Expanded multilevel noise code generator employing butting

Claim 3

The method of claim 1 wherein said one code portion comprises the second code portion of said second expanded code.

Claim 4

The method of claim 1 wherein said one code portion comprises the second code portion of said first expanded code.

Claim 5

The method of claim 1 wherein said first and second codes comprise multibit digital codes of equal code length and wherein said second amplitude is greater than said first amplitude by a predetermined gain factor.

Claim 6

The method of claim 4 wherein said first and second digital codes comprise a pair of noise codes.

Claim 7

The method of claim 5 wherein said first and second codes comprise digital noise codes which upon matched filter detection produces an impulse autocorrelation function.

Claim 8

The method of claim 6 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.

Claim 9

The method of claim 7 wherein said step of generating said first expanded code comprises delaying said second code of second amplitude by a time equal to the code length of said first and second codes to provide a delayed code and adding it to the end of said first code to provide thereby said first and second butted code portions of a first 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 the code length of said first and second codes to provide a delayed code and adding it to the end of said first code of second amplitude to thereby provide said first and second butted code portions of a second code mate.

Claim 10

The method of claim 8 wherein said one code portion of said first and second expanded codes comprises one of said delayed codes.

Claim 11

The method of claim 9 wherein said one delayed code comprises the delayed code of said second expanded code.

Claim 12

The method of claim 10 wherein said one delayed code comprises a delayed code of first amplitude.

Claim 13

The method of claim 11 wherein said one code portion of said first and second expanded codes comprises the second code portion of said first expanded code.

Claim 14

The method of claim 11 wherein said one code portion of said first and second expanded code comprises the second code portion of said second expanded code.

Claim 15

The method of claim 13 wherein said second code portion of said second expanded code is of said second amplitude.

Claim 16

The method of claim 7 wherein said step of generating said first expanded code comprises delaying said first code of first amplitude by a time delay equal to the length of said first and second codes and adding it to the end of said second code of said second amplitude to provide thereby said first and second code butted code portions of a first code mate, and wherein said step of generating said second expanded code comprises delaying said first code of second amplitude by a time delay equal to the code length of said first and second codes and adding it to the end of said second code of first amplitude providing thereby said first and second butted code portions of a second code mate.

Claim 17

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 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; means for generating a first expanded code comprised of first and second butted code portions including a said first code of first amplitude and a second said code of second amplitude; means for generating a second expanded code comprised of first and second butted 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 butted 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 18

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 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; means for generating a first expanded code comprised of first and second butted code portions including a said first code of first amplitude and a second said code of second amplitude; means for generating a second expanded code comprised of first and second butted 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 butted 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

The apparatus of claim 16 wherein said one code portion comprises the second butted code portion of said second expanded code.

Claim 20

The apparatus of claim 16 wherein said one code portion comprises the second butted code portion of said first expanded code.

Claim 21

The apparatus of claim 16 wherein said first and second codes comprise multibit digital codes of equal code length and wherein said second amplitude is greater than said first amplitude by a predetermined gain factor.

Claim 22

The method of claim 19 wherein said first and second digital codes comprise a pair of noise codes.

Claim 23

The apparatus of claim 20 wherein said first and second codes comprise digital noise codes which upon matched filter detection produces an impulse autocorrelation function.

Claim 24

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.

Claim 25

The apparatus of claim 22 wherein said means generating said first expanded code includes means for delaying said second code of second amplitude by a time equal to the code length of said first and second codes to provide a delayed code and means for adding the delayed said second code of second amplitude to the end of said first code to provide thereby said first and second butted code portions of a first code mate, and wherein said means generating said second expanded code includes means for delaying said second code of first amplitude by a time delay equal to the code length of said first and second codes to provide a delayed code and means for adding the delayed said second code of first amplitude to the end of said first code of second amplitude to thereby provide said first and second butted code portions of a second code mate.

Claim 26

The apparatus of claim 23 wherein said one code portion of said first and second expanded codes comprises one of said delayed codes.

Claim 27

The apparatus of claim 24 wherein said one delayed code comprises the delayed code of said second expanded code.

Claim 28

The apparatus of claim 25 wherein said one delayed code comprises a delayed code of first amplitude.

Claim 29

The apparatus of claim 26 wherein said one code portion of said first and second expanded codes comprises the second code portion of said first expanded code.

Claim 30

The apparatus of claim 26 wherein said one code portion of said first and second expanded code comprises the second code portion of said second expanded code.

Claim 31

The apparatus of claim 28 wherein said second code portion of said second expanded code is of said second amplitude.

Claim 32

The apparatus of claim 22 wherein said means generating said first expanded code includes means for delaying said first code of first amplitude by a time delay equal to the length of said first and second codes and means for adding the delayed said first code of first amplitude to the end of said second code of said second amplitude to provide thereby said first and second code butted code portions of a first code mate, and wherein said means generating said second expanded code includes means for delaying said first code of second amplitude by a time delay equal to the code length of said first and second codes and means for adding the delayed said first code of second amplitude to the end of said second code of first amplitude providing thereby said first and second butted code portions of a second code mate.