CALF: a CORDIC adaptive lattice filter

CALF is a CORDIC processor implementation of an adaptive lattice filter. Unlike previously reported studies which simply used a CORDIC processor to implement the lattice algorithm formulated for conventional multiply-and-accumulate-type arithmetic units, the novel adaptive normalized lattice algorithm reported directly updates the rotation angles rather than the reflection coefficients. Thus, this angle updating lattice algorithm is derived specifically for implementation with a CORDIC processor. Moreover, the authors further modified this algorithm to a sign-sign algorithm to take advantage of the fact that the CORDIC processors only rotate a finite number of distinct rotation angles. Computer simulation results showed good converging properties even at rather coarsely quantized angles