Patent ID: 8655300

Claim:
A method of operating a wireless receiver to receive a wanted signal, the method comprising the steps of: receiving a first signal comprising the wanted signal and any unwanted signals; downconverting the first signal to a first analog baseband signal using a first oscillator frequency; band pass filtering the first analog baseband signal to obtain a filtered first analog baseband signal; converting the filtered first analog baseband signal to a first digital baseband signal representing a frequency band including the wanted signal; identifying the position of any first interfering signal in the first filtered digital baseband signal; downconverting the first signal to a second analog baseband signal using a second oscillator frequency; band pass filtering the second analog baseband signal to obtain a filtered second analog baseband signal; converting the filtered second baseband signal to a second digital baseband signal representing a frequency band directly above or below that of the wanted signal; identifying the position of any second interfering signal in the second digital baseband signal; comparing the identified first and second interfering signals; determining the required frequency of a band reject filter based on the comparison; filtering the first analog baseband signal using the band reject filter at the determined frequency; and obtaining the wanted signal from the first filtered digital baseband signal.