A near field communication, NFC, device (102, 104), comprising: a modulator module configured to modulate a detection signal (302, 552) onto a carrier wave to provide a modulated detection signal; an antenna module configured to apply the modulated detection signal to an inductive coupling element to generate a magnetic field to provide the detection signal (302, 552) having a first power level for a first duration to provide a first interval (304.1), a second power level for a second duration to provide a second interval (304.2), and a third power level for a third duration to provide a third interval (304.3); a demodulator module configured to demodulate the detection signal (302, 552) to provide a recovered detection signal; and a controller module configured to: determine a plurality of signal metrics (308, 604) including a first signal metric (308.1, 604.1), a second signal metric (308.2, 604.2) and a third signal metric (308.3, 604.3) of the recovered detection signal; estimate a signal metric estimate (310, 606) of the recovered detection signal based upon a statistical relationship between the first and second signal metrics (308.1, 604.1, 308.2, 604.2); and compare the signal metric estimate (310, 606) and the third signal metric (308.3, 604.3) to determine whether the third signal metric (308.3, 604.3) is non-linearly related to the first and second signal metrics (308.1, 604.1, 308.2, 604.2) indicating that another NFC capable device (102, 104) is present within the magnetic field of the device (102, 104). a modulator module configured to modulate a detection signal (302, 552) onto a carrier wave to provide a modulated detection signal; an antenna module configured to apply the modulated detection signal to an inductive coupling element to generate a magnetic field to provide the detection signal (302, 552) having a first power level for a first duration to provide a first interval (304.1), a second power level for a second duration to provide a second interval (304.2), and a third power level for a third duration to provide a third interval (304.3); a demodulator module configured to demodulate the detection signal (302, 552) to provide a recovered detection signal; and a controller module configured to: determine a plurality of signal metrics (308, 604) including a first signal metric (308.1, 604.1), a second signal metric (308.2, 604.2) and a third signal metric (308.3, 604.3) of the recovered detection signal; estimate a signal metric estimate (310, 606) of the recovered detection signal based upon a statistical relationship between the first and second signal metrics (308.1, 604.1, 308.2, 604.2); and compare the signal metric estimate (310, 606) and the third signal metric (308.3, 604.3) to determine whether the third signal metric (308.3, 604.3) is non-linearly related to the first and second signal metrics (308.1, 604.1, 308.2, 604.2) indicating that another NFC capable device (102, 104) is present within the magnetic field of the device (102, 104). determine a plurality of signal metrics (308, 604) including a first signal metric (308.1, 604.1), a second signal metric (308.2, 604.2) and a third signal metric (308.3, 604.3) of the recovered detection signal; estimate a signal metric estimate (310, 606) of the recovered detection signal based upon a statistical relationship between the first and second signal metrics (308.1, 604.1, 308.2, 604.2); and compare the signal metric estimate (310, 606) and the third signal metric (308.3, 604.3) to determine whether the third signal metric (308.3, 604.3) is non-linearly related to the first and second signal metrics (308.1, 604.1, 308.2, 604.2) indicating that another NFC capable device (102, 104) is present within the magnetic field of the device (102, 104).