Optimization of frequency-response-masking based FIR filters with reduced complexity

Recently, it has been observed that the complexity of finite-impulse-response (FIR) filters using the frequency-response masking technique can be significantly reduced by simultaneously optimizing all the subfilters. In order to reduce the filter complexity even further, this paper considers the optimization a class of FIR filters based on the use of the generalized frequency-response masking approach originally introduced by Lim and Lian (see IEEE Trans. Circuits Syst. II, vol. 41, p. 518-525, Aug. 1994). For this class of filters, the two masking filters are constructed by using a common filter part. Again, the simultaneous optimization of all the subfilters is used, resulting in a considerable reduction in the overall filter complexity. An example taken from the literature illustrates the benefits of the proposed approach.