Research On Inter-Cell Interference Control For 3GPP LTE And Its Evolved Systems

Limited frequency resource becomes the leading factor to the improvement of the system performance along with the development of mobile telecommunication, and how to improve the frequency efficiency is one of the most popular topics. Especially with the developments of wideband wireless access technology like WiMAX, HSPA technology could not satisfy the variable streaming service in the future. As more competitive wireless access technologies, LTE and LTE-Advanced were forwarded by 3GPP in recent years. They are intended to achieve the peak rate 1Gbps/500Mbps (LTE-Advanced), guarantee the cell-edge data rate, and become more competitive in the future communication field.In order to realize the target of high frequency efficiency and capacity, interference is one of the top problems need to be solved. OFDM technology adopts in LTE system can provide orthogonal sub-carriers, so intra-cell interference can be avoided. However, due to the limited frequency resources, inter-cell interference can not be avoided and this kind of interference has a strong impact on the cell-edge data rate. Therefore, it is necessary to take some effective actions to mitigate the inter-cell interference.Different kinds of inter-cell interference control schemes for LTE Macrocell, Home eNodeB and LTE-Advanced systems have been discussed and analyzed respectively in this article. It includes power control in interference coordination, which is to control UE/eNodeB transceiver power to make a balance between SINRs and interferences; SFR/FFR, which is to divide frequency resource into several reuse sets and then make cell-edge region use orthogonal frequencies to reduce the interference of cell-edge users; Link technologies, including interference randomization techniques such as scrambling, IDMA and frequency hopping; HeNB receiver gain control, to relieve uncontrolled UEs on the uplink interference and reduce the noise rise of HUEs; and multi-cell joint scheduling technology for LTE-A, which may use a linear equation method to compute interferences and then adjust the transmission power.This paper carried on a detailed study on interference control technologies, so as to find suitable interference control schemes through this work, and propose solutions to the problems left over by 3GPP for reference to actual network applications.