H04K3/228

Symbol detection is shared wireless channel subject to jamming interference

A communication system receives a jammed signal including a sequence of complex numbers encoding one or combination of symbols transmitted by multiple transmitters. The system transforms the sequence of complex numbers into an image of real numbers having at least two columns and multiple rows, with real values of real and imaginary parts of each complex number forming different columns but the same row of the first image, processes the image with a neural network trained to suppress the wideband signal in the received signal, and detects the symbols transmitted by the transmitters from the de-jammed signal.

SELF-TUNING N-PATH FILTER

A radio frequency (RF) filter includes a signal conditioning circuit and a bandstop filter. The signal conditioning circuit receives a broadband RF signal that includes both a jamming signal at a jamming frequency and a signal of interest and generates a plurality of clock signals. Each of the plurality of clock signals has a substantially same frequency as the jamming frequency, but a different phase shift. The bandstop filter receives the RF signal and the plurality of clock signals. The bandstop filter attenuates signals within a bandstop centered at the frequency of the plurality of clock signals. A self-tuning N-path filter is provided.

Automatic External RF Gain Calibration and Continuous Jamming Measurement
20210208285 · 2021-07-08 ·

A system and method provide automatic RF path gain calibration independent of RF interference levels to preserve solution trust capabilities. After a system is powered ON, or a new antenna is attached (hot swap), a smart antenna assembly combined with a jammer power estimator within an RF receiver functions to autonomously measure internal gains within the RF path, calibrate the new antenna installation, and thereby measure a level of interference associated with the external environment from that point forward. A controller commands the antenna calibration retrieving antenna details and RF path gain calibration while measuring local jamming at the receiver input. Should the controller determine a level of jamming effectiveness is present, it offers a user a display of the local jamming levels enabling the user accurate theater decision making regarding the accuracy and availability of desirable signal.

METHODS AND SYSTEMS TO DETECT AND COUNTER DENIAL OF SERVICE ATTACK IN VEHICLE COMMUNICATIONS

A method for detecting and countering denial of service attacks in V2X communication includes providing a vehicle with a wireless communication system including an antenna and providing a controller in communication with the wireless communication system. The method includes receiving a wireless communication, analyzing the wireless communication and determining if a first condition is satisfied. When the first condition is satisfied, the method includes calculating an angle of arrival of the wireless communication, predicting a location of a source of the wireless communication relative to the vehicle, and adjusting a gain pattern of the antenna to block reception of additional wireless communications from the source of the wireless communication.

Methods, systems, and computer readable media for utilizing a jamming-resistant receiver device

A method for utilizing a jamming-resistant receiver (JrRx) device includes receiving, by a BJM engine, a plurality of individual subcarrier signals that comprises separate signal portions of a combined signal stream, wherein the combined signal stream is a combination formed by a source signal stream from a sender device and one or more interfering jamming signals from a plurality of unknown jammer devices and computing, by the BJM engine, a respective plurality of BJM filters for the plurality of individual subcarrier signals in the absence of channel information corresponding to the interfering jamming signals. The method further includes applying, by the BJM engine, the plurality of BJM filters to the respective plurality of individual subcarrier signals to decode data packets of the plurality of individual subcarrier signals in order to produce a plurality of source signal stream portions as decoded output, and recovering, by the BJM engine, the source signal stream by combining the decoded output from each of the plurality of BJM filters.

Link 16 transceiver with integral signal nulling system

A secure wireless transceiver, such as a link 16 transceiver, receives signals using an antenna array having an SOC associated with each antenna element in the array. The SOC's digitize and channelize received data for transmission to a message nulling system that mitigates jamming. The antenna array can be conformal, and can replace an existing Link 16 blade. The disclosed transceiver can be a modified CMN-4 transceiver with digitizing and channelizing moved to the SoC's, and replaced by the nulling system. The transceiver uses applicable TRANSEC information to assign received data to the logical Link 16 channels before nulling, and embodiments apply nulling only to channels of interest, thereby improving the nulling and reducing side lobes. Embodiments distinguish between desired and unwanted signals based on known Link 16 signal features and/or situational awareness, rather than signal amplitudes, thereby enabling nulling of even weak jamming signals.

METHOD FOR CHECKING THE INTEGRITY OF A SATELLITE RADIONAVIGATION SIGNAL
20200292711 · 2020-09-17 ·

A method and a function for checking the integrity of the processing of a radionavigation signal emitted by a satellite, the signal being received by a receiver comprising reception means and processing means, the processing means comprising a linear anti-interference filter, the integrity checking method comprising at least a first phase of detection of a risk of false lock-on comprising the following steps: a step of recovery of a nominal theoretical self-correlation function of the received signal not processed by the linear anti-interference filter; a step of determination of a mean theoretical self-correlation function of the signal received and processed by the linear anti-interference filter over a defined integration period; a step of determination of the number of local maxima of the modulus or of the modulus squared of the mean theoretical self-correlation function, a risk of false lock-on being detected if the number of local maxima is greater than or equal to two.

Symbol Detection is Shared Wireless Channel Subject to Jamming Interference

A communication system receives a jammed signal including a sequence of complex numbers encoding one or combination of symbols transmitted by multiple transmitters. The system transforms the sequence of complex numbers into an image of real numbers having at least two columns and multiple rows, with real values of real and imaginary parts of each complex number forming different columns but the same row of the first image, processes the image with a neural network trained to suppress the wideband signal in the received signal, and detects the symbols transmitted by the transmitters from the de jammed signal.

Mitigation of spoofer satellite signals
10739466 · 2020-08-11 · ·

A technology is described for mitigating global positioning system (GPS) spoofer signals. A potentially spoofed GPS signal received via an antenna coupled to a GPS receiver can be identified. The potentially spoofed GPS signal can be applied to a spoofer signal nulling loop to generate a set of spoofer nulling weights. The set of spoofer nulling weights can produce a direction vector associated with the potentially spoofed GPS signal. The direction vector can be compared to a beamsteering vector. The potentially spoofed GPS signal can be determined as being a spoofer GPS signal when a misalignment between the direction vector and the beamsteering vector is above a defined threshold. The spoofer GPS signal can be converted to a spoofer mitigation signal that is applied to satellite track channels of the GPS receiver. The spoofer mitigation signal can produce a spatial null in a direction of the spoofer GPS signal.

Spoofing detection and anti-jam mitigation for GPS antennas

There is provided an apparatus comprising an antenna (105) configured to receive a signal from a global navigation satellite system, wherein the antenna includes a first feed and a second feed; a hybrid coupler (110) including a first hybrid input, a second hybrid input, a first hybrid output, a second hybrid output, and wherein the first hybrid output is shifted in phase by 90 degrees relative to the second hybrid output; a variable phase shifter (150) including a shifter input and a shifter output, hybrid output; and a combiner (155) including a first combiner input, a second combiner input, and a combiner output, wherein the first combiner input is coupled to the shifter output, and the second combiner input is coupled to the second hybrid output, and wherein the combiner output is provided to detection circuitry (197).