A Hybrid Dominant-Interferer Approximation for SINR Coverage in Poisson Cellular Networks

Accurate radio propagation and interference modeling is essential for the design and analysis of modern cellular networks. Stochastic geometry offers a rigorous framework by treating base station locations as a Poisson point process and enabling coverage characterization through spatial averaging, but its expressions often involve nested integrals and special functions that limit general applicability. Probabilistic interference models seek closed-form characterizations through moment-based approximations, yet these expressions remain tractable only for restricted parameter choices and become unwieldy when interference moments lack closed-form representations. This work introduces a hybrid approximation framework that addresses these challenges by combining Monte Carlo sampling of a small set of dominant interferers with a Laplace functional representation of the residual far-field interference. The resulting dominant-plus-tail structure provides a modular, numerically stable, and path-loss-agnostic estimator suitable for both noise-limited and interference-limited regimes. We further derive theoretical error bounds that decrease with the number of dominant interferers and validate the approach against established stochastic geometry and probabilistic modeling benchmarks.