EP0241974A1
Expired / Lapsed
EP
⏱️ 0.0 years remaining
Device for the regeneration of channel-clock information in data transmission and data-recovery arrangement comprising such a device.
Assignee: Koninklijke Philips NV
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Filing: 1987-03-31
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Granted: —
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Expires: 2007-03-31
Abstract
Abstract A sampled synchronous transmission signal Vt is represented by a series of samples J at equidistant sampling instants. A computing circuit 5 computes the positions R of the sampling instants relative to the rising edges of a virtual reference clock Cref which is phase-locked to the channel clock. For each sampling instant the position R is determined on the basis of the position R of a preceding sampling instant and a measure Q of the difference in time between the sampling interval T and the period L of the virtual reference clock Cref. From the values of the successive samples J an interpolation circuit 2 derives the positions N of the detection-level crossings by the transmission signal Vt, which crosssings represent a fixed phase position of the channel clock. After each detections-level crossing the measure Q of the time difference is corrected by means of circuit 3 and 4 depending on the difference between the positions N and R. A data recovery arrangement recovers the data depending on the values determined for the positions R.
Inventors
- 👤 Kornelis Antonie Schouhamer Immink
- 👤 Josephus Arnoldus Henricus Maria Kahlman
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-06 08:49
CPC Classifications
H; H04; H04L; H04L7/00; H04L7/02; H04L7/033; H04L7/0334
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
206 words
A device for the regeneration of channel-clock information from a series of samples which represent the signal values of a band-limited transmission signal at equidistant sampling instants, which transmission signal is synchronous with the channel clock, comprising computing means for deriving first positions of sampling instants relative to reference instants defined by fixed phase positions of a reference clock from the positions determined for previous sampling instants, detection means for detecting crossings of a detection level by the transmission signal between successive sampling instants from the values of samples corresponding to the sampling instants, interpolation means which are responsive to a level-crossing detection for determining second positions of sampling instants relative to the level crossings from the values of samples in the proximity of the detection-level crossings, and means for comparing the second positions and the first positions of the sampling instants with each other, characterized in that the device comprises means for correcting a measure of the time difference between the period of the reference clock and the sampling interval depending on the differences between first positions and second positions which have been compared, and in that the computing means are adapted to derive the first positions depending on the measure of the time difference.
Claim 2
Independent Claim
206 words
A device for the regeneration of channel-clock information from a series of samples which represent the signal values of a band-limited transmission signal at equidistant sampling instants, which transmission signal is synchronous with the channel clock, comprising computing means for deriving first positions of sampling instants relative to reference instants defined by fixed phase positions of a reference clock from the positions determined for previous sampling instants, detection means for detecting crossings of a detection level by the transmission signal between successive sampling instants from the values of samples corresponding to the sampling instants, interpolation means which are responsive to a level-crossing detection for determining second positions of sampling instants relative to the level crossings from the values of samples in the proximity of the detection-level crossings, and means for comparing the second positions and the first positions of the sampling instants with each other, characterized in that the device comprises means for correcting a measure of the time difference between the period of the reference clock and the sampling interval depending on the differences between first positions and second positions which have been compared, and in that the computing means are adapted to derive the first positions depending on the measure of the time difference.
Claim 3
Dependent Claim
54 words
A device as claimed in Claim 1, characterized in that the means for adapting the measure of the time difference comprise summing means for forming the sum of the differences between the first positions and the second positions and means for deriving the measure of the time difference from the sum of the differences.
Claim 4
Dependent Claim
72 words
A device as claimed in Claim 2, characterized in that the means for adapting the measure comprise correction means for correcting the difference determined between the first position and the second position by a value corresponding to the period of the reference clock in response to a detection of a difference between the first position and the second position larger than a value corresponding to half the period of the reference clock.
Claim 5
Independent Claim
119 words
A device as claimed in any one of the preceding Claims, characterized in that the computing means for computing the first positions comprise means for adapting the previously determined first position by the measure of the time difference in response to a detection that time interval between the preceding first position and the corresponding reference instant is smaller than the sampling interval and means for adapting the preceding first position by a value whose magnitude corresponds to the sampling interval and whose sign is opposite to that of the measure of the time difference in response to a detection that the time interval between the preceding first position and the corresponding reference instant is larger than the sampling interval.
Claim 6
Dependent Claim
33 words
An arrangement for the recovery of data represented by a sampled band-limited transmission signal which is synchronous with a channel clock, comprising a device as claimed in any one of the preceding Claims.
Claim 7
Dependent Claim
75 words
An arrangement for the recovery of data as claimed in Claim 5, characterized in that the data-recovery arrangement comprises comparison means for determining whether the values of the first positions are situated within bounds which are situated at an interval corresponding to the sampling interval from each other and counting means for counting the number of times that the values determined for the first positions between two successive detection-level crossings are situated within said bounds.
References Cited (Backward Citations)
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