无线传感器网络信号突变监控模块的电路设计

传统的无线电监测系统主要通过单站监测的方法对信号突变进行监测,但不能对复杂的高频宽带无线电信号突变进行准确监测。因此,设计无线传感网络信号突变监控模块的实现电路,其由高频激发器、窄带滤波器、程控放大器、A/D采集电路、FPGA和主控制器等构成。编制开发无线传感网络信号突变监控模块的上位机控制软件,并向下位机主控器传递控制指令,确保各电路模块协作完成无线信号突变的监控。实验结果表明,所设计监控模块的电路,可对无线传感网络信号突变情况进行准确、高效率的监控。     

电机温度监测系统低功耗无线节点模块设计

提出了一种用于电机温度监测系统的无线数据收发节点模块设计方案,利用LPC1114的省电耗模式配合Si4432集成芯片实现无线收发模块的低功耗。另外,针对模块硬件实现RF前端高频电路设计和前期仿真做出详细说明,模块的RF性能指标分别做了测试,分析了本模块的耗能数据,可以满足大部分的低功耗、低速率、高灵敏度的实时无线数据传输需求,本模块已经可靠、稳定地应用于系统中。     

Implementation of cost-effective wireless photovoltaic monitoring module at panel level

Given the rapidly increasing market penetration of photovoltaic (PV) systems in many fields, including construction and housing, the effective maintenance of PV systems through remote monitoring at the panel level has attracted attention to quickly detect faults that cause reductions in yearly PV energy production, and which can reduce the whole-life cost. A key point of PV monitoring at the panel level is cost-effectiveness, as the installation of the massive PV panels that comprise PV systems is showing rapid growth in the market. This paper proposes an implementation method that involves the use of a panel-level wireless PV monitoring module (WPMM), and which assesses the cost-effectiveness of this approach. To maximize the cost-effectiveness, the designed WPMM uses a voltage-divider scheme for voltage metering and a shunt-resistor scheme for current metering. In addition, the proposed method offsets the effect of element errors by extracting calibration parameters. Furthermore, a design method is presented for portable and user-friendly PV monitoring, and demonstration results using a commercial 30-kW PV system are described.     

基于GPRS的小型机电设备无线监测模块设计

为实现小型机电设备的无线监测需求,提出了一种基于GPRS传输协议的小型机电设备无线监测模块设计方案,并完成其软硬件设计。该模块硬件部分采用stm32单片机、SIM900模块实现,软件部分采用MDK进行编程,能够实现对采用S7-200 PLC作为主控器的小型机电装备的状态参数进行监测。该监测模块具有成本低、稳定性好、应用广泛的特点。     

A novel power-amplifier module for quad-band wireless handset applications

This paper presents a novel power-amplifier module (PAM) designed for GSM850-, GSM900 MHz, DCS1800- and PCS1900-MHz handset applications. The module combines an InGaP HBT power-amplifier integrated circuit, two integrated couplers, a dual-band logarithmic RF power detector/controller, and some additional passive components. The logarithmic RF power detector was implemented in the module to accomplish linear-in-decibel output power dependency. This allows the handset manufacturers to calibrate output power (Pout) at one or two points, with error as low as +/-0.3 dB, thus reducing test time in mass production. Due to higher accuracy, our novel design significantly reduces the power consumption during normal operation. Our design is the first to include two integrated directional couplers in a handset RF PAM. It significantly improves power control accuracy over load variations. In this paper, we show that the directivity of the integrated couplers is critical for establishing accurate power control over phase variations at high values of load mismatch. In addition, the presented module features fully integrated impedance matching at input and output ports with DC blocks. The entire module is plastic encapsulated on a 10 mm /spl times/ 10 mm laminate substrate. The module offers higher accuracy of Pout control, smaller size, lower bill-of-materials, and a shorter Pout calibration time to handset manufacturers. It is a very desirable RF PAM to handset designers because of its unique features. Under a low single supply voltage of 3.2 V, the PAM provides 35-dBm output power, 55% power-added efficiency (PAE) in the GSM900 band, and 33 dBm and 50% PAE in the DCS1800 band.     

基于无线传感网的工厂环境监控系统设计

为了方便地管理无线传感网络,文中以工厂生产环境监控为例提出了一种新的层次型的无线传感网络控制系统,该系统具有很好的系统移植特性及扩展特性,经测试证明,该系统具有较好的市场前景,可以推广到商业应用中。     

基于ARM9的无线环境监控系统的实现

介绍了基于ARM的无线环境监控系统的实现过程。此系统用于监控工厂的环境参数,并将这些数据通过GPRS模块实时的发送到数据监控中心,这样就实现了对环境的远程监控。嵌入式监控终端是基于S3C2410微控制器的,选择Linux作为其操作系统。监控终端的实现,涉及到硬件的构架、Linux环境的建立、设备驱动程序的编写、及RS-232串口通信和GPRS模块的应用等知识。此系统不仅能应用于环境监控,也能方便地移植到其他嵌入式系统中。     

