Chapter Six. Infinite Impulse Response Filters

Infinite Impulse Response Filters

Infinite impulse response (IIR) digital filters are fundamentally different from FIR filters because practical IIR filters always require feedback. Where FIR filter output samples depend only on past input samples, each IIR filter output sample depends on previous input samples and previous filter output samples. IIR filters' memory of past outputs is both a blessing and a curse. Like all feedback systems, perturbations at the IIR filter input could, depending on the design, cause the filter output to become unstable and oscillate indefinitely. This characteristic of possibly having an infinite duration ...

Get Understanding Digital Signal Processing, Second Edition now with O’Reilly online learning.

O’Reilly members experience live online training, plus books, videos, and digital content from 200+ publishers.