Time-Varying Lagrange Interpolation

To allow for time-varying $\Delta$ , the coefficients $\hbar _\Delta(k)$ can be moved out of the $(q-1)^k$ chain as follows:

• In this case the lower-order interpolations are not readily available.

• As in the Farrow structure, we obtain a variable linear combination of fixed FIR filters $(1-z^{-1})^k$ , $k=0,1,2,\ldots N$ .