Patent US3794978A successfully refreshed from Google Patents.
US3794978A
Expired / Lapsed
US
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Systems for the transmission of control and/or measurement information
Assignee: CGG SA
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Filing: 1971-08-20
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Granted: 1974-02-26
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Expires: 1991-08-20
Abstract
Abstract Apparatus for and method of synchronous transmission of digital control and/or measurement information over a high frequency transmission link with high reliability. A predetermined number of known pseudo-random sequences of selected duration are generated synchronous with a low-frequency sinusoidal subcarrier, each representing one datum of digital information. These sequences are used to phase-reversal modulate the subcarrier which in turn modulates a high-frequency carrier. A receiver demodulates the signal, restoring the original series of pseudorandom sequences. The same pseudo-random sequences as are generated in the transmitter are independently generated in the receiver and are phase-locked and individually compared with each restored sequence. When a correlation is found, the datum of information which corresponds to the transmitted pseudo-random sequence is known. A preferred application is to seismic experimentation.
Inventors
- 👤 P Staron
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-23 18:26
CPC Classifications
H; H04; H04J; H04J13/00; H04J13/0007; H04J13/0022; G; G01; G01V; G01V1/00; G01V1/22; G01V1/223; H04B; H04B1/00; H04B1/69; H04B1/707; H04L; H04L27/00; H04L27/18; H04L27/20; H04L27/2032; H04L27/2035; H04L27/22; H04L27/227; H04L27/2275; H04L27/2278; H04L7/00; H04L7/04; H04L7/041; H04L7/043
Claims Analysis
Total Claims: 14
Claim 1
Independent Claim
210 words
The method of synchronising transmission of information through a transmission channel between a transmitting station and a receiving station, comprising the steps of a. generating a low frequency sinusoidal sub-carrier of known period at said transmitting station, b. generating a consecutive repetition of a known pseudo-random sequence of selected duration having a particular timesuccession of two different states, the time-period at each state in the succession being equal to or a multiple of said known period, c. phase-reversal modulating the sinusoidal sub-carrier depending upon the successive states in said consecutive repetition, d. generating at said receiving station a local low frequency sub-carrier having said known period and being synchronous with the sub-carrier received from the transmitting station, e. generating a shiftable local consecutive repetition of said known pseudo-random sequence of selected duration, the duration of each state in the succession being equal to or a multiple of the known period, f. phase reversal modulating the local sub-carrier depending upon the successive states in said consecutive repetition, g. comparing the phase reversal modulated sub-carrier received from the transmission with the phase reversal modulated local sub-carrier, and shifting said local consecutive repetition of the known pseudorandom sequence until the comparison indicates that it is synchronous with the consecutive repetition received from transmission.
Claim 2
Independent Claim
210 words
The method of synchronising transmission of information through a transmission channel between a transmitting station and a receiving station, comprising the steps of a. generating a low frequency sinusoidal sub-carrier of known period at said transmitting station, b. generating a consecutive repetition of a known pseudo-random sequence of selected duration having a particular timesuccession of two different states, the time-period at each state in the succession being equal to or a multiple of said known period, c. phase-reversal modulating the sinusoidal sub-carrier depending upon the successive states in said consecutive repetition, d. generating at said receiving station a local low frequency sub-carrier having said known period and being synchronous with the sub-carrier received from the transmitting station, e. generating a shiftable local consecutive repetition of said known pseudo-random sequence of selected duration, the duration of each state in the succession being equal to or a multiple of the known period, f. phase reversal modulating the local sub-carrier depending upon the successive states in said consecutive repetition, g. comparing the phase reversal modulated sub-carrier received from the transmission with the phase reversal modulated local sub-carrier, and shifting said local consecutive repetition of the known pseudorandom sequence until the comparison indicates that it is synchronous with the consecutive repetition received from transmission.
Claim 3
Dependent Claim
53 words
The method of claim 1, wherein the step of generating a local low frequency sub-carrier at said receiving device comprises generating a local low frequency sub-carrier having a period adjustable about said known period, and adjusting the period of the local sub-carrier until it is synchronous with the sub-carrier received from the transmission.
Claim 4
Dependent Claim
100 words
The method of claim 1 wherein the step of comparing the received phase-reversal modulated sub-carrier with the local phase reversal modulated sub-carrier comprises the steps of coherently demodulating the received phase reversal modulated sub-carrier with the local phase reversal modulated sub-carrier, with the signal from the demodulation being an instantaneous representation of the correspondence between the transmitted pseudo-random sequence and the local pseudo-random sequence, integrating the signal from the deModulation for the duration of the local pseudo-random sequence, and comparing the integrated signal to a reference value, with the synchronism being admitted when the integrated signal exceeds the reference value.
