Abstract: A system includes a signal processing unit including an antenna configured to receive a radio frequency signal as a received radio frequency signal, and a baseband amplifier coupled to the antenna. The system includes a processor configured to cause the communication unit to stop generating a radio frequency polling signal, set an amplification gain of the baseband amplifier to a first gain value, periodically record, at a sample rate, an indication of a magnitude of the amplified radio frequency signal to generate a plurality of sample values, at a predetermined time interval after the communication unit stopped generating the radio frequency polling signal, set the amplification gain of the baseband amplifier to a second gain value, and transmit the plurality of sample values to a classifier module to determine whether the radio frequency signal is received from a near-field communication-enabled device.