Geo-location assisted spectrum sensing for cognitive coexistent heterogeneous networks

Different from the conventional networks with single secondary network, the spectrum sensing scheme for cognitive coexistent networks should not only detect the primary signal but also detect the secondary signals to avoid the interference with both the primary network and the operating coexistent secondary networks. Therefore, the sensing scheme in coexistent networks should be able to differentiate the primary signal from the secondary signals. Due to the heterogeneity of the secondary networks, the secondary signals may exploit different PHY modes (some of them may be the same as the primary PHY mode), which imposes difficulties in the coherent signal detection schemes. Aiming at overcoming such difficulties, this paper proposes a non-coherent spectrum sensing scheme with the assistance of the geo-locations of the primary and secondary nodes. In the proposed scheme, the differentiation between the primary and secondary signals is formulated into a problem of solving a non-homogeneous linear equation matrix. During the signal detection, the characteristics of both primary and secondary signals are not required. Both the analysis and the simulation results show the feasibility and efficiency of the proposed scheme.