Claim 5
Independent Claim
292 words
A method of synchronous transmission of information using a transmission channel between a transmitting station and receiving station, comprising the steps of a. generating at said transmitting station a low frequency sinusoidal sub-carrier of known period, b. generating a consecutive repetition of each of a predetermined number of known pseudo-random sequences of selected duration, each having a particular time succession of two different states, the time period at each state in the succession being equal to or a multiple of said known period, at least certain of said sequences being representative each of a respective datum of information to be transmitted, c. phase-reversal modulating the sinusoidal sub-carrier depending upon the successive states of successively selected ones of the pseudo-random sequences, thereby permitting the transmission of data of information, the transmission instants of each datum coinciding with the commencement of the generation of the corresponding pseudo-random sequences, d. generating at said receiving station a local low frequency sub-carrier having said known period and being synchronous with the sub-carrier received from the transmitting station, e. generating a local consecutive repetition of each of said predetermined number of known pseudo-random sequences of selected duration, the duration of each state in the succession being equal to or a multiple of the known period, f. separately phase-reversal modulating the local sub-carrier according to each repetition of a known pseudo-random sequence, depending upon the successive states therein, g. separately correlating the phase-reversal modulated sub-carrier received from the transmission station with each of the phase-reversal modulated local sub-carriers, and h. continuously comparing the locally phase-reversal modulated sub-carrier with the phase-reversal modulated sub-carrier received from the transmission station and accepting the correlation thereof as a datum of information, whereby there is no delay in the transmission but said known duration.
Claim 6
Independent Claim
292 words
A method of synchronous transmission of information using a transmission channel between a transmitting station and receiving station, comprising the steps of a. generating at said transmitting station a low frequency sinusoidal sub-carrier of known period, b. generating a consecutive repetition of each of a predetermined number of known pseudo-random sequences of selected duration, each having a particular time succession of two different states, the time period at each state in the succession being equal to or a multiple of said known period, at least certain of said sequences being representative each of a respective datum of information to be transmitted, c. phase-reversal modulating the sinusoidal sub-carrier depending upon the successive states of successively selected ones of the pseudo-random sequences, thereby permitting the transmission of data of information, the transmission instants of each datum coinciding with the commencement of the generation of the corresponding pseudo-random sequences, d. generating at said receiving station a local low frequency sub-carrier having said known period and being synchronous with the sub-carrier received from the transmitting station, e. generating a local consecutive repetition of each of said predetermined number of known pseudo-random sequences of selected duration, the duration of each state in the succession being equal to or a multiple of the known period, f. separately phase-reversal modulating the local sub-carrier according to each repetition of a known pseudo-random sequence, depending upon the successive states therein, g. separately correlating the phase-reversal modulated sub-carrier received from the transmission station with each of the phase-reversal modulated local sub-carriers, and h. continuously comparing the locally phase-reversal modulated sub-carrier with the phase-reversal modulated sub-carrier received from the transmission station and accepting the correlation thereof as a datum of information, whereby there is no delay in the transmission but said known duration.
Claim 7
Dependent Claim
101 words
Apparatus for the synchronous transmission of information comprising a. a transmitter for generating a high-frequency carrier wave, said transmitter including means for generating a sinusoidal sub-carrier, having a known low frequency, b. shift register means for continuously generating a pseudo-random sequence of selected duration having a particular time succession of two different states and synchronous with said sub-carrier, and c. means for effecting phase-reversal modulation of the sinusoidal sub-carrier depending upon the successive states in the pseudo-random sequence, the sub-carrier thus phase-modulated modulating in turn the high-frequency carrier wave, thereby effecting the transmission over the transmission link of the pseudo-random sequence.
Claim 8
Dependent Claim
101 words
Apparatus for the synchronous transmission of information comprising a. a transmitter for generating a high-frequency carrier wave, said transmitter including means for generating a sinusoidal sub-carrier, having a known low frequency, b. shift register means for continuously generating a pseudo-random sequence of selected duration having a particular time succession of two different states and synchronous with said sub-carrier, and c. means for effecting phase-reversal modulation of the sinusoidal sub-carrier depending upon the successive states in the pseudo-random sequence, the sub-carrier thus phase-modulated modulating in turn the high-frequency carrier wave, thereby effecting the transmission over the transmission link of the pseudo-random sequence.
Claim 9
Dependent Claim
144 words
The apparatus of claim 5, further including a receiver for receiving the high-frequency carrier wave originating from the transmitter and restoring the phase reversal modulated low-frequency sub-carrier of the transmitter with increased noise, said receiver comprising a. means for generating a low-frequency local signal, having substantially said known low-frequency, b. means for phase-locking said low-frequency local signal relative to the said restored sub-carrier, c. shift register means for continuously generating the same pseudo-random sequence of selected duration as at said transmitter, synchronous with said phase-locked low-frequency local signal. d. means for phase-reversal modulating the low-frequency local signal with the pseudo-random sequence, e. correlating means for correlating said restored phase reversal modulated low-frequency sub-carrier with the local phase-reversAl modulated low-frequency signal, and f. means for altering the shifting of said shift-register means until the received phase-reversal modulated sub-carrier correlates with the phase-reversal modulated local signal.
