Techniques and apparatus for tuning a wireless data transmission system in an electronic device. One example method includes receiving a measured impedance value corresponding to a current user interaction state with respect to one or more antennas of a mobile device; determining a user interaction stability state of the mobile device based on the measured impedance value and a set of historical impedance values; classifying the current user interaction state based at least on the measured impedance value and a plurality of impedance values from the set of historical impedance values; and tuning the one or more antennas based on the classified current user interaction state and the determined user interaction stability state of the mobile device.