A digital filtering arrangement 24 which may be used in a radio receiver comprises a filter such as an IIR wave digital filter 40 and means for performing a time reversal of the signal such as a last in first out (LIFO) memory 42. In use, digital input signals are applied to the filter twice with an intermediate time reversal, having the effect of cancelling any phase distortion introduced by the filter and allowing a non-linear filter to be used enabling a reduction in power consumption and silicon area use. A second matched digital filter may be used instead of applying the signal to the same filter twice.