Research On Cell Selection Scheme Of Heterogeneous Cellular Networks

With the rapid development of the terminal equipment and the explosive growth of the number of mobile users, the demand for high speed communication services in the future is also increasing, and the wireless mobile communication technology will face a huge challenge. The heterogeneous cellular networks that composed by macro base station and small base station can alleviate this problem well. The appearance of small base can improve the network performance and system capacity efficiently. But due to the unreasonable setting of base station parameters and allocating of resource will cause the load imbalanced and reduce resource utilization rate and decrease the overall experience. A good cell selection scheme in heterogeneous network is one of the hot spots.While the power of macro base station is more than small base station, mobile users tend to associate with macro base station, leading to macro cell overload. This paper proposed a dynamic Range Expansion Cell method based on the load of base station. This method can adaptively adjust the bias according to the load of every base station and change the coverage of small base station. The method also considers the capacity of small base and the speed of UE. The simulation results show that the scheme in this paper can effectively reduce the load of macro base station and improve the user rate and the overall performance of the system.This paper also proposes a cell selection scheme based on fuzzy logic.The reference signal received power, load of base station and the speed of mobile terminal are considered as decision factors. The algorithm combines the network status with the users own state to select the cell for Service. The simulation results prove that this algorithm has certain advantages. Not only enhanced the capacity of the network, but also avoided the ping-pong effect and reduced the unnecessary waste of resources. It can provide satisfactory quality of service for every user.