Novel low complexity lattice filters with overflow property close to the normalized lattice

The excellent finite wordlength property of the lattice digital filter is well known. The four-multiplier normalized lattice, with signal power at all delay elements normalized to unity, has particular advantage in its overflow property. However, when used to implement an Nth order digital filter, the normalized lattice implementation requires 5N +1 multipliers. In this paper, we present a novel lattice filter structure derived by combining the "tapped numerator" and "injected numerator" lattices. This new "tapped numerator" and "injected numerator" hybrid lattice has overflow property close to that of the normalized lattice but requires only 3N+1 multipliers when used to realize an Nth order IIR digital filter.