To improve the total throughput of the uplink orthogonal frequency division multiple access system,a low complexity hybrid power distribution（HPD） combined with subcarrier allocation scheme is proposed.For the fairn...To improve the total throughput of the uplink orthogonal frequency division multiple access system,a low complexity hybrid power distribution（HPD） combined with subcarrier allocation scheme is proposed.For the fairness mechanism for the subcarrier,the inter-cell interference is first analyzed to calculate the capacity of the multi-cell.The user selects the subcarrier with the largest channel gain.Based on the above subcarrier allocation scheme,a new kind of HPD scheme is proposed,which adopts the waterfilling-power-distributed scheme and the equal-power-distributed scheme in the cell-boundary and the cellcenter,respectively.Simulation results show that compared with the waterfilling-power-distributed scheme in the whole cell,the proposed HPD scheme decreases the system complexity significantly,meanwhile its capacity is 2% higher than that of the equal-powerdistributed scheme over the same subcarrier allocation.展开更多
The resource allocation for device-to-device(D2D)multicast communications is investigated.To achieve fair energy efficiency(EE)among different multicast groups,the max-min fairness criterion is used as the optimizatio...The resource allocation for device-to-device(D2D)multicast communications is investigated.To achieve fair energy efficiency(EE)among different multicast groups,the max-min fairness criterion is used as the optimization criterion and the EE of D2D multicast groups are taken as the optimization objective function.The aim is to maximize the minimum EE for different D2D multicast groups under the constraints of the maximum transmit power and minimum transmit rate,which is modeled as a non-convex and mixed-integer fractional programming problem.Here,suboptimal resource allocation algorithms are proposed to solve this problem.First,channel assignment scheme is performed to assign channel to D2D multicast groups.Second,for a given channel assignment,iterative power allocation schemes with and without loss of cellular users’rate are completed,respectively.Simulation results corroborate the convergence performance of the proposed algorithms.In addition,compared with the traditional throughput maximization algorithm,the proposed algorithms can improve the energy efficiency of the system and the fairness achieved among different multicast groups.展开更多
该文研究满足用户速率需求的子载波配对、动态子载波分配和功率分配的联合优化,建立了使传输速率与用户期望速率之差最小化的优化数学模型.首先提出平均功率分配下基于用户期望速率的子载波配对和动态子载波分配算法(dynamic subcarrier...该文研究满足用户速率需求的子载波配对、动态子载波分配和功率分配的联合优化,建立了使传输速率与用户期望速率之差最小化的优化数学模型.首先提出平均功率分配下基于用户期望速率的子载波配对和动态子载波分配算法(dynamic subcarrier allocation based on expected rate,ERDSA).为了保证用户的公平性,提出在系统资源不足时按比例减小接入用户期望速率的子载波配对和动态子载波分配算法(enhanced dynamicsubcarrier allocation based on expected rate,EERDSA).由于平均功率分配时,第1跳子载波与第2跳子载波的速率存在不完美匹配的问题,进而提出联合子载波配对、动态子载波分配和功率分配算法(dynamic jointsubcarrier and power allocation,DJSPA).分析表明3种算法的复杂度仅与子载波数呈线性关系,均为低复杂度的优化算法.仿真表明,这几种算法可满足用户的期望速率,降低系统功耗.展开更多
基金supported by the National Basic Research Programof China (973 Program) (2007CB310601)the Major Science-Technology Project of Next Generation Wireless Mobile Communication Network (2009ZX03004-001)
文摘To improve the total throughput of the uplink orthogonal frequency division multiple access system,a low complexity hybrid power distribution（HPD） combined with subcarrier allocation scheme is proposed.For the fairness mechanism for the subcarrier,the inter-cell interference is first analyzed to calculate the capacity of the multi-cell.The user selects the subcarrier with the largest channel gain.Based on the above subcarrier allocation scheme,a new kind of HPD scheme is proposed,which adopts the waterfilling-power-distributed scheme and the equal-power-distributed scheme in the cell-boundary and the cellcenter,respectively.Simulation results show that compared with the waterfilling-power-distributed scheme in the whole cell,the proposed HPD scheme decreases the system complexity significantly,meanwhile its capacity is 2% higher than that of the equal-powerdistributed scheme over the same subcarrier allocation.
