A Low Power Non-Volatile LR-WPAN Baseband Processor with Wake-Up Identification Receiver

The paper proposes a low power non-volatile baseband processor with wake-up identification(WUI) receiver for LR-WPAN transceiver.It consists of WUI receiver,main receiver,transmitter,non-volatile memory(NVM) and power management module.The main receiver adopts a unified simplified synchronization method and channel codec with proactive Reed-Solomon Bypass technique,which increases the robustness and energy efficiency of receiver.The WUI receiver specifies the communication node and wakes up the transceiver to reduce average power consumption of the transceiver.The embedded NVM can backup/restore the states information of processor that avoids the loss of the state information caused by power failure and reduces the unnecessary power of repetitive computation when the processor is waked up from power down mode.The baseband processor is designed and verified on a FPGA board.The simulated power consumption of processor is 5.1uW for transmitting and 28.2μW for receiving.The WUI receiver technique reduces the average power consumption of transceiver remarkably.If the transceiver operates 30 seconds in every 15 minutes,the average power consumption of the transceiver can be reduced by two orders of magnitude.The NVM avoids the loss of the state information caused by power failure and energy waste caused by repetitive computation.

Passive Localization of Multiple Sources Using Joint RSS and AOA Measurements in Spectrum Sharing System

In spectrum sharing systems,locating mul-tiple radiation sources can efficiently find out the in-truders,which protects the shared spectrum from ma-licious jamming or other unauthorized usage.Com-pared to single-source localization,simultaneously lo-cating multiple sources is more challenging in prac-tice since the association between measurement pa-rameters and source nodes are not known.More-over,the number of possible measurements-source as-sociations increases exponentially with the number of sensor nodes.It is crucial to discriminate which measurements correspond to the same source before localization.In this work,we propose a central-ized localization scheme to estimate the positions of multiple sources.Firstly,we develop two computa-tionally light methods to handle the unknown RSS-AOA measurements-source association problem.One method utilizes linear coordinate conversion to com-pute the minimum spatial Euclidean distance sum-mation of measurements.Another method exploits the long-short-term memory(LSTM)network to clas-sify the measurement sequences.Then,we propose a weighted least squares(WLS)approach to obtain the closed-form estimation of the positions by linearizing the non-convex localization problem.Numerical re-sults demonstrate that the proposed scheme could gain sufficient localization accuracy under adversarial sce-narios where the sources are in close proximity and the measurement noise is strong.

深海会聚区声场多途时延差分析及声源距离估计

深海会聚区声道由于传播损失低因而具有传播距离远的优势,对实现近海面目标远程探测具有十分重要的意义。本文基于虚源理论,推导了深海会聚区的多途到达时延结构,给出了会聚区内不同声线路径的时延差曲线随接收深度变化的近似表达式;通过分析时延差曲线与声源水平距离之间的关系,提出了一种利用多途时延差估计深海会聚区近海面声源距离的方法;仿真实验验证了该方法原理的正确性,南中国海实验结果表明:当收发距离在42-52 km时,会聚区爆炸声源距离估计结果同实际爆炸距离吻合较好,估计误差为0.6%-6.1%,验证了该方法的有效性。

双极型LCC-HVDC直流系统作为黑启动电源的启动方法及策略

科学合理的黑启动电源及方案是应对电网灾变停电的最有效策略,可加快其系统恢复进程,大幅减少停电损失。双极型换相换流器型高压直流系统(LCC-HVDC)具有调节灵活输电容量大的优势,但其作为黑启动电源存在一定的困难。提出了以双极型LCC-HVDC为黑启动电源的黑启动方法及完整过程,实现向受端无源网络恢复供电,以加速其恢复进程。首先给出了双极型LCC-HVDC作为黑启动电源时所面临的问题及相应的解决策略;进而给出了双极型LCC-HVDC作为黑启动电源恢复向受端无源网络恢复供电的实现过程。该过程包括2个阶段,第1阶段实现双极型LCC-HVDC的仿融冰模式启动;第2阶段为从仿融冰模式过渡到向受端无源网络恢复供电过程。算例证实了该启动方法的有效性和正确性。该方法使双极型LCC-HVDC具备了黑启动能力,并利用直流系统为受端电网的系统恢复过程提供了电压和频率支撑。

