UWB高精度定位系统中标签的设计

介绍了UWB高精度定位系统中标签的设计,标签是一种便携式、低功耗无线通信模块。本设计是基于C8051F921单片机和nRF24L01低功耗无线收发芯片组成的硬件结构,设计包括电源的设计,采用了尺寸较小的锂电池。UWB窄带脉冲可以达到纳秒级,延时抖动延时完全在允许的范围内。最终设计的标签实现了在系统的控制下,完成数据收发,使定位精度在30cm内。     

通讯专讯

太阳诱电演示UWB收发系统 日本太阳诱电日前开发成功了使用超宽带的无线技术“UWB”收发系统,并在日本电子展“CEATEC JAPAN 2003”上进行了无线数据传输演示。收发芯片组采用了美国XtremeSpectrum的产品,该芯片组2002年夏季产品发布,目前已部分开始提供样品。不过,太阳诱电还是第一次使用这种芯片组进行实际演示。太阳诱电此前也曾发布过UWB     

基于DW1000的超宽带室内定位系统设计

为了提高室内无线传感器网络的定位精度,设计了一个基于UWB的无线传感器网络定位系统,该系统在上位机软件上运用TDOA算法进行定位计算,硬件设计上锚节点采用deca Wave公司生产的DW1000为无线收发芯片,在其控制器STM32内部写入嵌入式程序,完成数据记录、收发。该系统理论定位精度可达到10cm,抗多径能力强、稳定性高,为无线网络传感器定位提供了更多的参考。     

C 波段小型化高精度驱动延时组件的研制

介绍了延时线在雷达中的工作原理,分析了延迟时间误差与延迟幅度误差对信号合成的影响。针对驱动延时组件小型化、高精度设计的难点进行了评估,并提出采用微波多层印制电路实现小型化、采用新型调相电路与衰减电路解决延时高精度的设计方案。在此基础上,设计并实现了一种集成延时、放大与功率分配/合成功能的驱动延时组件。根据驱动延时组件各态收发指标测试结果,幅度带内平坦度优于±0.4 d B,延时相位精度≤±5°,延时幅度精度≤±0.5 d B。     

基于Hermite 插值滤波器的直接延时补偿超宽带波束形成技术研究

超宽带(UWB)信号波束形成是UWB 雷达的关键性技术。传统的波束形成方法存在瞬时带宽和扫描角度受限,波束偏移等问题,直接延时补偿法是避免上述问题的有效途径。该文提出了基于Hermite 插值滤波器的直接延时补偿波束形成方法,理论分析和仿真结果均表明Hermite 插值滤波器幅频特性和群时延特性优于目前常用的Lagrange 和径向基插值滤波器。超宽带线性调频信号实例仿真也表明了该方法在超宽带波束形成性能方面的优越性。      

基于MMSE信道估计准则的TH—PPM UWB通信系统多径性能分析

基于MMSE估计准则对TH-PPM UWB多径环境下的系统接收性能进行了分析。首先介绍了TH—UWB信道的传播特征,对IEEE UWB信道模型CM1做了仿真,并分析了MMSE多径信道估计特性,在此基础上对幅值最强两条多径信号的多径延时和多径幅值误差的标准方差进行了仿真,结果表明信号越强延时估计误差越小。最后对采用MMSE估计接收和参数已知接收两种方式下系统的性能进行了仿真,结果表明采用MMSE信道估计的Rake接收机性能可以达到信道参数完全已知的Rake接收机性能。     

基于复自然谐振的无芯RFID标签的设计

本文提出了一种基于复自然谐振的无芯RFID标签的设计。标签由两个梯形金属贴片组成,两组谐振频率邻近的缝隙谐振器分别加载在两个贴片上。在不增加缝隙间相互耦合的前提下,标签在UWB频段内容纳的数据位数提高了一倍,在35mm×33mm的合理尺寸内,12个缝隙谐振器对应12位数据。仿真给出了标签的RCS曲线和极点分布图,实测是在双站天线配置下进行,在频域内测出了传输系数和极点分布图。实测和仿真结果一致,验证了本设计的合理性。该标签具有低剖面、低成本和高数据率的优点,因其只需要一个导电层,所以能被直接印刷在ID卡甚至纸张上面。     

