Research On The Technology Of LTE Heterogeneous Network Downlink Inter-cell Interference Coordination

Long-Term Evolution (LTE) allows operators to use new and wider spectrum withhigher data transmission rates, lower latency, and a flat all-IP-based networkarchitecture as3G network supplementary. At present, the LTE radio link performanceis approaching to the theoretical limit. The next performance leap in wireless networkswill come from the network topology. Heterogeneous networks mix macro, pico,Femto and Relay base-stations which enable flexible and low-cost deployments andprovide a uniform broadband experience to users anywhere in LTE network.In order to compensate for the blind spot of macro base station indoor coverage,LTE network introduces a kind of base station with low-power and low cost——homebase station (Home eNodeB, HeNB), to provide high-quality services for indoor users.HeNBs are generally deployed in the same frequency band with macro base stations,and most of them work on the closed user group (Close Subscriber Group CSG) mode,which only provide business services to the users in CSG-HeNB white list. Therefore,CSG-HeNB will cause serious downlink interference to its vicinal non-CSG users,such as macro users.To the end, this paper researchs LTE heterogeneous network downlink inter-cellinterference coordination techniques following by3GPP(The3rd GenerationPartnership Project) standards and proposals, which is also called LTE enhanceddownlink inter-cell interference coordination. Based on the techniques of frequencyreuse and power control, this paper proposed a solution of ABS-based(Almost BlankSubframe) heterogeneous network downlink inter-cell interference coordinationtechnology.ABS-based heterogeneous network downlink inter-cell interference coordinationtechnology solution includes the ABS configuration mode design, ABS configurationmode binding method, the control method of interference coordination mechanism,active MUE(Macro User Equipmen) scheduling program and idle state MUEprotection program. Then, the decision threshold of MeNB(Macro eNode B) detection ABS subframe is detailedly analyzed.In this paper, the performance of ABS-based heterogeneous network downlinkinter-cell interference coordination technology solution is assessed through LTEsystem level simulation platform, then compared with power control interferencecoordination technology in terms of throughput performance. It is found thatABS-based heterogeneous network downlink inter-cell interference coordinationtechnology is superior to the power control interference coordination technology bothin macro cell throughput and CSG-HeNB cell throughput.Finally, the next step research program is planned based on the problem inABS-based heterogeneous network inter-cell interference coordination technologyresearch.