Efficiently update coefficients of an adaptive filter

摘要

An adaptive filter configured to filter an input signal comprises Fourier transforming unit configured to transform the input signal into a frequency domain signal upon the basis of the Fourier transform, weighting unit configured to weight at least a portion of the frequency domain signal with a filter coefficient of the dispersion filter in frequency domain to obtain a filtered signal in frequency domain, correlating unit configured to correlate the filtered signal in frequency domain to obtain a correlation value, and adaptation unit configured to adapt the filter coefficient upon the basis of the correlation value.

主权项

1. An adaptive filter configured to filter an input signal, comprising:
a processor configured to transform the input signal into a frequency domain signal upon the basis of the Fourier transform; a processor weighting unit configured to weight at least a portion of the frequency domain signal with a filter coefficient of the dispersion filter in frequency domain to obtain a filtered signal in frequency domain; a processor configured to correlate the filtered signal in frequency domain to obtain a correlation value; and a processor configured to adapt the filter coefficient upon the basis of the correlation value;whereinthe processor is configured to transform a further input signal into a further frequency domain signal upon the basis of the Fourier transform;the processor is configured to select a further filter coefficient from a plurality of predetermined filter coefficients upon the basis of the correlation value, and to replace the filter coefficient by the further filter coefficient;the processor is configured to weight at least a portion of the further frequency domain signal with the further filter coefficient to obtain a further filtered signal in frequency domain;the processor is configured to correlate the further filtered signal in frequency domain, in particular to auto-correlate the further filtered signal in frequency domain, to obtain a further correlation value; and whereinthe processor is configured to determine a mean value of the correlation value or a mean value of an absolute value of the correlation value and a further mean value of the further correlation value or a further mean value of an absolute value of the further correlation value, wherein the processor is further configured to compare the mean value with the further mean value and to choose the filter coefficient for further weighting if the mean value is smaller than or equal to the further mean value, or to choose the further filter coefficient for further filtering if the further mean value is smaller than or equal to the mean value.