Patent US3808367A successfully refreshed from Google Patents.
US3808367A
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Method and circuit for timing signal derivation from received data
Assignee: Lockheed Martin Corp
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Filing: 1972-04-19
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Granted: 1974-04-30
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Expires: 1992-04-19
Abstract
Abstract A method and circuit for deriving timing signals from received data through the detection of a predetermined digital code in the received data, the modification of the synchronization response rate in response to the detected code and the instantaneous control of timing signal phase in response to the detected code and its complement. A locally generated clock signal is rapidly synchronized at a first response rate until the code is detected. Thereafter, the clock signal synchronization is maintained at a second response rate lower than the first rate to provide a high degree of stability. A means is provided to retain clock signal synchronization during received outages.
Inventors
- 👤 W Wigner
- 👤 A Sabin
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 12:55
CPC Classifications
H; H04; H04W; H04W88/00; H04W88/18; H04W88/185; H04W88/187; H04L; H04L7/00; H04L7/0079; H04L7/0083; H04L7/04; H04L7/041; H04W88/02; H04W88/022; H04W88/025; H04W88/026; H04L7/0004; H04L7/02; H04L7/033; H04L7/042
Claims Analysis
Total Claims: 28
Claim 1
Independent Claim
217 words
Apparatus for recovering timing information from a digital data modulated signal comprising: means for receiving a digital split phase data modulation signal; means operably connected to said receiving means for recovering the digital split phase data modulation signal; means responsive to said recovering means for detecting the transitions of the modulation signal and generating a transition signal having a repetition rate related thereto at a repetition rate approximately twice the bit rate of the modulation signal; means for generating a local signal having a repetition rate variable through a range of repetition rates including a repetition rate related to the repetition rate of the transition signal; means operably connected to said detecting means and to said generating means for comparing the phase of the transition signal with the phase of the local signal; means for generating a control signal responsively to said comparing means; and, means responsive to the recovered split phase data modulation and said local signal for detecting a predetermined digital code in the recovered split phase data modulation, the repetition rate of said local signal being varied in response to said control signal at a first rate prior to detection of said predetermined digital code and at a second rate lower than the said first rate subsequent to detection of said predetermined digital code.
Claim 2
Dependent Claim
217 words
Apparatus for recovering timing information from a digital data modulated signal comprising: means for receiving a digital split phase data modulation signal; means operably connected to said receiving means for recovering the digital split phase data modulation signal; means responsive to said recovering means for detecting the transitions of the modulation signal and generating a transition signal having a repetition rate related thereto at a repetition rate approximately twice the bit rate of the modulation signal; means for generating a local signal having a repetition rate variable through a range of repetition rates including a repetition rate related to the repetition rate of the transition signal; means operably connected to said detecting means and to said generating means for comparing the phase of the transition signal with the phase of the local signal; means for generating a control signal responsively to said comparing means; and, means responsive to the recovered split phase data modulation and said local signal for detecting a predetermined digital code in the recovered split phase data modulation, the repetition rate of said local signal being varied in response to said control signal at a first rate prior to detection of said predetermined digital code and at a second rate lower than the said first rate subsequent to detection of said predetermined digital code.
Claim 3
Dependent Claim
60 words
The apparatus of claim 1 wherein said local signal generating means includes: means for generating a first signal having a repetition rate variable through a range of repetition rates including a multiple of the repetition rate of the transition signal; and, means for dividing the repetition rate of said first signal by said multiple to thereby generate said local signal.
Claim 4
Dependent Claim
57 words
The apparatus of claim 2 wherein said local signal generating means includes means for dividing the repetition rate of said local signal in half to thereby generate a clock signal having a repetition rate approximately equal to the bit rate of said modulation signal and having one of two predetermined phase relationships relative to said modulation signal.
Claim 5
Dependent Claim
49 words
The apparatus of claim 1 including: means for decoding a portion of said modulated signal responsively to said clock signal; and, means responsive to the decoded portiOn of said modulated signal for determining which of said two predetermined phase relationships exists between said clock signal and said modulation signal.
Claim 6
Dependent Claim
31 words
The apparatus of claim 1 including means for storing said control signal to provide control of the repetition rate of said local signal in the absence of a recovered modulation signal.
