LTE全双工系统干扰特性及性能分析

发布时间：2018-09-05 08:54

【摘要】：为了解决下一代移动通信系统频谱资源短缺的问题,一种全新的双工方式——同时同频全双工获得了关注。然而,全双工节点处由发送天线到接收天线间的回路产生的自干扰是全双工方式运用所遇到的重大难题。因此,本论文主要针对全双工系统中的自干扰问题展开研究。首先,本文分析了全双工链路系统残留自干扰模型,引入了自干扰信道估计重建法。根据自干扰信道特性,设计了特殊的导频图案并改进了基于线性最小均方误差(Linear Minimum Mean Square Error,LMMSE)的信道估计算法。仿真结果表明,改进算法成功地降低了残留自干扰并有效地改善了全双工系统的自干扰抑制性能。其次,本文分析了全双工系统的干扰模型。通过搭建仿真平台,对LTE全双工系统进行仿真,得出了与理论公式一致的仿真结果。基于仿真平台,对比研究了全双工和半双工技术的信干噪比、速率等性能指标。仿真结果表明,在速率方面,全双工系统较半双工系统有大幅度提升。此外,本文还设计了适用于不同系统负载的改进用户配对算法,该算法以平均速率为优化目标,在兼顾公平性的同时充分提升了全双工系统的整体性能,并通过仿真获得了验证。最后,本文还研究了基于空间点过程的全双工多小区网络,对比分析了六边形网络拓扑结构以及根据泊松点过程(Poisson Point Process,PPP)和Matern硬核过程Ⅱ生成的网络拓扑结构的系统性能。通过合理设计仿真参数,得出了覆盖率以及单位面积频谱效率等性能结果。
[Abstract]:In order to solve the problem of spectrum resource shortage in the next generation mobile communication system, a new duplex mode, simultaneous full duplex, has been paid attention to. However, the self-interference generated by the loop between the transmit antenna and the receiving antenna at the full-duplex node is a major problem in the full-duplex mode. Therefore, this thesis focuses on self-interference in full duplex systems. Firstly, the residual self interference model of full duplex link system is analyzed, and the self interference channel estimation and reconstruction method is introduced. According to the characteristics of self-interference channel, a special pilot pattern is designed and the channel estimation algorithm based on linear minimum mean square error (Linear Minimum Mean Square Error,LMMSE) is improved. Simulation results show that the improved algorithm successfully reduces the residual self-interference and effectively improves the self-interference suppression performance of the full-duplex system. Secondly, the interference model of full duplex system is analyzed. The LTE full-duplex system is simulated on a simulation platform, and the simulation results are consistent with the theoretical formula. Based on the simulation platform, the performance indexes of full duplex and half duplex technology, such as signal-to-noise ratio and rate, are compared and studied. The simulation results show that the full-duplex system can greatly improve the rate compared with the half-duplex system. In addition, this paper also designs an improved user pairing algorithm for different system loads. The algorithm takes the average rate as the optimization objective, and fully improves the overall performance of the full-duplex system while taking fairness into account. It is verified by simulation. Finally, we study the full duplex multicell network based on the spatial point process, and compare and analyze the topological structure of hexagonal network and the system performance of the network topology generated by Poisson point process (Poisson Point Process,PPP) and Matern hard core process II. Through reasonable design of simulation parameters, the performance results of coverage and spectral efficiency per unit area are obtained.
【学位授予单位】：西南交通大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TN929.5

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