A method for sensing spatial spectrum holes based on interference temperature

Cognitive radio is a key technique to effectively solve the spectrum underutilization problem. Spectrum sensing, as the very task upon which the entire operation of cognitive radio rests, has attracting overwhelming attention. Nevertheless, detecting the spatiotemporal spectrum holes accurately, effectively, robustly in a computationally manner is still a challenge for spectrum sensing. A novel approach that utilizes information of the interfering sources to estimate the spatial spectrum holes characteristic is proposed in the paper. Information of interfering sources is derived by means of the array signal processing technique. Then, spatial interference temperature in a free space propagation model can be figured out with the geographical features in the area. Also, the distribution of the interference temperature contour (ITC) can be plotted according to the data computed formerly. Both of the theoretical analysis and the simulation demonstrate that the approach presented in the paper improves the precision in detecting spatial spectrum holes.