基于空间谱域的分布式无源雷达成像性能分析

无源雷达成像即利用空间中存在的多个辐射源和接收站,同时对同一目标进行多角度成像,从而获取丰富的目标特征信息,它是当前雷达成像领域的研究热点之一。文章对无源雷达成像性能的影响因素进行分析,从多个辐射源、多个接收站和目标组成的空间三维构型出发,建立了目标回波模型,推导出回波数据与点散射函数之间存在的空间谱域映射关系。以北斗卫星辐射源为例,使用后向投影(back projection,BP)算法对多点目标进行成像仿真。仿真实验从辐射源与接收站数量、辐射源与接收站排布间隔以及辐射源与接收站构型三方面,有效验证了空间谱填充与成像质量的关系,为后续无源雷达成像系统的设计提供理论支撑。

单站卫星外辐射源无源雷达布站方法研究

由于障碍物会对电磁波的传播形成遮挡效应,为了避免遮挡盲区对无源雷达系统探测性能造成影响,以接收信噪比最大为优化目标,将接收站部署区域限制和障碍物遮挡作为约束,建立遮挡条件下单站卫星外辐射源无源雷达接收站部署的数学模型,并用粒子群优化算法给出接收站最佳部署位置的求解方法。仿真分析表明:上述基于接收信噪比最大化的布站方法解决了遮挡条件下的单站卫星外辐射源无源雷达布站问题。

Passive source range estimation with a single receiver in shallow water

An approach for long-range passive impulsive source ranging with a single receiver in shallow water is proposed, which utilizes the frequency spectrum of the warped signal autocor- relation function via warping transform. For an ideal waveguide, there are invariable frequency features both in the frequency spectrum of the warped signal corresponding to modal cut-off frequencies and the warped signal autocorrelation function due to modal interference. These intrinsic frequency features can be used to passive source ranging. So, the approximate rela- tionship between the frequency of warped signal at an unknown source range and the intrinsic frequency extracted by the time warping transform is derived. These rules can be generalized to an actual shallow water waveguide. Employing an acoustic model to offer the invariable frequency spectrum features, the impulsive signal data collected by a single hydrophone in the North Yellow Sea in December 2011 are analyzed to verify the proposed source ranging ap- proach. The estimated ranges are in good agreement with the ranges measured by GPS, and the mean relative error of range estimation is less than 10%.

A reconfigurable passive mixer for multimode multistandard receivers in 0.18 μm CMOS

This paper presents a reconfigurable quadrature passive mixer for multimode multistandard receivers. By using controllable transconductor and transimpedance-amplifier stages, the voltage conversion gain of the mixer is reconfigured according to the requirement of the selected communication standard Other characteristics such as noises figure, linearity and power consumption are also reconfigured consequently. The design concept is verified by implementing a quadrature passive mixer in 0.18 μm CMOS technology. On wafer measurement results show that, with the input radio frequency ranges from 700 MHz to 2.3 GHz, the mixer achieves a controllable voltage conversion gain from 4 to 22 dB with a step size of 6 dB. The measured maximum IIP3 is 8.5 dBm and the minimum noise figure is 8.0 dB. The consumed current for a single branch （I or Q） ranges from 3.1 to 5.6 mA from a 1.8 V supply voltage. The chip occupies an area of 0.71 mm2 including pads.

A wideband current-commutating passive mixer for multi-standard receivers in a 0.18μm CMOS

This paper reports a wideband passive mixer for direct conversion multi-standard receivers.A brief comparison between current-commutating passive mixers and active mixers is presented.The effect of source and load impedance on the linearity of a mixer is analyzed.Specially,the impact of the input impedance of the transimpedance amplifier（TIA）,which acts as the load impedance of a mixer,is investigated in detail.The analysis is verified by a passive mixer implemented with 0.18 μm CMOS technology.The circuit is inductorless and can operate over a broad frequency range.On wafer measurements show that,with radio frequency（RF） ranges from 700 MHz to 2.3 GHz,the mixer achieves 21 dB of conversion voltage gain with a-1 dB intermediate frequency（IF） bandwidth of 10 MHz.The measured IIP3 is 9 dBm and the measured double-sideband noise figure（NF） is 10.6 dB at 10 MHz output.The chip occupies an area of 0.19 mm2 and drains a current of 5.5 mA from a 1.8 V supply.

