GSM-RF Channel Characterization Using a Wideband Subspace Sensing Mechanism for Cognitive Radio Networks

Figure 2

Estimated PSDs obtained in each acquisition point: (a) position 1, (b) position 2, (c) position 3, and (d) position 4. The vertical red lines mark the active ARFCNs.

(a)

(b)

(c)

(d)