Design of finite wordlength 2-D recursive digital filters using all-pass building blocks

A technique for the design of IIR filters by using only finite wordlength all-pass subfilters is presented. It is known that all-pass filters are less sensitive to the coefficient quantization noise than most of the other types of filters. To show this fact, a stable band-pass filter is designed by using infinite wordlength all-pass subfilters through a nonlinear optimization process. A branch and bound technique is then utilized to optimize the quantized infinite precision coefficients.