Research On Interference Coordination Scheme Of Macro-Pico Hetergeneous Networks

3GPP(3rd Generation Partnership Project)introduces the heterogeneous networks(HetNets)in LTE-A(Long Time Evolution Advanced)in order to meet the users’ explosive growth of mobile data.HetNets are such a cellular system that adds low-power nodes in the data traffic hotspots and the blind coverage spot of existing marco cell,and therefore enhance throughput and coverage of cell system.In order to balance traffic load between low-power nodes and macro cell,3GPP also proposed CRE(Cell Range Expansion)technology which makes more users accessing to low-power nodes.However,the introduction of low-power nodes and CRE not only brings benefits to the system,but also great challenges to network resource allocation and interference management.To this end,interference coordination schemes in HetNets,as a promising solution to improve system performance,has become a research hotspots of wireless communications in recent years.In this paper,we investigate interference coordination technology in the classic Macro-Pico two-tier HetNets,aiming to both reducing inter-tier interference and improving throughput.Specific works are included as following:First,we study and analyze traditional CRE algorithms,and propose an adaptive CRE algorithm based on two bias thresholds to alleviate performance degradation of some edge users.Second,we study the time domain inter-cell interference coordination schenme of LP-ABS(Low Power Almost Blank Sub-frame)and propose an adaptive scheme of LP-ABS to improve the flexibility of resource utilizations.In order to reduce the users’ interference and further improve resource utilization,we study the scheme that combining CoMP(Coordinated Multiple Points)with LP-ABS scheme and propose a CoMP-LP-ABS hybrid interference coordination scheme based on the analysis of the pros and cons of the CoMP and LP-ABS technologies.The proposed scheme can achieve both interference cancellation and spectrum utilization improvement,by making full use of the virtues of the two schemes.In addition,considering the introduction of CoMP transmission will increase the energy consumption of the system,we also analyze the tradeoff between energy efficiency and spectrum efficiency of the proposed scheme.Last,we build up a system-level simulation platform based on MATLAB,and carry out a set of simulations that verify the effectiveness and efficiency of the proposed schemes.