带内全双工OFDMA网络资源分配研究

发布时间：2018-10-05 16:08

【摘要】：无线通信业务爆炸式增长与频谱资源短缺之间的外在矛盾,驱动着无线通信理论与技术的内在变革。提升FDD与TDD的频谱利用效率,并消除对频谱资源使用和管理方式的差异性,成为未来移动通信技术革新的目标之一。带内全双工(In-Band Full-Duplex,IBFD)无线通信系统因其支持每一时隙使用相同频率进行收发通信的特点,被视作一种极具吸引力的解决方案。带内全双工OFDMA网络能够提供比较高的频谱利用效率,同时有效的资源分配方案能够进一步提升网络性能。本文针对带内全双工OFDMA网络的资源分配问题展开研究,提出了两种适应不同网络结构的资源分配算法,以解决网络中载波与功率分配、上下行用户匹配等问题。首先针对基站与用户在同一子载波进行双向全双工无线通信的OFDMA网络,提出最大化网络传输速率的关于子载波和功率分配的优化问题。在约束条件下,利用拉格朗日乘子法和KKT条件求出了此问题最优解的必要条件。根据最优载波分配和功率分配满足的必要条件,提出一种子载波与功率联合分配算法。该算法分为三个步骤:首先利用功率注水算法预先给各个用户分配功率预估传输速率;利用修正匈牙利算法和预估速率分配子载波;最后在子载波分配结果的基础上再利用功率注水算法分配合适的功率以最大化传输速率。仿真结果表明,与对比算法相比,本文所提出的子载波与功率联合分配算法提升了网络总传输速率,并且使得用户间的公平性更好。另一方面,在一对上下行用户和基站在同一子载波进行三节点带内全双工通信的OFDMA网络中,除了残余自干扰,节点间干扰也是需要考虑的问题。本文针对此网络中的上下行用户匹配与子载波分配问题提出了一种基于三维匹配的上下行用户匹配与子载波分配算法;同时针对上行链路传输速率的约束条件,提出一种功率分配方法,降低残余自干扰对系统性能的影响。本文还分析了此算法的收敛性和算法复杂度,并仿真比较了穷举法、随机分配和此算法的网络性能。仿真结果表明,此算法接近最优算法的性能,并且算法复杂度较低,不仅能比较好解决上下行用户匹配与子载波分配问题,而且利用功率分配满足了上行传输速率约束。最后,总结全文的带内全双工OFDMA网络资源分配有关的研究内容及本文研究的不足,并展望了带内全双工无线通信未来的研究方向。
[Abstract]:The external contradiction between the explosive growth of wireless communication services and the shortage of spectrum resources drives the internal transformation of wireless communication theory and technology. To improve the efficiency of spectrum utilization between FDD and TDD and to eliminate the differences in the use and management of spectrum resources has become one of the targets of future mobile communication technology innovation. In-band full-duplex (In-Band Full-Duplex,IBFD) wireless communication system is regarded as an attractive solution because of its ability to transmit and receive each time slot using the same frequency. In-band full-duplex OFDMA networks can provide high spectral efficiency and efficient resource allocation schemes can further improve the network performance. In this paper, the resource allocation problem of full-duplex OFDMA network in band is studied, and two resource allocation algorithms are proposed to solve the problems of carrier and power allocation, uplink and downlink user matching and so on. Firstly, for the OFDMA network in which the base station and the user perform two-way full-duplex wireless communication in the same sub-carrier, the optimization of sub-carrier and power allocation to maximize the transmission rate of the network is proposed. The necessary conditions for the optimal solution of the problem are obtained by using the Lagrange multiplier method and the KKT condition under the constraint conditions. According to the necessary conditions of optimal carrier allocation and power allocation, a joint subcarrier and power allocation algorithm is proposed. The algorithm is divided into three steps: firstly, power injection algorithm is used to pre-assign power to each user to estimate transmission rate, and modified Hungarian algorithm and predictive rate are used to allocate subcarriers. Finally, based on the subcarrier allocation results, the power injection algorithm is used to allocate the appropriate power to maximize the transmission rate. Simulation results show that the proposed joint subcarrier and power allocation algorithm improves the total transmission rate of the network and makes the fairness between users better than the contrast algorithm. On the other hand, in the OFDMA network where a pair of uplink and downlink users and base stations communicate with each other in the same sub-carrier, in addition to residual self-interference, inter-node interference is also a problem to be considered. In this paper, a 3D matching algorithm for uplink and downlink user matching and subcarrier allocation is proposed for the uplink and downlink user matching and sub-carrier allocation problem, and the constraints of uplink transmission rate are also discussed. A power allocation method is proposed to reduce the influence of residual self-interference on system performance. The convergence and complexity of the algorithm are analyzed, and the network performance of exhaustive method, random assignment method and this algorithm are simulated and compared. Simulation results show that the algorithm is close to the performance of the optimal algorithm, and the complexity of the algorithm is low, which can not only solve the problem of uplink and downlink user matching and sub-carrier allocation, but also satisfy the uplink transmission rate constraint by power allocation. At last, the paper summarizes the research contents of the full duplex OFDMA network resource allocation and the deficiency of this paper, and looks forward to the future research direction of the full duplex wireless communication in the band.
【学位授予单位】：中国矿业大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TN929.5

【参考文献】