An improved lattice IIR digital filter structure

In this paper, a new digital lattice filter structure with minimum signal power ratio is derived, which is actually an improved version of the recently proposed structure reported in [15]. Signed power-of-two (SPT), which is one of the most well known methods for reducing implementation complexity, is applied to a part of the structure parameters. The optimum structure problem is formulated in terms of minimizing the signal power ratio with respect to the two sets of free parameters in the proposed structure by using genetic algorithm. A numerical example is given as well as simulations in order to shows that the newly derived structure can achieve much better performance than the structure proposed in [15] in terms of finite wordlength properties.