This paper proposes a novel unmanned aerial vehicle(UAV)-based illegal radio station(IRS) localization scheme, where the transmit power of the IRS, the channel model and the noise model are unknown to the UAV. A direc...This paper proposes a novel unmanned aerial vehicle(UAV)-based illegal radio station(IRS) localization scheme, where the transmit power of the IRS, the channel model and the noise model are unknown to the UAV. A direction-aware Q-learning algorithm is developed to process received signal strength(RSS) values collected by a directional antenna, as well as directions corresponding to the RSS values. This algorithm determines the direction the UAV flies towards and thereby finds the IRS. The proposed scheme is compared to two baseline schemes. One baseline locates the IRS by a UAV equipped with an omnidirectional antenna, where conventional Q-learning is exploited to process the measured RSS and determine the UAV's trajectory. The other baseline locates the IRS by a directional-antenna UAV, where the UAV flies towards the direction with respect to the maximum RSS value. Numerical results show that, especially for a low receive SNR, the proposed scheme can outperform the two baselines in terms of the localization efficiency, providing a smoother trajectory for the UAV.展开更多
The paper deals the popular news-talk radio station ＂Echo of Moscow＂ which is one of the most interesting and successful one in Moscow FM range. It provides thorough analysis of different previous and nowadays progr...The paper deals the popular news-talk radio station ＂Echo of Moscow＂ which is one of the most interesting and successful one in Moscow FM range. It provides thorough analysis of different previous and nowadays programs and web projects in comparison with main multimedia sphere trends. A particular attention is paid to ＂Echo of Moscow＂ web page as multimedia portal strongly packed with different functions such as its integration with social nets.展开更多
With the explosive growth of highspeed wireless data demand and the number of mobile devices, fog radio access networks(F-RAN) with multi-layer network structure becomes a hot topic in recent research. Meanwhile, due ...With the explosive growth of highspeed wireless data demand and the number of mobile devices, fog radio access networks(F-RAN) with multi-layer network structure becomes a hot topic in recent research. Meanwhile, due to the rapid growth of mobile communication traffic, high cost and the scarcity of wireless resources, it is especially important to develop an efficient radio resource management mechanism. In this paper, we focus on the shortcomings of resource waste, and we consider the actual situation of base station dynamic coverage and user requirements. We propose a spectrum pricing and allocation scheme based on Stackelberg game model under F-RAN framework, realizing the allocation of resource on demand. This scheme studies the double game between the users and the operators, as well as between the traditional operators and the virtual operators, maximizing the profits of the operators. At the same time, spectrum reuse technology is adopted to improve the utilization of network resource. By analyzing the simulation results, it is verified that our proposed scheme can not only avoid resource waste, but also effectively improve the operator's revenue efficiency and overall network resource utilization.展开更多
针对传统杆状天线在现代化战争应用场景中存在的带宽窄、质地硬以及隐蔽性与便携性较差等问题,提出了一种基于柔性介质材料的可穿戴式天线,该天线采用平面单极子天线的形式,极大地降低天线的剖面。借助电磁仿真软件CST Studio Suite 202...针对传统杆状天线在现代化战争应用场景中存在的带宽窄、质地硬以及隐蔽性与便携性较差等问题,提出了一种基于柔性介质材料的可穿戴式天线,该天线采用平面单极子天线的形式,极大地降低天线的剖面。借助电磁仿真软件CST Studio Suite 2023进行仿真分析,该天线尺寸为270 mm×270 mm×1.1 mm,重量仅有120 g,包含0.37~1.8 GHz的实测宽带频段,在人体加载影响下,实测频段范围超过0.3~1.8 GHz。给出了反射系数S_(11)、辐射方向图的结果,分析了人体对天线的影响,结合通信电台开展实物对比测试。仿真与实测表明,可穿戴式天线在士兵手持电台中具有一定的应用前景。展开更多
