This paper studies a simultaneous wireless information and power transfer system with multiple external eavesdroppers and internal curious users.We model the random network by Poisson cluster process in consideration ...This paper studies a simultaneous wireless information and power transfer system with multiple external eavesdroppers and internal curious users.We model the random network by Poisson cluster process in consideration of the case where eavesdroppers hide around certain targets.Focusing on the users that work in harvesting-transmitting mode with time switching receivers,we establish communication model via time division multiple access.On this basis,we propose a lightweight secure transmission scheme based on dual-thresholds for physical-layer security enhancement,which consists of two protocols applied to the downlink(DL) and uplink(UL) transmission respectively.In the DL,we design a dynamic information-power switching transmission protocol based on signal-to-noise ratio threshold,which provides an opportunistic approach to reform the fixed period allocation of information and power transfer;in the UL,an energy threshold is proposed for users to control the transmission,which is called a user-led on-off transmission protocol.Furthermore,we give a comprehensive performance analysis for the proposed scheme in terms of delay,reliability,security and secrecy throughput.Based on the analysis results,we optimize the two thresholds and the DL-UL allocationcoefficient to maximize the secrecy throughput.Simulation results show the proposed scheme can bring about a substantial secrecy gain.展开更多
Power integrity (PI) has become a limiting factor for the chip's overall performance, and how to place in-package decoupling capacitors to improve a chip's PI performance has become a hot issue. In this paper,...Power integrity (PI) has become a limiting factor for the chip's overall performance, and how to place in-package decoupling capacitors to improve a chip's PI performance has become a hot issue. In this paper, we propose an improved trans- mission matrix method (TMM) for fast decoupling capacitance allocation. An irregular grid partition mechanism is proposed, which helps speed up the impedance computation and complies better with the irregular power/ground (P/G) plane or planes with many vias and decoupling capacitors. Furthermore, we also ameliorate the computation procedure of the impedance matrix whenever decoupling capacitors are inserted or removed at specific ports. With the fast computation of impedance change, in-package decoupling capacitor allocation is done with an efficient change based method in the frequency domain. Experimental results show that our approach can gain about 5× speedup compared with a general TMM, and is efficient in restraining the noise on the P/G plane.展开更多
针对现有无线电能与反向信号同步传输(simultaneous wireless power and reverse signal transmission,SWPRST)系统存在较大无功功率、负载电压易受信号传输发生波动或需要额外增加高频信号源等问题,提出一种基于谐波通讯的SWPRST技术,...针对现有无线电能与反向信号同步传输(simultaneous wireless power and reverse signal transmission,SWPRST)系统存在较大无功功率、负载电压易受信号传输发生波动或需要额外增加高频信号源等问题,提出一种基于谐波通讯的SWPRST技术,通过利用逆变器输出方波电压中的基波分量传输电能,三次谐波分量传输信号。不需要外加高频信号发射电路,实现了可靠的电能与反向信号同步传输。首先,给出基于谐波通讯的SWPRST系统结构,对其工作模式和基本原理进行分析;接着,建立系统等效数学模型,分析系统参数取值对信号与电能传输之间的互扰影响;然后,对信号的调制解调电路进行设计,分析信号检测通道参数对信号传输速率的影响;最后,搭建实验平台对理论分析进行验证,实验结果表明,该方法在有效实现了无线电能与反向信号同步传输的同时,信号无误码率传输速率可达5 kbps,同时系统具有无功小,输出负载电压几乎无波动(电压波动率0.33%)等优点。该方法采用谐波作为信号载体,为多频利用式实现电能与反向信号同步传输系统提供一种新的思路,具有较好的理论意义与实际工程应用价值。展开更多
能量捕获无线传感器网络是解决传统无线传感器网络能量问题的有效途径之一,无线携能通信网络SWIPT(Simultaneous wireless information and power transfer)是其中的一个重要研究方向。研究了一种SWIPT场景,在源节点总功率的约束条件下...能量捕获无线传感器网络是解决传统无线传感器网络能量问题的有效途径之一,无线携能通信网络SWIPT(Simultaneous wireless information and power transfer)是其中的一个重要研究方向。研究了一种SWIPT场景,在源节点总功率的约束条件下,最大化总传输速率。源节点通过在不同的频谱上分配不同的功率发送携能信号给多个中继节点,中继节点对于接收到的携能信号通过功率分配将一部分信号转化为能量,一部分信号解码为信息;中继节点利用捕获的能量将信息转发给目的节点。建立数学模型求解最优的功率分配因子,运用拉格朗日乘数法求得源节点在每个频谱上分配功率的表达式,按照注水算法求得最终分配的功率和最大化的总传输速率,最后通过数值模拟进行了有效性验证。展开更多