Claim 7
Independent Claim
183 words
A method for recovering timing information from a digital data modulated signal comprising the steps of: a. recovering a digital data signal from a digital data modulated signal; b. detecting the transitions of the digital data signal; c. generating a transition signal having a repetition rate related to the transition signal; d. generating a local signal having a repetition rate variable through a range of repetition rates including a repetition rate related to the repetition rate of the transition signal; e. comparing the phase of the transition signal with the phase of the local signal; f. generating a control signal responsively to the phase comparison of the transition and local signals; g. modifying the repetition rate of the local signal in response to the control signal; and, h. detecting a predetermined digital code within the digital data signal, the repetition rate of said local signal being modified in response to said control signal at a first rate prior to detection of said predetermined digital code, and at a second rate lower than the first rate subsequent to detection of said predetermined digital code.
Claim 8
Independent Claim
183 words
A method for recovering timing information from a digital data modulated signal comprising the steps of: a. recovering a digital data signal from a digital data modulated signal; b. detecting the transitions of the digital data signal; c. generating a transition signal having a repetition rate related to the transition signal; d. generating a local signal having a repetition rate variable through a range of repetition rates including a repetition rate related to the repetition rate of the transition signal; e. comparing the phase of the transition signal with the phase of the local signal; f. generating a control signal responsively to the phase comparison of the transition and local signals; g. modifying the repetition rate of the local signal in response to the control signal; and, h. detecting a predetermined digital code within the digital data signal, the repetition rate of said local signal being modified in response to said control signal at a first rate prior to detection of said predetermined digital code, and at a second rate lower than the first rate subsequent to detection of said predetermined digital code.
Claim 9
Dependent Claim
56 words
The method of claim 6 including the step of generating a clock signal having a repetition rate approximately equal to the bit rate of the digital data signal and having one of two predetermined phase relationships relative to the digital data signal by dividing the repetition rate of the local signal by a factor of two.
Claim 10
Dependent Claim
49 words
The method of claim 7 including the steps of: decoding a portion of the digital data signal responsively to the generated clock signal; and, determining which of the two predetermined phase relationships exists between the clock signal and the digital data signal in response to the digital data signal.
Claim 11
Dependent Claim
32 words
The method of claim 8 including the step of storing the control signal to provide control of the repetition rate of the local signal in the absence of a digital data signal.
Claim 12
Dependent Claim
70 words
The method of claim 6 wherein the phase of the transition signal is compared with the phase of the local signal by generating a series of pulses having a repetition rate approximately equal to the repetition rate of the transition signal and a duration related to the phase difference between the transition signal and the local signal; and, wherein the control signal is generated by integrating the series of pulses.
Claim 13
Dependent Claim
34 words
The method of claim 10 including the steps of modifying the time constant of integration from one predetermined vaule to a higher value in response to a predetermined portion of the digital data signal.
Claim 14
Dependent Claim
122 words
Apparatus for synchronizing a locally generated clock signal to a received data signal, the locally generated clock signal having a repetition rate variable through a range of repetition rates including a predetermined repetition rate related to the repetition rate of the data signal, said apparatus comprising: circuit means operable at first and second response rates for respectively rapidly synchronizing and maintaining the locally generated clock signal at the predetermined repetition rate related to the repetition rate of the data signal at a predetermined phase relationship relative thereto; means for detecting a predetermined synchronization signal in the data signal; and, means responsive to said detecting means for switching the response rate of said circuit means from said first to said second response rate.
Claim 15
Dependent Claim
122 words
Apparatus for synchronizing a locally generated clock signal to a received data signal, the locally generated clock signal having a repetition rate variable through a range of repetition rates including a predetermined repetition rate related to the repetition rate of the data signal, said apparatus comprising: circuit means operable at first and second response rates for respectively rapidly synchronizing and maintaining the locally generated clock signal at the predetermined repetition rate related to the repetition rate of the data signal at a predetermined phase relationship relative thereto; means for detecting a predetermined synchronization signal in the data signal; and, means responsive to said detecting means for switching the response rate of said circuit means from said first to said second response rate.
Claim 16
Dependent Claim
56 words
The apparatus of claim 12 wherein the clock signal has one of two predetermined phase relationships relative to said data signal and further including: means for detecting the complemenT of said synchronization signal; and, means for selecting one of said two predetermined phase relationships responsively to the detection of said predetermined synchronization signal and its complement.
Claim 17
Dependent Claim
97 words
Apparatus for synchronizing a locally generated clock signal to a received data signal comprising: means for detecting transitions in signal level of the data signal and generating a transition signal related in repetition rate to the repetition rate of the data signal; means for modifying the repetition rate of the locally generated clock signal responsively to said transition signal; means for detecting a predetermined synchronization pattern and the complement thereof in the data signal; and, means for controlling the phase of the locally generated clock signal responsively to one of the detected synchronization patterns and its complement.
