Continuous-time digital filters for sample-rate conversion in reconfigurable radio terminals

Reconfigurable radio terminals must cope with a multitude of master clock r ates of diverse mobile communications air interfaces. Digital sample rate c onversion (SRC) is an elegant way to enable the processing of signals with sample rates incommensurate to the clock rate of a nonsynchronized analog-t o-digital converter. SRC is a process of resampling and thus, requires anti -aliasing filtering. The well-known Farrow-structure provides a means of im plementing digital SRC on a parameterizable hardware platform enabling the adaptation to different rate change factors. Still, the Farrow-structure ca n only implement filters with poor anti-aliasing characteristics. The trans posed Farrow-structure introduced in this article overcomes these problems and thus, represents a perfect means for SRC in reconfigurable radio termin als.