Patent US5483551A successfully refreshed from Google Patents.
US5483551A
Expired / Lapsed
US
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Crosstalk suppression technique
Assignee: AT&T Inc
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Filing: 1993-07-30
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Granted: 1996-01-09
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Expires: 2013-07-30
Abstract
Abstract To reduce near-end crosstalk (NEXT) in systems possessing excess bandwidth, a signal is transmitted from a first to a second location. At the second location, the received signal is examined and a characteristic of this signal is determined while the delay provided in the transmit signal path at this location is varied. Based on this examination, a particular amount of delay is introduced into the transmit signal path which reduces NEXT. This process is repeated for each direction of transmission. In the disclosed embodiment, the characteristic of the received signal which is determined is the mean square error and the amount of delay selected is that corresponding to the minimum mean square error.
Inventors
- 👤 Gang Huang
- 👤 Gi-Hong Im
- 👤 Jean-Jacques Werner
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 12:36
CPC Classifications
H; H04; H04B; H04B3/00; H04B3/02; H04B3/20; H04B3/23
Claims Analysis
Total Claims: 12
Claim 1
Independent Claim
78 words
Transceiver apparatus including a transmitter and a receiver for use in a communications system, said apparatus comprising means in the receiver being responsive to an incoming signal after propagation through a communications channel for determining a predetermined signal characteristic; and means in the transmitter being responsive to said determined predetermined characteristic for providing a particular amount of delay into an outgoing signal transmitted by said transmitter in said transceiver apparatus to reduce near-end crosstalk in said communications channel.
Claim 2
Dependent Claim
78 words
Transceiver apparatus including a transmitter and a receiver for use in a communications system, said apparatus comprising means in the receiver being responsive to an incoming signal after propagation through a communications channel for determining a predetermined signal characteristic; and means in the transmitter being responsive to said determined predetermined characteristic for providing a particular amount of delay into an outgoing signal transmitted by said transmitter in said transceiver apparatus to reduce near-end crosstalk in said communications channel.
Claim 3
Dependent Claim
33 words
The apparatus of claim 1 wherein said communications channel introduces distortion which causes said incoming signal to differ from what was originally transmitted and said predetermined characteristic is a function of this difference.
Claim 4
Dependent Claim
24 words
The apparatus of claim 2 wherein said predetermined signal characteristic is an average of the algebraic square of this difference over some time interval.
Claim 5
Dependent Claim
28 words
The apparatus of claim 1 wherein said determining apparatus makes its determination by measuring said predetermined characteristic for a plurality of different delays provided to said outgoing signal.
Claim 6
Dependent Claim
24 words
The apparatus of claim 4 wherein said determining means selects said particular amount of delay corresponding to a minimum value of said predetermined characteristic.
Claim 7
Dependent Claim
15 words
The apparatus of claim 1 wherein said determining means determines a mean square error signal.
Claim 8
Dependent Claim
19 words
The apparatus of claim 6 wherein said determining means determines a minimum value for said mean square error signal.
Claim 9
Independent Claim
78 words
A method for use in a transceiver apparatus including a transmitter and a receiver for use in a communications system, said method comprising the steps of determining in the receiver a predetermined signal characteristic of the incoming signal after propagation through a communication channel; and providing a particular amount of delay into an outgoing signal transmitted by said transmitter in said transceiver apparatus in response to said determined predetermined characteristic to reduce near-end crosstalk in said communications channel.
Claim 10
Independent Claim
78 words
A method for use in a transceiver apparatus including a transmitter and a receiver for use in a communications system, said method comprising the steps of determining in the receiver a predetermined signal characteristic of the incoming signal after propagation through a communication channel; and providing a particular amount of delay into an outgoing signal transmitted by said transmitter in said transceiver apparatus in response to said determined predetermined characteristic to reduce near-end crosstalk in said communications channel.
Claim 11
Dependent Claim
122 words
A communications system comprising a first transceiver including a first transmitter and a first receiver coupled to a second transceiver including a second transmitter and second receiver via a communications link, said first transceiver comprising means in said first transmitter for transmitting a signal in said communications link to said second receiver in said second transceiver and said second transceiver comprising means in said second receiver being responsive to said signal after propagation through the communications link for determining a predetermined signal characteristic; and means in said second transmitter being responsive to said determined characteristic for providing a particular amount of delay into an outgoing signal transmitted by the transmitter of said second transceiver to reduce near-end crosstalk in said communications link.
Claim 12
Dependent Claim
122 words
A communications system comprising a first transceiver including a first transmitter and a first receiver coupled to a second transceiver including a second transmitter and second receiver via a communications link, said first transceiver comprising means in said first transmitter for transmitting a signal in said communications link to said second receiver in said second transceiver and said second transceiver comprising means in said second receiver being responsive to said signal after propagation through the communications link for determining a predetermined signal characteristic; and means in said second transmitter being responsive to said determined characteristic for providing a particular amount of delay into an outgoing signal transmitted by the transmitter of said second transceiver to reduce near-end crosstalk in said communications link.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1999-01-08 | 1999-07-10 | 2000-01-09 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2003-01-08 | 2003-07-10 | 2004-01-09 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2007-01-08 | 2007-07-10 | 2008-01-09 | $7700.00 | Window Closed / Lapsed |