Research On Inter-cell Interference Coordination Technologies Of Heterogeneous Networks In LTE-A

Over the last decade, cellular mobile communications technology developed rapidly. In order to meet the growing and diverse needs of mobile communications, on the basis of the homogeneous network, heterogeneous network is developed. In the standards-setting process of 3GPP LTE-A, the heterogeneous network technology is also being placed on an important position. Because LTE-A heterogeneous network changed the original network topology, how to deal with the inter-cell interference in heterogeneous networks has become an important research topic.In LTE-A heterogeneous network inter-cell interference coordination techniques, power control and interference coordination techniques most attention in the time domain. Cell Range Expansion(CRE) technology and Almost Blank Sub-frame(ABS) technology have become the key technologies of LTE-A inter-cell interference coordination of heterogeneous networks. CRE technology can break the load imbalance of macro-cell and pico-cell caused by the different user access capability. ABS technology is by making macro base station does not transmit data signals on certain sub-frames to reduce inter-cell interference of pico-cell UE in CRE domain caused by macro base station, thereby improve the pico-cell throughput.In this dissertation, the heterogeneous networks in LTE-A and the main concern among all kinds of inter-cell interference coordination technology of heterogeneous network in LTE-A are introduced. The inter-cell interference coordination technology in frequency domain and time domain and interference coordination technology by power control are introduced. The enhancement inter-cell interference coordination technology is focused on in this dissertation. Therefore, the LTE-A heterogeneous network simulation model is established, and the ABS technology is simulated and analyzed.The CRE technology of e ICIC in time domain in LTE-A heterogeneous network is detailed introduced. The LP-ABS based on ABS is focused on and the improvement of system performance of LP-ABS compared with conventional ABS is studied. Different conditions of CRE and the impact of different power attenuation value of LP-ABS on system performance is analyzed. Moreover, the influence of LP-ABS technology at different power attenuation value on macro layers and pico layers is analyzed. According to the simulation data analysis, summed up the use of LP-ABS program, various parameters setting method.The combination of ABS technology and Co MP technology has been studied. An adaptive ABS-Co MP scheme is proposed. By comparing the system capacity of ABS and Co MP scheme, choose the better scheme adaptively, so that enhanced the overall system gain. Moreover, adaptive ABS-Co MP scheme is modeled and simulated. The gains and shortcomings of this ABS-Co MP scheme compared to traditional solutions and pure ABS program is separately analyzed. Moreover, the impact of ABS-Co MP scheme on macro-cell users, pico-cell edge users and pico-cell center users is analyzed separately.