Research Of Resources Allocation And Handover Technique Based On MIMO Ultra-Dense Heterogeneous Network

As the demand for wireless services grows rapidly,network resources(such as spectrum,energy,space,etc.)become an important factor affecting system performance.However,there are some drawbacks in existing system,such as lower throughput,higher energy consumption,higher delay etc.Therefore,it cannot meet the future demand of application in massive traffic,green network and internet of things.It is focus to make fully use of utilization and value of these limited resources(such as frequency spectrum,energy,space),which has ever been concerned by many scholars and researchers.Dense deployment of low-power base stations is an effective way to reduce energy consumption and improve resource utilization.These densely deployed base stations and existing communication networks form an ultra-dense heterogeneous network,and this brings a great challenge to network resource management and handover between networks.Based on the research of MIMO technology and ultradense heterogeneous network,this dissertation designs a resource allocation and switching scheme suitable for new networks,which is of great significance for promoting the application of 5G technology.The summarizations of the work are as following:Aiming at the networking problem of 5G communication system,based on the network self-organizing(SON)and IP methods,the dissertation constructs ultra-dense heterogeneous network architecture including macro base stations,micro base stations,pico base stations,WiFi,WLAN,3G and LTE etc.By adopting technologies such as intelligent management,MIMO,and full-frequency orthogonal multiple access,the architecture effectively improves spectrum resource utilization,reduces system energy consumption and delay,reduces networking costs,and improves network openness,flexibility and scalability.To solve the problem of spectrum resource’s low utilization ratio in and high energy consumption wireless communication networks,an improved pattern search and multi-objective particle swarm optimization algorithm for network resource allocation is proposed.First,fully consider the characteristics of ultra-intensive heterogeneous networks,the factors affecting spectrum utilization and energy consumption are analyzed and the problems that need to be optimized are modeled.Then,in order to maximize system throughput,according to the convex optimization method,the user’s dynamic water injection power is derived by using the KKT condition analysis in the Lagrangian duality.The improved pattern search and the multi-objective particle swarm algorithm are used to solve the constrained optimization target,and in the iterative operation,the subgradient is used to solve the non-differentiable Lagrangian multiplier problem in the optimization objective equation.The result shows that the proposed algorithm can significantly improve the spectral utilization and reduce the energy consumption.For the problem of low utilization of authorized spectrum,a joint resource allocation algorithm based on spectrum sensing and spatial channel control is proposed.Firstly,a optimization mathematical model is established in an ultra-dense heterogeneous network environment.Then,in order to maximize the system capacity,the Lagrange dual and beam power constrained relaxation conditions are used to solve the optimal beam vector set of non-convex problems.In order to simplify the solution,a solution method of beam control vector based on interference cancellation is also given.Next,according to the resource scheduling,the spectrum resource is allocated to the sensing user,and the transmission data is loaded on the controlling beam vector.Since the scheme effectively reduces interference between the primary user and the secondary user,the utilization of the idle spectrum is improved.The simulation results show joint control algorithms have greater system capacity than existing methods.For solving the problem of network selection in the ultra-dense heterogeneous network handover,the scheme of region sensoring based on Bayesian decision is proposed.Firstly,through area perception is adopted,the coverage probability of users in each base station is analyzed.Then,according to the maximum likelihood estimation,the conditional probability is calculated that the user needs to switch under the coverage condition of each base station.Next,according to the Bayesian principle,the Bayesian probability of each base station is calculated.The network with the largest Bayesian probability is selected as the user’s handover target network.At the same time,it is proposed to combine the user service requirements(rate,RSS)to form a joint handover strategy to achieve seamless access for users.Experiment results show the proposed scheme can deal with effectively network selection problem in the handoff of UDHN.