Network Strategy In Small Cell Enhancement Based On User Behavior Analysis Of4G

The volume of wireless data will grow explosively in4G and future wireless network. The question is how this enormous data capacity will be realized, while meeting customer quality of service expectations and operators’requirements for cost-effective service delivery. The answer is a significant ramping up of small cell deployment. Small cells are umbrella term for operator-controlled, low-power radio access nodes. Small cells facilitate a new breed of mobile service that exploits the technology’s ability to detect presence, and connect and interact with existing networks. Power control is an important aspect in network strategy and it will be the research contents of this thesis. The thesis studies uplink power control and downlink power allocation in small cells to improve the quality of services, improve energy efficiency of systems and improve overall performance of customers. In this thesis, the main research contents are as follows:User behavior analysis is very important in wireless communications This thesis analyzes user behaviors in TD-LTE hot spot coverage. Firstly, a special APP is used to track user behavior data in TD-LTE networks. Then, we choose one hundred main services in TD-LTE to analyze user behaviors pattern. Evaluation indicators include the number of users in different services, total traffic of services visit, uplink traffic of services visit, downlink traffic of services visit, number of use, duration of use, download speed and some other aspects. This thesis proves the three core characteristics in TD-LTE networks:high rate, low latency and high capacity, especially high rate. It’s a trend that future wireless network will offer faster download speed, better overall network quality, mobile video living broadcast, video conference, online game and some other applications. It’s necessary to introduce small cells which could improve cellular coverage, capacity and applications. In the thesis, an uplink power control scheme and a downlink power allocation scheme are studied for small cells.In heterogeneous networks, the evolved NodeBs (eNBs) have different downlink transmission power and the power imbalance problem cannot be avoided. In order to solve this problem, Uplink/Downlink (UL/DL) split for users in Cell Range Expansion (CRE) region of small cells has been proposed in3GPP. In this paper, we propose an uplink power control scheme based on game theory for UL/DL split users. In the scheme, the convex pricing function is an exponential pricing function of users’transmission power, which reflects the interference that macro users are suffering from UL/DL split users. It will ensure that UL/DL split users will be penalized when they cause serious interference to macro users. The scheme based on non-linear pricing obtains more improvements than the linear one with numerical simulations. Furthermore, a Dynamic Power Adjustment (DPA) algorithm is added to the scheme in order to speed up the convergence process.Generally, equal transmission power allocation in downlink is always used. However, it will waste power and reduce system energy efficiency (EE) in some cases. Game theory is implemented on the power allocation strategy to maximize the system EE performance. The system consists of macro eNBs and co-channel small eNBs. The constraints of guaranteeing the users QoS are also considered. Based on the features of the optimization problem, the implemented game model is non-cooperative with pricing functions as the revenue of system EE for eNBs. The penalty definition is considered with using the macro eNBs for potential more power consumed and severe interferences caused. The existence and uniqueness of the Nash Equilibrium for the proposed game model is also verified in the paper.A summary is given at the end, and the future research directions related to this master’s thesis are also given.