一款新型电荷泵功率管驱动电路

提出了一款新型功率管驱动电路。P沟道功率管驱动电路加入了防死锁模块防止了死锁的出现,提高了瞬态响应;N沟道功率管驱动电路加入了附加的充电支路,提高了驱动能力和瞬态响应。整个电路基于0.6μm BCD工艺,在Cadence Spectre下仿真。和传统的功率管驱动电路相比,新的P沟道功率管驱动电路的上升时间由60ns减少到14ns,下降时间由240ns减少到30ns,并且功耗从2mW减少到1mW;新的N沟道功率管驱动电路的上升时间由360ns减少到27ns,功耗从1.1mW减少到0.8mW。     

A novel charge pump drive circuit for power MOSFETs

Novel improved power metal oxide semiconductor field effect transistor (MOSFET) drive circuits are introduced. An anti-deadlock block is used in the P-channel power MOSFET drive circuit to avoid deadlocks and improve the transient response. An additional charging path is added to the N-channel power MOSFET drive circuit to enhance its drive capability and improve the transient response. The entire circuit is designed in a 0.6 μm BCD process and simulated with Cadence Spectre. Compared with traditional power MOSFET drive circuits, the simulation results show that improved P-channel power MOSFET drive circuit makes the rise time reduced from 60 to 14 ns, the fall time reduced from 240 to 30 ns, and its power dissipation reduced from 2 to 1 mW, while the improved N-channel power MOSFET drive circuit makes the rise time reduced from 360 to 27 ns and its power dissipation reduced from 1.1 to 0.8 mW.     

Analyzing lifetime of energy harvesting underwater wireless sensor nodes

Underwater Wireless Sensor Networks (UWSNs) are utilized to monitor underwater environments that pose many challenges to researchers. One of the key complications of UWSNs is the difficulty of changing node batteries after their energy is depleted. This study aims to diminish the issues related to battery replacement by improving node lifetime. For this goal, three energy harvesting devices (turbine harvester, piezoelectric harvester, and hydrophone harvester) are analyzed to quantitate their impacts on node lifetime. In addition, two different power management schemes (schedule‐driven and event‐driven power management schemes) are combined with energy harvesters for further lifetime improvement. Performance evaluations via simulations show that energy harvesting methods joined by power management schemes can improve node lifetime substantially when actual conditions of Istanbul Bosporus Strait are considered. In this respect, turbine harvester makes the biggest impact and provides lifetime beyond 2000 days for most cases, while piezoelectric harvester can perform the same only for low duty cycle or event arrival values at short transmission ranges.     

A CMOS AC/DC charge pump for a wireless sensor network

实现了一种应用于无线网络传感器的基于MOS管的AC/DC电荷泵,提出的AC/DC电荷泵在0.13μm公益平台实现能够提供稳定的工作电压,同时具有低功耗及高充电效率。电荷泵采用了具有低阈值（Vth）的MOSFET二极管,提高了转换效率。给出了电压倍增器的模型,仿真结果和芯片测试结果。     

A dual-mode energy efficient encryption protocol for wireless sensor networks

This paper presents a novel link-layer encryption protocol for wireless sensor networks. The protocol design aims to reduce energy consumption by reducing security related communication overhead. This is done by merging security related data of consecutive packets. The merging (or combining packets) based on simple mathematical operations helps to reduce energy consumption by eliminating the requirement to send security related fields in headers and trailers. We name our protocol as the Compact Security Protocol referred to as C-Sec. In addition to energy savings, the C-Sec protocol also includes a unique security feature of hiding the packet header information. This feature makes it more difficult to trace the flow of wireless communication, and helps to minimize the cost of defending against replay attacks. We performed rigorous testing of the C-Sec protocol and compared it with well-known protocols including TinySec, MiniSec, SNEP and Zigbee. Our performance evaluation demonstrates that the C-Sec protocol outperforms other protocols in terms of energy savings. We also evaluated our protocol with respect to other performance metrics including queuing delay and error probability.     

