Quantization of filter coefficients

For LTI filters, when coefficients are quantized the system function can be written as follows: $$ \hat{H}(z) = \sum_{n} \left \{ h[n] + \color{red}{ \Delta h[n] } \right \} z^{-n} = H(z) + \color{red}{\Delta H(z)} $$ which is depicted in Fig. 1.

Thus the quantization errors may be modeled as $H(z)$ in parallel with $\Delta H(z)$. As a conclusion it follows that quantization:

• Does not introduce non-linearity effects,
• Will influence the filter characteristics.