QoS-based radio resource management for 5G ultra-dense heterogeneous networks

In the fifth generation wireless networks, the heterogeneous deployment of ultra-dense small cells such as femtocells is seen as a major solution to cope with the exponential traffic growth and to improve coverage especially in indoor environments. However, the unplanned and ultra-dense deployment of femtocells in the coverage area of conventional macrocells introduces new challenges such as cross-tier interference (interference between macrocells and femtocells), co-tier interference (interference between neighbouring femtocells), and inadequate quality of service (QoS) provisioning, which can negatively affect the overall performance of the network. Hence, efficient radio resource management (RRM) algorithms are necessary to address these challenges. Therefore, in this paper, we propose a joint radio resource allocation with adaptive modulation and coding (AMC) scheme. The RRM problem is formulated as an optimization problem, which belongs to the class of mixed integer non-linear programming (MINLP). A reformation-linearization technique (RLT) is introduced to simplify the aforementioned MINLP. Finally, the performance of the proposed algorithm is evaluated and the simulation results show that the proposed algorithm reduces interference and enhances QoS in terms of the overall throughput and fairness when compared with other state-of-the-art algorithms.