GB1525706A – Automatic passband equalizer for data transmission system
– Google Patents
GB1525706A – Automatic passband equalizer for data transmission system
– Google Patents
Automatic passband equalizer for data transmission system
Info
Publication number
GB1525706A
GB1525706A
GB51626/75A
GB5162675A
GB1525706A
GB 1525706 A
GB1525706 A
GB 1525706A
GB 51626/75 A
GB51626/75 A
GB 51626/75A
GB 5162675 A
GB5162675 A
GB 5162675A
GB 1525706 A
GB1525706 A
GB 1525706A
Authority
GB
United Kingdom
Prior art keywords
phase
signal
equalizer
tap
signals
Prior art date
1974-12-20
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired
Application number
GB51626/75A
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Telecommunications Radioelectriques et Telephoniques SA TRT
Original Assignee
Telecommunications Radioelectriques et Telephoniques SA TRT
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
1974-12-20
Filing date
1975-12-17
Publication date
1978-09-20
1975-12-17
Application filed by Telecommunications Radioelectriques et Telephoniques SA TRT
filed
Critical
Telecommunications Radioelectriques et Telephoniques SA TRT
1978-09-20
Publication of GB1525706A
publication
Critical
patent/GB1525706A/en
Status
Expired
legal-status
Critical
Current
Links
Espacenet
Global Dossier
Discuss
Classifications
H—ELECTRICITY
H04—ELECTRIC COMMUNICATION TECHNIQUE
H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
H04L27/00—Modulated-carrier systems
H04L27/01—Equalisers
Abstract
1525706 Adaptive equalizers TELECOMMUNICATIONS RADIOELECTRIQUES ET TELEPHONIQUES 17 Dec 1975 [20 Dec 1974] 51626/75 Heading H4R In an adaptive transversal equalizer for equalizing pass band signals at the input of a receiver for phase modulated data signals the input signals and a 90 degree phase shifted version of the input signal are applied to respective transversal filters L and L’, Fig. 1, the outputs of which are combined at 10 to provide the equalizer output signal Y(t) to be fed to a detector 2. In order to obtain adjusting signals for the filter, multiplier coefficients a(m), b(m), the equalizer output and a 90 degree phase shifted version thereof are sampled at clock frequency by samplers 12 and 13 and fed to difference circuits 17 and 18 both direct, at 15, 16, and via a one clock period delay 19, 20, and a phase shifter 23, which provides a phase shift proportional to the sum of the phase shift due to the transmitted signal, derived from the detector 2, and the phase shift of the carrier between successive samples at clock frequency. The difference signals, e(nT) and Û(nT) respectively, at the outputs of difference circuits 17 and 18 correspond to the in-phase and quadrature components of the error vector between the actual equalizer output and the estimated correct equalizer output. An equalizer multiplier coefficient updating circuit is provided for each tap of the equalizer filter and comprises a pair of difference circuits 29, 30, fed on one input 31, 32, with the signal on the corresponding tap of the filter, sampled at clock frequency, and on the other input 35, 36, the signal from the following tap of the equalizer after it has been subject, in-phase shifter 39, to a phase shift equal to that in-phase shifter 23, i.e. the phase shift due to the estimated signal plus the phase shift of the carrier between successive sampling instants, so that the outputs, d(nT-mT) and #d(nT-mT) respectively, of the difference circuits 29, 30, are the in-phase and inquadrature components of the error signal between the signal at the respective tap and the estimated correct signal at that tap. This tap error signal is applied to a calculating circuit 41 where the inphase and in-quadrature components are multiplied and cross multiplied by the in-phase and inquadrature components of the equalizer output error signal from difference circuits 17, 18 and the signals combined to give factors e(nT).d(nT-mT) + Û(nT.#d(nT-mT) and e(nT).#d(nT-mT) – Û(nT).d(nT-mT) which are respectively the tap multiplier adjustment factors for the m
GB51626/75A
1974-12-20
1975-12-17
Automatic passband equalizer for data transmission system
Expired
GB1525706A
(en)
Applications Claiming Priority (1)
Application Number
Priority Date
Filing Date
Title
FR7442251A
FR2295649A1
(en)
1974-12-20
1974-12-20
SELF-ADAPTIVE LINE EQUALIZER FOR DATA TRANSMISSION SYSTEM
Publications (1)
Publication Number
Publication Date
GB1525706A