Claim 18
Dependent Claim
97 words
Apparatus for synchronizing a locally generated clock signal to a received data signal comprising: means for detecting transitions in signal level of the data signal and generating a transition signal related in repetition rate to the repetition rate of the data signal; means for modifying the repetition rate of the locally generated clock signal responsively to said transition signal; means for detecting a predetermined synchronization pattern and the complement thereof in the data signal; and, means for controlling the phase of the locally generated clock signal responsively to one of the detected synchronization patterns and its complement.
Claim 19
Dependent Claim
38 words
The apparatus of claim 14 wherein said modifying means includes means for generating a control signal related in amplitude to the repetition rate of said transition signal, and wherein said modifying means is responsive to said control signal.
Claim 20
Dependent Claim
26 words
The apparatus of claim 15 including means for storing said control signal to provide control of said modifying means during the absence of said data signal.
Claim 21
Dependent Claim
136 words
Apparatus for synchronizing a locally generated clock signal to a received data signal comprising: circuit means operable at first and second response rates for respectively rapidly establishing and maintaining a predetermined repetition rate and phase relationship between the locally generated clock signal and the received data signal; means for detecting a predetermined synchronization signal in the received data signal; and, means for modifying the response rate of said circuit means from said first response rate to said second response rate in response to the detection of said predetermined synchronization signal, the first rate being substantially higher than the second rate whereby after the predetermined relationship is rapidly established and said synchronization signal is detected, the predetermined relationship is maintained with a high degree of stability and is relatively unaffected by tolerable errors in the data signal.
Claim 22
Dependent Claim
136 words
Apparatus for synchronizing a locally generated clock signal to a received data signal comprising: circuit means operable at first and second response rates for respectively rapidly establishing and maintaining a predetermined repetition rate and phase relationship between the locally generated clock signal and the received data signal; means for detecting a predetermined synchronization signal in the received data signal; and, means for modifying the response rate of said circuit means from said first response rate to said second response rate in response to the detection of said predetermined synchronization signal, the first rate being substantially higher than the second rate whereby after the predetermined relationship is rapidly established and said synchronization signal is detected, the predetermined relationship is maintained with a high degree of stability and is relatively unaffected by tolerable errors in the data signal.
Claim 23
Independent Claim
90 words
A method of synchronizing a locally generated clock signal to a data signal received from a remote location comprising the steps of: a. generating a clock signal; b. modifying the frequency of the generated clock signal at a first rate of change until synchronization of the clock to the data signal within predetermined limits is obtained for rapid acquisition of synchronization; and, c. thereafter modifying the frequency of the generated clock signal at a second rate of change less than the first rate of change for stable maintenance of synchronization.
Claim 24
Independent Claim
90 words
A method of synchronizing a locally generated clock signal to a data signal received from a remote location comprising the steps of: a. generating a clock signal; b. modifying the frequency of the generated clock signal at a first rate of change until synchronization of the clock to the data signal within predetermined limits is obtained for rapid acquisition of synchronization; and, c. thereafter modifying the frequency of the generated clock signal at a second rate of change less than the first rate of change for stable maintenance of synchronization.
Claim 25
Dependent Claim
39 words
The method of claim 18 including the further steps of: d. determining the phase relationship of the clock signal relative to the data signal; and, e. effecting a predetermined phase relationship between the clock signal and the data signal.
Claim 26
Dependent Claim
30 words
The method of claim 12 including the steps of detecting a predetermined bit pattern in the data signal; and, modifying the rate of change of clock frequency modification responsively thereto.
Claim 27
Independent Claim
81 words
A method of synchronizing a locally generated clock signal to a data signal received from a remote location comprising the steps of: a. detecting transitions in the signal level of the data signal; b. generating a clock signal; c. modifying the frequency of the clock signal responsively to the frequency of transitions detected; d. detecting a predetermined bit pattern in the data signal; e. changing the rate of clock signal frequency modification responsively to the detection of the predetermined bit pattern.
Claim 28
Independent Claim
81 words
A method of synchronizing a locally generated clock signal to a data signal received from a remote location comprising the steps of: a. detecting transitions in the signal level of the data signal; b. generating a clock signal; c. modifying the frequency of the clock signal responsively to the frequency of transitions detected; d. detecting a predetermined bit pattern in the data signal; e. changing the rate of clock signal frequency modification responsively to the detection of the predetermined bit pattern.
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) | 1977-04-29 | 1977-10-29 | 1978-04-30 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-04-29 | 1981-10-29 | 1982-04-30 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-04-29 | 1985-10-29 | 1986-04-30 | $7700.00 | Window Closed / Lapsed |