LTE上行虚拟MIMO用户配对算法研究
发布时间：2019-05-08 01:38
【摘要】：人们对无线通信的高速率需求日益增强,利用有限的时频资源实现更高的数据传输速率显得愈加重要。MIMO技术能够显著提升通信系统容量,缓解频率资源日益紧张的现状,已经被多个无线通信标准所采用。然而,在LTE上行链路中,终端设备在功耗、成本等方面受到限制,通常只能配置一根发射天线,不能通过MIMO技术的空分复用提高数据传输速率。为解决这一问题,虚拟MIMO技术将多个用户虚拟配对,组成虚拟MIMO系统,占用相同的时频资源传输数据,能够在不提升终端硬件规格的前提下,有效改善频谱利用率和系统容量。在虚拟MIMO系统中,用户配对算法直接影响着系统性能。本文针对LTE上行虚拟MIMO系统中的用户配对算法,进行了如下的研究工作:第一,搭建LTE上行系统级仿真平台。结合LTE上行系统模型和3GPP相关协议,按照系统级仿真流程,对LTE上行系统进行仿真建模,为LTE上行虚拟MIMO系统中的用户配对算法的性能验证提供了仿真平台。第二,研究LTE上行虚拟MIMO系统中的对称资源用户配对算法。首先,提出的贪婪多用户配对算法以简化的容量因子作为度量值,每次选出一个最优用户,并在确保能给系统带来额外容量的情况下选其为配对用户。然后,在贪婪算法的基础上,用多个二阶行列式的乘积代替高阶行列式,得到了复杂度更低的简化算法。最后,在简化算法的基础上结合比例公平准则,兼顾系统容量和用户公平性。仿真表明,在LTE上行虚拟MIMO系统中,每个小区40个用户,配对深度为4时,与双重比例公平配对算法相比,简化的贪婪比例公平多用户配对算法获得的5%边缘用户吞吐量和小区平均吞吐量分别提升116.67%和13.41%。第三,研究LTE上行虚拟MIMO系统中的非对称资源用户配对算法。提出的部分非对称资源配对算法首先对频率资源进行分块,然后从每段的第一个RB开始选择配对用户,接着进行RB扩展,直至分配完全部RB。提出的完全非对称资源配对算法完全不考虑已调度用户的RB占用情况,根据比例公平准则选择配对用户。仿真表明:在两用户配对的LTE上行虚拟MIMO系统中,每个小区40个用户时,与双重比例公平配对算法相比,两种算法获得的5%边缘用户吞吐量分别提升236.73%和256.79%,获得的小区平均吞吐量分别提升40.70%和47.38%。本文针对MIMO技术在上行系统中受到限制的问题,对LTE上行虚拟MIMO系统中的用户配对算法进行了研究,提出了对称资源下的贪婪、简化的贪婪和简化的贪婪比例公平算法,以及非对称资源下的部分非对称和完全非对称算法。提出的算法可以用于LTE、LTE-Advanced及其它采用虚拟MIMO技术的通信系统,能够提升频谱利用率和系统容量,改善通信质量。
[Abstract]:With the increasing demand for high-speed wireless communication, it is more and more important to use limited time-frequency resources to achieve higher data transmission rate. MIMO technology can significantly improve the capacity of communication system and alleviate the increasing shortage of frequency resources. Has been adopted by multiple wireless communication standards. However, in the LTE uplink, the terminal devices are limited in power consumption and cost, usually only one transmit antenna can be configured, and the data transmission rate can not be improved by the space division multiplexing of MIMO technology. In order to solve this problem, virtual MIMO technology pairs multiple users into a virtual MIMO system, which takes up the same time-frequency resources to transmit data, and can improve spectrum efficiency and system capacity effectively without raising the hardware specification of the terminal. In the virtual MIMO system, the performance of the system is directly affected by the user pairing algorithm. In this paper, the user pairing algorithm in LTE uplink virtual MIMO system is studied as follows: firstly, the simulation platform of LTE uplink system level is built. Combined with the LTE uplink system model and 3GPP related protocols, according to the system level simulation flow, the LTE uplink system is simulated and modeled, which provides a simulation platform for the performance verification of user pairing algorithm in LTE uplink virtual MIMO system. Secondly, the symmetric resource user pairing algorithm in LTE uplink virtual MIMO system is studied. Firstly, the proposed greedy multi-user pairing algorithm takes the simplified capacity factor as the metric to select one optimal user at a time, and chooses it as the paired user under the condition that it can bring extra capacity to the system. Then, on the basis of greedy algorithm, a simplified algorithm with lower complexity is obtained by using the product of multiple second-order determinant instead of higher-order determinant. Finally, based on the simplified algorithm, the proportional fairness criterion is combined to take into account the system capacity and user fairness. Simulation results show that in the LTE uplink virtual MIMO system, 40 users per cell with a pairing depth of 4 are compared with the dual proportional fair pairing algorithm. The 5% edge user throughput and the cell average throughput obtained by the simplified greedy proportional fair multi-user pairing algorithm increased by 116.67% and 13.41%, respectively. Thirdly, the user pairing algorithm of asymmetric resources in LTE uplink virtual MIMO system is studied. The proposed partial asymmetric resource pairing algorithm first blocks the frequency resource, then selects the pairing user from the first RB of each segment, then extends the RB until all the RB. is allocated. The proposed completely asymmetric resource pairing algorithm does not consider the RB occupation of scheduled users at all, and selects pairing users according to the proportional fairness criterion. The simulation results show that compared with the dual proportional fair pairing algorithm, the throughput of 5% edge users in the two-user paired LTE uplink virtual MIMO system increases by 236.73% and 256.79%, respectively, when 40 users are in each cell. The average cell throughput was increased by 40.70% and 47.38% respectively. Aiming at the limitation of MIMO technology in uplink system, this paper studies the user pairing algorithm in LTE uplink virtual MIMO system, and puts forward the greedy, simplified greedy and simplified greedy proportional fair algorithm under symmetric resources. And partially asymmetric and completely asymmetric algorithms under asymmetric resources. The proposed algorithm can be used in LTE,LTE-Advanced and other communication systems using virtual MIMO technology, which can improve spectrum efficiency and system capacity, and improve communication quality.
