Granted Patent B1

US 12,627,312 · App. 18/434,247 · Granted May 12, 2026

Inventors: Michael A. Zalucki (Hollis, NH); Daniel Wasson (Billerica, MA); Anthony J. Crawford (Milford, NH)

Assignee: BAE Systems Information and Electronic Systems Integration Inc.

H03M1/126H03M1/181

Abstract

Claims (59)

1 . A system comprising:

a first analog to digital converter (ADC) configured to operate at a first sampling frequency, and a second ADC configured to operate at a second sampling frequency different from the first sampling frequency, wherein each of the first and second ADCs are configured to receive a plurality of radio frequency (RF) pulses, and generate a first ADC output and a second ADC output, respectively;

a first digital receiver to process the first ADC output and generate a first plurality of pulse description data signals (PDDs), and a second digital receiver to process the second ADC output and generate a second plurality of PDDs, wherein each PDD of the first and second plurality of PDDs is indicative of attributes of a corresponding RF pulse of the plurality of RF pulses;

a correlator configured to corelate a first PDD of the first plurality of PDDs with a second PDD of the second plurality of PDDs, and generate a correlation signal indicative of the correlation of the first PDD with the second PDD, wherein each of the first PDD and the second PDD includes attributes of a same RF pulse of the plurality of RF pulses;

a third ADC configured to operate at a third sampling frequency different from each of the first and second sampling frequencies, wherein the third ADC is configured to receive the plurality of RF pulses, and generate a third ADC output; and

a third digital receiver to process the third ADC output and generate a third plurality of PDDs;

wherein to corelate the first PDD of the first plurality of PDDs with the second PDD of the second plurality of PDDs, the correlator is configured to:

compare the first PDD with each of two or more PDDs of the second plurality of PDDs and two or more PDDs of the third plurality of PDDs, to determine a first match between the first PDD and the second PDD, and to further determine a second match between the first PDD and a third PDD of the third plurality of PDDs; and

select, from the first and second matches, the first match between the first PDD and the second PDD, thereby correlating the first PDD with the second PDD.

2 . The system of claim 1 , wherein to select the first match from the first and second matches, the correlator is configured to:

determine that the first PDD matches with the second PDD, and the second PDD matches with the first PDD, to thereby determine that the first match between the first PDD and the second PDD is a reciprocal match;

determine that the first PDD matches with the third PDD, and the third PDD does not match with the first PDD, to thereby determine that the second match between the first PDD and the third PDD is a non-reciprocal match; and

select, from the first and second matches, the first match, based on the first match being a reciprocal match and the second match being a non-reciprocal match.

3 . The system of claim 1 , wherein to select the first match from the first and second matches, the correlator is configured to:

determine that an attribute in the first and second PDDs differ by a first difference, and the attribute in the first and third PDDs differ by a second difference greater than the first difference, wherein the attribute is one of a corresponding RF pulse amplitude and a corresponding RF pulse time of arrival (TOA); and

select, from the first and second matches, the first match, based on the second difference being greater than the first difference.

4 . The system of claim 1 , wherein to corelate the first PDD of the first plurality of PDDs with the second PDD of the second plurality of PDDs, the correlator is configured to:

compare, at a first comparator, one or more attributes of the first PDD with one or more attributes of the second PDD, to determine that the second PDD is a match with the first PDD;

compare, at a second comparator different from the first comparator, one or more attributes of the second PDD with one or more attributes of the first PDD, to determine that the first PDD is a match with the second PDD;

determine that the first PDD and the second PDD have reciprocal matching, based at least in part on (i) the second PDD being a match with the first PDD and (ii) the first PDD being a match with the second PDD; and

corelate the first PDD with the second PDD, based at least in part on the first PDD and the second PDD having the reciprocal matching.

5 . The system of claim 1 , wherein to corelate the first PDD of the first plurality of PDDs with the second PDD of the second plurality of PDDs, the correlator is configured to:

compare one or more attributes of the first PDD with one or more attributes of the second PDD, to determine that the second PDD is a match with the first PDD;

wherein the one or more attributes of the first PDD comprise an amplitude of the RF pulse, as sampled by the first ADC and detected by the first digital receiver; and

wherein the one or more attributes of the second PDD comprise an amplitude of the RF pulse, as sampled by the second ADC and detected by the second digital receiver.

6 . The system of claim 1 , wherein to corelate the first PDD of the first plurality of PDDs with the second PDD of the second plurality of PDDs, the correlator is configured to:

compare one or more attributes of the first PDD with one or more attributes of the second PDD, to determine that the second PDD is a match with the first PDD;

wherein the one or more attributes of the first PDD comprise a time of arrival (TOA) of the RF pulse at the first ADC; and

wherein the one or more attributes of the second PDD comprise another TOA of the RF pulse at the second ADC.

