Methods and apparatuses are disclosed for dynamic adjustment of the receiver gain during magnetic resonance imaging (MRI) scan. To account for distortions introduced by the receiver that may be different at various receiver gains, a reference radio frequency (rf) signal is applied to the receive chain by an additional antenna. In some disclosed embodiments the reference signal is adjusted such that its frequency lies at the border of the frequency band detected by the MR scan. Comparing the a priori known amplitude and phase of the reference signal with the amplitude and phase of the received reference signal allows determination of the distortions introduced at the respective receiver gain which are subsequently corrected. In some disclosed embodiments, the reference signal is used to synchronize the modulation and demodulation units of a wireless transceiver system.