Patent US1463513A successfully refreshed from Google Patents.
Patent US4860323A successfully refreshed from Google Patents.
US4860323A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method and device for the acquisition of synchronization bits in data transmission systems
Assignee: THOMSON - CSF 173 BLVD HAUSSMANN 75008 PARIS FRANCE
•
Filing: 1988-06-29
•
Granted: 1989-08-22
•
Expires: 2008-06-29
Abstract
Abstract The method comprises, at each receiver of the system, the steps of making a comparison, modulo the number of bits contained in a frame of transmitted data, of the value of each of the bits received with the pre-supposed values of the synchronization bits, totalizing the results of the comparisons made on each bit and identifying, in the received bits, the bit positions modulo the number of bits contained in a frame for which the totals obtained are greater than an adjustable threshold value, modulo the number of bits contained in a frame, as a function of the number of comparisons already made for each bit of a frame and adapted according to the probabilities of false alarms and of non-detection which characterize the transmission.
Inventors
- 👤 Remi Malter
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 17:39
CPC Classifications
H; H04; H04L; H04L7/00; H04L7/04; H04L7/041; H04L7/043
Claims Analysis
Total Claims: 14
Claim 1
Independent Claim
208 words
A method for acquisition of synchronization bits in systems for transmission of data transmitted between at least one transmitter and one receiver, of the type in which the flow of information exchanged between a transmitter and a receiver is cut up into frame blocks belonging to one or more channels, each synchronized frame being separated from the following frame by at least one synchronization bit, comprising the steps of: initially determining pre-supposed synchronization values; receiving a plurality of bits to be synchronized; making comparisons with said pre-supposed synchronization values, modulo a number of bits in a frame, and during a predetermined number of frames of the value of each of the bits received; totalizing results of the comparisons made on each bit in said making comparisons step; identifying, in the received bits, bit positions modulo the number of bits in a frame for which the totals obtained in said totalizing step are greater than an adjustable threshold value, modulo the number of bits contained in a frame, said threshold value being determined as a function of a number of comparisons already made in said making comparisons step for each bit of a frame and adapted according to probabilities of false alarms and of non-detection which characterize the transmission.
Claim 2
Independent Claim
208 words
A method for acquisition of synchronization bits in systems for transmission of data transmitted between at least one transmitter and one receiver, of the type in which the flow of information exchanged between a transmitter and a receiver is cut up into frame blocks belonging to one or more channels, each synchronized frame being separated from the following frame by at least one synchronization bit, comprising the steps of: initially determining pre-supposed synchronization values; receiving a plurality of bits to be synchronized; making comparisons with said pre-supposed synchronization values, modulo a number of bits in a frame, and during a predetermined number of frames of the value of each of the bits received; totalizing results of the comparisons made on each bit in said making comparisons step; identifying, in the received bits, bit positions modulo the number of bits in a frame for which the totals obtained in said totalizing step are greater than an adjustable threshold value, modulo the number of bits contained in a frame, said threshold value being determined as a function of a number of comparisons already made in said making comparisons step for each bit of a frame and adapted according to probabilities of false alarms and of non-detection which characterize the transmission.
Claim 3
Dependent Claim
36 words
A method according to claim 1 comprising the further step of memorizing positions of the bits identified in the sequence of received bits to determine, according to their relative address, an order of the synchronized channels.
Claim 4
Dependent Claim
49 words
A method according to claim 2 comprising the further step of performing said totalizing step up to a maximum number corresponding to a number Nmax of frames, beyond which it can be ensured that, if no totalizing operation has exceeded the threshold value, the analyzed frames are not synchronized.
Claim 5
Dependent Claim
56 words
A method according to claim 3 wherein the pre-supposed values of the synchronization bits may be one of the two binary values "one" or "zero", and wherein said totalizing step is performed simultaneously upon the occurrence of an event, namely bit 1, and of its contrary, namely bit zero, to recognize inversions in the synchronization bits.
Claim 6
Dependent Claim
20 words
A method according to claim 4 wherein the synchronization bits are generated at transmission, following a sequence of pseudo-random bits.
Claim 7
Dependent Claim
41 words
A method according to claim 5 wherein said initially determining step includes multiplying the already received synchronization bits by a generating polynomial which was used to generate them at transmission, in order to obtain the pre-supposed value of a synchronization bit.
Claim 8
Dependent Claim
55 words
A method according to claim 6 further comprising the step of correcting the errors on the received synchronization bits by assigning, to each received synchronization bit, a bit reflecting its quality and by computing the expected value of each synchronization bit, by means of a majority vote weighted by the quality of the bits received.
Claim 9
Dependent Claim
20 words
A method according to claim 7 wherein modifications are provoked in the sequence of synchronization bits to transmit supplementary messages.
Claim 10
Dependent Claim
24 words
A method according to claim 8 wherein the error rate of the transmission is determined by measuring the error rate of the synchronization bits.
Claim 11
Dependent Claim
41 words
A method according to claim 9 further comprising the step in deciding, at all times, through correlations on the bits received, the holding of the synchronization without modifying it, or its modification only on that part which is modified at transmission.
Claim 12
Independent Claim
145 words
A device for acquisition of synchronization bits in systems for transmission of data transmitted between at least one transmitter and one receiver comprising, in the receiver: first means for comparing, modulo a number of bits contained in a frame and during a predetermined number of frames, a value of each of the bits received with presupposed values of synchronization bits; second means, coupled to first means, for totalizing results of the comparisons made on each bit; third means for identifying in the received bits the bit positions, modulo a number of bits contained in a frame, for which the totals obtained are greater than an adjustable threshold value, said threshold value being determined as a function of a number of comparisons already executed for each bit of a frame and adapted according to probabilities of false alarms and of non detection which characterize the transmission.
Claim 13
Independent Claim
145 words
A device for acquisition of synchronization bits in systems for transmission of data transmitted between at least one transmitter and one receiver comprising, in the receiver: first means for comparing, modulo a number of bits contained in a frame and during a predetermined number of frames, a value of each of the bits received with presupposed values of synchronization bits; second means, coupled to first means, for totalizing results of the comparisons made on each bit; third means for identifying in the received bits the bit positions, modulo a number of bits contained in a frame, for which the totals obtained are greater than an adjustable threshold value, said threshold value being determined as a function of a number of comparisons already executed for each bit of a frame and adapted according to probabilities of false alarms and of non detection which characterize the transmission.
Claim 14
Independent Claim
24 words
A method according to anyone of the claims 1 to 10 wherein said receiving a plurality of bits step uses a radioelectric wave receiver.
References Cited (Backward Citations)
US3648237A
Cited
GB1401261A
Cited
DE2345491A1
Cited
US4002845A
Cited
US4310921A
Cited
US4306308A
Cited
JPS579147A
Cited
US4517679A
Cited
JPS609241A
Cited
US4638497A
Cited
JPS60227542A
Cited
US4697277A
Cited
US4748623A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1992-08-21 | 1993-02-20 | 1993-08-22 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1996-08-21 | 1997-02-20 | 1997-08-22 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2000-08-21 | 2001-02-20 | 2001-08-22 | $7700.00 | Window Closed / Lapsed |