A discrete optimization method for high-order FIR filters with finite wordlength coefficients

A transfer function is Constructed in a cascade form, using a low-order error free function and a high-order function. The high-order function is discretely optimized so that its error spectrum is suppressed by the error-free function. In order to save computing time, the error spectrum is equivalently evaluated in a time domain, and the coefficients are divided into small groups in a discrete optimization procedure.