In an embodiment, a method for tracking a target using a millimeter-wave radar includes: receiving radar signals using the millimeter-wave radar; generating a range-Doppler map based on the received radar signals; detecting a target based on the range-Doppler map; tracking the target using a track; generating a predicted activity label based on the track, where the predicted activity label is indicative of an actual activity of the target; generating a Doppler spectrogram based on the track; generating a temporary activity label based on the Doppler spectrogram; assigning an uncertainty value to the temporary activity label, where the uncertainty value is indicative of a confidence level that the temporary activity label is an actual activity of the target; and generating a final activity label based on the uncertainty value.