Code generator to produce permutations of code mates
AssigneeInternational Telephone and Telegraph Corporation
InventorFrank S. Gutleber
Life of this patent
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Abstract
A class of pseudo-noise multiplexed codes including coding mates having cooperating autocorrelation function which upon detection provides an impulse autocorrelation function. The code mates include at least one blank digit slot in the repetitious period of at least one of the codes of the code mates. One form requires a digit of either binary condition in the first and last digit slot of the code structure with the blank slot being disposed therebetween. The number of code mates can be increased by repeatedly solving the equations of FIG. 5 for the original code mates and the resultant new code mates. The interleaving process required in the equations is achieved by logic circuitry controlled by a control signal having a period equal to the period of a digit slot of the input code mates.
Claims10
A system for generating codes which upon detection will produce an impulse autocorrelation function comprising:
- first means to produce a first code and a second code each having a plurality of digit time slots and cooperating autocorrelation functions to produce upon detection of said first and second codes said impulse autocorrelation function including an impulse output at a given time and a zero output at all oother times, each of said digit time slots having a given period;
- second means to produce a control signal having a period equal to said given period;
- at least one third means coupled to said first and second means responsive to said control signal to produce a first output code including the digit time slots of one of said first and second codes interleaved with the digit time slots of the other of said first and second codes;
- and
- at least one fourth means coupled to said first and second means responsive to said control signal to produce a second output code including the digit time slots of one of said first code and the complement of said second code interleaved with the digit time slots of the other of said first code and the complement of said second code;
- said first and second output codes having cooperating autocorrelation functions to produce upon detection of said first and second output codes said impulse autocorrelation function.
Dependencies are inferred from the claim text.