Research And Application On Network Coding Power Allocation In Cognitive Cooperative System

With the rapid development of wireless communications technology, the future wireless mobile communication systems require a higher data rate, higher spectrum efficiency, higher reliability and lower communication transmit power. The cognitive radio (CR) technology, thereby becomes the development trend of wireless communications technology, and becomes the preferred technology of the next generation wireless communication because of its high spectral efficiency, sufficient flexibility to support high data rates and to ensure system reliability. This paper studies the cognitive radio technology and its applications on the following elements:First of all, this paper introduces the definition of cognitive radio and gives the basic model of cognitive radio; the definition of cognitive radio reveals the two features of cognitive radio, cognitive ability and reconfigurability; and finally describes the status of cognitive radio development and broad application scenarios.Secondly, this paper has done an introduction of cooperative communication briefly and its application on the cognitive radio. This paper presents a basic understanding of cooperative communication model. The primary user is made up of a point to point communication structure, while the second user consists of cognitive source node, cognitive relay and terminal node. Through this model, the ergodic rate of the secondary user is analyzed, combined with the characteristics of primary user's own request, forms an optimization problem. Then the optimal method is proposed to give its solution and a new algorithm is proposed for the power allocation. The simulation results confirm our theoretical derivation.Again, the basic principle of network coding is described. And then we introduce a multicast cell with an opportunistic relay with network coding. We have proposed three different strategies, by analyzing the three strategies, we analyze the stability region and waiting time of the three strategies, we prove that the strategies with network coding perform better than that without network coding strategy in both waiting time and the stability region. Simulation results confirm the theoretical prediction.Finally, the work is summarized and future research prospect is proposed.