Offloading in HetNets over shadowed Nakagami-m fading channel

Abstract

Small cell deployments are one of the most significant long-term strategic policies of the mobile network operators since small cell architecture delivers not only the required capacity boost but also the flexibility important for immensely-localized deployments in high-traffic environments. In HetNets, small cells serve as offloading spots in the radio access network to offload users and their associated traffic from congested macrocells. In this paper, we perform analytical analysis and investigate how the radio propagation effects such as multipath and shadowing, and small cell base station density affect macro users' offloading to small cell networks. In particular, we exploit composite fading channel in our evaluation when a macro user is offloaded to small cells networks within the stochastic heterogeneous networks framework. We derive the expressions for outage probability (equivalently success probability) of the macro user in macro network and small cells network for Nakagami-lognormal desired and interfering signals. We propose efficient approximation for the probability density functions of the channel fading power for shadowed Nakagami-m fading distribution that does not have closed-form expression employing Gauss-Hermite quadrature. Finally, the outage probability performance of macro user with and without offloading options/services is analyzed for various settings of fading channels.