WLS Design of Variable Fractional-Delay FIR Filters Using Coefficient Relationship

In this brief, a new coefficient relationship is proposed for the design of variable fractional-delay (VFD) finite-impulse response (FIR) filters by the weighted least-squares (WLS) method so that the number of filter coefficients to be designed can approximately be halved. To reduce the computational cost, closed-form expressions for the elements of related vectors and matrices are derived. Several design examples are presented, and the comparisons show that the overall performance of the proposed method is comparable with that of the conventional method; however, the number of filter coefficients to be designed for the proposed method is about half of that in the conventional method.