Digital filter combination
View Patent ↗The invention features a filter arrangement for filtering an input signal that includes a transmitter signal having a predetermined pulse shape at a receiving end to transmit the input signal, a decimation filter to decimate the input signal that includes a passband frequency range and a wide transition frequency range with an amplitude attenuation, and a matching filter to match the input signal to the pulse shape of the transmitter signal. Such filter arrangements also feature passband frequency ranges for decimation filters which are smaller than the ranges for matching filters.
1. A filter arrangement for filtering an input signal derived from a transmitter signal with a predetermined pulse shape at a receiving end, the filter arrangement comprising:
a decimation filter to decimate the input signal, the decimation filter having a first passband frequency range and a wide transition frequency range with an amplitude attenuation; and
a matching filter to match the input signal to the pulse shape of the transmitter signal; wherein
the first passband frequency range of the decimation filter is smaller than a second passband frequency range of the matching filter, and
the matching filter has an amplitude boost in a specific frequency range of the first passband frequency range for the compensation of the amplitude attenuation of the decimation filter within the first passband frequency range.
2. The filter arrangement of claim 1 wherein the amplitude boost of the matching filter in the specific frequency range is at least 1 dB (decibel).
3. The filter arrangement of claim 1 wherein the decimation filter has a passband frequency range of zero.
4. The filter arrangement of claim 1 wherein a frequency bandwidth of the decimation filter transmission frequency range following the passband frequency range is associated with a symbol frequency rate.