Further Desensitized FIR Halfband Filters

A halfband filter´s sensitivity to coefficient quantization can be significantly reduced by constructing the filter as a cascade of sections. The further desensitized FIR halfband filter presented here has an increased reduction in coefficient sensitivity. This is accomplished by doubling the number of extracted (1+z^-1) blocks in the cascade filter structure. The relationship between the resulting further-desensitized halfband filter´s structure and the halfband filter´s transfer function is also demonstrated through reasoning, as well as showing the same for the previous desensitized halfband filter, for which the present filter represents an improvement. Further, it is shown how such insensitivity can be exploited in the filter-design process to yield halfband filters with reduced hardware complexity, leading to lower power consumption and/or higher operating speeds.