A novel spectrum sensing scheme with sensing time optimization for energy-efficient CRSNs

Wireless Networks - The cognitive radio technology enables secondary users (SUs) to occupy licensed bands when primary users (PUs) are not occupy them. Spectrum sensing is a key technology for SUs...     

Evaluating the Performance of Cooperative NOMA with Energy Harvesting Under Physical Layer Security

Wireless Personal Communications - In this paper, we consider a non-orthogonal multiple access system with imperfect successive interference cancellation and physical layer security where the...     

An optimum interference mitigating combining scheme for the CDMA downlink with the same complexity as MRC

This letter presents a new optimum interference mitigating combining (OIMC) scheme for the code-division multiple-access downlink RAKE receiver. The OIMC scheme optimizes the RAKE weights and maximizes the signal-to-interference-plus-noise ratio (SINR) at the RAKE combiner output. Unlike other interference mitigation schemes, the new scheme does not need to estimate the interference or data correlation matrix (and its inverse) of the received signal to render a reliable and low complexity receiver. The OIMC scheme mitigates interference by inversely proportionately weighting the finger output by its associated interference power, while simultaneously mitigating multipath fading. The interference power is found to be directly related to the finger's associated multipath channel gain, rendering the OIMC scheme with the same order of complexity as a maximal ratio combining (MRC) scheme. Under realistic channel conditions, simulation results show that the proposed OIMC scheme always outperforms MRC with a gain of up to more than 1 dB.     

用5520A建立数字多用表校准装置测量不确定度评定

该文对应用5520A建立六位半及以下数字多用表计量校准装置的测量不确定度评定进行了详细分析;对测量原理、测量方法、数学模型、方差及传播系数、不确定度来源也作了描述;可以作为撰写数字多用表计量标准技术报告的参考资料.     

Templated Crosslinked Imidazolyl Acrylate for Electronic Detection of Nitroaromatic Explosives

A low‐voltage operable, highly sensitive, and selectively responsive polymer for the detection of nitroaromatic explosives is investigated. Resistive devices are fabricated by simple spin‐coating on flexible and transparent substrates in addition to silicon substrates and are stable under ambient temperature and oxygen levels before exposure to the nitroaromatics. After exposure to 2,4,6‐trinitrotoluene (TNT), the devices show increased conductance, even with picogram (pg) quantities of TNT, accompanied by a confirming color change from colorless to deep red. The relative conductance increase per unit exposure is the highest yet reported for TNT. Aromatic anion salts, on the other hand, do not induce any electronic responses. ¹H NMR and microscopic analyses show chemical interactions and morphological changes correlated with the electronic responses, some of which are specific to TNT in relation to other nitroaromatics. The binding constant for the imidazole rings and TNT is on the order of tens of M ^?1. The materials are promising for rapid indication of exposure to nitroaromatic compounds.     

A 6 Gbps/pin Low‐Power Half‐Duplex Active Cross‐Coupled LVDS Transceiver with Switched Termination

A novel linear switched termination active cross‐coupled low‐voltage differential signaling (LVDS) transceiver operating at 1.5 GHz clock frequency is presented. On the transmitter side, an active cross‐coupled linear output driver and a switched termination scheme are applied to achieve high speed with low current. On the receiver side, a shared preamplifier scheme is employed to reduce power consumption. The proposed LVDS transceiver implemented in an 80 nm CMOS process is successfully demonstrated to provide a data rate of 6 Gbps/pin, an output data window of 147 ps peak‐to‐peak, and a data swing of 196 mV. The power consumption is measured to be 4.2 mW/pin at 1.2 V.     

浅谈WAP的应用

WAP（Wireless Application Protocol）是无线应用协议,是一个为实现新的移动业务而定义的语言,通信协议及工具的集合。阐述了WAP的一些内容及经典的WAP结构模型,介绍了一些WAP服务器的连接模型,并对将来WAP服务器的应用作了简要的概述。     

国外战术导弹半实物仿真试验验证能力发展分析

半实物仿真是战术导弹等先进武器装备在研制试样、性能评估、作战演练中必不可少的主要仿真方法和手段。从多物理场/控制耦合、导航、多模/宽谱段制导、导引头抗干扰、靶场试验等五个方面,介绍了国外战术导弹半实物仿真试验设备、试验技术的具体情况,分析了其半实物仿真验证能力的发展现状及发展趋势,提出了战术导弹半实物仿真应重点关注在复杂战场环境、新型物理效应、多弹协同/多体飞行器协同等方面的能力建设,分析结果可对未来战术导弹半实物仿真能力建设发展具有借鉴意义。     

Cohesively Enhanced Conductivity and Adhesion of Flexible Silver Nanowire Networks by Biocompatible Polymer Sol–Gel Transition

Silver nanowire (AgNW) networks are a promising candidate to replace indium tin oxide (ITO) as transparent conductors. In this paper, a novel transparent composite conductor composed of AgNW/biocompatible alginate gel on a flexible polyethylene terephthalate (PET) substrate, with synchronously enhanced adhesion and reduced resistivity, is prepared without high‐temperature annealing. The sheet resistance of the flexible AgNW/PET film reduces from 300 to 50.3 Ohm sq^?1 at transmittance of 94%. The optical and electrical performance is superior to that obtained from the flexible ITO film on PET. Meanwhile, the sheet resistance does not show great change after tape test, suggesting a good adhesion of AgNW to the polymer substrate. Moreover, the AgNW composite film shows a good stability to resist long‐term storage, solvent damage, and ultrasonication. Finally, polymer solar cells employing the composite AgNW film as the electrode are realized, displaying an efficiency of 2.44%.     

基于STC12C5A60S2的多功能测量系统设计

本文介绍了基于STC12C5A60S2单片机的多功能测量系统,系统实现对空气温湿度、CO2浓度以及室内光照强度的检测,同时具有万年历时钟显示功能.阐述了系统硬件和软件的整体设计方案、器件选型、单元电路设计及整体电路连接.通过理论分析及实验证明能有效测出温湿度、CO2含量及室内光照强度,测量准确,参数调节方便,使用效果良好.