基于DW1000的室内定位系统设计与测距优化方法

文章提出了基于Deca Wave的单片收发一体射频芯片DW1000的UWB定位方案,设计了系统的软硬件框,讨论了相关定位算法及测距的优化算法。系统中被测节点(tag)与锚节(anchor)点通过双向TDOA算法等到两者之间的距离,tag与多个anchor的距离通过UWB通信被汇总至定位服务器,由定位服务器三角质心定位算法测算出tag的三维空间坐标。经实验研究表明,系统在LOS环境下具有较高的精度,在NLOS环境下也具有良好表现。     

一种电子货架标签系统（ESLS）的设计

针对目前商业领域纸质标签的信息更新滞后、手工更换效率低、易出错等缺点,采用 自顶向下设计方法设计了一种基于有源远距离RFID技术的电子货架标签系统。该设计集计算 机控制、远程收发、微功耗设计特性为一体,辅以完善的应用系统设计。该系统业务管理方 便,信号覆盖范围可扩展,标签显示模块的电池寿命可达3～5年,具有普遍应用意义和广 泛应用前景。     

UWB信号射频特性分析及分形天线的应用

UWB信号具有相当宽的信号带宽,UWB辐射场是方向角,时间和信号波形的三维函数,传统天线设计很难满足设计要求。通过分析UWB系统的特点,将分形天线应用于UWB的射频设计中,并仿真验证了其宽带效应。     

A CMOS IR-UWB Transceiver Design for Contact-Less Chip Testing Applications

This paper presents a novel CMOS impulse radio (IR) ultra-wide-band (UWB) transceiver system design for future contact-less chip testing applications using inductive magnetic coupling as wireless interconnect. The proposed architecture is composed of a simple and robust design of a Gaussian monocycle impulse generator at the transmitter, a wideband short-range on-chip transformer for data transmission, and a g_m-boosted common-gate low-noise amplifier in the UWB receiver path. SpectreRF post-layout simulation with a 90-nm CMOS technology shows that the transceiver operates up to a 5 Gb/s data rate, and consumes a total of 9 mW under a 1-V power supply.     

On the coexistence of power-controlled ultrawide-band systems with UMTS, GPS, DCS1800, and fixed wireless systems

Ultrawide bandwidth (UWB) wireless technology will play a key role in short-range wireless connectivity supporting very high bit rates availability, low power consumption, and location capabilities. UWB can be conveniently deployed in the design of wireless local and personal area networks, providing advanced integrated multimedia services to nomadic users within hot-spot areas. The very large bandwidth required by the UWB signals cannot be exclusively allocated; thus, UWB band overlaps with the bands allocated to many other narrow-band systems. Therefore, the assessment of the interference caused by UWB devices on already-existing systems is of primary importance to ensure coexistence and, therefore, to guarantee acceptance of UWB technology worldwide. We study the coexistence issues between an UWB-based system and universal mobile telecommunication systems, global positioning systems, DCS1800, and fixed wireless access systems and point-to-point (PP) links terminals. UWB interference is evaluated accounting for the UWB signal model, a realistic UWB master/slave system architecture with power-controlled terminals. Furthermore, we analyze the dependence of the UWB interference from the UWB signal parameters and demonstrate through computer simulation that, in all practical cases, a UWB system can coexist with the selected victim terminals without causing any dangerous interference.     

低功耗无线收发电路系统设计

目前,无线通信技术发展极其迅速,随之引起系统功耗不断上升。因此人们近几年来对无线通信网络中各方面的低功耗技术进行了深入的研究,使节能成为无线通信发展的一个重要方向。设计了低功耗无线收发电路系统,采用STM32L151系列超低功耗芯片和UTC4432系列无线通信模块作为核心电路系统,通过软件设计及调试实现整个低功耗收发电路系统功能。结果表明:采用合适的微控制器和无线通信模块对于控制无线收发电路系统的功耗有着极其重要的作用,再加上对软件编程的控制,能够使整个系统的功耗大幅度降低。     

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.     

