A modem includes a modulator and a demodulator. The demodulator includes a direct current removing (DCR) circuit to transition between an acquisition mode, where the DCR circuit operates with a first loop gain; and a tracking mode, where the DCR circuit operates with a second loop gain. The second loop gain is smaller than the first loop gain, and the timing of the transition between the acquisition mode and tracking mode is programmable.

A modem includes a modulator and a demodulator. The demodulator includes a direct current removing (DCR) circuit to transition between an acquisition mode, where the DCR circuit operates with a first loop gain; and a tracking mode, where the DCR circuit operates with a second loop gain. The second loop gain is smaller than the first loop gain, and the timing of the transition between the acquisition mode and tracking mode is programmable.