Research On Green Resource Allocation Algorithm In Cooperative Networks

As the age of 5G is coming and the new variety of wireless data services are emerging,people put forward higher requirements on the information transmission rate,which makes energy consumption increase rapidly and the shortage of wireless resources more serious in communication network.Therefore,under the condition of ensuring high speed and high reliability communication,how to realize the green communication with low power consumption of the system and high utilization rate of resources has become an urgent problem to be solved.In this thesis,we focus on the optimization problem of multidimensional resource based on spectrum efficiency and energy efficiency in cooperative networks.Firstly,this thesis outlines the research significance and the research situation at home and abroad of the multidimensional resource optimization in cooperative network,so we have a preliminary understanding of the project.Secondly,the key transmission technologies used in cooperative communication are introduced briefly,including the principles and characteristics of relaying and energy harvesting technology.Afterward,convex optimization theory is described.Finally,the wireless resource allocation problem is studied and the different optimization algorithms are proposed from two aspects of energy consumption and energy harvesting in cooperative networks.For the resource scheduling problem in energy-constrained cooperative relaying,a single-user system model with the assistant of multi-relay is established,and a multidimensional resource allocation algorithm based on incremental AF-OFDM protocol is proposed,of which the transmission mechanism is designed for improving spectrum efficiency.In the view of "throttling",the rational use of energy,subcarriers,nodes and other resources can not only achieve the information transmission rate of the user requirements,but reduce the transmission energy consumption of network nodes and prolong the lifetime of battery-operated network.Compared the global optimal algorithm with other related schemes by simulation when the same conditions exists,the results show that the network lifetime is maximum with the proposed algorithm for multiple degrees of freedom considered.In addition,a two-nested search loops is designed to solve the non-convex optimization problem,in which the inner loop finds the optimal value of optimize variable by Lagrange duality theory while the outer loop gets the optimal goal value by bisection criterion.The strong duality is verified by simulation in the model,namely,the solution of the dual problem is equivalent to the solution of the original problem.For the resource scheduling problem in energy-harvested cooperative relaying,a multi-user system model with the assistant of single-relay is established,and a multidimensional resource allocation algorithm based on PS energy harvesting is proposed,of which the transmission mechanism remains incremental AF-OFDM protocol.In the view of "open source",SWIPT technology is introduced to the research of resource optimization problem,so the relay node can obtain energy from the RF signal transmitted by source node for forwarding information.Similarly,the rational use of power,subcarriers and other resources,not only can ensure the rate of each user,but improve the system throughput.In addition,the complexity of the algorithm is analyzed.Finally,compared the proposed algorithm with degenerated algorithm by simulation,the results show that the proposed algorithm serves as the performance upper bound.