Abstract: Disclosed are methods and systems for mitigating unwanted signal components. A received carrier signal is downconverted using a local reference signal that imposes an frequency perturbation or dither. Later, when an intermediate digitized signal is filtered to remove the DC offset that is an artifact of the sampling process, the dither in the carrier signal serves to distinguish the carrier from the unwanted offset. The preferred offset filter is a low pass filter with a passband that is narrow relative to the frequency range of the dither.

Abstract: Disclosed are methods and systems for mitigating unwanted signal components. A received carrier signal is downconverted using a local reference signal that imposes an frequency perturbation or dither. Later, when an intermediate digitized signal is filtered to remove the DC offset that is an artifact of the sampling process, the dither in the carrier signal serves to distinguish the carrier from the unwanted offset. The preferred offset filter is a low pass filter with a passband that is narrow relative to the frequency range of the dither.

Abstract: Systems and methods for reducing spurious signals in digital receivers. A system includes a digital navigation receiver having a controllable reference oscillator configured to generate a reference frequency based on a control signal input and a control signal generator in signal communication with the controllable reference oscillator. The control signal generator is configured to generate a waveform that sweeps in frequency such that the reference frequency is based on the waveform. A triangular waveform that sweeps in frequency is used in an example embodiment. A method includes generating a waveform that sweeps in frequency and controlling the reference oscillator based on the waveform.