Inter-operator Interference Coordination in the Spectrum-Sharing Overlapping Area

With the widespread application of dynamic spectrum access technology, sharing spectrum with the same primary systems by multiple operators will become a common scenario. Serious co-channel interference (CCI) needs to be mitigated if there is no coordination among the operators. In this paper, a cluster-based interference management algorithm is proposed to reduce the inter-operator CCI in the spectrum-sharing overlapping area. The proposed algorithm consists of two major steps: (1) undirected weighted graph-based clustering and spectrum allocation; (2) signal to interference and noise ratio (SINR) margin-based power adjustment. A novel weight is defined and employed in the clustering procedure to take the SINR requirement of each secondary user (SU) into account. Simulation results show that the ratio of satisfied SUs (whose SINR exceeds their SINR thresholds) can be increased while the sum of co-channel interference is significantly reduced. Furthermore, by introducing a third-party agent, direct exchange of sensitive SU information between different operators can be avoided for better privacy protection.