Noise-Reducing, Nonrecursive Digital Filters.

摘要

Techniques for the design of noise-reducing,nonrecursive digital filters are compared. Special emphasis is placed on a simple method for constraining the response of a filter at selected frequencies,including the edges of the passband,while minimizing the filter output noise power over a specified stopband of frequencies. These constraints can be used to shape the passband response,for example. The above mentioned constrained-points (CP) method is compared with three other of digital filter design which are based on the criteria of maximum energy-ratio or maximum SNR,minimax error subject to upper and lower restraining functions and least-squares approximation. The special problem of rejecting strong sinusoidal interferences without excessive change in passband response or putput noise power is shown to be well suited to the CP method of design. (Author)