7 . The system of claim 1 , wherein to corelate the first PDD of the first plurality of PDDs with the second PDD of the second plurality of PDDs, the correlator is configured to:

determine a first observed frequency of the RF pulse at the first digital receiver, wherein the first PDD includes an indication of the first observed frequency;

determine a second observed frequency of the RF pulse at the second digital receiver, wherein the second PDD includes an indication of the second observed frequency;

determine a first plurality of possible alias frequencies of the RF pulse within corresponding different Nyquist zones of the first sampling frequency of the first ADC, based at least in part on the first observed frequency and the first sampling frequency;

determine a second plurality of possible alias frequencies of the RF pulse within corresponding different Nyquist zones of the second sampling frequency of the second ADC, based at least in part on the second observed frequency and the second sampling frequency; and

determine that the first PDD is a match with the second PDD, in response to a substantial match between one of the first plurality of possible alias frequencies with one of the second plurality of possible alias frequencies.

8 . The system of claim 1 , comprising:

a frequency measurement module configured to receive the correlation signal, and measure a frequency of the RF pulse, based at least in part on the first PDD, the second PDD, the first sampling frequency, and the second sampling frequency.

9 . The system of claim 8 , wherein to measure the frequency of the RF pulse, the frequency measurement module is configured to:

detect a Nyquist zone of the first sampling frequency that encompasses the frequency the RF pulse, based at least in part on (i) a first observed frequency of the RF pulse, as indicated by the first PDD, (ii) a second observed frequency of the RF pulse, as indicated by the second PDD, (iii) the first sampling frequency, and (iv) the second sampling frequency.

10 . The system of claim 9 , wherein to detect the Nyquist zone of the first sampling frequency that encompasses the frequency the RF pulse, the frequency measurement module is configured to:

determine a ratio between (i) a difference in the first and second observed frequencies of the RF pulse, and (ii) a difference in the first and second sampling frequencies; and

detect the Nyquist zone of the first sampling frequency, based on the ratio.

11 . The system of claim 9 , wherein to measure the frequency of the RF pulse, the frequency measurement module is configured to:

measure the frequency of the RF pulse, based at least in part on (i) the first observed frequency of the RF pulse, as indicated by the first PDD, (ii) the first sampling frequency, and (iii) the detected Nyquist zone of the first sampling frequency that encompasses the frequency the RF pulse.

12 . A method comprising:

operating a first analog to digital converter (ADC), a second ADC, and a third ADC at a first sampling frequency, a second sampling frequency, and a third sampling frequency, respectively;

sampling, by each of the first, second, and third ADCs, a plurality of radio frequency (RF) pulses, to respectively generate a first ADC output, a second ADC output, and a third ADC output;

processing each of the first, second, and third ADC outputs, to respectively generate a first plurality of pulse description data signals (PDDs), a second plurality of PDDs, and a third plurality of PDDs, wherein each PDD of the first, second, and third plurality of PDDs is indicative of one or more attributes of a corresponding RF pulse of the plurality of RF pulses;

comparing a first PDD of the first plurality of PDDs with each of two or more PDDs of the second plurality of PDDs and two or more PDDs of the third plurality of PDDs;

correlating the first PDD and with a second PDD of the second plurality of PDDs, based at least in part on the comparing, wherein the first PDD and the second PDD are indicative of one or more attributes of a same RF pulse; and

measuring a frequency of the RF pulse, based at least in part on the first PDD, the second PDD, the first sampling frequency, and the second sampling frequency.

13 . The method of claim 12 , wherein correlating the first PDD and with the second PDD comprises:

determining a first match between the first PDD and the second PDD, and a second match between the first PDD and a third PDD of the third plurality of PDDs; and

selecting, from the first and second matches, the first match between the first PDD and the second PDD, thereby correlating the first PDD with the second PDD.

14 . The method of claim 12 , wherein comparing the first PDD with each of the two or more PDDs of the second plurality of PDDs and the two or more PDDs of the third plurality of PDDs comprises:

comparing one or more attributes of the first PDD with corresponding one or more attributes of each of the two or more PDDs of the second plurality of PDDs and the two or more PDDs of the third plurality of PDDs, wherein the one or more attributes comprises one or more of (i) an amplitude of an RF pulse indicated by each PDD, (ii) a time of arrival (TOA) of an RF pulse to an ADC, as indicated by each PDD, and (iii) an observed frequency of an RF pulse, as indicated by each PDD.

15 . The method of claim 12 , wherein measuring the frequency of the RF pulse comprises:

detecting a Nyquist zone of the first sampling frequency that encompasses the frequency the RF pulse, based at least in part on (i) a first observed frequency of the RF pulse, as indicated by the first PDD, (ii) a second observed frequency of the RF pulse, as indicated by the second PDD, (iii) the first sampling frequency, and (iv) the second sampling frequency; and

measuring the frequency of the RF pulse, based at least in part on (i) the first observed frequency of the RF pulse, as indicated by the first PDD, (ii) the first sampling frequency, and (iii) the detected Nyquist zone of the first sampling frequency that encompasses the frequency the RF pulse.

Assignments (1)

References Cited (30)