FIR Filter Design via Extended Optimal Factoring

An improved optimal factoring and zero-grouping algorithm is presented that reduces the hardware needed to implement FIR filters in a cascade structure, with better factors obtained via an optimal grouping of both off-unit-circle as well as on-unit-circle transfer-function zeros. The concept, additional design techniques, and benefits are examined here using practical examples. It is shown that the extended approach offers access to more features that can be exploited to achieve a greater reduction in coefficient quantization levels, thereby creating filters having minimal hardware complexity.