Research On Interference Suppression Method In IMT-A Heterogeneous Wireless Networks

In order to meet the exponential growth of data flow which people needs, mobile communication technology has developed rapidly from2G to3G, now to LTE/LTE-A. However, the new technology also bring the interference problem while bringing higher throughput and higher network response speed. On the one hand, the LTE-A signal is high frequency, which has higher value of path loss and transmission loss, in order to achieve a good quality of wireless coverage, deployment of wireless village will be more intense than ever. On the other hand, Femtocell and macro base station, Relay and transceiver are using the same frequency, the more the cell number, the more serious the cell inter layer interference and Co-layer interference, which will reduce the quality of mobile communication. Therefore, how to suppress the interference has become a hot research topic in the field of mobile communications. This paper mainly studies the IMT-A in heterogeneous wireless network interference suppression methods.This paper analysis of the interference suppression method of heterogeneous wireless networks in IMT-A system. And we propose two strategies, one is distributed uplink power control for Two-Tier Femtocell Network via convex pricing and the other is joint relay selection and power allocation method in two-way relay network, both of them can suppress the interference of heterogeneous wireless network.Distributed uplink power control for Two-Tier Femtocell Network via convex pricing is consist of four parts. Firstly, Macro actively choose a fit interference cap to ensure a minimum SINR. Secondly, femtocell user choose a reasonable power to maximize its own capacity. Thirdly, in order to improve the efficiency of the game, we introduce convex pricing and the fairness among femtocell users has been considered. Forth, a non cooperative game model has been established, then the existence and uniqueness of the Nash equilibrium solution are studied. Simulation results show that the proposed scheme can improve energy efficiency of femtocell networks and mitigate the cross-and co-tier interference significantly while guaranteeing the minimum QoS requirement of macrocell users.The joint relay selection and power allocation method in two-way relay network is consist of three parts. Firstly, we get separate SINR and derive the total transmission system outage probability and system capacity weighting from two source node. Secondly, we use the total transmit power as the constraint and the probabilities of the systems’ interruption and system capacity as the objective function. Thirdly, under the constraint of the total transmission power, we conduct the dynamic relay selection and power allocation adaptively with the two source nodes and relay nodes until we get the best solution and maximize the objective function.