全双工无线通信系统自干扰消除技术的分类研究与应用

发布时间：2018-10-20 14:11

【摘要】：作为5G的关键技术,同时同频全双工以相同的时间和相同的频率发送和接收信号,与时分双工和频分双工相比,理想情况下最高可获得两倍的频谱利用率,是提高下一代无线通信系统容量的有效措施之一。但是,正因为其同时同频收发信号的特性,严重的环路自干扰成为制约其发展的主要因素。本文将对全双工系统自干扰消除技术进行研究,具体包括:(1)研究范围广泛的各类多输入多输出(Multiple-Input Multiple-Output,MIMO)中继自干扰消除方案,包括自然隔离,时域消除和空域抑制。其中空域抑制又分为天线选择,波束选择,零空间投影和最小均方误差滤波。推导各类方案的中继自干扰表达式时利用了系统的等效模型,为了最小化自干扰功率,采用独立,分离和联合三种设计方式为三类消除算法设计了最优滤波器。通过仿真评价和比较各类消除方案的性能,结果表明自干扰能够得到有效抑制。(2)采用自干扰信号频域重建抑制方法进行数字自干扰抑制,对正交频分复用(Orthogonal Frequency Division Multiplexing,OFDM)信号数字自干扰抑制展开验证,分析了数字自干扰抑制方法的原理模型和数字自干扰抑制能力,证明了自干扰信道的估计精度是影响自干扰抑制效果的关键因素。研究了压缩传感(Compressed Sensing,CS)估计方法用于自干扰信道估计,仿真结果表明,通过提供自干扰信道更加精确的估计,CS估计方法的自干扰抑制效果优于传统的最小二乘(Least Square,LS)信道估计方法。
[Abstract]:As the key technology of 5G, at the same time, the same frequency full duplex transmits and receives signals at the same time and the same frequency. Compared with time division duplex and frequency division duplex, the highest spectrum efficiency can be obtained in the ideal condition. It is one of the effective measures to improve the capacity of the next generation wireless communication system. However, because of the characteristics of simultaneous transceiver signals, the serious self-interference of loop becomes the main factor restricting its development. In this paper, the self-interference cancellation techniques for full-duplex systems are studied, including: (1) various kinds of multi-input multiple-output (Multiple-Input Multiple-Output,MIMO) relay self-interference cancellation schemes, including natural isolation, time-domain elimination and spatial domain suppression, are studied. Spatial domain suppression is divided into antenna selection, beam selection, zero space projection and minimum mean square error filtering. In order to minimize the self-interference power, the optimal filter is designed for three kinds of elimination algorithms by using three design methods: independence, separation and association, in order to minimize the self-interference power by using the equivalent model of the system when deducing the expressions of relay self-interference of various schemes. The simulation results show that the self-interference can be suppressed effectively. (2) the digital self-interference suppression is carried out by using the frequency domain reconstruction suppression method of the self-interference signal. The digital self-interference suppression of orthogonal Frequency Division Multiplexing (Orthogonal Frequency Division Multiplexing,OFDM) signal is verified. The principle model and the digital self-interference suppression ability of the digital self-interference suppression method are analyzed. It is proved that the estimation accuracy of the self interference channel is the key factor affecting the self interference suppression effect. The compression sensing (Compressed Sensing,CS) estimation method for self-interference channel estimation is studied. The simulation results show that the self-interference suppression effect of the CS estimation method is better than that of the traditional least squares (Least Square,LS) channel estimation method by providing more accurate estimation of the self-interference channel.
【学位授予单位】：南京邮电大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TN929.5

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