US4837780A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Transmit line buildout circuits
Assignee: Nortel Networks Ltd
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Filing: 1987-07-27
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Granted: 1989-06-06
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Expires: 2007-07-27
Abstract
Abstract A characteristic of a signal received via a receive line is monitored and used for automatic control of a line buildout circuit in a transmit signal path. The characteristic is conveniently an amplitude level, or differential amplitude levels for different signal bandwidths, of the received signal. The transmit line buildout circuit includes a transversal filter in which multiplier coefficients or delay times are controlled. The arrangement is particularly useful for digital signal interfaces on a digital cross connect.
Inventors
- 👤 Wayne D. Grover
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 18:43
CPC Classifications
H; H04; H04L; H04L25/00; H04L25/02; H04L25/03; H04L25/03006; H04L25/03012; H04L25/03019; H04L25/03038; H04B; H04B3/00; H04B3/02; H04B3/04; H04B3/06
Claims Analysis
Total Claims: 19
Claim 1
Independent Claim
131 words
A transmit line buildout circuit comprising: control means for producing a control signal in dependence upon a level of a signal on a receive path, said level being dependent upon the length of a receive line via which the signal on the receive path is received; and signal modifying means responsive to the control signal for modifying in a predetermined manner a transmit path signal to be transmitted via a transmit line, thereby to compensate for a corresponding length of the transmit line; wherein the control means comprises spectral filtering means for filtering the signal on the receive path to produce at least two receive path signals with different frequency bands, and means for producing the control signal in dependence upon level differences between said at least two receive path signals.
Claim 2
Dependent Claim
131 words
A transmit line buildout circuit comprising: control means for producing a control signal in dependence upon a level of a signal on a receive path, said level being dependent upon the length of a receive line via which the signal on the receive path is received; and signal modifying means responsive to the control signal for modifying in a predetermined manner a transmit path signal to be transmitted via a transmit line, thereby to compensate for a corresponding length of the transmit line; wherein the control means comprises spectral filtering means for filtering the signal on the receive path to produce at least two receive path signals with different frequency bands, and means for producing the control signal in dependence upon level differences between said at least two receive path signals.
Claim 3
Dependent Claim
49 words
A transmit line buildout circuit as claimed in claim 1 wherein the signal modifying means comprises at least one delay means for delaying the transmit path signal, and summing means for summing the delayed and undelayed transmit path signals with respective weights to produce a modified transmit path signal.
Claim 4
Dependent Claim
21 words
A transmit line buildout circuit as claimed in claim 2 and including means for low-pass filtering the modified transmit path signal.
Claim 5
Dependent Claim
20 words
A transmit line buildout circuit as claimed in claim 2 wherein said respective weights are dependent upon the control signal.
Claim 6
Dependent Claim
26 words
A transmit line buildout circuit as claimed in claim 4 wherein there are two delay means for producing two different delays of the transmit path signal.
Claim 7
Dependent Claim
26 words
A transmit line buildout circuit as claimed in claim 2 wherein there are two delay means for producing two different delays of the transmit path signal.
Claim 8
Dependent Claim
27 words
A transmit line buildout circuit as claimed in claim 2 wherein delay of the transmit path signal by the delay means is dependent upon the control signal.
Claim 9
Dependent Claim
66 words
A transmit line buildout circuit as claimed in claim 1 wherein the signal modifying means comprises delay means and summing means for summing with respective weights the transmit path signal with a first delayed transmit path signal or a second delayed transmit path signal, depending upon the control signal, the first and second delayed transmit path signals being delayed by the delay means by different amounts.
Claim 10
Dependent Claim
19 words
A transmit line buildout circuit as claimed in claim 1 wherein the spectral filtering means comprises a high-pass filter.
Claim 11
Dependent Claim
19 words
A transmit line buildout circuit as claimed in claim 8 wherein the spectral filtering means comprises a high-pass filter.
Claim 12
Dependent Claim
21 words
A transmit line buildout circuit as claimed in claim 10 and including means for low-pass filtering the modified transmit path signal.
Claim 13
Dependent Claim
142 words
Apparatus comprising: separate transmit and receive paths, for connection to separate transmit and receive lines respectively, for respectively transmitting and receiving signals via said lines; control means for producing a control signal in dependence upon a predetermined characteristic of a signal on the receive path, said predetermined characteristic being dependent upon the length of the receive line, the control means comprising spectral filtering means for filtering the signal on the receive path to produce at least two receive path signals with different frequency bands, and means for producing the control signal in dependence upon differences between said at least two receive path signals; and signal modifying means responsive to the control signal for modifying in a predetermined manner a signal on the transmit path to be transmitted via the transmit line, thereby to compensate for a corresponding length of the transmit line.
Claim 14
Dependent Claim
142 words
Apparatus comprising: separate transmit and receive paths, for connection to separate transmit and receive lines respectively, for respectively transmitting and receiving signals via said lines; control means for producing a control signal in dependence upon a predetermined characteristic of a signal on the receive path, said predetermined characteristic being dependent upon the length of the receive line, the control means comprising spectral filtering means for filtering the signal on the receive path to produce at least two receive path signals with different frequency bands, and means for producing the control signal in dependence upon differences between said at least two receive path signals; and signal modifying means responsive to the control signal for modifying in a predetermined manner a signal on the transmit path to be transmitted via the transmit line, thereby to compensate for a corresponding length of the transmit line.
Claim 15
Dependent Claim
45 words
Apparatus as claimed in claim 12 wherein the signal modifying means comprises at least one delay means for delaying the transmit path signal, and summing means for summing the delayed and undelayed transmit path signals with respective weights to produce a modified transmit path signal.
Claim 16
Dependent Claim
17 words
Apparatus as claimed in claim 13 and including means for low-pass filtering the modified transmit path signal.
Claim 17
Dependent Claim
16 words
Apparatus as claimed in claim 13 wherein said respective weights are dependent upon the control signal.
Claim 18
Dependent Claim
23 words
Apparatus as claimed in claim 13 wherein delay of the transmit path signal by the delay means is dependent upon the control signal.
Claim 19
Dependent Claim
62 words
Apparatus as claimed in claim 12 wherein the signal modifying means comprises delay means and summing means for summing with respective weights the transmit path signal with a first delayed transmit path signal or a second delayed transmit path signal, depending upon the control signal, the first and second delayed transmit path signals being delayed by the delay means by different amounts.
References Cited (Backward Citations)
US3483335A
Cited
US3578914A
Cited
US3989906A
Cited
US3989907A
Cited
US4037066A
Cited
US4061883A
Cited
US4071842A
Cited
US4377858A
Cited
US4381561A
Cited
US4592068A
Cited
US4413240A
Cited
US4605826A
Cited
US4700357A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1992-06-05 | 1992-12-05 | 1993-06-06 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1996-06-05 | 1996-12-05 | 1997-06-06 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2000-06-05 | 2000-12-05 | 2001-06-06 | $7700.00 | Window Closed / Lapsed |