Patent US3701018A successfully refreshed from Google Patents.
US3701018A
Expired / Lapsed
US
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Acquisition method for multi-transmission position locating or navigating systems
Assignee: Motorola Solutions Inc
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Filing: 1971-02-22
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Granted: 1972-10-24
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Expires: 1991-02-22
Abstract
Abstract A method is disclosed for reducing the time needed to synchronize N code receivers at one station with respect to ones of N code transmitters at different stations wherein all transmitters radiate the same code word, but time delayed relative to each other by fractional word length intervals which may be inversely proportional to the number (N) of transmitters and include an additional small time interval, which may be a lead or a lag, added to or subtracted from all codes but one for identification purposes. In the initial search mode of the synchronization, all N of the receivers are used with the receiver coders being moved together but retaining a fixed relationship with each other. Code words, which are generated locally in each receiver, and which are identical with the transmitted code words, are time-delayed with respect to each other by a fractional word length interval which may be inversely proportional to the square of the number of transmitters, whereby the initial search time for one of the receivers to lock up with or acquire one of the transmitters is reduced on the average to a small fraction equal to 1/2N2, for example, of a word length. When synchronization of any one transmitter with any one receiver is accomplished, the known delay between the transmissions (without taking into account the identification delay) is used to synchronize transmissions of the remaining transmitters with locally generated signals of the remaining receivers. Then the known identifying lag or lead delay is used to identify the particular transmitters which have been synchronized with particular receivers.
Inventors
- 👤 Edward John Groth Jr
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 05:45
CPC Classifications
G; G01; G01S; G01S1/00; G01S1/02; G01S1/08; G01S1/20
Claims Analysis
Total Claims: 14
Claim 1
Independent Claim
137 words
The method of synchronizing the internally generated codes of a plurality of receivers which are at one location with respect to the transmitted codes of respective ones of a plurality of transmitters at different locations comprising: generating an identical cyclical code at each of said transmitters, transmitting the code of each transmitter delayed in time from transmitter to transmitter by a predetermined amount, generating said identical cyclical codes at each of said receivers but delayed in time by an amount which is substantially less than said predetermined amount, applying the transmitted codes of all of said transmitters to all of said receivers, and changing the time of relationship of all of the receiver codes together relative to all the codes applied to the receivers until one of the receiver codes synchronizes with one of the transmitted codes.
Claim 2
Independent Claim
137 words
The method of synchronizing the internally generated codes of a plurality of receivers which are at one location with respect to the transmitted codes of respective ones of a plurality of transmitters at different locations comprising: generating an identical cyclical code at each of said transmitters, transmitting the code of each transmitter delayed in time from transmitter to transmitter by a predetermined amount, generating said identical cyclical codes at each of said receivers but delayed in time by an amount which is substantially less than said predetermined amount, applying the transmitted codes of all of said transmitters to all of said receivers, and changing the time of relationship of all of the receiver codes together relative to all the codes applied to the receivers until one of the receiver codes synchronizes with one of the transmitted codes.
Claim 3
Dependent Claim
26 words
The method of claim 1 in which said predetermined time interval is equal to the length of the code word divided by the number of transmitters.
Claim 4
Dependent Claim
17 words
The method of claim 2 wherein the said time interval includes a plus or minus small amount.
Claim 5
Dependent Claim
19 words
The method of claim 3 in which the said small amount is a lag or lead transmitter identification period.
Claim 6
Dependent Claim
46 words
The method of claim 1 wherein after one receiver code is synchronized with one transmitted code, the time relationship of the other receiver generated codes are shifted by an amount related to the delays between the said transmissions to synchronize the other receivers to respective transmitters.
Claim 7
Dependent Claim
43 words
The method of claim 2 wherein after one receiver code is synchronized with one transmitted code, the time relationship of other receiver generated codes are shifted by amounts related to the delay between said transmissions to synchronize the other receivers to respective transmitters.
Claim 8
Independent Claim
144 words
The method of synchronizing the internally generated code words of a plurality of receivers which are at one location with respect to the transmitted code words of respective ones of a plurality of transmitters at different locations comprising: generating identical cyclical code words at each of said transmitters, transmitting the code words of each transmitter delayed in time from transmitter to transmitter by a predetermined amount, generating said identical cyclical code words at each of said receivers but delayed in time by an amount which is substantially less than said predetermined amount, applying the transmitted codes of all of said transmitters to all of said receivers, and changing the time relationship of all the receiver code words together relative to all of the code words applied to the receivers until one of the receiver code words synchronizes with one of the transmitted code words.
Claim 9
Independent Claim
144 words
The method of synchronizing the internally generated code words of a plurality of receivers which are at one location with respect to the transmitted code words of respective ones of a plurality of transmitters at different locations comprising: generating identical cyclical code words at each of said transmitters, transmitting the code words of each transmitter delayed in time from transmitter to transmitter by a predetermined amount, generating said identical cyclical code words at each of said receivers but delayed in time by an amount which is substantially less than said predetermined amount, applying the transmitted codes of all of said transmitters to all of said receivers, and changing the time relationship of all the receiver code words together relative to all of the code words applied to the receivers until one of the receiver code words synchronizes with one of the transmitted code words.
Claim 10
Dependent Claim
18 words
The method of claim 7 in which said predetermined amounts are chosen to include a transmitter identification period.
Claim 11
Dependent Claim
28 words
The method of claim 7 in which all of said receivers are varied differing amounts determined by said predetermined amount whereby said receivers match up with respective transmitters.
Claim 12
Dependent Claim
170 words
In the system of synchronizing the internally generated codes of a plurality of receivers which are at one location with respect to the transmitted codes of respective ones of a plurality of transmitters which are at different locations wherein the transmitters transmit the same code word delayed in one transmitter with respect to another transmitter by a time interval equal to the time length of said code divided by the number of transmitters, the method comprising: generating said identical code words in each of said receivers but delayed by an amount in one receiver with respect to another which is equal to the length of said code word divided by the square of the number of transmitters, applying the transmitted waves of all of said transmitters to all of said receivers and, changing the time relationship of all of the receiver code words together relative to all of the code words applied to the receivers until one of the receiver code words synchronizes with one of the transmitted code words.
Claim 13
Dependent Claim
170 words
In the system of synchronizing the internally generated codes of a plurality of receivers which are at one location with respect to the transmitted codes of respective ones of a plurality of transmitters which are at different locations wherein the transmitters transmit the same code word delayed in one transmitter with respect to another transmitter by a time interval equal to the time length of said code divided by the number of transmitters, the method comprising: generating said identical code words in each of said receivers but delayed by an amount in one receiver with respect to another which is equal to the length of said code word divided by the square of the number of transmitters, applying the transmitted waves of all of said transmitters to all of said receivers and, changing the time relationship of all of the receiver code words together relative to all of the code words applied to the receivers until one of the receiver code words synchronizes with one of the transmitted code words.
Claim 14
Dependent Claim
45 words
The system of claim 10 wherein the receivers which are not synchronized with transmitters, the code words are adjusted by amounts related to the transmitter and receiver delays until each remaining receiver code word is synchronized with a respective one of the transmitter code words.
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) | 1975-10-24 | 1976-04-24 | 1976-10-24 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-10-24 | 1980-04-24 | 1980-10-24 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-10-24 | 1984-04-24 | 1984-10-24 | $7700.00 | Window Closed / Lapsed |