A processing device (40) for processing an analog complex input signal generated by downconversion of an aggregated-spectrum radio-frequency signal in a radio-receiver (10), wherein the complex input signal comprises a plurality of sub bands (S1-S4) scattered across a total frequency band (4) of the complex input signal. The processing device (40) comprises a plurality of processing paths (P1-PN). wherein each processing path (P1-PN) is adapted to process an associated sub band (S1-S4). Each processing path comprises a complex mixer (CM1-CMN) adapted to frequency translate the complex input signal, and an analog channel-selection filter (CSF1-CSFN) arranged to filter an output signal of the complex mixer (CM1-CMN) and pass the frequency translated associated sub band (S1-S4). A control unit (60) is adapted to receive control data indicating frequency locations of the sub bands (S1-S4) and, for each processing path (P1-PN). control the local oscillator signal of the complex mixer (CM1-CMN) of the processing path (P1-PN) based on the frequency location of the associated sub band (S1-S4) and the passband of the channel-selection filter (CSF1-CSFN) of the processing path (P1-PN), such that the frequency-translated associated sub band (S1-S4) appears within a passband of the channel-selection filter (CSF1-CSFN) of the processing path (P1-PN). The distortion monitored in the unused paths may be used to improve the performance of the used paths.