Predictive semi-active laser pulse correlator and method

A predictive semi-active laser (SAL) pulse correlator, comprising:

• a circular buffer configured to store a timestamp at a corresponding address for each of a plurality of received pulses;
• a successive approximation (SA) state machine configured to search the circular buffer, based on an indicator for each of the plurality of received pulses, for a specified number of pulse matches corresponding to a pulse train match;
• a master state machine configured to:
• generate a TimeLow signal and a TimeHi signal, wherein the TimeLow signal and the TimeHi signal define a time window for the search by the SA state machine for each pulse match of the specified number of pulse matches, wherein the TimeLow signal is provided to a low comparator and the TimeHi signal is provided to a high comparator;
• initiate the search of the circular buffer for the pulse train match;
• and
• after identifying the pulse train match, predict, at a current time, that reception of a pulse during a future interval would verify a correlation of the pulse train match;
• and
• an AND gate configured to, in response to receiving the pulse during the future interval predicted by the master state machine, verify the correlation by comparing the predicted correlation to the received pulse.

A method for performing correlation for a semi-active laser (SAL) system, comprising:

• storing an indicator for each of a plurality of received pulses;
• searching the indicators for a specified number of pulse matches corresponding to a pulse train match;
• for each search for one of the specified number of pulse matches, generating a TimeLow signal and a TimeHi signal to define a window for the search;
• providing the TimeLow signal to a low comparator and providing the TimeHi signal to a high comparator;
• after identifying the pulse train match, predicting, at a current time, that reception of a pulse during a future interval would verify a correlation of the pulse train match;
• and
• in response to receiving the pulse during the future interval predicted, verify the correlation by comparing the predicted correlation to the received pulse.