Research On The Scheme Of Enhanced Inter Cell Interference Coordination In LTE-A System

According to prediction, 60% of voice services and 80% of data services occur in the indoors environment in LTE-A communication system. It is well known that signals operate in high frequency section in LTE-A communication system. So signals decay will be very large when signals through wall. At this time, signals quality indoor cannot meet the LTE-A system specifications. It will not only increase the operating costs of the network, but also can cause co-channel interference of inter-cell macro base stations by pushing to enhance the base station’s power to coverage indoor network. Therefore, the technology of heterogeneous network is adopted to solve the problem of network coverage in LTE-A communication system. During the process of heterogeneous networking, some low power nodes are adopted to enable locations of users closer to the base station node, such as Relay, RRF and femtocell. This method can be a very good solution for the problem of indoor coverage. Due to the femtocell with low transmit power, low cost of construction, environmental protection and other advantages, are widely used in the LTE-A system.Femtocell can be a good solution for the problem of indoor coverage. But the introduction of the femtocell has brought a very complex interference issues in the macrocell. In order to solve the interference, a scheme that dynamic frequency resource allocation combined with partial power control has been proposed. The scheme based on partial frequency reuse algorithm and make full use of the characteristics of partial frequency reuse algorithm. According to the characteristics of the algorithm, the femtocells are divided in geographic location. Then, according to the different location of the femtocells, the corresponding dynamic frequency resource allocation and partial power control scheme are adopted to solve the interference between femtocells and macro base station. Finally, simulation results show that the proposed scheme can not only solve the problem of cross-layer interference between the macro base station and the femtocell, but improve LTE-A system performance. Especially, the scheme has greatly improve in terms of the frequency of utilization.This paper mainly to complete the work:Firstly, the development process and framework of LTE-A communication system are researched deeply. Then the core techniques and inter-cell interference schemes of LTE-A system are been introduced in detail.Secondly, the characteristics, deployment and operation principle of femtocell are researched in detailed. And the interference scenarios are analyzed that generated after femtocells deployment into macro base stations. Then, according to the type of interference scenarios, the interference are classified.Thirdly, some classical femtocell interference coordination schemes are introduced, and the disadvantages of these schemes are analyzed. Then, according to disadvantages of traditional interference coordination schemes, a scheme that dynamic frequency resource allocation combined with partial power control is proposed. The scheme is based on the partial frequency reuse algorithm. First of all, the femtocells are divided in geographic location. Then, according to the different location of the femtocells, the corresponding dynamic frequency resource allocation and partial power control scheme are adopted to solve the cross-layer interference between femtocells and macro base stationFinally, the simulation results indicate that the proposed scheme can not only solve the inter-cell interference problems, but also improve the performance of LTE-A system. Especially, the scheme has improved in the cell throughput and spectrum efficiency.