patent ceased through non-payment of renewal feeCeasedGBPC	GBPC	EP
2020-11-18	Amendments to the register in respect of changes of name or changes affecting rights (sect. 32/1977)REGISTERED BETWEEN 20201022 AND 20201028732E	732E	GB
2020-06-18	Change of applicant/patenteeR081	R081	DE
2020-06-18	Change of representativeR082	R082	DE
2019-10-31	Annual fee paid to national office [announced via postgrant information from national office to epo]GrantedPGFP	PGFP	EP
2019-08-30	Annual fee paid to national office [announced via postgrant information from national office to epo]GrantedPGFP	PGFP	EP
2018-06-26	Fee paymentPLFP	PLFP	FR
2017-06-27	Fee paymentPLFP	PLFP	FR
2016-06-28	Fee paymentPLFP	PLFP	FR
2012-10-31	Amendments to the register in respect of changes of name or changes affecting rights (sect. 32/1977)REGISTERED BETWEEN 20121004 AND 20121010732E	732E	GB
2012-10-31	Lapsed in a contracting state [announced via postgrant information from national office to epo]LapsedPG25	PG25	EP
2012-10-17	Correction of errors in patents and applications (sect. 117/patents act 1977)CORRECTIONS ALLOWED; REQUEST FOR CORRECTION UNDER SECTION 117 FILED ON 10 AUGUST 2012 ALLOWED ON 21 SEPTEMBER 2012S117	S117	GB
2012-09-28	Lapsed in a contracting state [announced via postgrant information from national office to epo]LapsedPG25	PG25	EP
2012-09-28	Lapsed in a contracting state [announced via postgrant information from national office to epo]LapsedPG25	PG25	EP
2012-09-12	Correction of errors in patents and applications (sect. 117/patents act 1977)REQUEST FILED; REQUEST FOR CORRECTION UNDER SECTION 117 FILED ON 10 AUGUST 2012S117	S117	GB
2012-02-02	Change of applicant/patenteeR081	R081	DE
2012-02-02	Change of representativeR082	R082	DE
2012-02-02	Change of representativeR082	R082	DE
2012-02-02	Change of representativeR082	R082	DE
2012-02-02	Change of representativeR082	R082	DE
2011-12-12	Change of representativeR082	R082	DE
2011-11-21	Change of representativeR082	R082	DE
2011-04-29	Lapsed in a contracting state [announced via postgrant information from national office to epo]LapsedPG25	PG25	EP
2011-04-29	Lapsed in a contracting state [announced via postgrant information from national office to epo]LapsedPG25	PG25	EP
2011-04-29	Lapsed in a contracting state [announced via postgrant information from national office to epo]LapsedPG25	PG25	EP
2011-03-31	Lapsed in a contracting state [announced via postgrant information from national office to epo]LapsedPG25	PG25	EP
2011-01-31	Lapsed in a contracting state [announced via postgrant information from national office to epo]LapsedPG25	PG25	EP
2011-01-31	Lapsed in a contracting state [announced via postgrant information from national office to epo]LapsedPG25	PG25	EP
2011-01-31	Patent ceasedCeasedPL	PL	CH
2010-12-29	No opposition filedOpposition26N	26N	EP
2010-11-30	Lapsed in a contracting state [announced via postgrant information from national office to epo]LapsedPG25	PG25	EP
2010-11-30	Lapsed in a contracting state [announced via postgrant information from national office to epo]LapsedPG25	PG25	EP
2010-11-30	Lapsed in a contracting state [announced via postgrant information from national office to epo]LapsedPG25	PG25	EP
2010-11-26	No opposition filed within time limitOppositionORIGINAL CODE: 0009261PLBE	PLBE	EP
2010-11-26	Information on the status of an ep patent application or granted ep patentGrantedSTATUS: NO OPPOSITION FILED WITHIN TIME LIMITSTAA	STAA	EP
2010-10-29	Lapsed in a contracting state [announced via postgrant information from national office to epo]LapsedPG25	PG25	EP
2010-10-29	Lapsed in a contracting state [announced via postgrant information from national office to epo]LapsedPG25	PG25	EP
2010-10-29	Lapsed in a contracting state [announced via postgrant information from national office to epo]LapsedPG25	PG25	EP
2010-10-29	Lapsed in a contracting state [announced via postgrant information from national office to epo]LapsedPG25	PG25	EP
2010-10-29	Lapsed in a contracting state [announced via postgrant information from national office to epo]LapsedPG25	PG25	EP
2010-10-29	Lapsed in a contracting state [announced via postgrant information from national office to epo]LapsedPG25	PG25	EP
2010-08-31	Lapsed in a contracting state [announced via postgrant information from national office to epo]LapsedPG25	PG25	EP
2010-08-31	Lapsed in a contracting state [announced via postgrant information from national office to epo]LapsedPG25	PG25	EP
2010-07-30	Lapsed in a contracting state [announced via postgrant information from national office to epo]LapsedPG25	PG25	EP
2010-07-30	Lapsed in a contracting state [announced via postgrant information from national office to epo]LapsedPG25	PG25	EP
2010-07-30	Lapsed in a contracting state [announced via postgrant information from national office to epo]LapsedPG25	PG25	EP
2010-06-30	Lapsed in a contracting state [announced via postgrant information from national office to epo]LapsedPG25	PG25	EP
2010-05-26	Discontinued in the netherlands as no translation has been filedVDEP	VDEP	NL
2010-03-11	Corresponds to:REF	REF	EP
2010-03-03	European patents granted designating irelandGrantedFG4D	FG4D	IE
2010-01-29	European patent takes effect as a national patent in ch/liEP	EP	CH
2010-01-20	Designated contracting statesAK	AK	EP
2010-01-20	European patent grantedGrantedFG4D	FG4D	GB
2009-12-18	(expected) grantORIGINAL CODE: 0009210GRAA	GRAA	EP
2009-12-16	Grant fee paidORIGINAL CODE: EPIDOSNIGR3GRAS	GRAS	EP
2009-07-17	Despatch of communication of intention to grant a patentORIGINAL CODE: EPIDOSNIGR1GRAP	GRAP	EP
2008-03-19	First examination report despatched17Q	17Q	EP
2007-12-12	Supplementary search report drawn up and despatchedA4	A4	EP
2005-10-19	Request for extension of the european patent (deleted)DAX	DAX	EP
2005-06-15	Request for examination filed17P	17P	EP
2005-06-15	Designated contracting statesAK	AK	EP
2005-06-15	Request for extension of the european patentAX	AX	EP
2005-04-29	Public reference made under article 153(3) epc to a published international application that has entered the european phaseORIGINAL CODE: 0009012PUAI	PUAI	EP

Method and apparatus for channel equalization

Abstract

Term

Priority claims3

Members19

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