A new normalized relatively stable lattice structure

This paper proposes a new lattice filter structure that has the following p roperties. When the filter is linear time invariant (LTI), it is equivalent to the celebrated Gray-Markel lattice. When the lattice parameters vary wi th time, it sustains arbitrary rates of time variations without sacrificing a prescribed degree of stability, provided that the lattice coefficients a re magnitude bounded in a region where all LTI lattices have the same degre e of stability. We also show that the resulting LTV lattice obeys an energy contraction condition. This structure thus generalizes the normalized Gray -Markel lattice, which has similar properties but only with respect to stab ility as opposed to relative stability.