Back to results
US 12,627,394 B1Granted
Angle-of-arrival open-loop frequency-hopping communication system
AssigneeRockwell Collins, Inc.
InventorCarlos J. Chavez
Life of this patent
Estimating the term…
Abstract
A method and apparatus are provided for directional communication systems in tactical environments, utilizing frequency-hopping signals to enhance low-probability-of-intercept, -detection, and -geolocation (LPI/LPD/LPG) performance; along with anti-jamming (AJ) performance, multiple access, and performance in multipath channels. Because frequency-hopping signals vary their radio frequency from dwell-to-dwell, this prevents conventional angle-of-arrival (AOA) estimation based on phase-differences. This disclosure presents a technique for AOA estimation for frequency-hopping signals with techniques for combining phase-difference measurements from multiple frequency-hopping dwells to achieve high-performance AOA estimation.
Claims18
A system comprising:
- a directional aperture having at least two co-located apertures configured to receive at least one frequency-hopping signal from at least one transmitting source, wherein frequencies of each said frequency-hopping signal change among a range of frequencies within a set of frequency-hopping signals, each of said frequency-hopping signals within said set having a frequency dwell;
- at least one signal detector configured to:
- detect a phase-difference between phases-of-arrival from dwells received at said co-located apertures from said transmitting source of a plurality of said dwells;
- and
- generate a signal quality metric for said plurality of said dwells;
- and
- a processor configured to:
- receive said phase-difference and said signal quality metric for said plurality of dwells;
- generate a normalized phase-difference for each dwell by multiplying each said phase-difference by a normalization factor;
- convert each said normalized phase-difference into a unit vector;
- generate a quality weighted vector by multiplying each said unit vector by said signal quality metric associated with each said dwell;
- and
- generate a vector sum as a summation of each said quality weighted vector from each dwell;
- wherein a magnitude of the vector sum is associated with a combined quality metric and a phase of the vector sum associated with a combined-phase difference.
11 more elements
A system comprising:
- an aperture having at least two co-located sub-apertures configured to receive at least one frequency-hopping signal from at least one transmitting source, wherein frequencies of each said frequency-hopping signal change among a range of frequencies within a set of frequency-hopping signals, each of said frequency-hopping signals within said set having a frequency dwell;
- at least one signal detector configured to:
- detect a phase-difference between phases-of-arrival from dwells received at said aperture from said transmitting source of a plurality of said dwells;
- and
- generate a signal-to-noise ratio for said plurality of said dwells;
- and
- a processor configured to:
- receive said phase-difference and said signal-to-noise ratio for said plurality of said dwells;
- generate a normalized phase-difference for said plurality of said dwells by multiplying each said phase-difference by a normalization factor, wherein said normalization factor is a ratio of a reference frequency and a single frequency associated with said dwell;
- convert each said normalized phase-difference into a unit vector;
- generate a quality weighted vector by multiplying each said unit vector by said signal-to-noise ratio associated with each said dwell;
- and
- generate a vector sum as a summation of each said quality weighted vector from each dwell;
- wherein a magnitude of the vector sum is associated with a combined quality metric and a phase of the vector sum associated with a combined phase-difference.
11 more elements
A method for determining an angle-of-arrival, comprising:
- receiving via a signal detector associated with a directional aperture having at least a pair of co-located apertures or sub-apertures a phase-difference between phases-of-arrival for a plurality of dwells from a frequency-hopping signal;
- generating a normalized phase-difference for said plurality of dwells by multiplying each said phase-difference by a normalization factor;
- converting each said normalized phase-difference into a unit vector;
- generating a quality weighted vector by multiplying each said unit vector by a quality metric associated with each said dwells;
- and
- generating a vector sum as a summation of each said quality weighted vector from said plurality of said dwells, wherein a magnitude of the vector sum is associated with a combined quality metric and a phase of the vector sum associated with a combined phase difference.
3 more elements
Dependencies are inferred from the claim text.