US4568915A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Code generator for multilevel interleaved multiplexed noise codes
Assignee: United States Department of the Army
•
Filing: 1983-11-14
•
Granted: 1986-02-04
•
Expires: 2003-11-14
Abstract
Abstract Expanded multilevel noise codes are generated of a type termed "code mates"aving autocorrelation functions which, upon detection in a matched filter, provide an impulse autocorrelation function. More particularly, expanded multilevel code mate pairs are generated by interleaving two multi-bit codes comprising a mate pair wherein one of the codes in each expanded mate pair comprises a code having a larger amplitude than the other code and whose position is mutually transposed in the expanded mate pairs and further wherein one of the interleaved codes is the complement or negative of one of the original or basic code mates.
Inventors
- 👤 Frank S. Gutleber
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-06 01:39
CPC Classifications
H; H04; H04J; H04J13/00; H04J13/10; H04J13/102; H04J13/105
Claims Analysis
Total Claims: 26
Claim 1
Independent Claim
202 words
A method expanding a pair of digital codes, comprising the steps of: generating first and second time coincident multibit digital codes of a first amplitude and predetermined equal interpulse periods between code bits; generating a third code comprising the complement of one of said first and second codes; selectively altering the amplitudes of two codes selected from said first, second and third codes to provide first and second codes of a second amplitude; generating a first expanded code comprised of first and second interleaved code portions by selectively combining a said first code of first amplitude with a delayed said second code of second amplitude, said delay being less than said interpulse periods of said first and second codes of a first amplitude; generating a second expanded code comprised of first and second interleaved code portions by selectively combining a said first code of second amplitude with a delayed said second code of first amplitude, said delay being the same as the delay of said second code of second amplitude, and wherein one code portion of said code portions of said first and second expanded codes comprises said third code, said third code further being selectively of a first or second amplitude.
Claim 2
Independent Claim
202 words
A method expanding a pair of digital codes, comprising the steps of: generating first and second time coincident multibit digital codes of a first amplitude and predetermined equal interpulse periods between code bits; generating a third code comprising the complement of one of said first and second codes; selectively altering the amplitudes of two codes selected from said first, second and third codes to provide first and second codes of a second amplitude; generating a first expanded code comprised of first and second interleaved code portions by selectively combining a said first code of first amplitude with a delayed said second code of second amplitude, said delay being less than said interpulse periods of said first and second codes of a first amplitude; generating a second expanded code comprised of first and second interleaved code portions by selectively combining a said first code of second amplitude with a delayed said second code of first amplitude, said delay being the same as the delay of said second code of second amplitude, and wherein one code portion of said code portions of said first and second expanded codes comprises said third code, said third code further being selectively of a first or second amplitude.
Claim 3
Dependent Claim
35 words
The method of claim 1 wherein said delay of said second codes of first and second amplitude is substantially equal to one half the interpulse periods of said first and second codes of first amplitude.
Claim 4
Dependent Claim
20 words
The method of claim 1 wherein said one code portion comprises the second code portion of said second expanded code.
Claim 5
Dependent Claim
20 words
The method of claim 1 wherein said one code portion comprises the second code portion of said first expanded code.
Claim 6
Dependent Claim
34 words
The method of claim 1 wherein said first and second codes comprise digital codes of equal code length and wherein said second amplitude is greater than said first amplitude by a predetermined gain factor.
Claim 7
Dependent Claim
18 words
The method of claim 5 wherein said first and second digital codes comprise a pair of noise codes.
Claim 8
Dependent Claim
27 words
The method of claim 6 wherein said first and second codes comprise digital noise codes which upon matched filter detection and addition produces an impulse autocorrelation function.
Claim 9
Dependent Claim
66 words
The method of claim 5 wherein said first and second noise codes of a first amplitude are comprised of a pair of noise code mates which upon autocorrelation function detection and addition compress to a lobeless impulse and wherein said first and second expanded codes comprise a pair of equal length code mates which also compress to a lobeless impulse upon autocorrelation function detection and addition.
Claim 10
Dependent Claim
143 words
The method of claim 8 wherein said step of generating said first expanded code comprises delaying said second code of second amplitude by a time equal to one half the interbit period of said first and second codes of a first amplitude to provide a delayed code and adding it to said first code of first amplitude to provide thereby said first and second interleaved code portions of said first expanded code mate, and wherein said step of generating said second expanded code comprises delaying said second code of first amplitude by a time delay equal to one half the interbit period of said first and second codes of a first amplitude to provide a delayed code and adding it to said first code of second amplitude to thereby provide said first and second interleaved code portions of said second expanded code mate.
Claim 11
Independent Claim
115 words
A method of expanding a pair of digital codes into a pair of multilevel digital codes comprising the steps of: generating first and second multi-bit digital codes having predetermined interpulse periods; delaying said second code by a predetermined time interval which is a function of said interpulse periods of said first and second codes; altering the amplitude of said first code and the delayed second code by a predetermined gain factor to provide third and fourth codes, respectively; combining said first and fourth codes in a first manner to form a first interleaved multilevel code; combining said third code and said delayed second code in a second manner to form a second interleaved multilevel code.
