# US 12,184,409 B1 · Difference-based jammer detection system > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 12,184,409 B1 - Document ID: US12184409B1 - Status: Granted - Kind: B1 - Application number: 18/345,023 - Filed: 2023-06-30 - Published: 2025-01-02 - Granted: 2024-12-31 - Earliest claimed: 2023-06-30 - Assignees: BAE Systems Information and Electronic Systems Integration Inc. - Applicants: BAE SYSTEMS Information and Electronic Systems Integration Inc. - Inventors: Michael H. Stockmaster; Ying Cho J. Lai - Web page: https://patentgrep.com/patent/US12184409B1 ## CPC - H04K 3/224: {with countermeasures at transmission and/or reception of the jammed signal, e.g. stopping operation of transmitter or receiver, nulling or enhancing transmitted power in direction of or at frequency of jammer} - H01Q 3/2611: {Means for null steering; Adaptive interference nulling} - H04B 7/043: {using best eigenmode, e.g. beam forming or beam steering} - H04K 3/22: {including jamming detection and monitoring} - H04K 3/228: {Elimination in the received signal of jamming or of data corrupted by jamming (interference suppression in receivers H04B1/10)} - H04K 2203/32: including a particular configuration of antennas - H04K: SECRET COMMUNICATION; JAMMING OF COMMUNICATION - H01Q: ANTENNAS, i.e. RADIO AERIALS (radiators or antennas for microwave heating H05B6/72) - H04B: TRANSMISSION ## Abstract Techniques are provided for jammer detection. A methodology implementing the techniques according to an embodiment includes steering a beam in a specified direction to generate a power measurement, the specified direction selected from a plurality of directions, such that the method comprises scanning through the plurality of directions. The method also includes adaptively steering a null in the specified direction and measuring a gain of the received signal in the null direction. The method further includes calculating a difference between the power measurement and the measured gain and generating a difference-based detection that the received signal is associated with a jammer at the specified direction. The difference-based detection is based on a comparison of the power difference to a power difference threshold value. The power difference threshold value is based on a desired probability of false alarm and probability of detection, and/or desired angular resolution. ## Claims ### Claim 1 A system for detection of signal jammers, the system comprising: a beamforming circuit configured to steer a beam in a specified direction and measure a power of a received signal in the specified direction; an adaptive nulling circuit configured to steer a null in the specified direction and measure a gain of the received signal in the steered null direction; a differencing circuit configured to calculate a difference between the power and the gain; and a jammer assessment circuit configured to detect that the received signal is associated with a jammer, the detection based on a comparison of the difference to a threshold value. ### Claim 2 (depends on 1) The system of claim 1, wherein the specified direction comprises an azimuth angle and an elevation angle, the specified direction is selected from a plurality of directions, and the system is configured to scan through the plurality of directions. ### Claim 3 (depends on 1) The system of claim 1, wherein the threshold value is selected based on a desired probability of false alarm (Pfa), a desired probability of detection (Pd), and/or a desired angular resolution. ### Claim 4 (depends on 1) The system of claim 1, further comprising a jammer direction finding (DF) circuit configured to generate a DF pattern for identification of locations of potential signal jammers based on jamming signals included in the received signal. ### Claim 5 (depends on 4) The system of claim 4, wherein the jammer DF circuit is configured to generate the DF pattern based on execution of a minimum variance distortionless response (MVDR) process or a multiple signal classification (MUSIC) process. ### Claim 6 (depends on 4) The system of claim 4, wherein the threshold value is a first threshold value, and the system further comprises an angle of arrival (AOA) generation circuit configured to estimate AOAs of the jamming signals associated with the potential signal jammers based on a comparison of gain values of the DF pattern to a second threshold value, the second threshold value selected based on a desired Pfa, a desired Pd, and/or a desired angular resolution. ### Claim 7 (depends on 6) The system of claim 6, wherein the estimated AOA is employed as the specified direction. ### Claim 8 A computer program product including one or more non-transitory machine-readable mediums encoded with instructions that when executed by one or more processors cause a process to be carried out for detection of signal jammers, the process comprising: steering a beam in a specified direction and measuring a power of a received signal in the specified direction; adaptively steering a null in the specified direction and measuring a gain of the received signal in the steered null direction; calculating a difference between the power and the measured gain; and detecting that the received signal is associated with a jammer, the detection based on a comparison of the difference to a threshold value. ### Claim 9 (depends on 8) The computer program product of claim 8, wherein the specified direction comprises an azimuth angle and an elevation angle, and the process further comprises selecting the specified direction from a plurality of directions and scanning through the plurality of directions. ### Claim 10 (depends on 8) The computer program product of claim 8, wherein the threshold value is selected based on a desired probability of false alarm (Pfa), a desired probability of detection (Pd), and/or a desired angular resolution. ### Claim 11 (depends on 8) The computer program product of claim 8, wherein the process further comprises generating a DF pattern for identification of locations of potential signal jammers based on jamming signals included in the received signal. ### Claim 12 (depends on 11) The computer program product of claim 11, wherein the process further comprises generating the DF pattern based on execution of a minimum variance distortionless response (MVDR) process or a multiple signal classification (MUSIC) process. ### Claim 13 (depends on 11) The computer program product of claim 11, wherein the threshold value is a first threshold value, and the process further comprises estimating angles of arrival (AOAs) of the jamming signals associated with the potential signal jammers based on a comparison of gain values of the DF pattern to a second threshold value, the second threshold value selected based on a desired Pfa, a desired Pd, and/or a desired angular resolution. ### Claim 14 (depends on 13) The computer program product of claim 13, wherein the process further comprises employing the estimated AOA as the specified direction. ### Claim 15 A method for detection of signal jammers, the method comprising: steering, by a processor based system, a beam in a specified direction and measuring a power of a received signal in the specified direction; adaptively steering, by the processor based system, a null in the specified direction and measuring a gain of the received signal in the steered null direction; calculating, by the processor based system, a difference between the power and the measured gain; and detecting, by the processor based system, that the received signal is associated with a jammer, the detection based on a comparison of the difference to a threshold value. ### Claim 16 (depends on 15) The method of claim 15, wherein the specified direction comprises an azimuth angle and an elevation angle, and the method further comprises selecting the specified direction from a plurality of directions and scanning through the plurality of directions. ### Claim 17 (depends on 15) The method of claim 15, wherein the threshold value is selected based on a desired probability of false alarm (Pfa), a desired probability of detection (Pd), and/or a desired angular resolution. ### Claim 18 (depends on 15) The method of claim 15, wherein the method further comprises generating a DF pattern for identification of locations of potential signal jammers based on jamming signals included in the received signal. ### Claim 19 (depends on 18) The method of claim 18, wherein the method further comprises generating the DF pattern based on execution of a minimum variance distortionless response (MVDR) process or a multiple signal classification (MUSIC) process. ### Claim 20 (depends on 18) The method of claim 18, wherein the threshold value is a first threshold value, and the method further comprises estimating angles of arrival (AOAs) of the jamming signals associated with the potential signal jammers based on a comparison of gain values of the DF pattern to a second threshold value, the second threshold value selected based on a desired Pfa, a desired Pd, and/or a desired angular resolution, and employing the estimated AOA as the specified direction.