基于SWIPT系统的联合波束形成与人工噪声设计

发布时间：2018-06-28 22:47

本文选题：MISO + SWIPT　；参考：《哈尔滨工业大学》2017年硕士论文

【摘要】：随着科学技术的迅猛发展,小功率的移动通讯设备随处可见,这使得人们对电池便捷充电的需求越来越高。传统的电能传输是通过导线实现的,充电环境具有局限性,比如医用植入环境中有线充电就极为不方便。因此,无线充电技术在智能家居,医疗器械等领域有着广泛的应用前景。以射频信号作为介质的无线通信系统既可以进行无线信息传输,也可以进行无线电能传输。我们把有此双重功能的通信系统叫做无线信息与能量同传系统,即SWIPT(Simultaneous Wireless Information and Power Transfer)系统。由于自由空间的功率耗散严重以及能量接收机的能量转换电路转换效率较低,为了使能量接收机能够达到基本能量需求,基站必须具有较大的发送功率。本文主要针对能量接收机电能收集量低以及用户对基站发送功率要求高的问题,提出了两种有效的解决方案。首先,针对用户间干扰未得到合理利用的问题,本文提出了一种基于SWIPT系统的联合波束形成设计,该设计将单一的波束形成向量延伸到两个独立的波束形成向量,进而实现信息和能量的独立控制。该设计一方面可以实现信息的定向传输,另一方面可以扩展能量的来源。本文针对MISO广播系统下的联合波束形成设计进行了理论分析与软件仿真,并与常规波束形成和迫零波束形成设计进行了对比。仿真结果表明,该设计能够通过收集用户间干扰作为电能的来源,从而达到在同等电能收集量的情况下,有效地减小基站的发送功率。其次,针对能量接收机电能收集量低的问题,本文提出了一种基于最大化电能收集量的人工噪声设计方法。在该设计下,基站发送的信号中同时含有信息波束和人工噪声,一方面人工噪声可以作为电能的来源,从而提高电能收集量。另一方面人工噪声也可以对系统中潜在的窃听用户产生干扰,从而实现安全通信。本文针对MISO广播系统下的人工噪声设计进行了理论分析与软件仿真,并与未加人工噪声的网络进行了对比。仿真结果表明,该设计能够增加能量接收机的电能收集量,并且实现信息的保密传输。综上所述,本文针对以上两种可以有效提高电能收集量的方法进行了深入的研究,在研究过程中,我们取得了一些值得参考的成果,同时新方法的提出又拓宽了SWIPT技术的研究方向。
[Abstract]:With the rapid development of science and technology, low power mobile communication devices can be seen everywhere. Traditional electric power transmission is realized by wire, and the charging environment is limited. For example, wired charging in medical implant environment is very inconvenient. Therefore, wireless charging technology in smart home, medical devices and other fields have a wide range of applications. Radio-frequency communication system can transmit both wireless information and radio energy. The communication system with this dual function is called wireless information and energy simultaneous interpretation system (SWIPT). Because of the serious power dissipation in the free space and the low efficiency of the energy conversion circuit of the energy receiver, in order to make the energy receiver meet the basic energy demand, the base station must have a large transmission power. In this paper, two effective solutions are proposed to solve the problems of low energy collection and high demand for base station transmission power. Firstly, a joint beamforming design based on SWIPT is proposed, which extends a single beamforming vector to two independent beamforming vectors. Then realize the independent control of information and energy. On the one hand, the design can realize the directional transmission of information, on the other hand, it can expand the source of energy. In this paper, theoretical analysis and software simulation of joint beamforming design in miso broadcasting system are carried out, and compared with conventional beamforming and zero-forcing beamforming designs. The simulation results show that the design can effectively reduce the transmission power of the base station by collecting interuser interference as the source of electric energy and achieving the same amount of power collection. Secondly, aiming at the problem of low energy collection in energy receiver, this paper proposes a design method of artificial noise based on maximization of energy collection. In this design, the signal sent by the base station contains both information beam and artificial noise. On the one hand, the artificial noise can be used as the source of electric energy, thus increasing the amount of power collection. On the other hand, the artificial noise can interfere with the potential eavesdropping users in the system, so as to achieve secure communication. In this paper, the design of artificial noise in miso broadcasting system is analyzed theoretically and simulated by software, and compared with the network without artificial noise. The simulation results show that the design can increase the power collection of the energy receiver and realize the secure transmission of information. To sum up, the two methods mentioned above can effectively increase the amount of electric energy collection. In the course of the research, we have achieved some valuable results. At the same time, the new method broadens the research direction of SWIPT technology.
【学位授予单位】：哈尔滨工业大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TN92

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