Patent JPS6345865A successfully refreshed from Google Patents.
US5216697A
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US
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Signal quality detector circuit
Assignee: Fujitsu Ltd
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Filing: 1990-08-14
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Granted: 1993-06-01
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Expires: 2010-08-14
Abstract
Abstract A signal quality detector circuit which detects an error signal of an input signal, used for detecting transmission quality of a transmission line. The detector circuit equalizes the input baseband signal, analog-to-digital-converts the equalized signal to a digital bit signal, analog-to-digital converts the input baseband signal to a digital bit signal, compares the two analog-to-digital converted signals on a bit-by-bit basis and detects an error signal accumulates the error signal in a unit time, and detects transmission quality of a transmission line.
Inventors
- 👤 Masayuki Ohnuki
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 11:00
CPC Classifications
H; H04; H04L; H04L1/00; H04L1/20
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
96 words
A signal quality detector circuit for detecting signal quality of an input signal, said signal quality detector circuit comprising: equalization means for compensating for distortions in the input signal and for providing a compensated analog output; first conversion means for converting the compensated analog output signal to a first digital signal; second conversion means for converting the input signal to a second digital signal; comparison means for comparing the first and second digital signals and for providing an error signal; and detection means for detecting signal quality of the input signal based on said error signal.
Claim 2
Dependent Claim
96 words
A signal quality detector circuit for detecting signal quality of an input signal, said signal quality detector circuit comprising: equalization means for compensating for distortions in the input signal and for providing a compensated analog output; first conversion means for converting the compensated analog output signal to a first digital signal; second conversion means for converting the input signal to a second digital signal; comparison means for comparing the first and second digital signals and for providing an error signal; and detection means for detecting signal quality of the input signal based on said error signal.
Claim 3
Dependent Claim
60 words
A signal quality detector circuit according to claim 1, wherein said comparison means includes means for providing said error signal when said first and second digital signals differ by at least one bit, and wherein said detection means comprises accumulation means for accumulating said error signal for a predetermined time and means for detecting transmission quality based on said accumulation.
Claim 4
Dependent Claim
21 words
A signal quality detector circuit according to claim 2, wherein said accumulation means includes counter means for counting said error signal.
Claim 5
Dependent Claim
21 words
A signal quality detector circuit according to claim 2, wherein said accumulation means includes integrating means for integrating said error signal.
Claim 6
Dependent Claim
55 words
A signal quality detector circuit according to claim 2, further comprising: receiver means for receiving the input signal from at least one of a regular line and an alternative line; and means for providing a switch command based on said error signal so that said receiver means receives said input signal from the alternative line.
Claim 7
Dependent Claim
21 words
A signal quality detector circuit according to claim 5, wherein said receiver means includes means for receiving quadrature amplitude modulated signals.
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) | 1996-05-31 | 1996-11-30 | 1997-06-01 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2000-05-31 | 2000-11-30 | 2001-06-01 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2004-05-31 | 2004-11-30 | 2005-06-01 | $7700.00 | Window Closed / Lapsed |