Research on Interference Compression in LTE-A System
|School||Harbin Institute of Technology|
|Course||Information and Communication Engineering|
|Keywords||Inter-cell Coordination Channel Estimation Parameter FractionalFrequency Reuse Femtocell Power Control|
With the development of wireless communication, the number of mobile phonesubscriptions is continuing to grow rapidly with a great need for high speed data rateand improved communication service, thus traditional interference suppressionscheme cannot meet the performance requirements of LTE-A system. In order tomaintain the performance requirements proposed in LTE-A standard, a coveragesolution with frequency reuse factor of1between neighboring cells is adopted toimprove spectrum efficiency. Therefore, co-channel interference betweenneighboring cells has been a great obstacle to the communication capacity andquality. To improve the user experience of cell edge users as well as networkcapacity, research on effective inter-cell interference compression has profoundsignificance, theoretically and practically.This paper mainly intends to propose interference coordination scheme fordownlink inter-cell and the hybrid network containing Femtocell scenarios in LTE-Asystem. First, all possible inter-cell interference scenarios are listed and thecorresponding interference is measured through derived formula. Moreover, byvirtue of theoretical analysis and software simulation, the impact of inter-cellinterference on channel estimation parameters is measured to illustrate howinterference influences the performance of the overall system. In the following,this paper discuss three kinds of interference suppression schemes proposed by3GPP, containing interference cancellation, interference randomization and inter-cellinterference coordination, among which downlink inter-cell interferencecoordination schemes are focused on. A variety of relevant metrics includingspectrum effic iency, overall throughput and cell edge user throughput and the outageof cell edge users are compared between different conventional FFR. On the basis ofanalysis and comparison of the advantages and disadvantages of different cell centeruser and cell edge user divis ion scheme in FFR algorithm and the one based onSINR is adopted. The resource management and interference coordination arejointly formulated as an convex optimization problem while the allocationproportion of bandwidth, the reuse factor of cell edge bandwidth, and the selectedthreshold of user division work as deciding factors. Based on the above study, thispaper proposes a load-aware inter-cell interference coordination scheme forasymmetrical load scenario. The proposed scheme consists of two core algorithmcomponents: the cell edge bandwidth reusing algorithm and cell-center bandwidthcompensation algorithm. According to simulation results, the propose schemesurpass different conventional schemes in a variety of communication performance indicator. Finally, a novel interference coordination algorithm combining dynamicfrequency allocation and power control for hybrid network scenario is proposed toreduce the co-channel interference between Macrocells and Femtocells. Thesimulation results indicate that the proposed scheme improves the systemperformance cell throughput, outage rate.