基金Projects(61801237,61701255)supported by the National Natural Science Foundation of ChinaProject(SBH17024)supported by the Postdoctoral Science Foundation of Jiangsu Province,China+2 种基金Project(15KJB510026)supported by the Natural Science Foundation of the Jiangsu Higher Education Institutions,ChinaProject(BK20150866)supported by the Natural Science Foundation of Jiangsu Province,ChinaProjects(NY215046,NY217056)supported by the Introduction of Talent Fund of Nanjing University of Posts and Telecommunications,China
文摘The resource allocation for device-to-device(D2D)multicast communications is investigated.To achieve fair energy efficiency(EE)among different multicast groups,the max-min fairness criterion is used as the optimization criterion and the EE of D2D multicast groups are taken as the optimization objective function.The aim is to maximize the minimum EE for different D2D multicast groups under the constraints of the maximum transmit power and minimum transmit rate,which is modeled as a non-convex and mixed-integer fractional programming problem.Here,suboptimal resource allocation algorithms are proposed to solve this problem.First,channel assignment scheme is performed to assign channel to D2D multicast groups.Second,for a given channel assignment,iterative power allocation schemes with and without loss of cellular users’rate are completed,respectively.Simulation results corroborate the convergence performance of the proposed algorithms.In addition,compared with the traditional throughput maximization algorithm,the proposed algorithms can improve the energy efficiency of the system and the fairness achieved among different multicast groups.
文摘该文研究满足用户速率需求的子载波配对、动态子载波分配和功率分配的联合优化,建立了使传输速率与用户期望速率之差最小化的优化数学模型.首先提出平均功率分配下基于用户期望速率的子载波配对和动态子载波分配算法(dynamic subcarrier allocation based on expected rate,ERDSA).为了保证用户的公平性,提出在系统资源不足时按比例减小接入用户期望速率的子载波配对和动态子载波分配算法(enhanced dynamicsubcarrier allocation based on expected rate,EERDSA).由于平均功率分配时,第1跳子载波与第2跳子载波的速率存在不完美匹配的问题,进而提出联合子载波配对、动态子载波分配和功率分配算法(dynamic jointsubcarrier and power allocation,DJSPA).分析表明3种算法的复杂度仅与子载波数呈线性关系,均为低复杂度的优化算法.仿真表明,这几种算法可满足用户的期望速率,降低系统功耗.
文摘索引调制光OFDM虽可实现高频谱效率,但其误码性能还不够理想。为此,本文结合非对称限幅光OFDM技术,通过每组激活数目不等的子载波,提出了一种广义索引调制非对称限幅光OFDM(Asymmetrically Clipped Optical OFDM with Generalized Index Modulation,ACO-OFDM-GIM)方案。每个子载波块中选择激活数目不唯一的子载波,同时引入子载波分配算法进一步提升了系统的误码性能。文中详细介绍了ACO-OFDM-GIM调制映射原理,推导了其在湍流信道下的理论误码率,并采用仿真实验进一步验证了其性能。结果表明,与ACO-OFDM、ACO-OFDM-IM等系统对比,ACO-OFDM-GIM系统的传输速率和误码性能都有明显改善。在频谱效率相同的情况下,ACO-OFDM-GIM系统在大信噪比时能够获得比ACO-OFDM和ACO-OFDM-IM系统更好的误码性能。当误码率为1×10^(-4)时,强湍流条件下(4,[1,2])ACO-OFDM-GIM系统的信噪比相对于(4,2)ACO-OFDM-IM和ACO-OFDM系统分别改善了约2.5 dB和4.5 dB。ACO-OFDM-GIM方案为未来大气激光通信传输速率的提高提供了一种有效手段。
