Figure 5
From: Removing non-stationary noise in spectrum sensing using matrix factorization
Monitoring the 2.4 GHz ISM band: spectrogram. The spectrogram of the raw monitoring data (field strengths in dBm/Hz) w.r.t. the 2.4 GHz ISM band in the frequency range 2400–2483.5 MHz; the time instants are denoted as traces. Here the main Wi-Fi channels are 1, 6, and 11 which correspond to frequency bandwidths of respectively, 2402–2422 MHz, 2427–2447 MHz, and 2452–2472 MHz.