Adaptive notch filter to reject narrow-band interference signals

摘要

A new adaptive algorithm to reject narrow-band interference by an adaptive notch filter is proposed. The notch frequency and bandwidth of this filter are independently adjustable by varying two filter coefficients. In our proposed algorithm, we use the first derivative of mean squared error as an error-function. The LMS algorithm is used to adapt the notch bandwidth and frequency. To evaluate the validity of our proposed method, we define noise rejection factor as a ratio of powers of wide-band signal and narrow-band interference. Computer simulation to detect center frequency and bandwidth of narrow-band interference shows the validity of our proposed algorithm.