Claim 12
Independent Claim
115 words
A method of expanding a pair of digital codes into a pair of multilevel digital codes comprising the steps of: generating first and second multi-bit digital codes having predetermined interpulse periods; delaying said second code by a predetermined time interval which is a function of said interpulse periods of said first and second codes; altering the amplitude of said first code and the delayed second code by a predetermined gain factor to provide third and fourth codes, respectively; combining said first and fourth codes in a first manner to form a first interleaved multilevel code; combining said third code and said delayed second code in a second manner to form a second interleaved multilevel code.
Claim 13
Dependent Claim
21 words
The method of claim 10 wherein said step of combining in a first manner comprises the step of adding said codes.
Claim 14
Dependent Claim
40 words
The method of claim 11 wherein said step of combining in a second manner comprises the steps of generating the complement of said delayed second code and then adding said third code and said complement of said delayed second code.
Claim 15
Dependent Claim
40 words
The method as defined by claim 12 wherein said interpulse periods of said first and second codes are equal and wherein said predetermined time interval is substantially equal to one half said interpulse periods of said first and second codes.
Claim 16
Dependent Claim
59 words
The method as defined by claim 13 wherein said first and second noise codes are comprised of a pair of code mates which upon autocorrelation function detection and addition compress to a lobeless impulse and wherein said first and second interleaved codes comprise a pair of code mates which also compress to a lobeless impulse upon autocorrelation function detection.
Claim 17
Dependent Claim
57 words
The method of claim 14 wherein said steps of expanding are repeated in successive stages with each succeeding said predetermined time delay interval being reduced by one-half the interpulse periods of the code bits of the preceding stage until the time delay interval equals the pulse width of the code bits of said first and second codes.
Claim 18
Dependent Claim
178 words
Apparatus for generating a pair of expanded digital codes from a first pair of digital codes, comprising in combination: means for generating first and second time multibit coincident digital codes of a first amplitude; means for generating a third code comprising the complement of one of said first and second codes; means for selectively altering the amplitudes of two codes selected from said first, second and third codes to provide first and second codes of a second amplitude; first code interleaving means generating a first expanded code comprised of first and second interleaved code portions including a said first code of first amplitude and a second said code of second amplitude; second code interleaving means generating a second expanded code comprised of first and second interleaved code portions including a said first code of second amplitude with a said second code of first amplitude, and wherein said one code portion of said interleaved code portions of said first and second expanded codes comprises said third code, said third code further being selectively of a first or second amplitude.
Claim 19
Dependent Claim
178 words
Apparatus for generating a pair of expanded digital codes from a first pair of digital codes, comprising in combination: means for generating first and second time multibit coincident digital codes of a first amplitude; means for generating a third code comprising the complement of one of said first and second codes; means for selectively altering the amplitudes of two codes selected from said first, second and third codes to provide first and second codes of a second amplitude; first code interleaving means generating a first expanded code comprised of first and second interleaved code portions including a said first code of first amplitude and a second said code of second amplitude; second code interleaving means generating a second expanded code comprised of first and second interleaved code portions including a said first code of second amplitude with a said second code of first amplitude, and wherein said one code portion of said interleaved code portions of said first and second expanded codes comprises said third code, said third code further being selectively of a first or second amplitude.
Claim 20
Dependent Claim
21 words
The apparatus of claim 16 wherein said one code portion comprises the second interleaved code portion of said second expanded code.
Claim 21
Dependent Claim
21 words
The apparatus of claim 16 wherein said one code portion comprises the second interleaved code portion of said first expanded code.
Claim 22
Dependent Claim
38 words
The apparatus of claim 16 wherein said first and second codes comprise multibit digital codes of equal code length and interpulse periods and wherein said second amplitude is greater than said first amplitude by a predetermined gain factor.
Claim 23
Dependent Claim
18 words
The method of claim 19 wherein said first and second digital codes comprise a pair of noise codes.
Claim 24
Dependent Claim
27 words
The apparatus of claim 20 wherein said first and second codes comprise digital noise codes which upon matched filter detection and addition produces an impulse autocorrelation function.
Claim 25
Dependent Claim
62 words
The apparatus of claim 21 wherein said first and second noise codes are comprised of a pair of noise code mates which upon autocorrelation function detection and addition compress to a lobeless impulse and wherein said first and second expanded codes comprise a pair of equal length code mates which also compress to a lobeless impulse upon autocorrelation function detection and addition.
Claim 26
Dependent Claim
147 words
The apparatus of claim 22 wherein said first code interleaving means includes means for delaying said second code of second amplitude by a time equal to the interpulse period of said first and second codes to provide a delayed code and means for adding the delayed said second code of second amplitude to said first code of first amplitude to provide thereby said first and second interleaved code portions of said first expanded code mate, and wherein said second code interleaving means includes means for delaying said second code of first amplitude by a time delay equal to the interpulse period of said first and second codes to provide a delayed code and means for adding the delayed said second code of first amplitude to said first code of second amplitude to thereby provide said first and second interleaved code portions of said second expanded code mate.
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) | 1989-02-03 | 1989-08-05 | 1990-02-04 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1993-02-03 | 1993-08-05 | 1994-02-04 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1997-02-03 | 1997-08-05 | 1998-02-04 | $7700.00 | Window Closed / Lapsed |