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US4571733A
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Automatic equalization device and method of starting-up the same
Assignee: Fujitsu Ltd
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Filing: 1982-12-28
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Granted: 1986-02-18
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Expires: 2002-12-28
Abstract
Abstract An automatic equalization device used in a data communication system includes a unit for extracting a single pulse from a training signal sent from a transmitter and initializing a tap coefficient using the extracted single pulse. The automatic equalization device also includes a first equalization circuit and a second equalization circuit. In the first equalization circuit, an auto-correlation series of the signal corresponding to the single pulse is calculated to provide a symmetric single pulse. In the second equalization circuit, an inverse matrix is calculated from the symmetric single pulse using the auto-correlational series of single pulses. By these calculations, the speed of the initial setting of the tap coefficient is increased.
Inventors
- 👤 Takashi Kaku
- 👤 Shigeyuki Unagami
- 👤 Masayoshi Inoue
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 20:13
CPC Classifications
H; H04; H04L; H04L25/00; H04L25/02; H04L25/03; H04L25/03006; H04L25/03012; H04L25/03114; H04L25/03133
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
191 words
An automatic equalization device used in a communication system in which a transmitter and a receiver are connected by a transmission line, said transmitter including a means for transmitting an initialization signal including a component of a single pulse and subsequently transmitting a data signal, said receiver including said automatic equalization device for correcting the received signal and deriving the data signal transmitted from said transmitter, said automatic equalization device comprising: a means for extracting a single pulse having a distortion due to the characteristics of the transmission line from the received initialization signal; a means for deriving a coefficient for obtaining an auto-correlation or a cross-correlation series using said extracted single pulse; a first equalization circuit for correcting said extracted single pulse into a symmetric single pulse and correcting the data signal by the coefficient obtained by said deriving means; a generating means for generating a coefficient for deriving a single pulse coinciding with the single pulse included in the initialization signal transmitted from said transmitter, using said symmetric single pulse; and a second equalization circuit for correcting the data signal based on the coefficient obtained by said generating means.
Claim 2
Dependent Claim
191 words
An automatic equalization device used in a communication system in which a transmitter and a receiver are connected by a transmission line, said transmitter including a means for transmitting an initialization signal including a component of a single pulse and subsequently transmitting a data signal, said receiver including said automatic equalization device for correcting the received signal and deriving the data signal transmitted from said transmitter, said automatic equalization device comprising: a means for extracting a single pulse having a distortion due to the characteristics of the transmission line from the received initialization signal; a means for deriving a coefficient for obtaining an auto-correlation or a cross-correlation series using said extracted single pulse; a first equalization circuit for correcting said extracted single pulse into a symmetric single pulse and correcting the data signal by the coefficient obtained by said deriving means; a generating means for generating a coefficient for deriving a single pulse coinciding with the single pulse included in the initialization signal transmitted from said transmitter, using said symmetric single pulse; and a second equalization circuit for correcting the data signal based on the coefficient obtained by said generating means.
Claim 3
Dependent Claim
139 words
A data communication system comprising: transmitting means for transmitting a training signal and a data signal; receiver means for extracting a single pulse signal from said training signal; auto equalization means having a coefficient set in accordance with said single pulse signal, for equalizing said data signal, said auto equalization means including means for obtaining a complex conjugate series of said extracted single pulse signal; first equalization circuit means for calculating a series of auto-correlation of said single pulse signal using said obtained complex conjugate series as a tap coefficient, and for correcting said data signal; and second equalization circuit means for calculating a data series which is the inverse matrix of said auto-correlation series, for initializing said data series, which is the inverse matrix as the tap coefficient, and for correcting said data signal using said tap coefficient.
Claim 4
Dependent Claim
139 words
A data communication system comprising: transmitting means for transmitting a training signal and a data signal; receiver means for extracting a single pulse signal from said training signal; auto equalization means having a coefficient set in accordance with said single pulse signal, for equalizing said data signal, said auto equalization means including means for obtaining a complex conjugate series of said extracted single pulse signal; first equalization circuit means for calculating a series of auto-correlation of said single pulse signal using said obtained complex conjugate series as a tap coefficient, and for correcting said data signal; and second equalization circuit means for calculating a data series which is the inverse matrix of said auto-correlation series, for initializing said data series, which is the inverse matrix as the tap coefficient, and for correcting said data signal using said tap coefficient.
