Systems and methods for GNSS anti-jamming using interference cancellation are described herein. In certain embodiments, a system includes an antenna that receives signals, wherein the signals comprise a weak portion associated with one or more GNSS satellites and a strong interference portion from an interfering signal source. The system also includes a GNSS anti-jammer. The GNSS anti-jammer includes an interference isolator that receives the received signals and provides an estimated strong interference portion as an output. The GNSS anti-jammer also includes a summer that subtracts the estimated strong interference portion from the received signals to create a summed signal. Further, the GNSS anti -jammer includes a local noise remover that removes noise generated by the interference isolator from the summed signal, wherein the local noise remover is a processor that digitally removes the noise. Further, the system includes a GNSS receiver coupled to receive the summed signal from the processor.

A system and method are disclosed for producing nulls in a wideband jamming signal at specific frequency bands. A nulling signal is determined, either as a modification to one or more of the combined signals, or a separately determined nulling signal generated by combine a separate set of signals. The nulling signal is produced via feedback based on the output of the wideband jamming signal. Alternatively, a trained neural network outputs a nulling signal based on the wideband jamming signal and a desired availability band.

A system and method of index modulation based joint mode frequency hopping with vortex electromagnetic waves for anti-jamming are provided. The system is additionally provided with a transmit signal carrier selector that provides diversified options, a receive signal carrier selector that is strictly synchronized with the transmit signal carrier selector, and a group of fast Fourier transformation modules to output a binary demodulation signal with jamming eliminated. The method includes: binary information division; index modulation and information modulation; information loading and hopping; information transmission, de-hopping, and jamming filtering; and calculation of the jamming probability and an average bit error rate. The present disclosure combines orbital angular momentum modes and subcarrier frequencies to form OAM mode-subcarrier frequency pair sets so as to diversify information transmission carriers, and performs simultaneously modulation and hopping to increase a spectrum efficiency and enhance the anti-jamming capability.

Methods, systems, and computer program products are described for automatically reducing interference within received signals. A first radio frequency (RF) signal having (i) a desired component and (ii) an interference component with a noise component and a jammed component is received. A trained machine learning (ML) model extracts, from the RF signal, the jammed component and a portion of the noise component. The trained ML model generates and outputs a second RF signal comprising the desired component and a reduced noise component. The reduced noise component has the portion of the noise component removed. The jammed component is removed from the second RF signal.

A method for inhibiting jammed signal use includes: receiving a desired signal wirelessly at a receiver; receiving an undesired signal wirelessly at the receiver, the undesired signal varying in strength over time; and inhibiting measurement of the desired signal, or use of a measurement of the desired signal, based on a determination that the undesired signal is a jamming signal based on a variation of the undesired signal being indicative of jamming.

A deceiving signal detection system includes a first antenna, a second antenna, and a signal processor. The first antenna is configured to receive at least four radio wave signals. The signal processor determines that the radio wave signals are the deceiving signals by determining that a relative positional relation between the first antenna and the second antenna calculated on a basis of the radio wave signals deviates from an actual relative positional relation between the first antenna and the second antenna by more than a predetermined amount, and also determines whether an orientation of the aircraft determined based on positions of the first antenna and the second antenna matches an orientation of the aircraft calculated based on an inertial navigation system.

Various schemes for mitigating radio frequency (RF) interference are described, wherein an adaptive local oscillator (LO) is utilized. A receiver measures a jamming indicator which indicates a total power within a receiving band of the receiver. If the jamming indicator indicates a presence of substantial in-band interference, the receiver may program the LO to a different frequency and/or adjust a bandwidth of a filter accordingly to reject or reduce the interference. The receiver may adjust the LO and/or the filter repeatedly until the interference is rejected to a point that de-sense to the signal intended to be received is satisfactorily mitigated. The receiver may restore the LO and the filter to a default setting when the jamming indicator indicates that the interference is no longer present.

Providing signal-to-noise ratio information to a local transmitter node. A method includes receiving data in a signal transmitted on a data channel from the local transmitter node. A first signal-to-total-power ratio for the signal assuming no jamming of the signal is occurring is computed. A second signal-to-total-power ratio for the signal with factors included assuming jamming is occurring is computed. The first signal-to-total-power ratio to the second signal-to-total-power ratio are compared to determine if they differ by a predetermined amount. The method includes determining that the predetermined amount is exceeded, and as a result, a jammed signal-to-noise ratio is computed assuming jamming is occurring. The jammed signal-to-noise ratio is sent to the local transmitter node to allow the local transmitter to respond to the jammed signal-to-noise ratio.

A phased array anti-jamming device, comprising a plurality (N) of antennas and a plurality of splitters connected to the antennas and adapted to split an RF stream received from the antennas. The phased array anti-jamming device further includes at least one digital signal processor adapted to digitally analyze a digital output of digital processing channels and to split the output into a plurality of digital down converted representations of respective analog outputs of a plurality of analog digital processing channels in a plurality of different frequencies and calculate at least one instructions selected from phase shift, amplification, and attenuation instructions for each one of the plurality of antennas per each one of the plurality of different frequencies. The phased array anti-jamming device further includes a plurality of phase shifter groups a plurality of group combiners and a main combiner adapted to sum outputs of the plurality of group combiners.

A process for an electronically steerable parasitic array (ESPAR) antenna includes operating the ESPAR antenna with a receiver in Normal Mode until an internal flag is generated by the receiver indicating jamming RF noise preventing Normal Mode operation, causing the ESPAR antenna to switch to Anti-jam Mode. Anti-jam Mode includes a Search Mode and a Track Mode. The ESPAR antenna is steered in Search Mode, causing the ESPAR antenna to beam in a circular pattern to locate a spatial direction of the jamming RF noise, identify the spatial direction of the jamming RF noise preventing Normal Mode operation, and place a null in the spatial direction of the jamming RF noise. The ESPAR antenna switches to Track Mode to maintain the null in the spatial direction of the jamming RF noise until the jamming RF noise is not present. The ESPAR antenna then returns to operating in Normal Mode.