For suppression of continuous wave interferers at, e.g., up to four interferer frequencies (f.sub.1, f.sub.2, f.sub.3, f.sub.4) in a GNSS receiver base band circuit a raw digital signal is, in a band stop unit (21), shifted, by a first mixer (31a), by the negative of the first interferer frequency (f.sub.1) in the frequency domain whereupon the continuous wave interferer is suppressed by a band stop filter (30a), a linear phase FIR filter with a suppression band centered at zero, e.g., a filter subtracting a mean over previous subsequent signal values from the actual signal value. After further shifting of the shifted digital signal by the negative of the difference between the second interferer frequency (f.sub.2) and the first interferer frequency (f.sub.1) the shifted digital signal is again filtered by an identical band stop filter (30b) and so on. After the last filtering step the shifted digital signal is shifted back to its original position in the frequency domain to provide a filtered digital signal which corresponds to the raw digital signal with narrow interferer bands centered at the interferer frequencies (f.sub.1, f.sub.2, f.sub.3, f.sub.4) suppressed.

For suppression of continuous wave interferers at, e.g., up to four interferer frequencies (f.sub.1, f.sub.2, f.sub.3, f.sub.4) in a GNSS receiver base band circuit a raw digital signal is, in a band stop unit (21), shifted, by a first mixer (31a), by the negative of the first interferer frequency (f.sub.1) in the frequency domain whereupon the continuous wave interferer is suppressed by a band stop filter (30a), a linear phase FIR filter with a suppression band centered at zero, e.g., a filter subtracting a mean over previous subsequent signal values from the actual signal value. After further shifting of the shifted digital signal by the negative of the difference between the second interferer frequency (f.sub.2) and the first interferer frequency (f.sub.1) the shifted digital signal is again filtered by an identical band stop filter (30b) and so on. After the last filtering step the shifted digital signal is shifted back to its original position in the frequency domain to provide a filtered digital signal which corresponds to the raw digital signal with narrow interferer bands centered at the interferer frequencies (f.sub.1, f.sub.2, f.sub.3, f.sub.4) suppressed.

For suppression of continuous wave interferers at, e.g., up to four interferer frequencies (f.sub.1, f.sub.2, f.sub.3, f.sub.4) in a GNSS receiver base band circuit a raw digital signal is, in a band stop unit (21), shifted, by a first mixer (31a), by the negative of the first interferer frequency (f.sub.1) in the frequency domain whereupon the continuous wave interferer is suppressed by a band stop filter (30a), a linear phase FIR filter with a suppression band centered at zero, e.g., a filter subtracting a mean over previous subsequent signal values from the actual signal value. After further shifting of the shifted digital signal by the negative of the difference between the second interferer frequency (f.sub.2) and the first interferer frequency (f.sub.1) the shifted digital signal is again filtered by an identical band stop filter (30b) and so on. After the last filtering step the shifted digital signal is shifted back to its original position in the frequency domain to provide a filtered digital signal which corresponds to the raw digital signal with narrow interferer bands centered at the interferer frequencies (f.sub.1, f.sub.2, f.sub.3, f.sub.4) suppressed.

A method and apparatus resiliently despreads terrestrial navigation signals in which the spreading code duration is equal to an underlying baseband symbol rate, including ground beacons based on civil GNSS waveforms, and malicious spoofers. Symbol-rate synchronous channelizers exploit the baseband symbol rate, and means for blindly and resiliently detecting and determining geo-observables of those signals are described. Disclosed techniques can despread signals in arbitrary multipath, and subject to near-far interference in which the relative strength of the interferer is much higher than the despreading gain of the receiver, including near-far tonal and narrowband co-channel interference.

A method and apparatus for improving anti-jamming performance are provided. A threshold value level estimated in a GPS (global positioning system) receiver RF/IF stage, a threshold value weight, a median value of a median value of a 28 MHz bandwidth is estimated as a threshold value with respect to a frequency component exceeding the estimated threshold value level, and an adjustable K-median threshold scheme is provided in a multi-jamming environment.

A non-transitory device-readable medium, which may be embodied in a device, such as a radar receiver, stores instructions that, when executed by processing circuitry, are configured to perform operations to identify a region of interference. An analog signal is generated based on received signals reflected from a target object and an interfering object. The analog signal is converted to an initial time-domain data set. Processing circuitry is configured or instructed to perform a transform operation on the initial time-domain data set to generate a frequency-domain data set, based on which a region of interference may be identified. Subsequent operations may be performed to facilitate identification of the region of interest including thresholding, inverse transforming, subtracting, and/or combining. The processing circuitry may be further configured or instructed to generate repaired time-domain data from which corrupted time-domain samples to remove data associated with the interfering object.

A radar device includes processing circuitry to perform operations to identify corrupted data samples in an initial time-domain data set generated from return signals reflected from a target object and also signals from an interfering object causing the corruption. The processing circuitry also performs operations starting on the initial time-domain data set to generate reconstructed data corresponding to the corrupted data samples. An uncorrupted time-domain data set is then generated based on the initial time-domain data set and the corrupted data samples, and repaired time-domain data set is generated based on the uncorrupted time-domain data set and the reconstructed data. The operations performed include thresholding, transforming, inverse transforming, subtracting, and/or combining. The processing circuitry may be hard coded and/or be configured to execute software instructions stored in a memory to perform the processing.