The Research On Power Allocation For Dual-hop Cooperative Relay Network With Joint Power Limited

In recent years,the rapid development of communication technology,prompting users put forward higher requirements for communication service quality continuously.Cooperative relay technology in expanding wireless network coverage and improving the system performance shows very strong advantage.In the cooperative communication system,since each node has to transmit other node information in addition to transmitting its own information,it will generate more resource consumption.Compared with non-collaboration,collaborative communication is more necessary to integrate the system resources with the best allocation to achieve good system performance.In the increasingly tense demand for resources,the allocation of resources has been continued,and now the resources are mainly for the power,namely how to reasonably limited power resources are allocated,and help to improve the system performance better become the focus of research.In view of the half-duplex and full-duplex the operation mode of the two kinds of data communication.Among them,half-duplex mode receives or sends signals in orthogonal time slot or frequency,which will result in low spectrum efficiency.And full-duplex mode can receive and send signals at the same time slot or within the same frequency,greatly improving the spectrum efficiency of system,and the existence of inherent since the interference caused by its own mechanism,makes the performance cannot reach twice the half-duplex mode.In this paper,we will take both communication modes applied in cooperative relay networks,mainly studied power allocation problem under the condition of limited power of half-duplex and full-duplex one-way collaboration relay network,and with a variety of power allocation scheme for the simulation and performance comparison.First of all,considering the direct link from source point to destination point as a useful transmission and interference of two half duplex cooperative relay networks,are respectively using amplify-and-forward and decode-and-forward cooperation strategies for individual power and global power limited from maximizing system channel capacity under the constraint of power to reach optimal allocation algorithm and adaptive optimal power combination.Through the exhaustive search method to verify the accuracy and effectiveness of the results,and there is uniform power allocation,power allocation of single constraint conditions and total power allocation scheme for no collaboration relay network respectively were compared.Compared with no collaboration relay scheme,all schemes for cooperative relay networks have significantly better performance.And compared with uniform power allocation,both the power allocation of single constraint conditions and the power allocation of joint power constraint have better performance.Secondly,studying power allocation problem for the full-duplex collaboration relay network,we also consider two kinds of network scenarios about direct link as useful and interfere transmission,and apply amplify-and-forward and decode-and-forward cooperation strategies,also in individual power and global power limited from maximizing system channel capacity under the constraint of power to achieve optimal allocation algorithm and reach adaptive optimal power combination.In addition with exhaustive search,no cooperation relay total power allocation,uniform power allocation,and single constraint conditions scheme compared,we also compare optimal power allocation scheme in full-duplex mode with half-duplex scheme.Both single constraint conditions scheme and the joint constraint power allocation have better performance than no collaboration relay scheme and uniform power allocation scheme,at the same time,in full-duplex mode of joint performance of the optimal power allocation is significantly superior to half-duplex mode of joint optimal power allocation.