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Infinite Impulse Response filters

An Infinite Impulse Response (IIR) filter produces an output, y(n), that is the weighted sum of the current and past inputs, x(n), and past outputs.

The Linear Predictive model is a specical case of an IIR filter and shown in figure 7.

Figure 7: An IIR filter

The general IIR filter (figure 8) is given by:

Figure 8: The general linear filter

If p = 0 then the system represents a finite impulse response (FIR) filter. If p is not zero, then the system is an infinite impulse response (IIR) filter.

An example is the two pole resonator with center frequency tex2html_wrap_inline2853 and bandwidth related to r is:


Common types of IIR filter:


For more details see [4].

Speech Vision Robotics group/Tony Robinson