Research On Energy Efficiency Based Access Control And Resource Allocation In Multi-cell Heterogeneous Networks

With the continuous development of world economy and widespread application of communication technology, the number of mobile users and mobile broadband users are growing rapidly, the existing network has been unable to fully meet the needs of users, and the theory of the physical layer technology have infinite close to the limits of Shannon theory, the future communication network performance main will leap from the network topology technology.As one of the main features of the 3GPP LTE-A, Het Net(Heterogeneous Network) has been widely concerned. Het Net by inserting small, self-configurable small base station or relay into the existing macro cellular networks, provides a practical, scalable, high efficiency way to significantly improve the capacity of the wireless network. The presence of heterogeneous network lets wireless environment become more and more complicated, which makes its wireless resource management difficult. The existence of a large number of base station and node also brings a lot of energy consumption. National 863 plan of "green network key technology research" set out to learn the issue. This project topic is derived from its subject "efficient radio resource management protocols and algorithms design", is aimed at multi-cell heterogeneous network scenarios.In this case, the concept of “green network” means through the reasonable allocation of wireless network resources to reduce the energy consumption of system, improve the utility/energy value. So this article first related to heterogeneous network technology to understand and study, analyzes the current research status and the main technical characteristics, and then refer to the related literature has chosen the reasonable heterogeneous scene model, the cellular system and set up a reasonable system according to the demand model of energy efficiency. Through the analysis and deduction of the system energy efficiency formula, this paper presents an optimization idea of the system energy efficiency optimization algorithm. Then, according to the analysis ideas, this paper starts a detail design on the system energy efficiency optimization algorithm, mainly including user access control optimization algorithm and the allocation algorithm of resources in the district(including inside the village downlink subcarrier allocation and power adjustment algorithm). In part of the access control algorithm, this paper first gives a classification scheme of users, and analyses the characteristics of various types of users. Based on this, this paper gives a simplified algorithm: a user classification based heuristic layered access algorithm. In resource allocation algorithm part, in order to keep the system energy efficiency optimization, this paper introduces a game theory, by optimizing the system potential function to optimize the system efficiency. Then by deduction, this paper defines each cell’s profit function and the user’s profit function. Then here gives a power solution formula of each user on the downlink subcarriers; Secondly, in order to solve the subcarrier allocation problem, this paper gives two different algorithm with different complexity, which is greedy algorithm and weighted bipartite graph matching algorithm. At the end of the paper, here moved on to the simulation of the optimization algorithm designed in this paper, and then take a further analysis and argumentation of the algorithm.