Differentiate IIR and FIR systems.
1 Answer
Sr. No. IIR systems FIR systems
1. IIR stands for infinite impulse response systems FIR stands for finite impulse response systems
2. IIR filters are less powerful than FIR filters, & require less processing power and less work to set up the filters FIR filters are more powerful than IIR filters, but also require more processing power and more work to set up the filters
3. They are more easy to change "on the fly”. They are also less easy to change "on the fly" as you can by tweaking (say) the frequency setting of a parametric (IIR) filter
4. These are less flexible. Their,greater power means more flexibility and ability to finely adjust the response of your active loudspeaker.
5. It cannot implement linear-phase filtering. It can implement linear-phase filtering.
6. It cannot be used to correct frequency-response errors in a loudspeaker It can be used to correct frequency-response errors in a loudspeaker to a finer degree of precision than using IIRs
7. IIRs can provide good resolution even at low frequencies. FIRs can be limited in resolution at low frequencies, and the success of applying FIR filters depends greatly on the program that is used to generate the filter coefficients
8. Usage is generally more easier than FIR filters. Usage is generally more complicated and time-consuming than IIR filters
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10. IIR filter uses current input sample value, past input and output samples to obtain current output sample value. FIR filter uses only current and past input digital samples to obtain a current output sample value. It does not utilize past output samples.
11. Simple IIR equation is mention below.,y(n)= b(0)x(n) + b(1)x(n-1) + b(2)x(n-2) + b(3)x(n-3) + a(1)y(n-1) + a(2)y(n-2) + a(3)y(n-3) Simple FIR equation is mention below. y(n)= h(0)x(n) + h(1)x(n-1) + h(2)x(n-2) + h(3)x(n-3) + h(4)x(n-4)
12. Transfer function of IIR filter will have both zeros and poles and will require less memory than FIR counterpart Transfer function of FIR filter will have only zeros, need more memory
13. IIR filters are not stable as they are recursive in nature and feedback is also involved in the process of calculating output sample values. FIR filters are preferred due to its linear phase response and also they are non-recursive. Feedback is not involved in FIR, hence they are stable
14. IIR filter need more power due to more coefficients in the design. FIR filter consume low power
15. IIR filters have analog equivalent FIR have no analog equivalent.
16. IIR filters are more efficient FIR filters are less efficient
17. IIR filters are used as notch(band stop),band pass functions. FIR filters are used as anti-aliasing,low pass and baseband filters
18. IIR filter need lower order than FIR filter to achieve same performance FIR filter need higher order than IIR filter to achieve same performance.
19 Delay is less than FIR filter. Delay is more than IIR filter.
20. It has higher sensitivity than FIR filter It has lower sensitivity than IIR filter
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