基于无线传感器网络的路边停车检测系统设计

为了构建基于无线传感器网络的大规模、低成本、低功耗的城市路边停车检测系统,本文提出了一种停车检测传感器节点硬件及软件设计方案。该系统硬件部分利用磁阻传感器实现车辆磁信号检测．软件部分主要实现基于磁信号的车辆检测算法。实地部署了80多个传感器节点的路边停车检测系统,实际应用表明该系统车辆检测精度高,达到了设计要求。     

Investigation of wireless sensor node power consumption profile powered by heterogeneous hybrid energy harvesters with EPDD management algorithm

Node lifetime is the major challenge in the WSN design, which is directly related to the power consumption optimisation. Therefore, there is a necessity to investigate the node power profile so that the hardware designers will have a full picture about the system demand in an early stage of the design. Likewise, it helps the software designers in developing suitable energy-aware operating/routing protocols. This paper profiles an enhanced wireless sensor node called ‘WSN_{_3_HHEH}’ power consumption powered by heterogeneous hybrid energy harvesting and equipped with an improved energy-aware Event-Priority-Driven Dissemination (EPDD) algorithm. The extensive real-world empirical power profiling measurements for each unit and node system level during active and sleep modes are presented, which it provides data on the wireless sensor node architectural design that is applicable for low-power and IoT applications. The results point out that within the WSN_{_3_HHEH} the RF transceiver consumed the highest power of 24 mW, followed by the MCU with 7.5 mW, and the sensor module with 0.16 mW throughout the active period. During the sleeping period however, the MCU unit consumed a noticeable amount of power of 1.8 mW compared to the other sensor node units.     

A high efficiency charge pump circuit for low power applications

A high efficiency charge pump circuit is designed and realized. The charge transfer switch is biased by the additional capacitor and transistor to eliminate the influence of the threshold voltage. Moreover, the bulk of the switch transistor is dynamically biased so that the threshold voltage gets lower when it is turned on during charge transfer and gets higher when it is turned off. As a result, the efficiency of the charge pump circuit can be improved. A test chip has been implemented in a 0.18 μm 3.3 V standard CMOS process. The measured output voltage of the eight-pumping-stage charge pump is 9.8 V with each pumping capacitor of 0.5 pF at an output current of 0.18 μA, when the clock frequency is 780 kHz and the supply voltage is 2 V. The charge pump and the clock driver consume a total current of 2.9 μA from the power supply. This circuit is suitable for low power applications.     

一种高效率的适合于低功耗应用的电荷泵电路

设计实现了一种高效率的电荷泵电路。利用电容和晶体管对电荷传输开关进行偏置来消除开关管阈值电压的影响。同时,通过对开关管的的衬底进行动态的偏置使得在电荷传输期间当开关管打开时其阈值电压较低,在开关管关断时其阈值电压较高。该电荷泵电路的效率得到了提高。基于0.18μm,3.3V标准CMOS工艺实现了该电路。在每级电容为0.5pF,时钟频率为780KHz,电源电压为2V的情况下,测得的8级电荷泵的输出电压为9.8V。电荷泵电路和时钟驱动电路从电源处总共消耗了2.9μA的电流。该电荷泵电路适合于低功耗的应用。     

能量收集多跳D2D无线传感网络中的中继选择算法

针对无线功率传输技术的能量收集效率有限造成信噪比下降进而引发通信中断率增加的问题,在能量收集多跳D2D(Device to Device)无线传感网络中,提出一种基于改进K-means聚类的中继选择方法。首先,推导得到能量收集下的信噪比因子,使其作为K-means聚类特征。然后,利用最小欧氏距离原则得到距离聚类中心最近的实际节点的位置。最后,根据距离重排序得到中继节点,形成从源节点到目的节点的通信链路。仿真实验结果表明,相比最短路径算法和随机中继协作方案,所提出的改进算法链路信噪比更大,能够减小通信中断率,具有更好的中继性能。     

Wake-up radio receiver based power minimization techniques for wireless sensor networks: A review

In a short period of time Wireless Sensor Networks (WSN) captured the imagination of many researchers with the number of applications growing rapidly. The applications span large domains including mobile digital health, structural and environmental monitoring, smart home, energy efficient buildings, agriculture, smart cities, etc. WSN are also an important contributor to the fast emerging Internet of Things infrastructure. Some of the design specifications for WSN include reliability, accuracy, cost, deployment versatility, power consumption, etc. Power consumption is (most often) the dominant constraint in designing such systems. This constraint has multi-dimensional implications such as battery type and size, energy harvester design, lifetime of the deployment, intelligent sensing capability, etc. Power optimization techniques have to explore a large design search space. Energy neutral system implementation is the ultimate goal in wireless sensor networks ensuring a perpetual/greener use and represents a hot topic of research. Several recent advances promise significant reduction of the overall sensor network power consumption. These advances include novel sensors and sensor interfaces, low energy wireless transceivers, low power processing, efficient energy harvesters, etc. This paper reviews a number of system level power management methodologies for Wireless Sensor Networks. Especially, the paper is focusing on the promising technology of nano-Watt wake-up radio receiver and its combination with mature power management techniques to achieve better performance. Some of the presented techniques are then applied in the context of low cost and battery powered toy robots.     

