Least Pth Norm Linear Phase FIR Design (Digital Filter Design Toolkit)

You can design a linear phase FIR filter using the DFD Least Pth Norm Design VI by setting the following specifications. Set the denominator order to 0, the filter type to Symmetric or Antisymmetric, all phases in the band specifications to 0, and the group delay to half of the numerator order.

For example, suppose you want to design a linear phase FIR lowpass filter with a passband frequency range of [0, 0.2] and a stopband frequency range of [0.3, 0.5]. Set the specifications as shown in the following figure:

The following figure shows the magnitude response of the designed filter. Because p is 128, the designed filter is almost identical to the result using the Remez equi-ripple design with the same filter specification.