Decentralized Resource Allocation for Heterogeneous Cellular Networks

Heterogeneous Cellular Network (HetNet) is a promising technology for 5th generation mobile networks (5G) that can potentially improve spatial resource reuse and extend coverage, therefore allowing it to achieve significantly higher data rates than single tier networks. However, the performance of HetNet is limited by co-channel (inter-UE, inter-cell) interference. Hence, resource allocation is carefully done in this paper to ensure that the likely loss in achievable data rate due to interference doesn't diminish the gain in the achievable data rate due to higher spatial reuse. The resources which we consider in this paper are the spatial resource (unit-beamformer) and the power resource. We formulate our distributed spatial resource allocation problem as a quadratic optimization problem with non-convex quadratic constraints and solved it by exploiting stationarity karush-Kuhn-Tucker (KKT) conditions. While our proposed power resource allocation scheme is formulated as a convex optimization problem and is solved by exploiting karush-Kuhn-Tucker (KKT) conditions. Simulation results of our proposed method, when compared with other existing methods show significant improvement

Energy-Efficient Power Control: A Look at 5G Wireless Technologies

This work develops power control algorithms for energy efficiency (EE) maximization (measured in bit/Joule) in wireless networks. Unlike previous related works, minimum-rate constraints are imposed and the signal-to-interference-plus-noise ratio takes a more general expression, which allows one to encompass some of the most promising 5G candidate technologies. Both network-centric and user-centric EE maximizations are considered. In the network-centric scenario, the maximization of the global EE and the minimum EE of the network are performed. Unlike previous contributions, we develop centralized algorithms that are guaranteed to converge, with affordable computational complexity, to a Karush-Kuhn-Tucker point of the considered non-convex optimization problems. Moreover, closed-form feasibility conditions are derived. In the user-centric scenario, game theory is used to study the equilibria of the network and to derive convergent power control algorithms, which can be implemented in a fully decentralized fashion. Both scenarios above are studied under the assumption that single or multiple resource blocks are employed for data transmission. Numerical results assess the performance of the proposed solutions, analyzing the impact of minimum-rate constraints, and comparing the network-centric and user-centric approaches.Comment: Accepted for Publication in the IEEE Transactions on Signal Processin

The 5G Cellular Backhaul Management Dilemma: To Cache or to Serve

With the introduction of caching capabilities into small cell networks (SCNs), new backaul management mechanisms need to be developed to prevent the predicted files that are downloaded by the at the small base stations (SBSs) to be cached from jeopardizing the urgent requests that need to be served via the backhaul. Moreover, these mechanisms must account for the heterogeneity of the backhaul that will be encompassing both wireless backhaul links at various frequency bands and a wired backhaul component. In this paper, the heterogeneous backhaul management problem is formulated as a minority game in which each SBS has to define the number of predicted files to download, without affecting the required transmission rate of the current requests. For the formulated game, it is shown that a unique fair proper mixed Nash equilibrium (PMNE) exists. Self-organizing reinforcement learning algorithm is proposed and proved to converge to a unique Boltzmann-Gibbs equilibrium which approximates the desired PMNE. Simulation results show that the performance of the proposed approach can be close to that of the ideal optimal algorithm while it outperforms a centralized greedy approach in terms of the amount of data that is cached without jeopardizing the quality-of-service of current requests.Comment: Accepted for publication at Transactions on Wireless Communication