Patent attributes
The techniques of this disclosure enable frequency-modulated continuous-wave radar-based detection of living objects. Instead of generating a chirp pattern with each chirp separated by an idle period, a radar generates a chirp pattern with multiple chirps separated by an idle period. From applying a Fourier transform to receiver signals for each frame, the radar determines an amplitude as a function of range for each frame. The radar computes the standard deviation between the amplitudes of two frames and then, for each additional frame, the radar incrementally updates the standard deviation to be inclusive of the amplitude contribution of the additional frame. That is, rather than recalculate the standard deviation for each new frame, the radar increments the standard deviation by a fraction of the amplitude for the new frame, which is proportionate to the total quantity of frames generated thus far. In response to the standard deviation satisfying a noise threshold, the radar outputs an indication of a living object.
