Algorithm 3. Finding the frequency by the TOA-based method.

Find the TOA of every column of the matrix Wmn using the method given by Algorithm 2. Mean value subtraction: Find the mean of all of the TOA values and subtract it from each value. The resulting signal after mean subtraction is shown in Figure 9. Find the frequency domain signal by using the fast Fourier transform (FFT) algorithm. Search for the peak value of the spectrum as in Figure 10. The location of the peak value of the spectrum represents the frequency of the big gesture.