digital filter application?

Question

can somebody please tell me an application of digtal filters(low pass would be great) that would be easy to simulate in matlab.
specifications would be also great.

thank you.
best answer would be choosen.

Answer 1

You asked for an application, not a design, so I assume you know how to apply design rules for FIR or IIR filters. Digital filters are used extensively in communications and digital television. A simple application is a crossover filter for the subwoofer output of an audio receiver. All modern receivers digitize their signals and operate on them in the digital domain. A low-pass filter for a subwoofer output would have a cutoff frequency (3db down point) of 80Hz, and an attenuation after that of -12db per octave. This is usually an FIR filter for good stability. These parameters can be fed into the Ramirez algorithm to get the multipier coefficients. You will also have to select the number of taps in the filter in order to get the response you need.

EDIT: My memory failed me, it's Remez algorithm, not Ramirez.