초록 ▼

A system and method for pulse interval modulating signals in accordance with a code wherein the code resides in the spacing between adjacent pulses. The invention has particular utility in connection with laser designators and laser seekers and, while clearly not limited to this application, is disc

A system and method for pulse interval modulating signals in accordance with a code wherein the code resides in the spacing between adjacent pulses. The invention has particular utility in connection with laser designators and laser seekers and, while clearly not limited to this application, is disclosed hereinafter mainly in connection with laser designators and seekers. In connection with the laser environment, the system may include a pulse interval modulation encoder for encoding the laser designator output signal and a pulse interval modulation decoder for decoding by the laser seeker of the encoded designator signal. The encoder preferably employs an ordered arrangement of unique pulse interval pairs which cyclically repeats after a relatively long time period. Because of the length of the time period and the apparent randomness of the intervals forming the unique interval pairs, the code appears to enemy countermeasures to be random. The decoder is, however, capable of recognizing the code from a particular designator by locally generating the same ordered set of unique interval pairs for comparison with the incoming designator signal through the use of a digital code correlator having a unique arrangement of shift registers and logic gates. Thus, a number of laser designators may be operated selectively with predetermined seekers in the same area.

대표청구항 ▼

A wave energy decoding system comprising: means for receiving pulses of wave energy including pulses spaced in accordance with a pseudo-random, cyclically repetitive code, the spacing of the pulses of said code defining a plurality of sequential pairs of time intervals, each pair of time intervals b

A wave energy decoding system comprising: means for receiving pulses of wave energy including pulses spaced in accordance with a pseudo-random, cyclically repetitive code, the spacing of the pulses of said code defining a plurality of sequential pairs of time intervals, each pair of time intervals being unique within one cycle of said code; a first plural stage shift register; means responsive to said pulse receiving means for clocking received pulses into said first shift register at a first predetermined rate; means for generating a series of pulses defining said pseudo-random, cyclically repetitive code; a second plural stage shift register; means responsive to said pulse generating means for clocking generated pulses into said second shift register at a second predetermined rate higher than said first predetermined rate; means for comparing the signal levels of corresponding stages of said first and second shift registers; and, means responsive to said comparison means for generating a specific signal.