Weighted Max-Min Fairness oriented load-balancing and clustering for multicast Cache-Enabled F-RAN
Di Chen, Volker Kuehn · 2016
Content caching has been recently shown to be an efficient way to increase the Spectral Efficiency (SE) or Energy Efficiency (EE) of the network, as well as to reduce the burden on backhaul links. In this paper, the network design for the downlink of multicast Cache-Enabled Fog Radio Access Network (F-RAN) is investigated, where Radio Units (RUs) equipped with cache modules form different clusters to serve different multicast groups by Cooperative Multi-Point (CoMP) transmission. We aim to maximize the minimum scaled (weighted) SINR among all multicast groups for fairness, which depends on the associated user with the worst-case SINR. Moreover, load-balancing among backhauls is taken into account in order to meet their individual capacity constraints. Hence, based on the channel states, requested and cached files as well as individual capacities of backhaul links, a joint optimization of clustering formulation and multicast beamforming is required, so as to achieve the weighted Max-Min Fairness (wMMF) of the network. We show that this problem can be solved efficiently by combining the solution of a related power consumption minimization problem with the Bi-Section method. Numerical results show the correctness and effectiveness of the proposed algorithm.