Resraech On Time Domain EICIC Technology In LTE-Advanced Heterogenous Networks

Long Time Evolution-Advanced(LTE-A), which is proposed and driven by 3GPP has become the fourth generation mobile communication standard which is currently widely used. Because LTE-A use the same frequency as the network model, resulting in the same frequency interference between cells, bad cell-edge user experience and the drop on the capacity of the network system. So, the study about inter-cell interference mitigation algorithms has important theoretical and practical significance. eICIC is an interference coordination technology of LTE-A put forward lately, which can solve the problem of inter-cell interference in terms of time domain, frequency domain and power control. eICIC can effectively improve the overall performance of the heterogeneous network systems.This thesis is mainly focused on LTE-A downlink cell interference coordination study. First of all, the LTE-A system of related technical background is introduced. In the following, according to analysing a level of LTE system simulator based on MATLAB simulation, this thesis expands the extra module about how to determine the victim user on the original platform. In this thesis a comprehensive ABS framework is proposed to mitigate the interference in HetNet environments. This ABS framework proposes a tracking procedure to mark and unmark the macro-cell victim users according to threshold of SINR, to strengthen the coordination between network nodes. This ABS framework gets the channel state feedback by using the CQI and RSRP reports. In this thesis a novel approach is proposed to trigger the ABS mode at aggressor Home eNodB(HeNB). Moreover this novel approach for the estimation of victim users’ signal-to-interference-plus-noise ratio(SINR) level during ABS is used based on the well-known discrete Kalman filter. The performance evaluation results show that the proposed ABS framework significantly improves the throughput of the macro-cell victim users with a slight degradation in the throughput of the femtocells.On the basis of above research, this thesis proposes also a greedy interference coordination scheme based on time domain allocation and the fairness index of users is proposed sequentially. It can adjust the Femto’s ABS ratio of the whole and transmit power dynamically in real time according to the fairness index, effectively alleviating the interference of the macrocell users near the Femtocell and ensuring the HUE quality of service. Finally the simulation results have shown that this thesis can effectively keep better performance of Macro-Femto heterogeneous network from inter-cell interference, and also can obtain higher cell throughput at the same time.