射频识别(Radio Frequency Identification,RFID)技术利用电磁场自动识别和跟踪附着在物体上的标签。该技术分为被动RFID和主动RFID,前者不含电池,通过读取器提供的电磁波激活,后者则含有电池,能主动发送信号。基于此,深入探讨RFID技术...射频识别(Radio Frequency Identification,RFID)技术利用电磁场自动识别和跟踪附着在物体上的标签。该技术分为被动RFID和主动RFID,前者不含电池,通过读取器提供的电磁波激活,后者则含有电池,能主动发送信号。基于此,深入探讨RFID技术在广播电台数字音频系统中的应用,包括音频跟踪、管理及自动化,并通过具体案例分析展示其优化广播运作流程的潜力。展开更多
基金supported by China NSF Grants(61631020)Fundamental Research Funds for the Central Universities(NP2018103,NE2017103,NC2017003)
文摘This paper proposes a novel unmanned aerial vehicle(UAV)-based illegal radio station(IRS) localization scheme, where the transmit power of the IRS, the channel model and the noise model are unknown to the UAV. A direction-aware Q-learning algorithm is developed to process received signal strength(RSS) values collected by a directional antenna, as well as directions corresponding to the RSS values. This algorithm determines the direction the UAV flies towards and thereby finds the IRS. The proposed scheme is compared to two baseline schemes. One baseline locates the IRS by a UAV equipped with an omnidirectional antenna, where conventional Q-learning is exploited to process the measured RSS and determine the UAV's trajectory. The other baseline locates the IRS by a directional-antenna UAV, where the UAV flies towards the direction with respect to the maximum RSS value. Numerical results show that, especially for a low receive SNR, the proposed scheme can outperform the two baselines in terms of the localization efficiency, providing a smoother trajectory for the UAV.
文摘The paper deals the popular news-talk radio station ＂Echo of Moscow＂ which is one of the most interesting and successful one in Moscow FM range. It provides thorough analysis of different previous and nowadays programs and web projects in comparison with main multimedia sphere trends. A particular attention is paid to ＂Echo of Moscow＂ web page as multimedia portal strongly packed with different functions such as its integration with social nets.
基金supported in part by the National Natural Science Foundation of China (61771120)the Fundamental Research Funds for the Central Universities (N171602002)
文摘With the explosive growth of highspeed wireless data demand and the number of mobile devices, fog radio access networks(F-RAN) with multi-layer network structure becomes a hot topic in recent research. Meanwhile, due to the rapid growth of mobile communication traffic, high cost and the scarcity of wireless resources, it is especially important to develop an efficient radio resource management mechanism. In this paper, we focus on the shortcomings of resource waste, and we consider the actual situation of base station dynamic coverage and user requirements. We propose a spectrum pricing and allocation scheme based on Stackelberg game model under F-RAN framework, realizing the allocation of resource on demand. This scheme studies the double game between the users and the operators, as well as between the traditional operators and the virtual operators, maximizing the profits of the operators. At the same time, spectrum reuse technology is adopted to improve the utilization of network resource. By analyzing the simulation results, it is verified that our proposed scheme can not only avoid resource waste, but also effectively improve the operator's revenue efficiency and overall network resource utilization.
文摘针对传统杆状天线在现代化战争应用场景中存在的带宽窄、质地硬以及隐蔽性与便携性较差等问题,提出了一种基于柔性介质材料的可穿戴式天线,该天线采用平面单极子天线的形式,极大地降低天线的剖面。借助电磁仿真软件CST Studio Suite 2023进行仿真分析,该天线尺寸为270 mm×270 mm×1.1 mm,重量仅有120 g,包含0.37~1.8 GHz的实测宽带频段,在人体加载影响下,实测频段范围超过0.3~1.8 GHz。给出了反射系数S_(11)、辐射方向图的结果,分析了人体对天线的影响,结合通信电台开展实物对比测试。仿真与实测表明,可穿戴式天线在士兵手持电台中具有一定的应用前景。
文摘射频识别(Radio Frequency Identification,RFID)技术利用电磁场自动识别和跟踪附着在物体上的标签。该技术分为被动RFID和主动RFID,前者不含电池,通过读取器提供的电磁波激活,后者则含有电池,能主动发送信号。基于此,深入探讨RFID技术在广播电台数字音频系统中的应用,包括音频跟踪、管理及自动化,并通过具体案例分析展示其优化广播运作流程的潜力。
