Device and method for adaptively suppressing in-band interference signals in radio receivers

摘要

A circuit arrangement for adaptively suppressing interference signals includes a first local oscillator for generating a first local oscillator signal and a second local oscillator for generating a second local oscillator signal, each signal having an adjustable frequency. The circuit arrangement also includes a first mixer for converting a high-frequency signal into a corresponding intermediate frequency signal using the first local oscillator signal and a second mixer for converting the intermediate frequency signal into a corresponding baseband signal using the second local oscillator signal. The circuit arrangement also includes a notch filter with a rigidly defined blocking range. A control unit estimates the frequency of an interference signal contained in the intermediate frequency signal and to adjust the frequency of the local oscillator signals to the estimated frequency of the interference signal such that the frequency of the interference signal is converted into the blocking range of the notch filter.

主权项

1. A circuit arrangement for suppressing interference signals with the aid of a band-stop filter, the circuit arrangement comprising:
a first local oscillator for generating a first local oscillator signal with an adjustable frequency and a second local oscillator for generating a second local oscillator signal with an adjustable frequency; a first mixer for converting a radio-frequency signal into a corresponding intermediate-frequency signal using the first local oscillator signal with adjustable frequency; a second mixer for converting the intermediate-frequency signal into a corresponding baseband signal using the second local oscillator signal with adjustable frequency; a notch filter having a stop band defined by a predetermined frequency response; and a control unit configured to:
estimate the frequency of an interference signal contained in the intermediate-frequency signal; andcontrol the first local oscillator to shift, over time, the frequency of the local oscillator signals generated by the first local oscillator and fed to the first mixer to match the estimated frequency of the interference signal such that the frequency of the interference signal lies within the stop band of the notch filter.