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

摘要

In heterogeneous networks, the random deployment of femto access points(FAPs) and macro base stations (MBSs) with uncoordinated channel access imposehuge inter-tier interferences. In real-life networks, the process of MBSsdeployment exhibits the homogeneity, however the FAPs have the behavioralcharacteristic of clusters formation like in malls, apartments, offices, etc.Therefore, the composite modeling of the MBSs and the FAPs using Poisson pointprocess and Poisson cluster process is employed for the evaluation of coverageprobability. The scenario of the real-time traffic for macro-tier and thebest-effort traffic for femto-tier is considered. Cognition is introduced inthe clustered FAPs to control the inter-tier interference. Furthermore, theimpact of macro-tier load is analyzed by exploiting the inherent couplingbetween coverage probability and activity factor of an MBS. Further, we studythe effect of co-channel, orthogonal, and partial spectrum sharing modes on thecoverage for given parameters like load condition, FAPs/MBSs density, etc. Weprovide simulation validation for the derived expressions of coverage andpresent an comparative analysis for the mentioned spectrum sharing modes.