Outage Analysis for D2D Enhanced Heterogeneous Cellular Network under Maximum Power Constraint

In this work, we develop a tractable modeling paradigm for outage probability on device-to-device (D2D) enhanced K-tier heterogeneous cellular network (HCN). To offload traffic in the HCNs, mobile user equipments (UEs) can engage in D2D communications, whose activity is determined by a carrier sensing multiple access (CSMA) scheme. Due to the limited transmit power, the UEs employ a truncated channel inversion power control policy with a cutoff threshold and we show that there exists an optimal threshold for maximizing the probability of success D2D communication. We obtain the expressions for truncation outage probability and signal-to- interference-plus-noise-ratio (SINR) outage probability in the D2D enhanced HCNs. In addition, we evaluate how the D2D communications impact on the system performance.