Reserch And Simulation Of Next Generation Enhanced Intercell Interference Coordination In Heterogeneous Networks

Heterogeneous network consist of a mix of macrocells, remote radio heads, and low-power nodes such as picocells, femtocells, and relays. Leveraging network topology, increasing the proximity between the access network and the end users, has the potential to provide the next significant performance leap in wireless networks, improving spatial spectrum reuse and enhancing indoor coverage. Nevertheless, deployment of a large number of small cells overlaying the macrocells is not without new technical challenges. The interference between picocells and macrocells is a great technical challenge.Firstly, we study the impact of dynamically changing the range of low power nodes on the network performance, and then propose a dynamic cell range expansion (DCRE) algorithm, which adapts the dynamic network topology and network load. The algorithm reduces interference caused by macrocell user equipments (MUEs) to picocell. In the meantime, we select the suitable range expansion bia (REB) based on the change of network environment to balance traffic load between macrocell and picocell. We establish the utility function of picocell and macrocell based on the load condition of them and select the best step size of REB. Furthermore we change the update time interval dynamically.Secondly, we propose a new macrocell-picocell interference cooperation scheme based on the dynamic cell range expansion to decrease interference caused by macrocell base station (MBS) and MUEs to expanded regions (ERs) picocell user equipments (PUEs). Through the cooperation between macrocell and picocell, we set up optimization model to down link (DL) and up link (UL) interference respectively, minimizing the transmit power of MBS and MUEs in the premise of guaranteeing SINR of the MUEs to mitigate both DL and UL interference.In order to prove the feasibility and effectiveness of the two proposed algorithms, this thesis performs simulations by Matlab. The results showed that the two proposed algorithms can balance the traffic load between macrocell and picocells, guarantee SINR of the users, and increase throughput of the system as well as maximum bandwidth utilization efficiency.