An apparatus has demodulation circuitry to demodulate a radio frequency signal and produce a baseband signal, wherein the radio frequency signal comprises a periodic signal having a predetermined period. An analog-to-digital converter converts the baseband signal into a digital signal that comprises a periodic signal having the predetermined period. A first DC offset adjustment circuit estimates a DC offset contained in the digital signal based on digital samples in a sample period having a length equal to the predetermined period. A second DC offset adjustment circuit estimates the DC offset contained in the digital signal. A selection circuit selects one of the first DC offset adjustment circuit or the second DC offset adjustment circuit to be used to estimate the DC offset contained in the digital signal.