DEVICE AND METHOD FOR ADAPTIVELY SUPPRESSING IN-BAND INTERFERENCE SIGNALS IN RADIO RECEIVERS

摘要

Circuit arrangement for the suppression of interference signals with the aid of a notch filter; wherein the circuit arrangement has the following features:a first local oscillator (13) for generating a first local oscillator signal (lo1) and a second, digitally implemented local oscillator for generating a second digital local oscillator signal (l02), each with an adjustable frequency;a first mixer (11) for converting a high-frequency signal (rf _ in) in a corresponding intermediate frequency signal (if) according to the first local oscillator signal (lo1) with an adjustable frequency;a the first mixer (11) a downstream analog - digital - transducer (16) for digitizing of the intermediate frequency signal (if);a notch - filter (15) with a by means of a fixed predetermined frequency response defined stop band;a digitally implemented second mixer (12) for converting the intermediate frequency signal (if) in a corresponding baseband signal (out) in accordance with the second local oscillator signal (lo2) with an adjustable frequency;a control unit (10), which is a digital frequency estimator (101), which is designed for this purpose, the digitized intermediate frequency signal (if) to receive and, from this, the frequency (fs) of a in the intermediate frequency signal (if) to estimate interference signal contained in a digital,wherein the control unit (10) further comprises a local oscillator control (102), which is designed for this purpose, the frequency difference (f_E) between the estimated frequency (f_S) and the center frequency of the stop band of the notch - filter (15), and to the frequencies of the first and second local oscillator signal (lo1, lo2) corresponding to the determined frequency difference (f_E) , in such a way that the frequency (f_S) of the interference signal in the blocking zone of the notch - filter.n="16"