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.