Indoor localization based on wireless sensor networks

Indoor localization systems are becoming very popular because they enable the creation of very interesting location-based applications. This paper provides a short introduction about localization systems based on a sensor network and the actual state of the art. Important topics related to indoor localization like the necessary infrastructure, available technologies and their expected accuracy are treated. Additionally, the results of previous work referred to the performance evaluation of localization algorithms are shortly described. Finally, some ideas related to further investigations are presented.     

Power management circuits for self-powered systems based on micro-scale solar energy harvesting

In this paper, two types of power management circuits for self-powered systems based on micro-scale solar energy harvesting are proposed. First, if a solar cell outputs a very low voltage, less than 0.5 V, as in miniature solar cells or monolithic integrated solar cells, such that it cannot directly power the load, a voltage booster is employed to step up the solar cell’s output voltage, and then a power management unit (PMU) delivers the boosted voltage to the load. Second, if the output voltage of a solar cell is enough to drive the load, the PMU directly supplies the load with solar energy. The proposed power management systems are designed and fabricated in a 0.18-μm complementary metal–oxide–semiconductor process, and their performances are compared and analysed through measurements.     

基于分簇的有效无线传感器网络密钥管理方案

针对现有无线传感器网络密钥管理中计算量过大、存储空间过多和网络安全问题,在分簇结构无线传感器网络基础上,提出一种新的密钥管理方案,它通过将已存储的密钥部分地转化为即使被攻击者截获也无影响的特殊信息,来获取更加良好的安全性,同时又不降低网络的连通性。通过仿真与其他算法进行性能对比,结果显示这种方案具有更好的性能。     

基于簇结构超宽带无线传感器网络的传输功率优化选择算法

在簇结构超宽带无线传感器网络中,为了在可接受的实现成本范围内解决节能与功率控制问题,提出了一种传输功率优化选择算法,同时满足了预设的数据传输速度和最大限度的节能要求.然后详细地分析了该算法实现的可行性、复杂度和实现成本.仿真结果表明,本算法得出的最优传输功率大大小于传感器节点可获取的最大功率,并可以根据网络背景噪声和最大传输速度的变化而动态调整;该算法可以较为显著地延长传感器节点寿命;另外,仿真结果还表明本算法的实现成本是合理的且可接受的.     

IRS: application reconfiguration scheme for wireless sensor networks

Application reconfiguration is essential to achieving flexibility and adaptability of wireless sensor networks (WSNs) used in environment monitoring. In this paper, we present an integrated reconfiguration scheme (IRS) for implementing environment adaptive application reconfiguration (EAAR) in WSNs. In our scheme, application reconfiguration is implemented with the push‐based paradigm for densely distributed nodes and the cluster‐based hybrid reconfiguration (CHR) paradigm for sparsely distributed nodes. We demonstrate the energy‐efficiency and scalability of our scheme by analyzing the energy consumption based on a randomly deployed sensor network. Moreover, we derive the density threshold of reconfiguration nodes (RNs) for determining if the nodes are densely or sparsely distributed, and choose the mode of operation for IRS. We use extensive simulation experiments to demonstrate the effectiveness of our scheme. Copyright © 2009 John Wiley & Sons, Ltd.     

Energy aware efficient geographic routing in lossy wireless sensor networks with environmental energy supply

