A Novel Subcarrier-Level Spectrum Sensing Method by Utilizing Fine-Grained Channel State Information in Wireless Networks

Figure 3

Examples of using CSI to sense subcarrier-level interference: (a) SNRs of antenna 1 calculated by CSI without interference; (b) SNRs of antenna 2 calculated by CSI without interference; (c) SNRs of antenna 1 calculated by CSI with three ZigBee interferences; (d) SNRs of antenna 2 calculated by CSI with three ZigBee interferences.

(a)

(b)

(c)

(d)