Research On Clustering Routing Protocol For RF Energy Harvesting-cognitive Radio Sensor Networks Based On SWIPT

Clustering cognitive ratio sensor networks(CRSNs)can help improve the energy utilization efficiency and make full use of spectrum resources.Although clustering protocols can slow down the energy consumption of nodes,they cannot fundamentally solve the energy constraint problem.In addition,in existing uniform clustering protocols,the energy consumption rate of cluster heads(CHs)close to the sink is fast,which may result in energy holes or even network partition;Most existing uneven clustering protocols use fixed coefficient values to calculate cluster radius.Actually,it should be set according to specific network configurations.To address the above issues,energy harvesting(EH)technology and simultaneous wireless information and power transfer(SWIPT)technology are introduced into CRSNs to supplement and balance the battery energy of nodes in this article,and an in-depth research on EH-and SWIPT-based clustering routing protocols design for multi-hop CRSNs is conducted.The main cotents include:Firstly,an SWIPT-based multi-hop uneven clustering routing protocol(S-MUCRP)is proposed for CRSNs.Firstly,the energy consumption of control overhead and data transmission is comprehensively taken into consideration,and the cluster radii are theoretically derived with the purpose of minimizing the energy consumption of the outmost layer and balancing the net energy consumption of CHs in different layers.In this case,the energy consumption between CHs in different layers can be better balanced,and the load of CHs close to the sink is reduced;Secondly,intra-cluster SWIPT is introduced,and cluster members can decide whether they should transfer energy together with sensed data to their CHs according to their residual energy,which can further balance the intra-cluster energy consumption.In addition,energy level function-based CHs and relay selection criteria are defined to quantify node transmission potential from the joint energy and spectrum availability aspects.They are helpful in determining high-quality CHs and relays and enhancing energy sustainability and network connectivity.Simulation results show that compared with the existing clustering routing protocols for CRSNs,S-MUCRP can guarantee effective network surveillance during long network lifetime.Secondly,in order to prevent the premature death of relay nodes at critical positions,resulting in the inability of external CRSNs node data to be ultimately routed to sink nodes,an EH-and SWIPT based multi-hop uneven clustering routing protocol for CRSNs(ES-MUCRP)is proposed in this paper.Firstly,considering the dynamic changes in residual energy of CRSNs nodes caused by energy harvested from busy primary users or the sink,EH-based energy state function and the selection criteria for CHs and relays are proposed to extend the network lifetime;Secondly,the inter-cluster SWIPT mechanism is introduced,and routing nodes determine whether to transmit their excessive energy together with the data to the next hops based on their own energy level,which is helpful in balancing the inter-cluster remaining energy.In addition,an energy state control mechanism is introduced to prevent CRSNs nodes from dying due to insufficient energy and avoid energy waste caused by excessive activation of the SWIPT mechanism.Simulation results show that compared with the existing clustering routing protocols for CRSNs,the ES-MUCRP protocol can effectively extend the network lifetime,improve the energy balance degree among nodes and enhance the network surveillance capability.