Patent ID: 8085838

Claim:
A method of dynamically adapting a digital filter characteristic, the method comprising: storing a frequency domain representation of the filter characteristic; analyzing an input signal to determine a required filter characteristic based on a frequency of a narrowband interfering signal included in the input signal; adapting the frequency domain representation to match the required filter characteristic; transforming the adapted frequency domain representation to a time domain so as to obtain filter coefficients relating to the required filter characteristic; and applying the filter coefficients to effect the adaptation of the filter characteristic, wherein adapting the frequency domain representation to match the required filter characteristic includes at least one of: altering a bandwidth of the frequency domain representation by reducing or increasing a number of samples in the frequency domain representation according to the frequency of the narrowband interfering signal; and altering a frequency of the frequency domain representation by shifting samples of the frequency domain representation to a lower or higher frequency according to the frequency of the narrowband interfering signal.