Research On QoS-based Spectrum Resource Allocation Scheme In Femtocell

At the 2018 Shanghai World Mobile Conference,major operators have indicated that they plan to commercialize 5G networks by 2020,This is bound to mean a rapid increase in user traffic.According to statistics,about 70%-80% of mobile services currently occur indoors,and the ratio is likely to grow.However,the macro cellular network has a problem of poor signal coverage,which can't guarantee user's indoor traffic experience.So the introduction of Femtocell technology has a natural advantage in indoor communication.Femtocell is a low-cost,low-power home base station,but its intensive deployment will inevitably lead to serious co-layer interference problems.This paper focuses on the key technology of solving the co-layer interference and improving network performance in Femtocell,namely spectrum allocation technology,and uses the coloring algorithm in graph theory as the theoretical basis.The results were simulated and analyzed.The main works and research results of this paper are as follows:1.Aiming at the problem of co-layer interference caused by the dense deployment of Femtocell,a new graph theory coloring model is used for spectrum allocation,and an interference discrimination method based on signal to interference plus noise ratio(SINR)is proposed.First,the Femtocell is compared to the vertices in the graph theory.Then,the interference graph is built according to the SINR of each user,and the interference graph is converted into a neighbor matrix.Finally,the new graph theory coloring algorithm is used to color the vertices.The simulation shows that the SINR-based interference discriminant method can well identify the Femtocell's interfering base station.The new graph theory coloring algorithm can color all the vertices with the least color to improve the spectrum reuse rate.2.Aiming at the problem that the quality of service(QoS)of users in Femtocell can not be satisfied,a new graph theory coloring algorithm is used to color all base stations,and a spectrum allocation algorithm based on user QoS requirements is proposed.The colored base stations are first grouped,and then each group is allocated the actual number of sub-bands required based on the user's QoS requirements.The simulation results show that the improved spectrum allocation algorithm can significantly improve the user's spectrum efficiency and significantly improve the network capacity of the system.The spectrum allocation algorithm based on graph theory and user Qos demand utilizes the advantages of graph theory coloring algorithm,and takes the user's QoS requirements as an important condition for spectrum allocation,thus forming a Femtocell spectrum allocation algorithm that can guarantee the QoS requirements of users and improve system performance.3.Using MATLAB software to complete the development of the graphical user interface(GUI)platform for spectrum allocation in Femtocell,and integrate the Femtocell spectrum allocation algorithm in Chapter 3 with the GUI to visualize the spectrum allocation process.Using the GUI platform,you can intuitively feel the improvement of the graph theory and user QoS requirements based spectrum allocation scheme on the performance of Femtocell network.Finally,the coloring process is specifically demonstrated so that the reader can grasp the specific execution process of the algorithm when using it.