High-fidelity low-pass finite-impulse-response filters
Robert H. Wilkinson · Journal of Guidance Control and Dynamics · 1989
The paper describes a method of designing a low-pass finite-impulse response (moving-average) filter having a flat passband and an arbitrarily contoured stopband. The method effectively separates the design of the passband and the stopband, with independent control over the properties of each. The filter causes a controUably small amount of distortion when applied to a smooth input and is especially useful in connection with data rate conversion in those cases when the object is to process with precision a low-frequency signal. The method permits direct placement of stopband zeros, convenient for locating don't care bands in first stage data-rate-reduction filters, or suppressing large discrete sources of interference. The theory depends on the expansion of the filter weighting sequence (impulse response) as a power series of central-difference operators.