Claim 5
Dependent Claim
27 words
A data communication system according to claim 2, wherein said means for obtaining the complex conjugate series includes a normalizing means for normalizing said single pulse signal.
Claim 6
Dependent Claim
72 words
A data communication system according to claim 2, wherein said means for obtaining the inverse matrix of said auto-correlation series is derived as a first order approximation from the data series B J using the following expressions in the form of: B.sub.J =A.sub.-J (J≠0) B.sub.-J =-A.sub.J (J≠0) B.sub.O =A.sub.O =(1, 0) (complex number), where B J is the J-th data of said data series and A J and the J-th auto-correlation number.
Claim 7
Dependent Claim
85 words
A data communication system according to claim 4, wherein said means for obtaining a data series corresponding to said inverse matrix includes means for employing the Gaus-Seidel method as a sequential approximation method, and said equalization circuit means includes means for obtaining the data series corresponding to said inverse matrix by correcting said data series having the form of: B.sub.J (J=0, ±1, . . . , ±n) in the sequence B 0 , B.sub.±1, . . . , B.sub.±n and subsequently thereto repeating the correction.
Claim 8
Independent Claim
114 words
A method initializing a coefficient for the correction of a received signal in an automatic equalization device for correcting the received signal transmitted by a transmitter through a transmission line, said method comprising the steps of: (a) transmitting training signal; (b) extracting a pulse signal series corresponding to a single pulse signal from the training signal; (c) obtaining a complex conjugate series of said pulse signal series and setting said obtained complex conjugate series as a first equalization coefficient; (d) obtaining a correction series between said first equalization coefficient and said pulse signal series; and (e) setting the data series corresponding to the inverse matrix of said correlation series as a second equalization coefficient.
Claim 9
Independent Claim
114 words
A method initializing a coefficient for the correction of a received signal in an automatic equalization device for correcting the received signal transmitted by a transmitter through a transmission line, said method comprising the steps of: (a) transmitting training signal; (b) extracting a pulse signal series corresponding to a single pulse signal from the training signal; (c) obtaining a complex conjugate series of said pulse signal series and setting said obtained complex conjugate series as a first equalization coefficient; (d) obtaining a correction series between said first equalization coefficient and said pulse signal series; and (e) setting the data series corresponding to the inverse matrix of said correlation series as a second equalization coefficient.
Claim 10
Dependent Claim
36 words
A method according to claim 6, further comprising the step of: synthesizing said first equalization coefficient and said second equalization coefficient and said second equalization coefficient into another equalization coefficient in accordance with the convolutional operation.
Claim 11
Independent Claim
119 words
A method for initially setting a coefficient of an automatic equalization device in a data communication system, in which a training signal including components of a single pulse signal is transmitted by a transmitter and a single pusle signal is extracted from said training signal by a receiver, and setting an initial coefficient of said automatic equalization device using said extracted single pulse signal, said method comprising the steps of: (a) receiving said training signal; (b) generating a delayed training signal; (c) adding the received training signal and the delayed training signal to produce an extracted single pulse signal; and (d) initially setting a coefficient of said automatic equalization device in the receiver using said extracted single pulse signal.
Claim 12
Independent Claim
119 words
A method for initially setting a coefficient of an automatic equalization device in a data communication system, in which a training signal including components of a single pulse signal is transmitted by a transmitter and a single pusle signal is extracted from said training signal by a receiver, and setting an initial coefficient of said automatic equalization device using said extracted single pulse signal, said method comprising the steps of: (a) receiving said training signal; (b) generating a delayed training signal; (c) adding the received training signal and the delayed training signal to produce an extracted single pulse signal; and (d) initially setting a coefficient of said automatic equalization device in the receiver using said extracted single pulse signal.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1989-02-17 | 1989-08-19 | 1990-02-18 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1993-02-17 | 1993-08-19 | 1994-02-18 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1997-02-17 | 1997-08-19 | 1998-02-18 | $7700.00 | Window Closed / Lapsed |