Full-Duplex Heterogeneous Networks: Ergodic Rate Analysis with Realistic Interference Modeling

In this paper, we adopt a realistic approach to modeling a full-duplex heterogeneous cellular network (HetNet) consisting of a tier of small cell base stations (BSs) that can perform half-duplex (HD) or full-duplex (FD) transmission depending on which duplex transmission is needed by their associated users and a tier of macro BSs that only can perform HD transmission due to their strong self-interference (SI). Two realistic issues, void cell and imperfect SI cancellation, that could exist in this HetNet are also considered in the interference model of this two-tier HetNet. We first study the Laplace transforms of the reciprocals of the signal-to-interference power ratios of users and small cell BSs and derive their explicit expressions. These Laplace transforms lead to the derivations of the ergodic rates of users and small cell BSs found in a very compact form for general power-law channel models. We show that FD does not always outperform HD in terms of ergodic rates and demonstrate how to make FD/HD transmission benefits the ergodic rates by deploying macro and small cell BSs with appropriate intensities.