高危生产区域人员定位节点的电路设计

为了适应室内人员追踪定位系统对节点体积、供电、定位精度等的要求,提出了一种以ATmega128L单片机和NA5TR1无线收发芯片为核心的无线定位节点的硬件电路设计方案。ATmega128L单片机具有低功耗的休眠模式,能有效降低节点功耗,NA5TR1无线收发芯片采用线性调频扩频技术进行测距,经实验证明,该测距方法能有效地提高测距精度,从而提高定位的精度。     

基于DS18B20的短距无线温度检测系统

基于一种新型单线可编程数字温度传感器DS18820的测温原理,以低功耗的MSP430F1611单片机为微控制器,设计了一种的短距无线温度检测系统,并通过无线模块nRF401实现数据的无线收发。给出了微控制模块、LCD显示模块、无线收发模块和温度传感器模块的设计以及系统的软件开发。实验结果表明：系统实现了短距、多点的温度检测;利用无线收发模块和CLD显示模块,节约了现场调试时间,实现了系统的便携式设计并提高了温控系统的稳定性;利用MSP430单片机的超低功耗以及DS18820的单线接口方式,实现了整个系统的低功耗设计,并简化了系统的结构。     

An ultrawideband system architecture for tag based wireless sensor networks

With the latest improvements in device size, power consumption, and communications, sensor networks are becoming increasingly more popular. There has also been a great increase in the popularity of commercial applications based on ultrawideband (UWB). Impulse radio (IR) based UWB technology utilizes noise-like signal, has potentially low complexity and low cost, is resistant to severe multipath, and has very good time domain resolution allowing for location and tracking applications. In this paper, the architecture and performance of a noncoherent low complexity UWB impulse radio based transceiver designed for low data rate, low cost sensor network applications is presented. The UWB-IR transmitter is based on a delay locked loop (DLL) and UWB monocycle pulse generator. The UWB-IR receiver utilises a noncoherent, energy detection based approach, which makes it largely independent of the shape of the transmit waveform and robust to multipath channels. The test circuits are designed for 0.35 /spl mu/m SiGe BiCMOS technology. This paper presents system simulations results as well as the performance of key functional blocks of the designed UWB application specific integrated circuit (ASIC) transceiver architecture. The simulated power consumption of UWB-IR transceiver circuits is 136 mW with 100% duty cycle with a 3.3 V power supply.     

A Single Input-Multiple Output Time Reversal UWB Communication System

Time reversal is a promising technique for the improvement of UWB communication systems. Intersymbol interference (ISI) limits the system performance in such wireless systems. This paper presents a general ISI analysis for time reversal UWB communication systems. The time reversal UWB system gives good performance for rates below the coherence bandwidth but at higher data rates the performance of the system is limited by intersymbol interference and bit error rate saturates even for high signal-to-noise ratio. To mitigate the ISI effects, a single input/multiple output (SIMO) time reversal UWB system is used and its performance is analyzed. It is shown that by using a SIMO TR transceiver, ISI reduces and the system capacity increases. Transmitted signal power at SIMO time reversal decreases, therefore in low data rate SISO performance is better than SIMO, But in high rate scenario, SIMO TR suppresses the ISI better than the SISO TR and its performance is better than SISO TR. It is possible to compensate the reduced power by using a receiver with more sensitivity.     

消防模拟常规无线通信系统在定位中的应用

主要介绍如何利用现有消防350兆模拟常规无线通信系统实现消防车辆和人员的定位。通过建设GPS控制中心和对现有消防模拟常规电台终端的改造,GPS数据传输跳频设计,实现了无线对讲、GPS数据采集与传输、GIS定位图示的有机结合,最大程度的发挥了当前模拟无线通信系统的效能。经过改造后,在原有消防通信基站、通信频率等资源不变的情况下,普通模拟消防电台同时具备了语音通话和GPS定位功能。     

三维分布UWB设备对窄带无线系统干扰分析

针对超宽带(UWB)设备对其他相对窄带无线设备终端存在干扰的可能问题,通过建立的三维积分模型对无线系统终端受室内三维空间分布的多UWB设备合成干扰效果进行了分析。所提出的UWB干扰模型可以有效分析三维分布的多UWB设备对其他相对窄带无线系统的干扰,给出受干扰设备抗UWB干扰能力及UWB发射功率控制模板干扰保护强度等方面的数值评估,可作为现代化办公楼UWB设备布置及UWB功率控制研究方面的参考。