Design of a selective digital filter for a DAVIC compliant modem

This paper presents the implementation and the performance evaluation of a digital intermediate frequency (IF) filter dedicated to a DAVIC compliant modem. This work completes several studies comparing the performance of two different designs (analog and digital) for a radio-frequency stage in a modem application. These designs have been evaluated for a particular case defined in the DAVIC recommendation. This study was used as a starting point for the choice of the digital architecture. The main problem to implement such. An architecture is located in the IF stage that must operate at a high frequency. Another problem due to the DAVIC recommendation, is the variation of the sampling frequency which complicates the design of the filter. The verification of this method has been performed using the PTOLEMY software from Berkeley University