Joint Power And Admission Control For Multi-pair Massive MIMO AF Relaying System

Multi-pair massive Multiple-Input Multiple-Output(MIMO)Amplifyand-Forward(AF)relaying system can make full use of advantages of MIMO and relay technologies.Massive MIMO technology can provide the additional space gains,improve effectively system capacity and spectrum efficiency etc.Relay technology has some benefits such as expanding the coverage of the wireless network and reducing the wireless access costs.At the same time,in order to save the user's transmit power and improve the system's spectral efficiency and other performance,power allocation and user scheduling problems are promising research topics.Therefore,this paper will focus on power and admission control for multi-pair massive MIMO AF relaying system.According to the relevant literature both at home and abroad,the deflation based joint user removal and power allocation(DPA)algorithm is an effective method for joint power and admission control.The main feature of the DPA algorithm is the step-by-step iteration of power allocation and user scheduling problems until selected users are supported for communication.In view of the high computational complexity and poor system performance of this algorithm,the paper uses the new linear programming deflation(NLPD)algorithm,which can improve significantly the performance of power power and admission control problem.It is more instructive for practical applications.Firstly,NLPD algorithm is applied to the analysis of joint power and admission control in this paper.Under the same rate requirement for all users,the removal strategy of the NLPD algorithm is compared with the DPA algorithm and the effects of the number of relay's antennas and tansmit power are also analyzed for this system.Secondly,this paper also studies joint power and admission control based on the NLPD algorithm in the complex scenario with different user rates.In addition,this paper proposes a method for estimating the relay's transmit power,which can effectively estimate the maximum number of users that are supported communication.Monte-Carlo simulation results indicate that with thorough removal strategy,the NLPD algorithm can support more users than that of the DPA algorithm with almost equal average transmit powers allocated for each user-pair.Meanwhile,the computational complexity of the NLPD algorithm is much lower than that of the DPA algorithm,which can save a large amount of the calculation time.Experimental simulation results also show that the supported users' communication performance of the obtained estimating relay's transmit power is very close to that of optimal relay's power,which greatly improves the computational efficiency.Finally,the theoretical analysis and simulation results show that the NLPD algorithm adopted in this paper is superior to the DPA algorithm in different scenarios and can analyze the joint power and admission control more effectively.