LNG接收站构筑物钢结构耐火保护设计

液化天然气(Liquefied Natural Gas, LNG)接收站中结构单体涉及钢筋混凝土结构、钢结构以及混合结构等,其中钢结构耐火保护设计是结构安全的重要保证,建筑物钢结构耐火保护设计大多可在相应标准中查询,但构筑物钢结构耐火保护设计无统一规定,且涉及多个标准规范。对国内关于构筑物钢结构的耐火保护设计的标准规范进行整理,梳理出LNG接收站构筑物钢结构耐火保护设计的适用条款;结合LNG接收站构筑物钢结构单体功能特点,整理出LNG接收站构筑物钢结构耐火保护设计具体要求;对各构筑物钢结构单体是否属于防火范围进行分析,对单体在防火范围的结构构件耐火保护涂覆范围和作法进行了总结。形成的LNG接收站构筑物钢结构耐火保护设计标准化作法,可对后续类似项目的耐火保护设计提供设计依据和指导。

深海海底声反射区多途时延差分析与近海面声源定位

深海海底反射声工作方式下的声场主要由4条一次海底反射声线路径构成。根据4条声线路径到达接收点的时间不同,可以得到6个不同的声线到达时延差值,当声源位于近海面时,6条声线路径的时延差曲线随接收深度近似呈线性变化。本文基于虚源理论推导了海底声反射区的多途到达时延结构,给出了6条声线路径的时延差曲线随接收深度变化的近似表达式,通过分析时延差曲线与声源水平距离和深度之间的关系,提出了一种利用多途时延差估计深海海底声反射区近海面声源距离与深度的方法,仿真实验与影响因素分析验证了该原理的正确性。南海实验结果表明,当收发距离在10~33 km时,距离估计结果和深度估计结果都同实际声源距离和深度吻合较好,估计误差不超过15%,验证了该方法的有效性。

外辐射源雷达系统多站接收优化部署方法

针对多站接收情形下外辐射源雷达优化部署问题,在分析单个接收站场景下探测覆盖面积和基线距离之间关系的基础上,提出一种多站接收条件下的外辐射源雷达系统优化部署方法。采用积分法求出多站接收下探测覆盖面积和基线距离之间的关系,并对探测覆盖面积进行归一化处理,以归一化的探测覆盖面积最大为优化准则进行外辐射源雷达多站接收优化部署,并以2个和3个接收站场景为例,进行了优化部署。仿真分析表明,通过多站接收条件下优化部署,可以有效增大系统覆盖范围,提高系统探测效能。

外辐射源MIMO雷达机会信源选择与接收站布置联合设计

本文研究外辐射源多输入多输出(multiple-input multiple-output,MIMO)雷达目标位置和速度估计,通过控制接收站选用的机会信源个数来解决系统复杂度受限的问题.将机会信源选择变量引入到外辐射源MIMO雷达信号模型,基于此推导最优参数估计器及相应的克拉美罗界(Cramer-Rao bound,CRB).以CRB为系统参数估计性能评价标准,对机会信源优化选择、接收站优化布置、机会信源选择与接收站布置联合优化三种优化方式性能进行对比,三者分别属于整数型、连续型及混合整数型的优化问题.仿真表明,在系统复杂度受限的情况下,三种优化方法都有利于提高外辐射源MIMO雷达的估计性能,但联合优化的性能最佳.

