How would you start designing a low pass IIR filter? How long would it take you? Thank you!

Hi Matlab Fam, I wanted to design IIR low pass filter. There is an already designed FIR filter and need to extract the coefficients from there via FDA tool. This is being done to minimize the memory usage. I need to prepare the model as stable as possible and provide a report for it. I am taking this as a challenge and never did it before. Currently doing my desktop search.My question is: 1. How would you begin and what procedures would you follow? 2. On average, how long does it take till implementation and documentation? 3. Any sources if you can share would be highly appreciated!

Answer 1

[ES]

If you know the transfer function of the filter/filter coefficients, you can start with the Discrete Filter block in Simulink.

Or if you know about the temporal behaviour and order of the filter, you can start modelling the equation in Simulink. For example

y(n) = A0*y(n-1)+B0*x(n)+B1*x(n-1)

[Nirvana4Eva]

Thank you Chocolate Warrior. Yes I have the filter coefficients (a&b). Infact the following are the available data :

The following points are read from this chart: At 0 Hz: -1dB At 2.5Hz: -3dB At 5.4 Hz: 10dB At 7.4 Hz: -20dB At 9.3 Hz: -40dB For frequencies above 10Hz attenuation must be at least 40dB amounts 3dB point is at 3.0Hz

Accuracy of these frequencies: At 2.5 Hz +/- 0.2 Hz At 10 Hz: +/- 1 Hz. sampling frequency applies at 2400Hz

If you can take a little time to take me what need to be done to start with and what need to follow. I really appreciate your guidance!

[ES]

does this help?