US4158748A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Apparatus for digital data synchronization
Assignee: Motorola Solutions Inc
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Filing: 1977-06-27
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Granted: 1979-06-19
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Expires: 1997-06-27
Abstract
Abstract A system, including an encoder and decoder, for the transmission of digital information over a transmission medium. The encoder processes a data stream of length M and generates a transmission bit stream. The processing includes combination of the M data bits with N predetermined sync bits, via a modulo-2 adder. The resulting transmission stream has a total length less than M+N, thereby substantially minimizing the number of bits otherwise required. The decoder regenerates the data bit stream by modulo-2 subtraction of the transmission bit stream with said N sync bits, stored within the decoder. The resulting system thereby provides optimum synchronization and, therefore, data recovery, while requiring a minimum of transmission bits.
Inventors
- 👤 John En
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 17:08
CPC Classifications
H; H04; H04L; H04L7/00; H04L7/04; H04L7/048
Claims Analysis
Total Claims: 3
Claim 1
Independent Claim
176 words
A digital communication system for processing a data bit stream having a length M, said bit stream including a predetermined initial identification bit sequence, the system comprising: encoder means for encoding said data bit stream including: encoder bit storage means having N predetermined sync bits stored therein; combining means for predeterminedly combining said N sync bits with said M data bits to thereby produce a transmission bit stream having a bit length less than M+N; decoder means for decoding said transmission bit stream including; decoder sync bit storage means having said N predetermined sync bits stored therein; processing means for predeterminedly processing said transmission bit stream with said N sync bits to thereby regenerate said data bit stream; identification bit storage means having said initial identification bit sequence stored therein; and detector means for comparing the regenerated data bit stream with the contents of said identification bit storage and producing a detect indication output responsive to a predetermined minimum correlation therebetween to allow passage of the remainder of the regenerated bit stream to an output terminal.
Claim 2
Dependent Claim
176 words
A digital communication system for processing a data bit stream having a length M, said bit stream including a predetermined initial identification bit sequence, the system comprising: encoder means for encoding said data bit stream including: encoder bit storage means having N predetermined sync bits stored therein; combining means for predeterminedly combining said N sync bits with said M data bits to thereby produce a transmission bit stream having a bit length less than M+N; decoder means for decoding said transmission bit stream including; decoder sync bit storage means having said N predetermined sync bits stored therein; processing means for predeterminedly processing said transmission bit stream with said N sync bits to thereby regenerate said data bit stream; identification bit storage means having said initial identification bit sequence stored therein; and detector means for comparing the regenerated data bit stream with the contents of said identification bit storage and producing a detect indication output responsive to a predetermined minimum correlation therebetween to allow passage of the remainder of the regenerated bit stream to an output terminal.
Claim 3
Dependent Claim
48 words
The system of claim 1 wherein the combining means is comprised of a modulo-2 adder for modulo-2 adding said M data bits with said N sync bits and wherein the processing means comprises a modulo-2 subtractor for modulo-2 subtracting said N sync bits from the transmission bit stream.
References Cited (Backward Citations)
US3466601A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1982-06-18 | 1982-12-18 | 1983-06-19 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1986-06-18 | 1986-12-18 | 1987-06-19 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1990-06-18 | 1990-12-18 | 1991-06-19 | $7700.00 | Window Closed / Lapsed |