Coverage Analysis of Two-Tier HetNets for Co-Channel, Orthogonal, and Partial Spectrum Sharing Under Fractional Load Conditions.

In heterogeneous networks, the random deployment of femto access points (FAPs) and macro base stations (MBSs) with uncoordinated channel access imposes huge intertier interferences. In real-life networks, the process of MBSs’ deployment exhibits the homogeneity; however the FAPs have the behavioral characteristic of clusters formation, such as in malls, apartments, or offices. Therefore, the composite modeling of the MBSs and the FAPs using Poisson point process and Poisson cluster process is employed for the evaluation of coverage probability. The scenario of the real-time traffic for macrotier and the best-effort traffic for femto-tier is considered. Cognition is introduced in the clustered FAPs to control the intertier interference. Furthermore, the impact of the macrotier load is analyzed by exploiting the inherent coupling between coverage probability and activity factor of an MBS. Further, we study the effect of co-channel, orthogonal, and partial spectrum sharing modes on the coverage for given parameters, such as load condition and FAPs/MBSs density. We provide simulation validation for the derived expressions of coverage and present a comparative analysis for the mentioned spectrum sharing modes. [ABSTRACT FROM AUTHOR]