Research On Resource Allocation Mechanism In Coexisting Network Between The Femtocell And The Macrocell

Indoor communication is an important application scenario in wireless communication networks,the coexistence of the femto base station and the macro base station is considered to be an important feature of future wireless communications.How to allocate reasonable resources in the coexistence network between the femto base station and the macro base station so that limited resources are fully used has become an important research topic.This thesis studies from the two aspects of spectrum allocation and power control,the main content includes the following two parts.The existing femtocell network lacks an effective and timely sensing mechanism for spectrum usage of the macrocell network,as a result,the resource allocation of the femtocell network cannot be coordinated with the use of the macrocell resources,resulting in large mutual interference.Aiming at this problem,it is proposed that the femto base station receives signals at each frequency point within a time period,uses random matrix energy dynamically detects availability of spectrum,perceives spectrum holes in the network in real time,generates a set of borrowable frequency points,and selects a service request femto users with high service quality borrow this set,according to the perceived available spectrum and its quality,centralized resource allocation in this base station.This mechanism takes the complexity as a cost and avoids the use of signaling interaction to find the available spectrum,thereby reducing the network signaling overhead and reducing the interference between the femto base station and the macro base station.Simulation results show that the proposed mechanism can improve network capacity and fairness and network link efficiency.The existing femtocell network has a simple power control model,which results in the downlink transmit power of the femtocell network being fixed,resulting in greater energy loss of the base station and greater interference to non-service users.To solve this problem,an optimization algorithm is proposed to maximize the throughput of femtocell.The algorithm is seen the target rate of the macro user as a constraint,and then the expression of the femtocell transmit power that satisfies the user communication in the coexistence network between the femto base station and the macro base station can be obtained.Finally,using the Lagrange multiplier method to solve the optimization problem.The simulation results show that the proposed power control algorithm reduces the transmit power,significantly reduces the system interference of the femtocell and improves the system capacity and the energy efficiency of the femtocell.