true
GB1525706A
(en)
1978-09-20
Family
ID=9146460
Family Applications (1)
Application Number
Title
Priority Date
Filing Date
GB51626/75A
Expired
GB1525706A
(en)
1974-12-20
1975-12-17
Automatic passband equalizer for data transmission system
Country Status (9)
Country
Link
US
(1)
US4035725A
(en)
JP
(1)
JPS555290B2
(en)
BE
(1)
BE836826A
(en)
CA
(1)
CA1046597A
(en)
DE
(1)
DE2556959C3
(en)
FR
(1)
FR2295649A1
(en)
GB
(1)
GB1525706A
(en)
NL
(1)
NL173903C
(en)
SE
(1)
SE409535B
(en)
Families Citing this family (16)
* Cited by examiner, † Cited by third party
Publication number
Priority date
Publication date
Assignee
Title
FR2375773A1
(en)
*
1976-12-23
1978-07-21
Ibm France
ADAPTIVE PHASE DETECTION METHOD AND DEVICE
FR2367386A1
(en)
*
1976-10-06
1978-05-05
Trt Telecom Radio Electr
DEVICE FOR AUTOMATIC RESYNCHRONIZATION OF A RECEIVER FOR DATA TRANSMISSION
US4285061A
(en)
*
1979-09-14
1981-08-18
Bell Telephone Laboratories, Incorporated
Equalizer sample loading in voiceband data sets
US4245345A
(en)
*
1979-09-14
1981-01-13
Bell Telephone Laboratories, Incorporated
Timing acquisition in voiceband data sets
US4247940A
(en)
*
1979-10-15
1981-01-27
Bell Telephone Laboratories, Incorporated
Equalizer for complex data signals
US4464545A
(en)
*
1981-07-13
1984-08-07
Bell Telephone Laboratories, Incorporated
Echo canceller
JPS59228409A
(en)
*
1983-06-10
1984-12-21
Nec Corp
Automatic equalizer
US4564952A
(en)
*
1983-12-08
1986-01-14
At&T Bell Laboratories
Compensation of filter symbol interference by adaptive estimation of received symbol sequences
FR2641922B1
(en)
*
1988-12-30
1991-03-22
Alcatel Transmission
SELF-ADAPTIVE EQUALIZATION DEVICE FOR A DIFFERENTIALLY CONSISTENT DEMODULATION INSTALLATION
US5828700A
(en)
*
1993-08-05
1998-10-27
Micro Linear Corporation
Adaptive equalizer circuit
US5844941A
(en)
*
1995-07-20
1998-12-01
Micro Linear Corporation
Parallel adaptive equalizer circuit
US6005640A
(en)
*
1996-09-27
1999-12-21
Sarnoff Corporation
Multiple modulation format television signal receiver system
US6931089B2
(en)
*
2001-08-21
2005-08-16
Intersil Corporation
Phase-locked loop with analog phase rotator
US20060150047A1
(en)
*
2004-12-30
2006-07-06
Wolfgang Nikutta
Apparatus and method for generating a high-frequency signal
US20160057255A1
(en)
*
2014-08-22
2016-02-25
Mediatek Inc.
Unified communications receiver and associated method
US11107453B2
(en)
*
2019-05-09
2021-08-31
Dialog Semiconductor B.V.
Anti-noise signal generator
Family Cites Families (4)
* Cited by examiner, † Cited by third party
Publication number
Priority date
Publication date
Assignee
Title
NL7213335A
(en)
*
1972-10-03
1974-04-05
NL171215C
(en)
*
1973-03-09
1983-02-16
Trt Telecom Radio Electr
AUTOMATIC EQUALIZATION DEVICE FOR A DATA TRANSMISSION CHANNEL.
US3906347A
(en)
*
1973-10-11
1975-09-16
Hycom Inc
Transversal equalizer for use in double sideband quadrature amplitude modulated system
US3878468A
(en)
*
1974-01-30
1975-04-15
Bell Telephone Labor Inc
Joint equalization and carrier recovery adaptation in data transmission systems
1974
1974-12-20
FR
FR7442251A
patent/FR2295649A1/en
active
Granted
1975
1975-12-16
CA
CA241,874A
patent/CA1046597A/en
not_active
Expired
1975-12-16
NL
NLAANVRAGE7514612,A
patent/NL173903C/en
not_active
IP Right Cessation
1975-12-17
SE
SE7514237A
patent/SE409535B/en
not_active
IP Right Cessation
1975-12-17
GB
GB51626/75A
patent/GB1525706A/en
not_active
Expired
1975-12-18
US
US05/642,079
patent/US4035725A/en
not_active
Expired – Lifetime
1975-12-18
DE
DE2556959A
patent/DE2556959C3/en
not_active
Expired
1975-12-18
BE
BE162900A
patent/BE836826A/en
not_active
IP Right Cessation
1975-12-20
JP
JP15270475A
patent/JPS555290B2/ja
not_active
Expired
Also Published As
Publication number
Publication date
DE2556959C3
(en)
1981-01-08
CA1046597A
(en)
1979-01-16
FR2295649A1
(en)
1976-07-16
JPS555290B2
(en)
1980-02-05
DE2556959B2
(en)
1980-05-08
NL173903B
(en)
1983-10-17
FR2295649B1
(en)
1978-03-24
AU8765375A
(en)
1977-06-23
DE2556959A1
(en)
1976-07-01
SE409535B
(en)
1979-08-20
BE836826A
(en)
1976-06-18
JPS5188157A
(en)
1976-08-02
NL173903C
(en)
1984-03-16
NL7514612A
(en)
1976-06-22
US4035725A
(en)
1977-07-12
SE7514237L
(en)
1976-06-21
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Legal Events
Date
Code
Title
Description
1979-01-10
PS
Patent sealed [section 19, patents act 1949]
1995-08-16
PCNP
Patent ceased through non-payment of renewal fee
Effective date:
19941217
