Delay generation filter

摘要

An Nth order infinite impulse response digital filter for long-delay filtering of signals representing a digital input sequence. The Nth order infinite impulse response digital filter is synthesized by cascading in series N first order infinite impulse response filter stages. A filter stage operable on a digital computer with floating point capability is provided and comprises a multiplier which multiplies an input signal with a weighting factor. A summing element provides an output for the filter stage by summing the weighted input signal with a weighted and delayed output signal. A filter operable on a digital computer with fixed point capability is provided and comprises a summing element which sums an input signal with the output of a first multiplier, and the delayed output of a mask element. The output of the summing element is coupled to the input of a second multiplier and to the input of the mask element. The second multiplier provides an output for the filter stage which is also used, in a delayed form as the input of the first multiplier.