Backscatter communications will play an important role in connecting everything for beyond 5G(B5G)and 6G systems.One open challenge for backscatter communications is that the signals suffer a round-trip path loss so t...Backscatter communications will play an important role in connecting everything for beyond 5G(B5G)and 6G systems.One open challenge for backscatter communications is that the signals suffer a round-trip path loss so that the communication distance is short.In this paper,we first calculate the communication distance upper bounds for both uplink and downlink by measuring the tag sensitivity and reflection coefficient.It is found that the activation voltage of the envelope detection diode of the downlink tag is the main factor limiting the back-scatter communication distance.Based on this analysis,we then propose to implement a low-noise amplifier(LNA)module before the envelope detection at the tag to enhance the incident signal strength.Our experimental results on the hardware platform show that our method can increase the downlink communication range by nearly 20 m.展开更多
Internet of Things (IoT) has attracted extensive interest from both academia and industries, and is recognized as an ultimate infrastructure to connect everything at anytime and anywhere. The implementation of IoT gen...Internet of Things (IoT) has attracted extensive interest from both academia and industries, and is recognized as an ultimate infrastructure to connect everything at anytime and anywhere. The implementation of IoT generally faces the challenges from energy constraint and implementation cost. In this paper, we will introduce a new green communication paradigm, the ambient backscatter (AmBC), that could utilize the environmental wireless signals for both powering a tiny-cost device and backscattering the information symbols. Specifically, we will present the basic principles of AmBC, analyze its features and advantages, suggest its open problems, and predict its potential applications for our future IoT.展开更多
环境反向散射技术以低功耗、低成本的特点,被认为是分布式光伏场景的潜在解决方案之一。在未来的分布式光伏系统中,为实现对离散分布的光伏电站智能监测与管理,需要配备物联网信息终端,从多个位置采集传感数据并对采集节点进行精确定位...环境反向散射技术以低功耗、低成本的特点,被认为是分布式光伏场景的潜在解决方案之一。在未来的分布式光伏系统中,为实现对离散分布的光伏电站智能监测与管理,需要配备物联网信息终端,从多个位置采集传感数据并对采集节点进行精确定位。针对现有的反向散射定位系统依赖多个终端对单个环境物联网(Ambient Internet of Things,Ambient IoT)节点进行定位,限制了在复杂场景中的适用性问题,提出了一种仅使用单个物联网终端的环境反向散射智能通信与感知系统。系统利用反向散射信号的信道参数随时间变化更加稳定的特点,将反向散射信号从丰富的多径信号中分离并获取信道参数估计;反向散射标签进行开关键控(On-Off Keying,OOK)调制,利用调制的数据实现多个标签与相应的信道参数估计关联;利用获得的参数进行三角定位确定多个标签的位置;联合优化框架利用多个标签的位置估计,有效减轻了测量误差的影响。实验结果表明,系统实现了0.35 m的中位数定位精度和1.18 m的90%定位精度。展开更多
基金supported in part by National Natural Science Foundation of China under Grant Nos.61971029 and U22B2004in part by Beijing Municipal Natural Science Foundation under Grant No.L222002.
文摘Backscatter communications will play an important role in connecting everything for beyond 5G(B5G)and 6G systems.One open challenge for backscatter communications is that the signals suffer a round-trip path loss so that the communication distance is short.In this paper,we first calculate the communication distance upper bounds for both uplink and downlink by measuring the tag sensitivity and reflection coefficient.It is found that the activation voltage of the envelope detection diode of the downlink tag is the main factor limiting the back-scatter communication distance.Based on this analysis,we then propose to implement a low-noise amplifier(LNA)module before the envelope detection at the tag to enhance the incident signal strength.Our experimental results on the hardware platform show that our method can increase the downlink communication range by nearly 20 m.
基金supported in part by National Key R&D Program of China under Grant 2016YFE0200900part by Scientific Research Program of Beijing Municipal Commission of Education under Grant KM201910853003part by Major projects of Beijing Municipal Science and Technology Commission under Grant Z181100003218010
文摘Internet of Things (IoT) has attracted extensive interest from both academia and industries, and is recognized as an ultimate infrastructure to connect everything at anytime and anywhere. The implementation of IoT generally faces the challenges from energy constraint and implementation cost. In this paper, we will introduce a new green communication paradigm, the ambient backscatter (AmBC), that could utilize the environmental wireless signals for both powering a tiny-cost device and backscattering the information symbols. Specifically, we will present the basic principles of AmBC, analyze its features and advantages, suggest its open problems, and predict its potential applications for our future IoT.
文摘环境反向散射技术以低功耗、低成本的特点,被认为是分布式光伏场景的潜在解决方案之一。在未来的分布式光伏系统中,为实现对离散分布的光伏电站智能监测与管理,需要配备物联网信息终端,从多个位置采集传感数据并对采集节点进行精确定位。针对现有的反向散射定位系统依赖多个终端对单个环境物联网(Ambient Internet of Things,Ambient IoT)节点进行定位,限制了在复杂场景中的适用性问题,提出了一种仅使用单个物联网终端的环境反向散射智能通信与感知系统。系统利用反向散射信号的信道参数随时间变化更加稳定的特点,将反向散射信号从丰富的多径信号中分离并获取信道参数估计;反向散射标签进行开关键控(On-Off Keying,OOK)调制,利用调制的数据实现多个标签与相应的信道参数估计关联;利用获得的参数进行三角定位确定多个标签的位置;联合优化框架利用多个标签的位置估计,有效减轻了测量误差的影响。实验结果表明,系统实现了0.35 m的中位数定位精度和1.18 m的90%定位精度。
