Research On Energy Efficient User- Centric Small Cells Coordination Mechanism In Hyper Cellular Network

With the rapid development of mobile internet and internet of things,the number of terminals and users' traffic demand increase sharply. Hyper cellular network was proposed since the traditional cellular network cannot meet the demand of future users. It separates the control plane and the data plane of the network. The control plane maintains the network coverage while the data plane is responsible for transmitting data. Moreover, one single base station may not satisfy a user's high traffic demand and the user will need more serving base stations. This thesis studies on user-centric small cells coordination mechanism in hyper cellular network, including the following contents:First, in the scenario where small cells cannot sleep, this thesis designs a user-centric small cells coordination mechanism based on user's traffic demand and orthogonal resources allocation of small cells. The mechanism can improve the network throughput and energy efficiency. It consists of coordinative small cells selection scheme based on user's traffic demand and small cells orthogonal resources allocation scheme. Users can choose different coordinative small cells according to their service requirement and the macro cells will schedule the resources of small cells to ensure that the resources allocated to the target users by coordinative small cells are orthogonal.Second, in the scenario where small cells can sleep, this thesis combines small cell coordination with sleeping, and proposes an improved mechanism based on resources deallocation. Under the premise that the network throughput is guaranteed, the resources deallocation scheme in the improved mechanism enables some small cells to sleep, so the improved mechanism can be energy efficient.Finally, this thesis analyzes the performance of the small cells coordination mechanism through system level simulation. The results show that, compared to the mechanism that a user is served by one single base station, the first proposed mechanism can increase the network throughput and energy efficiency by 23.8% and 19.6% respectively in the scenario where small cells cannot sleep. In the scenario where small cells can sleep, the improved mechanism obtains an energy efficiency gain of 9.5% compared to the first mechanism.In summary, the energy efficient user-centric small cells coordination mechanism proposed in this article can improve the performance of hyper cellular network.