Difference Between FIR and IIR Filters

In Digital Signal Processing (DSP), Finite Impulse Response (FIR) and Infinite Impulse Response (IIR) filters are commonly used for signal processing. The main difference between FIR and IIR filters is in the characteristics of their impulse responses.

FIR Filters:

FIR filters have a finite impulse response, which means that their output is based on a weighted sum of past input values. FIR filters are typically linear phase filters, which means that they do not introduce phase distortion in the filtered signal. FIR filters are known for their stability and predictable frequency response.

IIR Filters:

IIR filters have an infinite impulse response, meaning that the output is recursively calculated based on both past input values and past output values. IIR filters can be more computationally efficient than FIR filters for certain applications. However, IIR filters are prone to stability issues and may introduce phase distortion in the filtered signal.

When to Use Each Filter:

1. Use FIR filters when a linear phase response is required, such as in audio processing applications where phase distortion must be minimized.

2. Use IIR filters when computational efficiency is important and phase distortion is less of a concern. IIR filters are commonly used in applications like control systems and communication systems.