Integration of wireless sensor networks in environmental monitoring cyber infrastructure

Wireless sensor networks (WSNs) have great potential to revolutionize many science and engineering domains. We present a novel environmental monitoring system with a focus on overall system architecture for seamless integration of wired and wireless sensors for long-term, remote, and near-real-time monitoring. We also present a unified framework for sensor data collection, management, visualization, dissemination, and exchange, conforming to the new Sensor Web Enablement standard. Some initial field testing results are also presented. The monitoring system is being integrated into the Texas Environmental Observatory infrastructure for long-term operation. As part of the integrated system, a new WSN-based soil moisture monitoring system is developed and deployed to support hydrologic monitoring and modeling research. This work represents a significant contribution to the empirical study of the emerging WSN technology. We address many practical issues in real-world application scenarios that are often neglected in the existing WSN research.     

无线内存模块全球化

1早期发展趋势 推动无线行业发展的技术正飞速前进,这一趋势源于日本.1993年,一般日本手机的尺寸是150cm3、重量约为200克.日本手机制造商多年来不懈努力来缩小手机尺寸、减轻手机重量.到2003年,一般日本手机尺寸约为84cm3、重量约为99克.最令人惊奇的是,手机尺寸越来越小而功能却越来越多.最新款手机除具备通话功能外,还有大彩屏、一个或多个相机、流视频、MP3以及和弦铃声.这些功能虽然需要更大的内存容量,但其整体外形却保持同样大小,甚至更小.     

无线数传模块的应用

文中讲解了TXD1100无线数传模块的特点,详细介绍了利用该模块设计、开发了＂主—被＂工作模式下的控制系统方案。该系统具有自动识别无线数传模块的工作参数和在存在同频干扰的情况下能够自动跳频等优点。     

UWB radio module design for wireless sensor networks

In this paper, we describe an impulse-based ultra wideband (UWB) radio system for wireless sensor network (WSN) applications. Different architectures have been studied for base station and sensor nodes. The base station node uses coherent UWB architecture because of the high performance and good sensitivity requirements. However, to meet complexity, power and cost constraints, the sensor module uses a novel non-coherent architecture that can autonomously detect the UWB signals. The radio modules include a transceiver block, a baseband processing unit and a power management block. The transceiver block includes a Gaussian pulse generator, a multiplier, an integrator and timing circuits. For long range applications, a wideband low noise amplifier (LNA) is included in the transceiver of the sensor module, whereas in short range applications it is simply eliminated to further reduce the power consumption. In order to verify the proposed system concept, circuit level implementation is studied using 1.5 V 0.18 μm CMOS technology. Finally, the UWB radio modules have been designed for implementation in liquid-crystal-polymer (LCP) based System-on-Package (SoP) technology for low power, low cost and small size integration. A small low cost, double-slotted, Knight’s helm antenna is embedded in the LCP substrate, which shows stable characterization and a return loss better than ?10 dB over the UWB band.     

无线数传模块的应用

文中讲解了TXD1100无线数传模块的特点,详细介绍了利用该模块设计、开发了“主—被”工作模式下的控制系统方案.该系统具有自动识别无线数传模块的工作参数和在存在同频干扰的情况下能够自动跳频等优点.     

基于ASK无线数传模块的新型安防系统

将无线数传模块和具有低噪声的策控制电路集成设计为一体，构成检测信号和开关量控制信号无线传输的功能模块，并将该模块嵌入到探头和控制器内部，建立无线通讯子网，应用于智能能楼宇安防系统。很好的解决了无线信息冲突问题。经过试运行，系统工作稳定，无线探头报警可靠性达到了使用需求。     

基才LabVIEW的水环境因子无线监测系统设计

为了解决传统水产养殖环境因子有线监测系统的布线复杂、可靠性较低等问题,以LabVIEW为开发平台,采用无线数据传输方式,设计了一种水产养殖环境因子无线监测系统。该系统实现了对水环境因子pH值的实时采集、显示和存储,以及历史数据查询等功能。试验结果表明,该系统运行稳定、能够准确地采集和显示水环境因子pH值,且具有操作简便、交互性好、性价比高和易扩展等优点。     

基于环境信息监测的无线传感器网络节点设计

针对海岸、海洋环境远程实时监测的需求,设计了由超低功耗MCU芯片MSP430F1611、无线收发器芯片CC2420及各种传感器接入电路构成的具有多种环境参数采集功能的无线传感器网络节点.该节点系统利用所搭载的各种传感器采集环境中的温度、湿度、光照强度等数据,通过相邻节点间的无线通信,以多跳传输的方式,将测量数据上传给上...     

