Downlink Distributed Inter-cell Interference Coordination Of Heterogeneous Networks

With the constant development of mobile communications,the demand for network capacity grows exponentially.In order to increase network capacity,3 GPP introduces a heterogeneous networking technology.HetNet covers a large number of low-power nodes in a single macrocell coverage to improve network capacity.Meantime,ICIC,namely,the Inter-cell Interference Coordination,tends to arouse attentions from the organization of scientific research because co-channel HetNet keeps causing serious problems of interference.The existing enhanced Inter-Cell Interference Coordination(eICIC)technology for HetNet can be divided between the frequency-domain eICIC based on carrier aggregation,and the time-domain eICIC based on almost blank subframe.At present eICIC of time-domain is the hottest research field.This paper analyzes the performance of different schemes of time-domain eICIC,and it also shows that the enhanced dynamic eICIC is superior to semi-statics and dynamic eICIC.However,the enhanced dynamic eICIC doesn't currently apply to the architecture of C-RAN,especially the hybrid Scenario of C-RAN.Moreover,this scheme doesn't consider the potential influence on its most adjacent surrounding cells.Hence,this paper proposes the distributed eICIC scheme based on Max-Network-Benefit and its optimized scheme based on Probabilistic Performance Metric to avoid the unreasonable decision.The decision of Max-Network-Benefit algorithm doesn't only consider the performance of center cell,but also the influence of adjacent surrounding cells.So that the optimal transmission state is determined only at the time when the performance metric ideally sets the Network Benefit as its basic standard.Meanwhile,above-mentioned scheme must assume that the adjacent cells should be fixed when the center cell defines the transmission state.As a result,the assumption might be different from the physical truth and then the performance will be under the influence of the assumption.This paper proposes that each cell collects the probability of transmission state to calculate the expectation of Network Benefit named Probabilistic Performance Metric.This metric can be a decision that the performance would be optimal.Simulation results showed that Max-Network-Benefit algorithm can improve the delay that the centrilazed eICIC exists.Performance has a great improvement.Besides,Max-Network-Benefit algorithm based on Probabilistic Performance Metric weakens the low performance because of the unreasonable assumption.The decision becomes more reasonable and the performance will be better and better as time went on.