Wireless sensor networks are characterized by multihop wireless lossy links and resource constrained nodes. Energy efficiency is a major concern in such networks. In this paper, we study Geographic Routing with Environmental Energy Supply (GREES) and propose two protocols, GREES-L and GREES-M, which combine geographic routing and energy efficient routing techniques and take into account the realistic lossy wireless channel condition and the renewal capability of environmental energy supply when making routing decisions. Simulation results show that GREESs are more energy efficient than the corresponding residual energy based protocols and geographic routing protocols without energy awareness. GREESs can maintain higher mean residual energy on nodes, and achieve better load balancing in terms of having smaller standard deviation of residual energy on nodes. Both GREES-L and GREES-M exhibit graceful degradation on end-to-end delay, but do not compromise the end-to-end throughput performance. Kai Zeng received his B.E. degree in Communication Engineering and M.E. degree in Communication and Information System both from Huazhong University of Science and Technology, China, in 2001 and 2004, respectively. He is currently a Ph.D. student in the Electrical and Computer Engineering department at Worcester Polytechnic Institute. His research interests are in the areas of wireless ad hoc and sensor networks with emphases on energy-efficient protocol, cross-layer design, routing, and network security. Kui Ren received his B. Eng. and M. Eng. both from Zhejiang University, China, in 1998 and 2001, respectively. He worked as a research assistant at Shanghai Institute of Microsystem and Information Technology, Chinese Academy of Sciences from March 2001 to January 2003, at Institute for Infocomm Research, Singapore from January 2003 to August 2003, and at Information and Communications University, South Korea from September 2003 to June 2004. Currently he is a PhD candidate in the ECE department at Worcester Polytechnic Institute. His research interests include ad hoc/sensor network security, wireless mesh network security, Internet security, and security and privacy in ubiquitous computing environments. Wenjing Lou is an assistant professor in the Electrical and Computer Engineering department at Worcester Polytechnic Institute. She obtained her Ph.D. degree in Electrical and Computer Engineering from University of Florida in 2003. She received the M.A.Sc. degree from Nanyang Technological University, Singapore, in 1998, the M.E. degree and the B.E. degree in Computer Science and Engineering from Xi’an Jiaotong University, China, in 1996 and 1993 respectively. From December 1997 to July 1999, she worked as a Research Engineer in Network Technology Research Center, Nanyang Technological University. Her current research interests are in the areas of ad hoc and sensor networks, with emphases on network and system security and routing. Patrick J. Moran received his MSEE from Carnegie Mellon University, 1993. He is currently the CTO and Founder of AirSprite Technologies Inc, and is driving the company to utilize advanced networking protocols for low-power wireless network systems. His interests include architecture, protocols and high performance implementation of emerging communication technologies. Patrick has been involved in deployment of communication and signal processing technologies since graduating from the University of Minn. in 1986. He holds several patents and publications relating to storage, medical and data processing information systems. He is a member of the IEEE.     

Combined spatial-temporal energy harvesting and relay selection for cognitive wireless powered networks

In order to improve the Energy Efficiency (EE) and spectrum utilization of Cognitive Wireless Powered Networks (CWPNs), a combined spatial-temporal Energy Harvesting (EH) and relay selection scheme is proposed. In the proposed scheme, for protecting the Primary User (PU), a two-layer guard zone is set outside the PU based on the outage probability threshold of the PU. Moreover, to increase the energy of the CWPNs, the EH zone in the two-layer guard zone allows the Secondary Users (SUs) to spatially harvest energy from the Radio Frequency (RF) signals of temporally active PUs. To improve the utilization of the PU spectrum, the guard zone outside the EH zone allows for the constrained power transmission of SUs. Moreover, the relay selection transmission is designed in the transmission zone of the SU to improve the EE of the CWPNs. In addition to the EE of the CWPNs, the outage probabilities of the SU and PU are derived. The results reveal that the setting of a two-layer guard zone can effectively reduce the outage probability of the PU and improve the EE of CWPNs. Furthermore, the relay selection transmission decreases the outage probabilities of the SUs.     

Towards a classification of energy aware MAC protocols for wireless sensor networks

Power management is an important issue in wireless sensor networks (WSNs) because wireless sensor nodes are usually battery powered, and an efficient use of the available battery power becomes an important concern specially for those applications where the system is expected to operate for long durations. This necessity for energy efficient operation of a WSN has prompted the development of new protocols in all layers of the communication stack. Provided that, the radio transceiver is the most power consuming component of a typical sensor node, large gains can be achieved at the link layer where the medium access control (MAC) protocol controls the usage of the radio transceiver unit. MAC protocols for sensor networks differ greatly from typical wireless networks access protocols in many issues. MAC protocols for sensor networks must have built‐in power conservation, mobility management, and failure recovery strategies. Furthermore, sensor MAC protocols should make performance trade‐off between latency and throughput for a reduction in energy consumption to maximize the lifetime of the network. This is in general achieved through duty cycling the radio transceiver. Many MAC protocols with different objectives were proposed for wireless sensor networks in the literature. Most of these protocols take into account the energy efficiency as a main objective. There is much more innovative work should be done at the MAC layer to address the hard unsolved problems. In this paper, we first outline and discuss the specific requirements and design trade‐offs of a typical wireless sensor MAC protocol by describing the properties of WSN that affect the design of MAC layer protocols. Then, a typical collection of wireless sensor MAC protocols presented in the literature are surveyed, classified, and described emphasizing their advantages and disadvantages whenever possible. Finally, we present research directions and identify open issues for future medium access research. Copyright © 2009 John Wiley & Sons, Ltd.