H04K3/228

SYSTEM AND METHOD FOR MITIGATING NARROWBAND INTERFERENCE
20180013514 · 2018-01-11 · ·

A system and method for mitigating interference of a radio frequency (RF) signal includes a receiver configured to include: a decomposition module that decomposes a received RF signal into sub-bands via a multi-stage filter, each sub-band being configured to operate on real and imaginary components of the RF signal, and each stage being scaled for separating time-frequency content of the desired signal from time-frequency content of the interference; a mitigation module that suppresses the interference of the RF signal in each sub-band by zeroing an output of a respective sub-band when the frequency content exceeds a predetermined threshold; and a reconstruction module that reconstructs the RF signal from the mitigation module minus the interference. The receiver is configured to determine whether the multi-stage filter is to be reinitialized with updated time and frequency resolution requirements to improve system response.

JAMMING SIGNAL CANCELLATION

There is disclosed an apparatus. The apparatus comprises means for performing: in response to detecting a jamming signal, obtaining a sample waveform of the jamming signal; and sending information of the jamming signal to another apparatus.

Method for checking the integrity of a satellite radionavigation signal
11693121 · 2023-07-04 · ·

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.

INTERFERENCE AND JAMMER CANCELLATION FOR RADIOS
20230101372 · 2023-03-30 ·

Methods, systems, and devices for reducing the impact of a jamming signal on wireless communications are described. Generally, the described techniques provide for receiving a first signal at a first antenna and receiving a second signal at a second antenna. An anti-jammer manager may process the first signal and the second signal to obtain a residual signal. The processing may include determining a weighting factor based at least in part on a correlation between the first signal and the second signal, applying the weighting factor to the first signal to create a weighted first signal, and subtracting the weighted first signal from the second signal to obtain the residual signal. A demodulator may demodulate the residual signal to obtain symbol information. A decoder may decode the symbol information to obtain data. The techniques may be used to recover a desired signal portion from a jammed signal.

Abrupt Interference Mitigation

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.

ALGORITHM AND TECHNIQUES FOR HIGH-RESOLUTION INTERFERENCE PARAMETER ESTIMATION IN LOW-SWAP ENVIRONMENT

Techniques for providing a multi-stage iterative scheme to determine fine granularity estimates of parameters of an interfering signal and for using the fine granularity estimates of the parameters to reduce an impact of the interfering signal against a signal of interest (SOI) are disclosed. An input signal is identified. A first set of estimation parameters that provide a coarse granularity estimate of a center frequency of the jamming signal and of a symbol rate of the jamming signal are determined. The first set of estimation parameters are refined to generate a medium granularity estimate of the center frequency and the symbol rate of the jamming frequency. The medium granularity estimates are also refined to produce a fine granularity estimate of the center frequency and the symbol rate. The fine granularity estimates are used to remove or reduce an influence of the jamming signal on the input signal.

INTERFERENCE DETECTION AND COARSE PARAMETER ESTIMATION USING LEARNED AND INFERRED BASELINE INFORMATION

Improved techniques for estimating parameters of a jamming signal. An input signal is identified. This input signal is suspected of being a jammed composite signal. Attributes of a reference signal are determined. The reference signal is an expected signal that was expected to be received. A form fitting operation is performed in which the reference signal is formed fitted with the input signal. The reference signal is subtracted from the input signal to generate an isolated output signal. A suspected portion of the isolated output signal is identified. An estimated symbol rate and an estimated center frequency for the jamming signal are determined based on the suspected portion. The estimated symbol rate and the estimated center frequency are used to facilitate a subsequent mitigation operation of eliminating or reducing an impact of the jamming signal against the signal of interest.

UNSTABLE JAMMING SIGNAL DETECTION

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.

ADJUSTABLE NULL STEERING IN A STATIONARY NETWORK
20220329345 · 2022-10-13 · ·

A null steering adjuster in a stationary wireless network identifies the presence or absence of a current set of phase differences in a dataset. The dataset includes legitimate sets of phase differences detected between radio frequency signals received by multiple antennas from respective legitimate sources. The current set of phase differences is detected between radio frequency signals currently received by the antennas. When the current set of phase differences is absent from the dataset, a null is created in the antenna pattern of the antennas in the direction of the currently-received radio frequency signals. When the current set of phase differences is present in the dataset, the antenna pattern is maintained.

EXPANDING TIME WINDOW FOR REMOTE COMMANDS
20170372537 · 2017-12-28 ·

A vehicle includes: receiver(s), a timer counting time, memory, and processor(s) configured to: receive a timestamped signal from a fob; compare the timestamp to a time window; reject the timestamp if the timestamp is outside the time window; expand the time window with the counted time; compute the time window as a trigonometric function of the counted time and a predetermined angle.