【学位授予单位】：电子科技大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TN929.5
，
本文编号：2471518
[Abstract]:With the increasing demand for high-speed wireless communication, it is more and more important to use limited time-frequency resources to achieve higher data transmission rate. MIMO technology can significantly improve the capacity of communication system and alleviate the increasing shortage of frequency resources. Has been adopted by multiple wireless communication standards. However, in the LTE uplink, the terminal devices are limited in power consumption and cost, usually only one transmit antenna can be configured, and the data transmission rate can not be improved by the space division multiplexing of MIMO technology. In order to solve this problem, virtual MIMO technology pairs multiple users into a virtual MIMO system, which takes up the same time-frequency resources to transmit data, and can improve spectrum efficiency and system capacity effectively without raising the hardware specification of the terminal. In the virtual MIMO system, the performance of the system is directly affected by the user pairing algorithm. In this paper, the user pairing algorithm in LTE uplink virtual MIMO system is studied as follows: firstly, the simulation platform of LTE uplink system level is built. Combined with the LTE uplink system model and 3GPP related protocols, according to the system level simulation flow, the LTE uplink system is simulated and modeled, which provides a simulation platform for the performance verification of user pairing algorithm in LTE uplink virtual MIMO system. Secondly, the symmetric resource user pairing algorithm in LTE uplink virtual MIMO system is studied. Firstly, the proposed greedy multi-user pairing algorithm takes the simplified capacity factor as the metric to select one optimal user at a time, and chooses it as the paired user under the condition that it can bring extra capacity to the system. Then, on the basis of greedy algorithm, a simplified algorithm with lower complexity is obtained by using the product of multiple second-order determinant instead of higher-order determinant. Finally, based on the simplified algorithm, the proportional fairness criterion is combined to take into account the system capacity and user fairness. Simulation results show that in the LTE uplink virtual MIMO system, 40 users per cell with a pairing depth of 4 are compared with the dual proportional fair pairing algorithm. The 5% edge user throughput and the cell average throughput obtained by the simplified greedy proportional fair multi-user pairing algorithm increased by 116.67% and 13.41%, respectively. Thirdly, the user pairing algorithm of asymmetric resources in LTE uplink virtual MIMO system is studied. The proposed partial asymmetric resource pairing algorithm first blocks the frequency resource, then selects the pairing user from the first RB of each segment, then extends the RB until all the RB. is allocated. The proposed completely asymmetric resource pairing algorithm does not consider the RB occupation of scheduled users at all, and selects pairing users according to the proportional fairness criterion. The simulation results show that compared with the dual proportional fair pairing algorithm, the throughput of 5% edge users in the two-user paired LTE uplink virtual MIMO system increases by 236.73% and 256.79%, respectively, when 40 users are in each cell. The average cell throughput was increased by 40.70% and 47.38% respectively. Aiming at the limitation of MIMO technology in uplink system, this paper studies the user pairing algorithm in LTE uplink virtual MIMO system, and puts forward the greedy, simplified greedy and simplified greedy proportional fair algorithm under symmetric resources. And partially asymmetric and completely asymmetric algorithms under asymmetric resources. The proposed algorithm can be used in LTE,LTE-Advanced and other communication systems using virtual MIMO technology, which can improve spectrum efficiency and system capacity, and improve communication quality.
【学位授予单位】：电子科技大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TN929.5
，
本文编号：2471518
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