Energy Consumption Optimization Of Cognitive Radio Relay Network Based On Energy Normalization

In recent years,with the rapid development of mobile devices,mobile phone,people's demand for wireless communications is increasing,such as wireless communication system data transmission quality and efficiency,but behind the opportunities,some bottleneck problem followed,the most affected is the limited nodes energy and the utilization of spectrum resources.Wireless spectrum is a scarce natural resources,according to the U.S.Federal Communications Commission(FCC)survey shows that the actual spectrum utilization rate assigned to the authorized user is very low in time and space,cognitive radio(CR)is an effective means to improve spectrum utilization rate,its core idea is under the premise of not affecting the primary user(PU)normal use,the secondary users(SU)can choose the free band for wireless communication,flexible use idle spectrum resources,improving the utilization of spectrum resources effectively.Network coding(NC)also is a common means to improve spectrum utilization,two way relaying(TWR)technology realized by network coding not only realize the spatial diversity gain,improve the channel utilization,but also improve the spectrum efficiency by rational using of channel bandwidth and increase the network security.At the same time,the rapid growth of energy consumption brought by the high rate,restrict the development of wireless communication technology.To reduce the communication cost,improve the life of the mobile terminal battery,reasonably balance the energy consumption of the nodes,and improve the energy efficiency(EE)of cognitive radio system has become an urgent problem to be solved.In this thesis,based on node energy and combined with the channel state information(CSI)and residual energy information(REI),we put forward an optimal relay selection algorithm.Combined with two-way relay and network coding technology,optimize traditional energy efficiency,we put forward concept of energy efficiency,and analyze the energy and spectrum resource optimization.It solves the problem that the primary users and cognitive users have shortsurvival time and low energy efficiency,to a certain extent,improving the energy consumption of wireless network.The main work and achievements of this thesis are as follows:1.Aiming at the problems of existing energy shortage,we put forward an optimal relay selection algorithm based on channel state information(CSI)and residual energy information(REI).The algorithm choice optimized relay nodes,take into account the node transmit power,the residual energy information and the power allocation between the source node and the relay node.The algorithm process is as follows: firstly,select the candidate relay,in which the source node can achieve the transmission rate;then,according to channel energy function select the forwarding relay;at last,according to the residual energy of nodes obtain the optimal relay.2.On the basis of rational use of energy,aiming at the problem of energy consumption unbalanced in cognitive networks,combined two way relay and network coding technology,we propose a resource optimization scheme based on energy balance.it improve the traditional energy efficiency and put forward the concept of "absolute efficiency".In this thesis,the current energy of the node is used as a new variable,and the normalized power of the wireless network is used to replace the traditional power.Joint optimization the transmit power and spectrum to balance the energy consumption of each node.