针对磁耦合无线电能与数据协同传输系统中磁耦合数据通信面临的传能装置谐波干扰,建立了基于DD线圈的通信和干扰感测相互隔离的射频通道,并在数字域采用基于递归最小二乘(Recursive Least Square,RLS)算法的数字干扰对消,抑制通信链路...针对磁耦合无线电能与数据协同传输系统中磁耦合数据通信面临的传能装置谐波干扰,建立了基于DD线圈的通信和干扰感测相互隔离的射频通道,并在数字域采用基于递归最小二乘(Recursive Least Square,RLS)算法的数字干扰对消,抑制通信链路的残余传能干扰。通过仿真验证了方案的可行性。建立了中心频率17.6 MHz、通信带宽2 MHz的通信与干扰感测通道,并基于GNU Radio和X310软件无线电平台完成了算法验证,成功恢复出受传能谐波干扰的正交相移键控(Phase-Shift Keying,QPSK)通信信号星座图,将带内干扰谐波抑制了12 dB以上,提升了磁耦合通信链路抗干扰能力。展开更多
基金supported in part by China High-Tech RD Program(863 Program) SS2015AA011306National Natural Science Foundation of China under Grants No.61379006,61401510,61501516,61521003
文摘This paper studies a simultaneous wireless information and power transfer system with multiple external eavesdroppers and internal curious users.We model the random network by Poisson cluster process in consideration of the case where eavesdroppers hide around certain targets.Focusing on the users that work in harvesting-transmitting mode with time switching receivers,we establish communication model via time division multiple access.On this basis,we propose a lightweight secure transmission scheme based on dual-thresholds for physical-layer security enhancement,which consists of two protocols applied to the downlink(DL) and uplink(UL) transmission respectively.In the DL,we design a dynamic information-power switching transmission protocol based on signal-to-noise ratio threshold,which provides an opportunistic approach to reform the fixed period allocation of information and power transfer;in the UL,an energy threshold is proposed for users to control the transmission,which is called a user-led on-off transmission protocol.Furthermore,we give a comprehensive performance analysis for the proposed scheme in terms of delay,reliability,security and secrecy throughput.Based on the analysis results,we optimize the two thresholds and the DL-UL allocationcoefficient to maximize the secrecy throughput.Simulation results show the proposed scheme can bring about a substantial secrecy gain.
基金the Ph.D Programs Foundation of Ministry of Education of China (No. 20060335065)the Natural Science Foundation of Zhejiang Province, China (No. Y106513)
文摘Power integrity (PI) has become a limiting factor for the chip's overall performance, and how to place in-package decoupling capacitors to improve a chip's PI performance has become a hot issue. In this paper, we propose an improved trans- mission matrix method (TMM) for fast decoupling capacitance allocation. An irregular grid partition mechanism is proposed, which helps speed up the impedance computation and complies better with the irregular power/ground (P/G) plane or planes with many vias and decoupling capacitors. Furthermore, we also ameliorate the computation procedure of the impedance matrix whenever decoupling capacitors are inserted or removed at specific ports. With the fast computation of impedance change, in-package decoupling capacitor allocation is done with an efficient change based method in the frequency domain. Experimental results show that our approach can gain about 5× speedup compared with a general TMM, and is efficient in restraining the noise on the P/G plane.
文摘针对现有无线电能与反向信号同步传输(simultaneous wireless power and reverse signal transmission,SWPRST)系统存在较大无功功率、负载电压易受信号传输发生波动或需要额外增加高频信号源等问题,提出一种基于谐波通讯的SWPRST技术,通过利用逆变器输出方波电压中的基波分量传输电能,三次谐波分量传输信号。不需要外加高频信号发射电路,实现了可靠的电能与反向信号同步传输。首先,给出基于谐波通讯的SWPRST系统结构,对其工作模式和基本原理进行分析;接着,建立系统等效数学模型,分析系统参数取值对信号与电能传输之间的互扰影响;然后,对信号的调制解调电路进行设计,分析信号检测通道参数对信号传输速率的影响;最后,搭建实验平台对理论分析进行验证,实验结果表明,该方法在有效实现了无线电能与反向信号同步传输的同时,信号无误码率传输速率可达5 kbps,同时系统具有无功小,输出负载电压几乎无波动(电压波动率0.33%)等优点。该方法采用谐波作为信号载体,为多频利用式实现电能与反向信号同步传输系统提供一种新的思路,具有较好的理论意义与实际工程应用价值。
文摘能量捕获无线传感器网络是解决传统无线传感器网络能量问题的有效途径之一,无线携能通信网络SWIPT(Simultaneous wireless information and power transfer)是其中的一个重要研究方向。研究了一种SWIPT场景,在源节点总功率的约束条件下,最大化总传输速率。源节点通过在不同的频谱上分配不同的功率发送携能信号给多个中继节点,中继节点对于接收到的携能信号通过功率分配将一部分信号转化为能量,一部分信号解码为信息;中继节点利用捕获的能量将信息转发给目的节点。建立数学模型求解最优的功率分配因子,运用拉格朗日乘数法求得源节点在每个频谱上分配功率的表达式,按照注水算法求得最终分配的功率和最大化的总传输速率,最后通过数值模拟进行了有效性验证。
