The Research Of Relay Selection And Power Allocation Of Cooperative Communication

In recent decades, wireless communication technology is in the rapid development around theworld; especially the recent4G (fourth generation mobile communication technology) has also beenput into commercial use. Researchers around the world have been much concern about cooperativecommunication technology for reducing fading and loss of space as a good wireless communicationtechnology. Cooperative communication is in that case that there are multiple users in a wirelesscommunication environment system; each user can use the other adjacent antennas to transmitinformation to enable the user to carry a single antenna to obtain a multi-antenna transmissionvirtual environment. Combined with diversity combining technology and other wirelesscommunications technologies, cooperative communication technology greatly improves thetransmission performance of wireless communication systems. In recent years, cooperativecommunication technology has become one of the hot areas of research and application engineeringsector. With the rapid development of wireless communication technologies and applicationsrelating to explosive growth, research on cooperation and communication technologies will be ofgreat applied significance.Firstly, we introduce several types of common network model and cooperative communicationsystems commonly used in relaying protocols and forwarding performance of each protocolanalysis and simulation. The simulation results show that the incremental strategy and other relayamplifier repeater having a better performance compared other strategy and decoded and forwardsstrategy making relatively poor performance.Then, we review and summarize the cooperative communication network relay selectionalgorithm based on different criteria and these relay selection algorithms are compared to analyzetheir strengths and weaknesses.Secondly, analysis of cooperative communications relay node has been the focus of attentionof researchers. When mobile users as well as the optional relay nodes increase, how to choose theright way of relaying and forwarding relay from a number of nodes used to make the correctinformation transmission and guarantee good performance has become very important. Performanceof cooperative communication in recent years mostly related to AF or DF-based cooperationstrategy and focused on a relatively fixed position of the relay node case, they rarely combine AFand DF together considering the circumstances of the channel. So in order to make rational use ofsystem resources, we propose an improved algorithm for the adaptive relay cooperation. The algorithm takes both the location information and channel link status of relay nodes intoaccount and considers two conditions including the optimal options and multiple relay nodes,making the results more in line with the actual situation and engineering applications.Finally, we propose a criterion of power allocation scheme based on the adaptive relayselection algorithm described in the last section. We make simulation analysis of LDPC codes zoomin forwarding decode forwarding, adaptive relay selection system performance under threecooperation strategies. Then, in the limited system resources, we regard noise ratio received by thedestination node as target function and allocate power between the source node and the relay nodeon condition that the system power constraints. We make simulation analysis of the ARS algorithmby Monte Carlo and compare with the traditional performance comparison. Simulation results showthat our proposed power allocation scheme compared with the traditional cooperativecommunication systems, such as power distribution systems consume fewer resources, thus savingoverhead to improve system performance and prolong the network lifetime.