基于ZigBee无线传感网络的环境监测系统的设计

ZigBee作为一种新兴的无线传感网络技术,具有低功耗、低复杂度、低传输速率、低成本、近距离传输等特点,实现起来简单,并且具备自组网功能,新传感器节点入网无需人工配置,考虑了系统异常的情况,在无线环境监测系统中得到广泛的应用。本文章设计了基于ZigBee无线传感网络的环境监测系统,即对环境中的温度和气体烟雾进行监测。该检测系统由传感器节点和协调器节点两部分组成,其结果由协调器传输给PC机来显示,从而完成对温度和气体烟雾的无线监测。经过多次可靠性试验,本系统已成功应用于某型号监测系统。     

Soft iterative multisensor multiuser detection in coded dispersiveCDMA wireless channels

A soft iterative multisensor array receiver for coded multiuser wideband code-division multiple-access wireless uplink channels is proposed, such channels are typically both frequency- and time-selective. A new equivalent discrete-time synchronous representation is used to model asynchronous multiuser dispersive channels that employ, in general, random spreading. The proposed scheme suppresses multiuser interference over a wide range of user signal powers, by iteratively exchanging soft information between a minimum mean-square-error (MMSE) multiuser demodulator and a bank of single-user decoders, feeding back the outputs of the latter to aid in soft multiuser multisensor MMSE-RAKE demodulation and subtractive interference cancellation, in the second and subsequent iterations. It displays near-far resistance since it behaves like a successive interference subtracter across iterations. The array responses are obtained via a multipass estimation scheme that uses both (temporal) pilot symbols and soft estimates fed back from the decoders to effectively provide multisymbol pilot signals and thence successively refined estimates with increasing iterations, while seeking neither to rely on the array geometry nor to estimate the directions from which users' signals arrive at the receiver. Simulation studies indicate that this scheme performs close to the single-user case with a two-sensor receiver array, and perfect channel state information, after four iterations; alternatively, it allows significantly increased user capacity compared with conventional receivers, and suffers only a modest loss with estimated array responses     

A flow-based network monitoring framework for wireless mesh networks

As an extension of wireless ad hoc and sensor networks, wireless mesh networks recently were developed as a key solution to provide high-quality multimedia services and applications, such as voice, data, and video, over wireless personal area networks, wireless local area networks, and wireless metropolitan area networks. A WMN has a hybrid network infrastructure with a backbone and an access network and usually is operated in both ad hoc and infrastructure modes with self-configuration and self-organization capabilities. In this article, we review security challenges, attacks, and countermeasures in the physical, medium access control (MAC), and network layers of wireless mesh backbone and access networks. We then extend the concept of traffic flow from IP networks and define meshflow in wireless mesh networks. Based on this new concept, we propose a comprehensive framework to realize network monitoring, user and router profiling, application and service balancing, and security protection in wireless mesh backbone networks. Practical issues and design trade-offs for implementing the proposed framework in real systems also are discussed.     

A wireless PDA-based physiological monitoring system for patient transport

This paper proposes a mobile patient monitoring system, which integrates current personal digital assistant (PDA) technology and wireless local area network (WLAN) technology. At the patient's location, a wireless PDA-based monitor is used to acquire continuously the patient's vital signs, including heart rate, three-lead electrocardiography, and SpO2. Through the WLAN, the patient's biosignals can be transmitted in real-time to a remote central management unit, and authorized medical staffs can access the data and the case history of the patient, either by the central management unit or the wireless devices. A prototype of this system has been developed and implemented. The system has been evaluated by technical verification, clinical test, and user survey. The evaluation of performance yields a high degree of satisfaction (mean = 4.64, standard deviation--SD = 0.53 in a five-point Likert scale) of users who used the PDA-based system for intrahospital transport. The results also show that the wireless PDA model is superior to the currently used monitors both in mobility and in usability, and is, therefore, better suited to patient transport.     

A reliable transmission protocol for ZigBee-based wireless patient monitoring

Patient monitoring systems are gaining their importance as the fast-growing global elderly population increases demands for caretaking. These systems use wireless technologies to transmit vital signs for medical evaluation. In a multihop ZigBee network, the existing systems usually use broadcast or multicast schemes to increase the reliability of signals transmission; however, both the schemes lead to significantly higher network traffic and end-to-end transmission delay. In this paper, we present a reliable transmission protocol based on anycast routing for wireless patient monitoring. Our scheme automatically selects the closest data receiver in an anycast group as a destination to reduce the transmission latency as well as the control overhead. The new protocol also shortens the latency of path recovery by initiating route recovery from the intermediate routers of the original path. On the basis of a reliable transmission scheme, we implement a ZigBee device for fall monitoring, which integrates fall detection, indoor positioning, and ECG monitoring. When the triaxial accelerometer of the device detects a fall, the current position of the patient is transmitted to an emergency center through a ZigBee network. In order to clarify the situation of the fallen patient, 4-s ECG signals are also transmitted. Our transmission scheme ensures the successful transmission of these critical messages. The experimental results show that our scheme is fast and reliable. We also demonstrate that our devices can seamlessly integrate with the next generation technology of wireless wide area network, worldwide interoperability for microwave access, to achieve real-time patient monitoring.