Low-sensitivity and low-roundoff noise multiple-loop feedback digital filters

By means of state-variable feedback techniques a special design procedure is leading to the development of a low-noise and low-coefficient sensitivity filter structure, which is suitable for signal processor implementations because its signal flow graph leads to a small number of processor operations. The investigations give much insight in the mechanism of coefficient insensitivity, especially in consideration of the relationship between filter topology and the available arithmetic of the filter implementation. In case of floating-point implementation of typical lowpass and bandpass transfer functions, the proposed filter topology leads to coefficient sensitivity and to roundoff noise properties which are always similar and in some cases even better than the properties of wave digital filters