Research On Resource Allocation Algorithm For CR-NOMA Network

The orthogonal multiple access(OMA)technology,which has always been a key technology in mobile communication,is also showing fatigue under higher user demands.Non-orthogonal multiple access(NOMA)technology emerged at the historic moment.By controlling the power of users,this technology transmits the information flow of different users on the channel with overlapping time,frequency or code domains,To achieve the goal of user reuse on the same wireless resources while distinguishing users based on power.Therefore,NOMA technology can meet the high requirements for energy efficiency and spectrum efficiency in wireless communication of the fifthgeneration mobile communication technology(5G)and even the future sixth-generation mobile communication technology(6G),effectively improving access scale and increasing user fairness.Cognitive radio(CR)technology can help secondary users(SU)choose appropriate frequency bands for communication through dynamic spectrum sensing process,autonomous learning and searching for free frequency bands.The CRNOMA technology,which combines CR technology with NOMA technology,can connect SU to the PU channel while ensuring the Quality of Service(Qo S)of the primary user(PU),thereby fully utilizing idle spectrum resources and improving bandwidth resource utilization.Therefore,how to effectively utilize CR-NOMA technology for the selection and allocation of PU and SU is a research focus for future communication business development needs.In response to the resource allocation scheme between PU and SU in CR-NOMA networks and the problem of mutual interference between users,this paper presents a hierarchical approach,first considering the power allocation and user access issues in two types of user networks from a single PU to multiple SUs,and then expanding to multiple PUs to multiple SUs.The main research content of this paper includes:(1)This paper proposes an energy efficiency based combined user dynamic power allocation method to address the issue of low channel bandwidth utilization when PU is multiplexed using the Underlay method in dense cell CR-NOMA network scenarios.This method considers the interference between users and the Signal to Interference Plus Noise Ratio(SINR)while ensuring the Qo S of PU.By optimizing and combining multiple user access schemes,it maximizes the number of channel access users and improves frequency band utilization.In addition,this article improves the residual power redistribution scheme based on the power difference ratio under channel gain,making the reuse of idle power more reasonable and effective.(2)A user channel allocation scheme based on matching theory is proposed to model the CR-NOMA network scenario in an urban 5G environment and address the issue of low channel bandwidth utilization when PU and SU are multiplexed using the Underlay method.The first part of this scheme is the delayed acceptance algorithm,which can optimize the matching strategy of bilateral users based on matching theory while ensuring the fairness of access users;The second part of the power redistribution scheme can calculate and improve the first part based on the interference between users and the SINR of each user.This scheme effectively improves frequency band utilization.