US3746799A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method and apparatus for encoding and decoding analog signals
Assignee: United States Department of the Navy
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Filing: 1971-09-27
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Granted: 1973-07-17
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Expires: 1991-09-27
Abstract
Abstract A method and apparatus for encoding and decoding clear signals of an analog nature, the amplitudes of which represent information. The method employs a key which controls the coding of the signals, a module shift and the coding of the moduloshift, the modulo shift being transmitted by time multiplex or on a separate channel from that of the encoded signal.
Inventors
- 👤 F Gentges
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-24 13:09
CPC Classifications
H; H04; H04L; H04L9/00; H04L9/06; H04L9/065; H04L9/0656; H04L2209/00; H04L2209/08; H04L2209/12
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
147 words
Apparatus for encoding and decoding analog signals comprising: adding means for adding a pseudo random binary key to a first signal to produce a second signal and for producing a third signal indicating whether module addition has occured; in said adding means said first signal being representative of an analog input signal; encoding means coupled to said adding means for encoding said third signal to produce a fourth signal; transmitting means coupled to said adding means and encoding means for transmitting said second and fourth signals; receiving means for separably receiving said second and fourth signals; decoding means coupled to said receiving means for decoding said fourth signal to reproduce said third signal; subtracting means coupled to said receiving means and said decoding means for subtracting said key from said second signal and adding said third signal resulting in a signal being representative of said first signal.
Claim 2
Dependent Claim
147 words
Apparatus for encoding and decoding analog signals comprising: adding means for adding a pseudo random binary key to a first signal to produce a second signal and for producing a third signal indicating whether module addition has occured; in said adding means said first signal being representative of an analog input signal; encoding means coupled to said adding means for encoding said third signal to produce a fourth signal; transmitting means coupled to said adding means and encoding means for transmitting said second and fourth signals; receiving means for separably receiving said second and fourth signals; decoding means coupled to said receiving means for decoding said fourth signal to reproduce said third signal; subtracting means coupled to said receiving means and said decoding means for subtracting said key from said second signal and adding said third signal resulting in a signal being representative of said first signal.
Claim 3
Dependent Claim
62 words
The apparatus defined in claim 1 including: an A/D converting means for converting said analog input signal to a digital signal, said digital signal being said first signal; said A/D converting means being connected to said adding means, said adding means including a digital adder; said encoding means further being coupled to said key and; said subtracting means including a digital adder.
Claim 4
Dependent Claim
23 words
The apparatus defined in claim 2 wherein: said encoding means includes an exclusive OR gate for encoding said third signal with said key.
Claim 5
Dependent Claim
72 words
The apparatus defined in claim 1 including: a first A/D converting means coupled to said adding means for converting said binary key to an analog key to be added to said first signal; said encoding means further being coupled to a portion of said binary key; a second A/D converting means coupled to said subtracting means for converting said binary key to an analog key to be subtracted from said second signal.
Claim 6
Dependent Claim
27 words
The apparatus defined in claim 4 wherein: said encoding means includes an exclusive OR gate or encoding said third signal with said portion of said binary key.
Claim 7
Dependent Claim
33 words
The apparatus defined in claim 1 wherein: said transmitting means and said receiving means comprise time division multiplex transmitter and receiver for time division multiplex transmitting and receiving said second and fourth signal.
Claim 8
Dependent Claim
46 words
The apparatus defined in claim 1 wherein: said transmitting means having two separate channels a first channel which transmits said second signal and a second channel which transmits said fourth signal; said receiving means similarly having two separate channels for receiving said second and fourth signals.
Claim 9
Independent Claim
112 words
A method of encoding and decoding analog signals comprisIng: adding a pseudo random binary key to a first signal to produce a second signal said first signal being an analog input signal converted to binary form; producing a third signal representative of whether a modulo shift in a shift register was indicated after said adding step; encoding said third signal to produce a fourth signal; separably transmitting said second and fourth signals; receiving said second and fourth signals; decoding said fourth signal to reproduce said third signal; subtracting said key from said second signal and; adding said third signal to said second signal to reproduce a signal representative of said first signal.
Claim 10
Independent Claim
112 words
A method of encoding and decoding analog signals comprisIng: adding a pseudo random binary key to a first signal to produce a second signal said first signal being an analog input signal converted to binary form; producing a third signal representative of whether a modulo shift in a shift register was indicated after said adding step; encoding said third signal to produce a fourth signal; separably transmitting said second and fourth signals; receiving said second and fourth signals; decoding said fourth signal to reproduce said third signal; subtracting said key from said second signal and; adding said third signal to said second signal to reproduce a signal representative of said first signal.
Claim 11
Dependent Claim
20 words
The method defined in claim 8 wherein: said step of encoding includes exclusive ORing said third signal with said key.
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) | 1976-07-16 | 1977-01-15 | 1977-07-17 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-07-16 | 1981-01-15 | 1981-07-17 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-07-16 | 1985-01-15 | 1985-07-17 | $7700.00 | Window Closed / Lapsed |