A novel tractable framework to analyse heterogeneous cellular networks

Heterogeneous cellular networks consisting of microcell, picocell, femtocell, distributed antennas and relays co-deployed in space and frequency with carefully planned tower-mounted base stations, increase the complexity of the cellular network structure, which makes a tractable analysis model difficult to obtain. Since the traditional system-level simulation suffers from a computational complexity and being not tractable, recent research focused on using stochastic geometry to develop new general models for both single tier and heterogeneous cellular networks. In this paper, we propose a tractable model for downlink heterogeneous cellular network and based on that, the signal-to-interference-plus-noise ratio (SINR) distribution and accordingly the coverage (or equivalently outage) probability for a randomly located mobile user in this network can be derived. Compared to previous work, this new equivalent received power connectivity model takes the effects of different transmit powers and outage thresholds across tiers into consideration, thus making the analysis more accurate for noise-limited scenarios and extendable for a more general circumstance, such as the frequency reuse scenario.