Energy efficient resource allocation for 5G Heterogeneous Networks

This paper investigates the downlink resource allocation problem in Orthogonal Frequency Division Multiple Access (OFDMA) Heterogeneous Networks (HetNets) consisting of macrocells and small cells sharing the same frequency band. The focus of this study is to devise an energy efficient scheme that allows shared spectrum access to small cells, while ensuring a certain level of quality of service for the macro cell users. It further enable us to minimize the overall energy consumption by switching the underutilized small cells to sleep mode. To devise such a mechanism, we have used a combination of linear binary integer programming and progressive analysis based heuristic algorithm. We evaluated our proposed solution by comparing the macrocell served users performance against Reuse 1 case. Moreover, we provide an analytical comparison of the network power consumption with and without the sleep mode capabilities. It has been shown that our proposed algorithm not only reduces the overall network energy consumption but also minimizes the interference caused by smalls cells to macrocell served users.