基于GDOP的多星单站无源雷达辐射源选取方法研究

由于导航卫星数量多、选择余地大,卫星外辐射源的选取成为制约无源雷达定位精度的关键因素。构建了基于导航卫星外辐射源的无源雷达多星单站定位模型,计算了可视导航卫星数目及位置,推导了系统定位误差方程,分析了定位误差影响因素,提出了一种基于定位精度的几何稀释(geometrical dilution of precision,GDOP)的多星单站无源雷达时差定位外辐射源优选方法。仿真结果表明,该优选方法能可靠地筛选出多星单站时差定位的最佳外辐射源,有效提高系统定位精度。

单星测频无源定位测试评估系统设计

为测试评估单星测频无源定位星载接收机的功能与性能指标,采用实物试验与仿真技术相结合的方式设计了一款单星测频无源定位测试评估系统,该系统包括高动态信号模拟收发分系统和仿真评估分系统。高动态信号模拟收发分系统基于ADI公司AD9364 RF捷变收发器和XILINX公司Zyqn7000系列芯片研制,完成上行信号的产生与发送和上行信号的接收与信号处理;仿真评估分系统采用Visual Studio软件开发,用于实现信道数学仿真和单星测频无源定位算法测试评估。测试结果表明,该测试评估设备能够测试评估单星测频无源定位星载接收机性能指标,且可灵活配置卫星参数和信号参数,适应性强。

A fully integrated CMOS super-regenerative wake-up receiver for EEG applications

A fully integrated super-regenerative wake-up receiver for wireless body area network applications is presented. The super-regeneration receiver is designed to receive OOK-modulated data from the base station. A low power waveform generator is adopted both to provide a quench signal for VCO and to provide a clock signal for the digital module. The receiver is manufactured in 0.18 μm CMOS process and the active area is 0.67 mm^2.It achieves a sensitivity of -80 d Bm for 10^（-3）BER with a data rate of 200 kbps. The power consumption of the super-regenerative wake-up receiver is about 2.16 m W.

基于MSP430的无源无线通信系统的研究与实现

环境反向散射技术是一种全新的通信方式,设备之间通过反向散射环境中的射频信号进行通信。文中设计的无源无线通信系统将环境中的射频信号作为唯一的能量源和信号源,利用环境反向散射技术实现无源设备之间的无线通信。该系统能够很好地解决为数量巨大、体积微小的微型嵌入式设备网络供电和通信的问题,从根本上摆脱了对电源和电线的依赖,使得微型嵌入式设备间的通信成本和维护成本几乎为零。文中针对如何提高无源无线通信系统的能量收集效率、通信速率和通信距离进行了深入研究,优化了5级电荷泵升压整流电路,基于超低功耗多天线解码算法设计了环境电磁波能量收集模块、无源发射器和无源接收器。实验测试结果表明,无源无线通信系统的通信速度能达到50 Kb/s,通信距离提高到1.8 m。

A baseband circuit for wake-up receivers with double-mode detection and enhanced sensitivity robustness

This paper proposes a baseband circuit for wake-up receivers with double-mode detection and enhanced sensitivity robustness for use in the electronic toll collection system.A double-mode detection method,including amplitude detection and frequency detection,is proposed to reject interference and reduce false wake-ups.An improved closed-loop band-pass filter and a DC offset cancellation technique are also newly introduced to enhance the sensitivity robustness.The circuit is fabricated in TSMC 0.18μm 3.3 V CMOS technology with an area of 0.12 mm2.Measurement results show that the sensitivity is -54.5 dBm with only a±0.95 dBm variation from the 1.8 to 3.3 V power supply,and that the temperature variation of the sensitivity is±1.4 dBm from -50 to 100℃. The current consumption is 1.4 to 1.7μA under a 1.8 to 3.3 V power supply.

直接检波式毫米波接收机研制

以被动式毫米波成像为应用背景,研制了一种频带宽4GHz、中心频率25GHz的集成直接检波式接收机的原理样机.介绍了接收机的工作原理,设计、制作、测试了原理样机各个功能模块并对整个系统进行了测试.

UHV交流输电线路对调幅广播收音台防护间距

为研究特高压交流输电线路对调幅广播收音台的防护间距,通过特高压交流试验基地的实测数据,得到了特高压交流输电线路的无线电干扰水平,为有源干扰的计算提供了强有力的数据支持。利用NEC电磁计算软件,建立了特高压输电线路的实体模型,计算了无源干扰随频率、入射角度以及防护间距的变化规律,得到了特高压交流线路3种典型塔型的无源干扰水平。最后通过比较有源干扰和无源干扰影响,给出了特高压交流架空输电线路对调幅广播收音台的防护间距计算值。