Claim 10
Dependent Claim
142 words
Apparatus for the synchronous transmission of information comprising a. a transmitter for generating a high-frequency carrier wave and a sinusoidal low-frequency sub-carrier thereof, b. shift register means for continuously generating a predetermined number of pseudo-random sequences of selected duration, each having a particular time succession of two different states, and synchronous with said sub-carrier, c. selecting means responsive to a series of datum transmission orders for serially selecting corresponding ones of the pseudo-random sequences, with a waiting sequence being selected in the lack of such order, and d. means for effecting phase-reversal modulation of the sinusoidal sub-carrier depending upon the successive states in each pseudo-random sequence of the series, the sub-carrier thus phase-modulated modulating in turn the high-frequency carrier wave, thereby effecting the transmission over the transmission link of a series of pseudo-random sequences each representative of a respective datum of information.
Claim 11
Dependent Claim
142 words
Apparatus for the synchronous transmission of information comprising a. a transmitter for generating a high-frequency carrier wave and a sinusoidal low-frequency sub-carrier thereof, b. shift register means for continuously generating a predetermined number of pseudo-random sequences of selected duration, each having a particular time succession of two different states, and synchronous with said sub-carrier, c. selecting means responsive to a series of datum transmission orders for serially selecting corresponding ones of the pseudo-random sequences, with a waiting sequence being selected in the lack of such order, and d. means for effecting phase-reversal modulation of the sinusoidal sub-carrier depending upon the successive states in each pseudo-random sequence of the series, the sub-carrier thus phase-modulated modulating in turn the high-frequency carrier wave, thereby effecting the transmission over the transmission link of a series of pseudo-random sequences each representative of a respective datum of information.
Claim 12
Dependent Claim
245 words
The apparatus of claim 7, further including a receiver for receiving the high-frequency carrier wave originating from the transmitter and restoring the phase-reversal modulated low-frequency sub-carrier of the transmitter with increased noise, said receiver comprising a. means for generating a low-frequency local signal having substantially said known low-frequency, b. means for restoring an unmodulated sub-carrier from the received phase-reversal modulated one, c. means for phase-locking said low-frequency local signal relative to the said restored sub-carrier, d. shift register means for continuously generating local pseudo-random sequences of selected duration, synchronous with said phase-locked low-frequency local signal, said local pseudo-random sequences being identical to corresponding pseudo-random sequences at said transmitter, e. means for altering the shifting of said shift register means until at least one local pseudo-random sequence substantially coincides in time with the same pseudo-random sequence from said transmitting station, f. means for separately phase-reversal modulating the low-frequency local signal with each of the local pseudo-random sequences, g. correlating means for separately correlating the said restored phase reversal modulated low-frequency sub-carrier with each local low-frequency signal, each of said signals being phase-reversal modulated with its own pseudo-random sequence, and h. decision means responsive to said correlating means for accepting at the end of said pseudo-random sequence from said transmitting station the datum of information corresponding to said pseudo-random sequence and for accepting no information in the presence of a waiting sequence, whereby there is no delay except for said unknown duration in the transmission of information.
Claim 13
Dependent Claim
149 words
The apparatus of claim 8, wherein said correlating means includes a. a plurality of coherent demodulators equal in number to that of the locally generated pseudo-random sequences, each for phase-reversal modulating the local low-frequency sub-carrier by one of said sequences and continuously and synchronously comparing it with said restored phase-reversal modulated low-frequency sub-carrier, each of said demodulators supplying at its output an electrical signal representing at the end of each pseudo-random sequence the identity of each of said pseudo-random sequences from said transmitting station. b. a plurality of integrators equal in number to that of the coherent demodulators, each integrator integrating the output signal from a respective coherent demodulator for and synchronous with said selected duration of the pseudo-random sequences, and c. a plurality of thresholD devices each coupled to a respective integrator for indicating a corresponding correlation when the amplitude of the integrated signal exceeds a reference value.
Claim 14
Dependent Claim
68 words
The apparatus of claim 9, wherein at said transmitter at least certain pseudo-random sequences have respective corresponding sequences in the predetermined number which are the exact logical inverse thereof, and at least certain corresponding ones of said threshold devices at said receiver selectively respond to the polarity of its input integration signal by indicating one or another correlation when the amplitude thereof exceeds the threshold in absolute value.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1977-02-25 | 1977-08-27 | 1978-02-26 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-02-25 | 1981-08-27 | 1982-02-26 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-02-25 | 1985-08-27 | 1986-02-26 | $7700.00 | Window Closed / Lapsed |