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851.
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. 相似文献
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855.
UHF频段无源RFID标签阅读距离影响因素分析 总被引:1,自引:0,他引:1
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. 相似文献
856.
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。 相似文献
857.
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).
相似文献
Josep SegarraEmail: |
858.
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. 相似文献
859.
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. 相似文献
860.