Research On Selection Cooperation Based On Energy Awareness

Cooperative communication technology can fully utilize wireless channel resources by configuring a single antenna at the sender and receiver,so that the advantages of multiple-input multiple-output systems can also be embodied in single-antenna systems.Therefore,it can effectively resist path fading in wireless communication systems and improve system transmission reliability.Selection cooperation is an important method in single-relay cooperation,which only needs one “best” relay node to participate in cooperative forwarding,and can achieve the same diversity performance as full-relay cooperation,so it has received extensive attention from the academic community.At present,the research on selection cooperation is usually assumes that the energy of network node is sufficient,and the transmission and cooperative behavior of nodes is considered to be independent of energy supply and consumption.However,in most practical networks,nodes are powered by batteries with limited energy.Once the node energy is exhausted,the node will be forced to exit the network and no longer participate in cooperation transmission,which seriously affects the network performance.Based on this,this thesis considers the actual energy status of the nodes in the wireless cooperative network,studies the impact of energy on the transmission performance of the system in energy-constrained network,designs a low-complexity energy-aware selection cooperation,and explores the relay selection strategy and power allocation method under energy constraints.The main research contents are as follows:Firstly,study the basic idea of cooperative communication and related technical,elaborate the relay forwarding mechanism and relay cooperation method,at the same time,introduce the basic auction mechanism and the best auction theory,and give the performance evaluation index of selection cooperation.Secondly,for the impact of energy on node behavior and network performance in a battery-powered wireless cooperative network,when nodes can perceive energy,a low-complexity energy-aware selection cooperation using the feedback information of the destination node is proposed in the energy-constrained network to improve the reliability of data transmission,which takes into account the channel quality,residual energy and transmission power of relay nodes.And the same time,in order to balance the energy consumption of nodes and extend the network lifetime,three relay selection strategies are presented,and the outage probability and energy residual rate of the system under different strategies are analyzed.The simulation results show that the proposed strategy can slow or balance energy consumption and prolong the networks lifetime.Finally,considering the competition and sharing of resources among nodes in practical cooperative networks,an auction-based relay selection strategy and power allocation method are proposed in the multi-source mutual energy-limited network.In the relay selection strategy,the auction theory is implemented between the source node that needs help and the candidate relay node to select the best relay.By bidding,the resource-rich nodes are encouraged to assist the resource-poor nodes and obtain corresponding monetary compensation.In the power allocation method,each candidate relay allocates its own transmission power and cooperative transmission power,and submits a bid to the source node to be coordinated,and the source node to be coordinated chooses the most suitable cooperative transmission power according to the sealed bidding method to realize the optimal allocation of transmission power for a single node,which enables a single node to ensure the reliability of its own data transmission while maximizing the assistance of other nodes,thereby improving network transmission performance.Simulation results show that the proposed method can improve the reliability of data transmission,and can extend node lifetime compared to full power selection cooperation transmission.This thesis makes a deep research on selection cooperation,relay selection strategy and power allocation method in energy-constrained network from the perspective of limited energy in real network.The research results provide a good reference for the application of selection cooperation in real network.