An Uplink Inter-Cell Interference Coordination Scheme Based On Multi-Cell Cooperative Scheduling

The 3GPP Long Term Evolution (LTE) is in the process of standardization for the next-generation mobile communication networks. LTE system simplified the network structure. Radio link controller and media access controller are in the same network node to make the joint optimization and design easily, for the air interface related functions are concentrated in the eNodeB(Enhanced-NodeB). Wireless access network is greatly simplified, and the core network will be an all-IP network in the future with its structure no longer vertical but plane. LTE with spectrum bandwidth of 20MHz is able to offer peak rate of 100Mbps in downlink, while 50Mbps in uplink. LTE can improve the performance of cell edge users, improve the cell capacity, reduce system latency, support the cell coverage of radius of 100Km, support paired or unpaired spectrum, and configure bandwidth flexibly from 1.25MHz to 20HMz.The packet scheduling and ICIC (inter-cell interference coordination) are researched in the structure of the LTE system, and the problems of these algorithms are analyzed in this paper. In packet scheduling algorithms, the SINR (Signal to Interference plus Noise Ratio) of a UE is set to determine the priority of the UE. It can perform high throughput inside the cell, but the large signal power will cause great interference to the neighbor cell and thereby will increase the inter-cell interference. In ICIC algorithms, the frequency of each cell is divided into two parts, cell center frequency and cell edge frequency, to depart the interference from neighbor cells, and the UE in cell edge can use cell edge frequency only. In this way, part of the cell edge frequency cannot be fully utilized, and decrease the frequency utilization.According to the research on the algorithms at present, an uplink inter-cell interference coordination scheme based on multi-cell cooperative scheduling is proposed in this paper. This scheme consider to judge the uplink interference level by the value of SLNR (Signal to Leakage plus Noise Ratio) and allocate resources to the UEs in a set of cooperative cells. The scheme manages to reduce the inter-cell interference by means of allocating resource reasonably by packet scheduling algorithm. Finally this scheme is simulated in system-level by MATLAB simulation tool, and the result shows that the ICIC scheme can not only reduce the interference among neighbor cells, but also increase the throughput of the system and improve the system performance.