Research On The Technologies Of Resource Allocation In Cellular Heterogeneous Networks

Smart devices, like smart-phones, provide a wide variety of wireless applications. The demand of high data rate experience and enjoyment of multimedia services whenever and wherever through wireless communication system is increasing rapidly. In order to satisfy the explosive growth of demands for data rate and service diversification, heterogeneous and irregular network architecture is the inevitable choice for the future mobile communication system. New low-power access nodes, such as Picocell, femtocell, relay and D2D, are introduced into heterogeneous networks to solve the "blind area" and "busy area" of coverage, thus the system capacity and spectrum utilization efficiency can be improved significantly. However, large-scale deployment of heterogeneous networks faces many technical challenges. On the other hand, radio resource allocation and network performance optimization play a crucial role in improvement of network performance for wireless network. Research of efficient radio resource allocation algorithms for heterogeneous network is not only the basic task for analyzing and deepening the theories of heterogeneous networks and applications, but is also significant for promoting the deployment and SON process for heterogeneous networks.In this paper, we choose resource allocation of heterogeneous network as the core of research. In order to promote heterogeneous deployment of wireless network and SON process, the theories are explored by analyzing potential performance of heterogeneous networks and designing new network resource allocation schemes. The main works of this paper are as follows:Combining the backhaul requirements of heterogeneous networks, a wireless backhaul based heterogeneous network resource allocation algorithm is proposed and realized. The proposed algorithm aims at maximizing system throughput and reducing cross-tier interference by integrating finite backhaul ability from low-power BS to Macro BS. The resource allocation based on wireless backhaul is studied for heterogeneous networks and dynamic optimization scheme is designed, which is based on game theory and punishment mechanism.In order to solve the cross-tier interence problem in heterogeneous networks, resource allocation algorithms based on Lyapunov stability are proposed and realized. Based on the analysis of Lyapunov stability, interference management algorithms which aim at maximizing average throughput of femtocell users under the constraint of queue stability of Macrocell users in heterogeneous networks are proposed. The Lyapunov drift method, which uses the Macro queue length to replace Lagrange multiplier, is used to convert the problem into a non-convex problem with linear constraints. Then the approximation and logarithmic approximation methods are used for analyzing closed-form solution of optimum power policy. Based on analysis of the optimal solutions, centralized and distributed power control algorithms are proposed. Finally, the performances of proposed algorithms are analyzed by simulation.In order to solve the unbalanced distribution of load caused by deployment of new nodes in heterogeneous networks and the problem of energy consumption caused by ultra-dense deployment of small base station, the downlink resource allocation algorithms which aim at maximizing energy efficiency is proposed and realized in heterogeneous networks. Considering the irregular user distribution in network, the circuit power consumption of BS and minimum data rate requirement, an iterative resource allocation algorithm based on Dinkelbach method is proposed. In each iteration of the algorithm, the PRB allocation algorithm based on graph theory and the power allocation algorithm based on dual decomposition are proposed.Based on the study of user’s perceived quality of experience (QoE), QoE-oriented resource allocation algorithms are proposed and realized. QoE assessment model for different types of applications are analyzed, and the subjective factors that can affect users’experience are introduced into resource allocation of heterogeneous networks. For different application types, an optimal resource allocation algorithm based on 0-1 relaxation and resource allocation algorithms based on cross-layer optimization are proposed. At the same time, a priority scheme is used to set different priorities to different users in heterogeneous networks.