Systems and methods for reducing a relatively high power, approximately constant envelope interference signal that spectrally overlaps a relatively low power desired signal

A system for processing a time-domain signal in rectangular coordinates, the time-domain signal including a relatively low power desired signal and a relatively high power, approximately constant envelope interference signal that spectrally overlaps the desired signal, the system comprising:

• a rectangular to polar converter configured to obtain a magnitude and a phase of the time-domain signal in polar coordinates;
• an interference magnitude estimator configured to estimate a magnitude of the interference signal based on the magnitude of the time-domain signal in polar coordinates;
• a subtractor configured to obtain a difference magnitude in polar coordinates based on the magnitude of the time-domain signal and the estimated magnitude of the interference signal in polar coordinates;
• and
• a polar to rectangular converter configured to obtain the desired signal in rectangular coordinates with reduced power of the interference signal based on the difference magnitude and the phase of the time-domain signal in polar coordinates,
• wherein the interference magnitude estimator is configured to estimate the magnitude of the interference using an envelope detector followed by an analog filter, and
• wherein the envelope of the interference signal is constant over a period equal to a group delay of the analog filter.

A method for processing a time-domain signal in rectangular coordinates, the time-domain signal including a relatively low power desired signal and a relatively high power, approximately constant envelope interference signal that spectrally overlaps the desired signal, the method comprising:

• obtaining a magnitude and a phase of the time-domain signal in polar coordinates;
• estimating a magnitude of the interference signal based on the magnitude of the time-domain signal in polar coordinates;
• obtaining a difference magnitude in polar coordinates based on the magnitude of the time-domain signal and the estimated magnitude of the interference signal in polar coordinates;
• and
• obtaining the desired signal in rectangular coordinates with reduced power of the interference signal based on the difference magnitude and the phase of the time-domain signal in polar coordinates,
• wherein the magnitude of the interference signal is estimated based on filtering the magnitude of the time-domain signal in polar coordinates, and
• wherein the envelope of the interference signal is constant over a period greater than a group delay of a filter used to apply the filtering.

A method for processing a time-domain signal in rectangular coordinates, the time-domain signal including a relatively low power desired signal and a relatively high power, approximately constant envelope interference signal that spectrally overlaps the desired signal, the method comprising:

• obtaining a magnitude and a phase of the time-domain signal in polar coordinates;
• estimating a magnitude of the interference signal based on the magnitude of the time-domain signal in polar coordinates;
• obtaining a difference magnitude in polar coordinates based on the magnitude of the time-domain signal and the estimated magnitude of the interference signal in polar coordinates;
• and
• obtaining the desired signal in rectangular coordinates with reduced power of the interference signal based on the difference magnitude and the phase of the time-domain signal in polar coordinates,
• wherein the magnitude of the interference signal is estimated based on filtering the magnitude of the time-domain signal in polar coordinates, and
• wherein the envelope of the interference signal is constant over a group delay of a filter used to apply the filtering.