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Patent US3873775A successfully refreshed from Google Patents.
US3873775A
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Method and an arrangement to indicate deterioration of PCM transmission quality
Assignee: International Standard Electric Corp
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Filing: 1973-12-13
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Granted: 1975-03-25
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Expires: 1993-12-13
Abstract
Abstract This arrangement is connected to the input of a repeater and provides two auxiliary threshold levels, one on each side of the usual threshold level separating the two states of a binary PCM signal (the threshold level separating binary 1 and binary 0). The PCM signal amplitude is compared with the auxiliary threshold levels and the result of the comparison is sampled at the beginning of each PCM bit. If the PCM signal amplitude is between the auxiliary threshold levels at the instant of sampling, an output pulse is produced indicating a deterioration of the PCM transmission.
Inventors
- 👤 Martin Chown
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 09:11
CPC Classifications
H; H04; H04L; H04L1/00; H04L1/20; H04L25/00; H04L25/02; H04L25/20; H04L25/24; H04L25/242
Claims Analysis
Total Claims: 16
Claim 1
Independent Claim
158 words
An arrangement to indicate deterioration of PCM signal transmission quality comprising: an input for said PCM signal; first means to produce two auxiliary threshold levels one on either side of a boundary level separating two adjacent signal states of said PCM signal; second means coupled to said first means and said input to determine whether said PCM signal has an amplitude disposed between said two auxiliary threshold levels and to produce a first output signal when this occurs; clock generating means coupled to said input to derive from only said signal states of said PCM signal a clock signal occurring at timing instants corresponding to the beginning of each PCM pulse period of said PCM signal; and third means coupled to said second means and said generating means, said third means responding to said clock signal to sample said first output signal at said timing instants to produce a second output signal indicating deterioration of said transmission quality.
Claim 2
Dependent Claim
158 words
An arrangement to indicate deterioration of PCM signal transmission quality comprising: an input for said PCM signal; first means to produce two auxiliary threshold levels one on either side of a boundary level separating two adjacent signal states of said PCM signal; second means coupled to said first means and said input to determine whether said PCM signal has an amplitude disposed between said two auxiliary threshold levels and to produce a first output signal when this occurs; clock generating means coupled to said input to derive from only said signal states of said PCM signal a clock signal occurring at timing instants corresponding to the beginning of each PCM pulse period of said PCM signal; and third means coupled to said second means and said generating means, said third means responding to said clock signal to sample said first output signal at said timing instants to produce a second output signal indicating deterioration of said transmission quality.
Claim 3
Dependent Claim
136 words
An arrangement according to claim 1, wherein said second means includes a first differential amplifier having an output and two inputs, one of said two inputs being coupled to said input for said PCM signal to receive said PCM signal and the other of said two inputs being coupled to said first means to receive one of said two auxiliary threshold levels, a second differential amplifier having an output and two inputs, one of said two inputs being coupled to said input for said PCM signal to receive said PCM signal and the other of said two inputs being coupled to said first means to receive the other of said two auxiliary threshold levels, and an AND gate coupled to the output of both said first and second differential amplifiers to produce said first output signal.
Claim 4
Dependent Claim
27 words
An arrangement according to claim 2, wherein said first means produces said two auxiliary threshold levels at fixed values relative to the value of said boundary level.
Claim 5
Dependent Claim
20 words
An arrangement according to claim 2, wherein said first means produces said two auxiliary threshold levels having periodically varying values.
Claim 6
Dependent Claim
28 words
An arrangement according to claim 2, further including fourth means coupled to said third means to average said second output signal over a plurality of PCM pulse periods.
Claim 7
Dependent Claim
27 words
An arrangement according to claim 1, wherein said first means produces said two auxiliary threshold levels at fixed values relative to the value of said boundary level.
Claim 8
Dependent Claim
20 words
An arrangement according to claim 1, wherein said first means produces said two auxiliary threshold levels having periodically varying values.
Claim 9
Dependent Claim
28 words
An arrangement according to claim 1, further including fourth means coupled to said third means to average said second output signals over a plurality of PCM pulse periods.
Claim 10
Independent Claim
112 words
A method of indicating deterioration of PCM signal transmission quality comprising the steps of: producing two auxiliary threshold levels one on either side of a boundary level separating two adjacent signal states of said PCM signal; determining when said PCM signal has an amplitude disposed between said two auxiliary thrEshold levels; deriving from only the signal states of said PCM signal a clock signal occurring at timing instants corresponding to the beginning of each PCM pulse period of said PCM signal; and sampling the results of said determining step by said clock signal at said timing instants, output pulses as the result of said sampling step indicating deterioration of said transmission quality.
Claim 11
Independent Claim
112 words
A method of indicating deterioration of PCM signal transmission quality comprising the steps of: producing two auxiliary threshold levels one on either side of a boundary level separating two adjacent signal states of said PCM signal; determining when said PCM signal has an amplitude disposed between said two auxiliary thrEshold levels; deriving from only the signal states of said PCM signal a clock signal occurring at timing instants corresponding to the beginning of each PCM pulse period of said PCM signal; and sampling the results of said determining step by said clock signal at said timing instants, output pulses as the result of said sampling step indicating deterioration of said transmission quality.
Claim 12
Dependent Claim
22 words
A method according to claim 9, further including the step of averaging said output pulses over a number of PCM pulse periods.
Claim 13
Dependent Claim
28 words
A method according to claim 10, wherein said two auxiliary threshold levels are maintained at a fixed predetermined value with respect to the value of said boundary level.
Claim 14
Dependent Claim
16 words
A method according to claim 10, wherein said two auxiliary threshold levels have periodically varied values.
Claim 15
Dependent Claim
28 words
A method according to claim 9, wherein said two auxiliary threshold levels are maintained at a fixed predetermined value with respect to the value of said boundary level.
Claim 16
Dependent Claim
16 words
A method according to claim 9, wherein said two auxiliary threshold levels have periodically varied values.
References Cited (Backward Citations)
US3777268A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1978-03-24 | 1978-09-23 | 1979-03-25 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-03-24 | 1982-09-23 | 1983-03-25 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-03-24 | 1986-09-23 | 1987-03-25 | $7700.00 | Window Closed / Lapsed |