Non-fragile observer-based passive control for uncertain time delay systems subjected to input nonlinearity

The problem of non-fragile observer-based passive control for uncertain time delay systems subjected to input nonlinearity is investigated by using sliding mode control. A novel control law is established such that the sliding surface in the state-estimation space can be reached in a finite time and chattering reduction is obtained. A sufficient condition for passivity and asymptotic stability of the combined system is derived via linear matrix inequality (LMI). Finally, a simulation example is presented to show the validity and advantages of the proposed method.     

低功耗RFID电源产生电路的优化设计

电子标签是创新消费模式、提升生活质量和工作效率的热门新科技,但是由于功耗和成本的原因阻碍了其广泛应用.介绍了一种电子标签芯片电源产生电路的优化设计,探讨了限幅电路、整流电路、模拟电源电路、数字电源电路和EEPROM高压电路的低功耗设计技术和实现方法,提出了融合并联分流的限幅电路、改进的桥式整流电路、带有低压检测复位功能的模拟电源电路.低功耗电源产生电路已成功应用到无源电子标签芯片的设计中,并在SMIC O.35μmCMOS工艺下流片成功.     

ISO/IEC18000-6B标签逻辑电路低面积设计

简要介绍了射频识别技术(RFID)协议ISO/IEC 18000-6B的通信,并基于该协议用VHDL语言设计了标签的逻辑部分电路.设计时运用命令分类、实时处理、资源共享等技术减少硬件资源,在SMIC 0.18μm工艺下综合为24 791μm2,并用Primepower测得功耗约10.6μW.设计采用Xilinx的FPGA开发平台进行了验证,逻辑分析仪结果表明设计满足要求.该电路应用于ISO/IEC18000-6B协议下RFID标签的数字部分.     

一种UHF频段宽带电子标签天线的设计分析

针对射频识别系统UHF频段的欧洲标准866~869 MHz和美国标准902~928 MHz,以及中国标准840~845 MHz和920~925 MHz,设计并制作了一种电磁耦合馈电结构的标签天线,其结构简单且便于调整匹配阻抗,带宽较宽且具有双频谐振特性,能同时适用于以上几种RFID标准。通过仿真和实测分析关键物理参数对天线特性的影响,结果表明该天线性能较佳且实用。     

UHF频段无源RFID标签阅读距离影响因素分析

在物品识别领域,RFID技术应用的快速发展对RFID标签的读出距离不断提出新的要求.通过对增加UHF900 MHz频段无源电子标签阅读距离的主要方法的研究,着重从电子标签设计中的如下几个要素进行了探讨:天线及标签芯片阻抗匹配、天线及标签芯片的品质因数以及标签基底材料的选择.     

软件测试自动化在黑盒测试中的应用

介绍黑盒测试的方法,对手工测试的不足以及自动化测试的特点进行研究。以XCRW-18型货车标签编程器软件(厂矿企业版)写标签数据测试为例,进行了测试问题的分析、测试用例的设计,并用VBScript编写自动化脚本,在QTP平台下实现了黑盒测试中的软件测试自动化,不但节省了人力,而且提高了测试的效率和可信度。     

A nesting ranging algorithm for a Hybrid WDM/TDM PON with colorless Reflective-ONUs under different distances OLT-ONUs

To reduce costs and cumbersome laser provisioning at the Optical Network Unit (ONU) user level in an access Passive Optical Network (PON), the use of a Reflective-ONU (R-ONU) is a good choice for up-data transmission. An optical carrier is sent by the Optical Line Terminal (OLT) at the Central Office, and a device at the ONU modulates the carrier with the upstream data. This allows all ONUs to be equal and colorless, without a light source in a Hybrid WDM/TDM architecture. A Dynamic Bandwidth Allocation is placed at the OLT, managing the lasers and photodetectors shared by all R-ONUs. The OLT laser and photodetector employed in an up-data transmission must be tuned for each ONU and a particular Round Trip Time (RTT), which is twice the propagation time from OLT to ONU. When an R-ONU is served by a laser, the photodetector must also be available after the RTT to demodulate the up-data. We propose a novel nesting ranging algorithm to deal with large different distances OLT–ONUs avoiding collisions and minimizing the delay under Priority Queuing with Quality of Service (QoS).

10 Gb/s TDM passive optical networks using four wavelengths multiplexed channels

We propose a new architecture for 10 Gb/s upstream traffic in TDM-PON using externally injection-locked Fabry-Perot laser diodes (FP-LDs) in each optical network unit (ONU). Four directly modulated 2.5 Gb/s FP-LDs were injection-locked by continuous wave (CW) carriers distributed from the optical line terminal (OLT). Hence, a total of 10 Gb/s upstream traffic can be achieved. Experimental results show negligible power penalty at a transmission of 25 km standard single mode fiber (SMF) without dispersion compensation. The performance of the injection-locked FP-LD is also studied.     

Advanced modulation formats for delivery of heterogeneous wired and wireless access networks

It is believed that the integration of wired and wireless access networks (or heterogeneous network) will provide high bandwidth and flexibility for both fixed and mobile users in a single and cost-effective platform. Here, we propose and demonstrate a signal remodulated wired and wireless network with wireless signal broadcast. Dark-return-to-zero (DRZ) and polarization-shift-keying (PolSK) signals are used for the downstream wired and wireless applications respectively. At the remote antenna unit (RAU), the PolSK signal is demodulated to produce the binary-phase-shift-keying (BPSK) signal, which will be used for the wireless broadcast application. Signal remodulation is demonstrated using reflective semiconductor optical amplifier (RSOA) as a colorless reflective modulator in the optical networking unit (ONU)/RAU. The downstream signal is remodulated at the ONU/RAU to produce the non-return-to-zero (NRZ) upstream signal.     

空时被动合成孔径阵列处理算法研究

本文介绍了两种被动合成孔径阵列处理算法。第一种算法是通过空时数据的互协方差矩阵估计,来精确估计相位校正因子,以提高孔径合成性能;另一种是在前一种算法基础之上,利用对信号子空间的低秩近似来提高低信噪比环境下相位校正因子的估计性能,从而提高被动合成孔径性能的算法。通过对仿真数据和实验数据的分析和比较,说明这两种新算法在较低信噪比下可以得到比传统的ETAM和后来的时域ETAM算法更好的相位估计与方位分辨性能和信号增益。