User pairing strategy for virtual multi-input multi-output （VMIMO） has been widely studied to improve system throughput, but most studies are based on perfect channel state information （CSI） and uniform power allo...User pairing strategy for virtual multi-input multi-output （VMIMO） has been widely studied to improve system throughput, but most studies are based on perfect channel state information （CSI） and uniform power allocation. However, perfect CSI is very difficult or even impossible to obtain in practical system. Moreover power allocation has significant impact on algorithm performance. Therefore, in this paper, a low-complex joint user pairing and power allocation algorithm based on aggressive discrete stochastic optimization and Lagrangian dual solution is proposed for uplink VMIMO with imperfect CSI. Simulation results show that the proposed algorithm can achieve desirable throughput performance, and restrict inter-user interference （IUI） efficiently.展开更多
Joint user pairing and power allocation approach is investigated to meet the rate requirement of enhanced mobile broadband(eMBB)slicing and delay constraint of ultra-reliable low-latency communication(URLLC)slicing si...Joint user pairing and power allocation approach is investigated to meet the rate requirement of enhanced mobile broadband(eMBB)slicing and delay constraint of ultra-reliable low-latency communication(URLLC)slicing simultaneously in downlink non-orthogonal multiple access(NOMA)system.For maximizing the proportional fairness among mobile terminals,a two-step algorithm is proposed.For a given user sets,the optimal user pairing sets and the factor of the power allocation in a group were obtained to ensure the quality of service(QoS)and the isolation between different types of slicings.Simulation results show that the proposed joint algorithm can provide better throughput than orthogonal multiple access(OMA).展开更多
Non-orthogonal multiple access(NOMA)is one of the leading technologies for 5G communication.User pairing(UP)and power allocation(PA)are the key controlling mechanisms for the optimization of the performance of NOMA sy...Non-orthogonal multiple access(NOMA)is one of the leading technologies for 5G communication.User pairing(UP)and power allocation(PA)are the key controlling mechanisms for the optimization of the performance of NOMA systems.This paper presents a novel UP and PA(UPPA)technique for capacity and fairness maximization in NOMA called(CFM-UPPA).The impact of the power allocation coefficient and the ratio between the channel gains of the paired users on the sum-rate capacity and the fairness in NOMA is firstly investigated.Then,based on this investigation,the PA and UP algorithms of the CFM-UPPA technique are proposed.The power allocation coefficient of the proposed PA is formulated as an exponentially decaying function of the ratio between the channel gains of the paired users to maximize the capacity and the fairness,and its maximum value is adjusted to guarantee the successive interference cancellation(SIC)constraints.The proposed UP is based on selecting the user that has the highest channel gain per subcarrier as the strong user to maximize the capacity and selecting the user that has the closest lower channel gain to the strong user’s channel gain as the weak user to improve the fairness and capacity.The performance evaluation of the proposed CFM-UPPA technique in terms of capacity,fairness,and outage probability demonstrates that its performance significantly outperforms that of the orthogonal multiple access(OMA)system and that of the NOMA system with random UP.Also,the simulation results demonstrate the efficiency of the proposed PA in improving the performance of other UP algorithms,such as the random UP algorithm.展开更多
基金supported by the National Natural Science Foundation of China (61271182)the National Natural Science Funds of China for Young Scholar (61001115)the National Science and Technology Major Project (2011ZX03001-007-03)
文摘User pairing strategy for virtual multi-input multi-output （VMIMO） has been widely studied to improve system throughput, but most studies are based on perfect channel state information （CSI） and uniform power allocation. However, perfect CSI is very difficult or even impossible to obtain in practical system. Moreover power allocation has significant impact on algorithm performance. Therefore, in this paper, a low-complex joint user pairing and power allocation algorithm based on aggressive discrete stochastic optimization and Lagrangian dual solution is proposed for uplink VMIMO with imperfect CSI. Simulation results show that the proposed algorithm can achieve desirable throughput performance, and restrict inter-user interference （IUI） efficiently.
基金supported by the Headquarters Science and Technology Project of State Grid Corporation of China(5700202019174A-0-0-00)。
文摘Joint user pairing and power allocation approach is investigated to meet the rate requirement of enhanced mobile broadband(eMBB)slicing and delay constraint of ultra-reliable low-latency communication(URLLC)slicing simultaneously in downlink non-orthogonal multiple access(NOMA)system.For maximizing the proportional fairness among mobile terminals,a two-step algorithm is proposed.For a given user sets,the optimal user pairing sets and the factor of the power allocation in a group were obtained to ensure the quality of service(QoS)and the isolation between different types of slicings.Simulation results show that the proposed joint algorithm can provide better throughput than orthogonal multiple access(OMA).
基金This research was supported by Taif University Researchers Supporting Project Number(TURSP-2020/147),Taif University,Taif,Saudi Arabia.
文摘Non-orthogonal multiple access(NOMA)is one of the leading technologies for 5G communication.User pairing(UP)and power allocation(PA)are the key controlling mechanisms for the optimization of the performance of NOMA systems.This paper presents a novel UP and PA(UPPA)technique for capacity and fairness maximization in NOMA called(CFM-UPPA).The impact of the power allocation coefficient and the ratio between the channel gains of the paired users on the sum-rate capacity and the fairness in NOMA is firstly investigated.Then,based on this investigation,the PA and UP algorithms of the CFM-UPPA technique are proposed.The power allocation coefficient of the proposed PA is formulated as an exponentially decaying function of the ratio between the channel gains of the paired users to maximize the capacity and the fairness,and its maximum value is adjusted to guarantee the successive interference cancellation(SIC)constraints.The proposed UP is based on selecting the user that has the highest channel gain per subcarrier as the strong user to maximize the capacity and selecting the user that has the closest lower channel gain to the strong user’s channel gain as the weak user to improve the fairness and capacity.The performance evaluation of the proposed CFM-UPPA technique in terms of capacity,fairness,and outage probability demonstrates that its performance significantly outperforms that of the orthogonal multiple access(OMA)system and that of the NOMA system with random UP.Also,the simulation results demonstrate the efficiency of the proposed PA in improving the performance of other UP algorithms,such as the random UP algorithm.
文摘当前非正交多址(Non-Orthogonal Multiple Access,NOMA)系统的用户配对和功率分配通常作为独立的问题进行研究,未考虑接收端不能完美执行串行干扰消除(Successive Interference Cancellation,SIC)的限制。鉴于此,提出一种不完美SIC下NOMA系统用户配对和功率分配联合优化(Joint User Pairing and Power Allocation,JUPPA)方法。给定功率分配方案,采用自适应遗传算法求解用户配对问题,并结合哈希表结构设计自适应交叉和变异算子。给定用户配对方案,利用连续凸逼近(Successive Convex Approximation,SCA)对目标函数下界进行松弛,构造卡罗需库恩塔克(Karush-Kuhn-Tucker,KKT)条件,并基于梯度下降法对功率分配问题进行优化。上述两个过程迭代直至收敛。仿真结果表明,相比于单独优化用户配对或功率分配,JUPPA具有更高的系统和速率。
