Research On Interference Coordination Algorithm Based On CRE Technology In LTE-advanced Heterogeneous Networks

With the high-speed development of Internet and communication technology and the widespread popularity of intelligent terminal, the future wireless mobile system will show explosive growth, which need to provide higher data rate to ensure the experience of the users.In order to solve this problem, The International Telecommunications Union and International Standardization Organization proposed the technology of Heterogeneous Network(HetNet).Deploying the new low power node such as Pico base station in the coverage of Macro base station can make full use of the time-frequency resources of LTE- A network and improve the overall system performance.While Pico base station is deployed in the heterogeneous network, the transmission power of Pico base station is far less than the transmission power of Macro base station. It will cause the number of users access to Pico base station to be very limited if using traditional cell access standards, which can not achieve the purpose of reduce the load of Macro base station. In order to make more users access to Pico base station, the introduction of Cell Range Extension(CRE) technology can expand the area coverage of Pico Cell in heterogeneous network. But the users within the region of CRE will be strongly disturbed by Macro base station.With the problem of the load of base station, the article analyzes the influence of the performance of the system network by the allocation of network resources. This paper proposes a optimization algorithm of CRE offset value. Aiming at the network load balance,optimization algorithm dynamically adjusts the CRE offset value, which makes the partial cell users switch to adjacent cell. Compared to the static setting of the CRE offset value, the dynamic setting method has a certain improvement on the system performance, which can adapt to different deployment scenarios.Aiming at the inter layer interference problem in heterogeneous networks, an improved method based on frequency domain interference coordination is proposed in this paper. The method redistributes the frequency domain resources the cell and reduces the transmissionpower of Macro base station at certain frequencies appropriately. On the basis of the CRE offset value adjustment, the further optimized algorithm combines with frequency domain interference coordination technology. The simulation results show that the improved algorithm can reduce the interference to the users in the region of the CRE and improve the quality of the communication services.