Inter-cell Interference Management Based On CoMP In Ultra-dense Networks

As one of the key technologies of the next generation wireless communication standard,the ultra-dense network has attracted more attention in recent years.By deploying a large number of small cells with low transmission power and small coverage,ultra-dense network can enhance the degree of spatial reuse of resources,thus improving the area system spectrum efficiency the system.At the same time,as the distance between the small base stations and the users is reduced,the transmission loss is also greatly reduced,which improves the system area energy efficiency.However,along with the network density and random,the distance between small cells gets close,and the inter-cell interference gets more severe.Inter-cell interference has become one of the key factors that limits the performance of ultra-dense network.In this thesis,the characteristics of ultra-dense network are modeled and analyzed,and the interference in ultra-dense network are analyzed.There are more interference sources and the interference is more complicated.The common methods of interference management are introduced,especially the coordinate multi-point transmission.At the same time,the resource allocation themes intra and inter cells are introduced.To manager the interference,a user-centered coordinate multi cell interference management method is introduced.The coordination cells are divided into the primary severing cells and subordinate cells according to the channel conditions.Then,a distributed greedy coloring algorithm is adopted to maximize the utilization of resources.In the end,when the network scale gets larger,the resource allocation has to be done in the overall system level which makes it a hard problem to solve.Therefore,the small cells are divided into clusters,so that the coordination only occurs insides the clusters as so the coordination scale is reduced.The coordination sets overlapped with each other are combined to generate the elementary clusters.but the scale of some of the elementary clusters may also too large.The larger clusters are then divided into secondary clusters.The max and min distance principle and k-means algorithm are applied to carry out to secondary clustering.By reducing the sizes of clusters,the coordination interference management can be carried out at a reasonable scale.