Location-Aware Cross-Tier Cooperation in Cache-Enabled Heterogeneous Networks

Interference management is an interesting topic to be studied in cache-enabled heterogeneous networks (HetNets). In this work, by carefully exploring the relationships among the nearest macro base station (MBS), the nearest small base station (SBS) that stores the requested file, and the nearest SBS that does not store the requested file of a typical user, we propose a location-aware cross-tier cooperation (LCC) scheme to mitigate the cross-tier interference in cache-enabled HetNets. Taking the successful transmission probability (STP) as the performance metric, we firstly derive the expression of it using stochastic geometry. Then, a local-optimal random caching strategy (LORC) that maximizes the STP is obtained. Finally, simulation results verify the effectiveness of the proposed LCC scheme, and demonstrate the advantages of the LORC over three existing caching strategies.