VLSI Digital Signal Processing Systems: Design and Implementation

11.8    CONCLUSIONS

Approaches to scaling and roundoff noise in state variable description based IIR and FIR digital filters have been addressed. In many digital filters, all roundoff noise nodes cannot be modeled as state variable nodes. These filters can be preprocessed using pipelining and/or M-slow transformation and retiming so that the output of every roundoff noise node can be described by a state variable. Fast algorithms for computation of state and output covariance matrices have also been presented. These matrices can be used to perform scaling and to compute roundoff noise.