Research On UE-Interfering Area Based Uplinkds Inter-Cell Interference Coordination Scheme

The growing demands on mobile networks to support data applications at higher throughputs and spectral efficiencies have driven the technique of Orthogonal Frequency Division Multiple Access (OFDMA) to be the core of 4th Generation (4G) networks.In Orthogonal Frequency Division Multiplexing (OFDM) system, different sub-carrier can be orthogonal, thus the co-channel interference from the other cells is the main factor to limit the networks'performances, which lead the cell central users with high Signal to Interference plus Noise Ratio (SINR) while the cell edge users with low throughput and Quality of Service. This crucial problem in OFDM network is called "Inter-Cell Interference".To solve this problem, the Inter-Cell Interference Coordination (ICIC) has been brought up by the Long Term Evolution (LTE) of 3rd Generation Partnership Project (3GPP). The idea of ICIC is to enhance the SINR in sensitive resource blocks, increase the cell edge throughput through the limitation for communication resources between several adjacent cells. In uplink case, the centre cell would suffer interferences from the User Equipments (UEs) in adjacent cells in majority of the frequency resources if the interfering UEs utilize the orthogonal resource blocks, which we call it "Interference Flooding". In uplink, cell centre UEs and cell edge UEs receives the same interference density, therefore the throughput of cell centre UEs would be harmed in certain uplink scenario. The existed researches in ICIC may mitigate cell edge UEs'inter-cell interference, but for the lack of proper uplink power control, the SINR of cell central UEs can't be guaranteed; in the meantime, as the eNodeB can't know how the UE interferes the neighboring cells, problem of "Interference Flooding" would happen and the uplink throughput would be decreased.. Therefore, this thesis proposes a UE-Interfering-Area (UIA) based Inter-Cell Interference Coordination scheme. Using UIA scheme, according to the UE's submission, the eNodeB (eNB) will set up an Interference Table, which infers each UE's interfering area. Based on this table, the UEs will be allocated different resource priorities and adopt different power control strategies, which could compensate for the path loss and enhance the performance without new interference creation. Simulation results show that the presented scheme can make the network support more serving UEs, improve the system uplink throughput both for cell central and cell edge users, increase the capacity for uplink service.