Research On Emergency Communication Mechanism Of UAV Based On Multi-hop Cognitive Network

The UAV emergency communication network has many advantages,such as strong mobility,good link quality and fast and convenient deployment.When combined with the cognitive network,it can greatly improve the utilization of network spectrum resources while having the above characteristics.However,in the face of the needs of large-capacity,high-interaction,and multi-access users in the 5G era,the shortcomings of the UAV platform’s limited energy and storage resources have gradually emerged.In some scenarios,it relies too much on a single link,which makes the network resource consumption concentrated.It will shorten the sustainable time of the network,and it is not in line with the trend of decentralization.In addition,the high mobility of the UAV can also cause the link to be unstable in some time slots,resulting in the phenomenon of communication failure.Aiming at the problems existing in the above-mentioned UAV emergency communication network,this paper conducts the following researches on the problem of UAV resource allocation:1.Aiming at bottlenecks such as the urgent need to improve the spectral efficiency of UAV communication networks,a hybrid decision-making relay selection algorithm for cognitive UAV networks is proposed,a design of handover tolerance and delay tolerance is constructed,and candidate relay clusters are determined by delay information.,so that the nodes with the best communication conditions can complete data transmission,improve the performance of interruption probability,and solve the problem of low reliability of link switching in shadow areas.The simulation results show that the proposed scheme can effectively improve the interrupt performance compared with the traditional scheme.2.Aiming at the malicious eavesdropping problem in multi-source multi-relay system,a load balancing relay selection algorithm based on physical layer security is proposed.The algorithm clarifies social attributes through joint similarity,determines potential denial-of-service relays,and builds a multi-dimensional decision-making process under low joint similarity,thereby avoiding the unlimited consumption of energy load and data load in a single node in the network and solving the problem of communication.The quality-constrained relay selection algorithm suffers from the unfairness of node resource consumption and low network lifetime.The simulation results show that compared with the traditional scheme,the proposed scheme has been improved in terms of network life and throughput,and improved the service quality.3.In the cache-assisted relay system,there is an unrealistic preset condition,that is,the social attributes among all nodes are highly overlapping and similar,but such a prerequisite is often not available in actual situations,because nodes often Have a certain selfishness.Therefore,this paper proposes a cache-assisted relay selection algorithm based on incentive cooperation to solve the problem of system performance degradation caused by the differences in the social attributes of nodes in cache-assisted networks.By incorporating the contribution of nodes to the system,nodes with poor social attributes are encouraged to actively participate,so as to achieve better incentive effects.Nodes with high competition function values have higher priority for information storage and transmission,improve the participation of low-attribute nodes,and buffer the impact of channel changes,thereby increasing network sustainability and achieving higher system efficiency.In view of the shortcomings of the UAV emergency communication network in different scenarios,this paper proposes targeted measures,namely,starting from the three dimensions of link switching,unfair consumption of resources and differences in social attributes,to build a new type of UAV emergency communication.system,improve the service quality and service efficiency of the system,and improve the performance of the UAV emergency communication system.