Energy Saving Based On Base Station Sleeping And Cooperative Multipoint Transmission In Ultra Dense Network

With the development of mobile Internet and the rise of the Internet of Things, the explosive growth of traffic continues. In response to this trend, the fifth generation mobile communication system (5G) came into being. 5G system requires higher network capacity and faster transmission rate, and Ultra Dense Network (UDN) is an effective way to achieve this goal.However, intensive deployment of the base station also brings a lot of problems. First of all, the network traffic load is dynamic, which will make the base station in many cases can not be effectively used, resulting in serious waste of energy. Secondly, in Ultra Dense Network, the distance between base stations is very close, which will cause serious interference between base stations. In this paper, the problem of energy consumption and interference in UDN is studied, and the scheme combining base station sleeping with cooperative multipoint transmission and energy saving is proposed. The main contents are as follows:Based on the nonuniform distribution of base station and the delay tolerance of traffic in Ultra Dense Network, this paper proposes an energy saving scheme combining base station sleeping and cooperative multipoint transmission. Firstly, the base stations are clustered according to the interference degree between the base stations, and the base stations with greater mutual influence are grouped into the same cluster. Then according to the number of base stations in the clusters, the clusters will be divided into two types. In the small cluster, we use dynamic programming algorithm combined with exhaustive algorithm to determine the state of base station. While in a large cluster, the base station's state is determined by the algorithm based on the dominant interference ratio. Simulation results show that the scheme can effectively reduce the energy consumption of the network under the premise of guaranteeing user QoS.Aiming at the contradiction between the mobility of users and the coverage of base station in Ultra Dense Network, this paper proposes an energy saving scheme based on user arrival probability which combines the multimode sleeping with cooperative multipoint transmission. First,the active base station is determined according to the load. The sleeping depth of base stations is then determined based on the probabilities that the users may reach. A base station with a higher probability of arrival is set to a light sleeping state and a base station with a lower probability of arrival is set to a deep sleeping state. At the same time, we use the improved dynamic cooperative multipoint transmission technology to ensure the users QoS in sleeping area. The simulation results show that the scheme can obtain a good energy saving effect.