排序方式: 共有43条查询结果,搜索用时 15 毫秒
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A non-coherent receiver for impulse radio ultra-wide band(IR-UWB)is presented.The proposed receiver front-end consists of a high gain LNA,a high frequency detector and an intermediate frequency(IF)amplifier to amplify the recovered signal and drive an external test instrument.To meet the requirements of high gain and a low noise figure(NF)under moderate power consumption for the LNA,capacitor cross coupled(CCC)and current reuse techniques were adopted.The detector consists of a squarer and an integrator.The overall circuit consumes 41.2mA current with a supply voltage of 1.8 V at a 400 MHz pulse rate.The resulting energy efficiency is 0.19 nJ/pulse.A chip prototype is implemented in 0.18-μm CMOS.The die area is 2.1×1.4 mm~2 and the active area is 1.7×0.98 mm~2. 相似文献
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低功耗输出脉冲幅度和频谱可调的超宽带发送机设计 总被引:1,自引:1,他引:0
A 3-5 GHz low power BPSK modulated impulse radio UWB transmitter is implemented in 0.13μm CMOS technology. In this design the amplitude and spectrum of the output impulse are both tunable to solve the special problem in IR-UWB, where it is difficult to control the spectrum. Measurement results indicate that, by changing the control bits in the gain control circuit and differential circuit, the 3-step peak-to-peak voltage amplitudes are 240, 170 and 115 mV and the center frequency of the impulse can be tuned from 3.2 to 4.1 GHz. A power controlled output buffer is designed to drive the antenna. The total power consumption is only 4.44 mW when transmitting a baseband signal of 100 MHz. The chip area is 1.2 × 1.4 mm^2. 相似文献
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IR-UWB系统中的密集多径和随机的时延扩展带来了严重的码间干扰,若不采取均衡技术抑制码间干扰,将严重限制系统的性能.针对接收机的位置改变能引起信道模式改变,设计了一个新型的MF-DFE接收机,根据传输速率信息和判决设备得到的信道模式的信息,在快时变的混合信道下,动态的配置判决反馈均衡器的长度进行均衡接收.仿真表明该接收机在快时变的IR-UWB混合信道情况下,在高的传输速率下仍能获得良好的性能. 相似文献
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将脉冲超宽带(IR-UWB)信号应用于航天测控领域,能够有效提高当前航天测控系统的隐蔽性、抗干扰性和测量性能,具有重要的现实意义.将DS-PAM(Direct Spread-Pulse Amplitude Mod-ulation)调制、TH-PPM(Time Hopping-Pulse Position Modulation)调制的信号和PSM(Pulse Shape Modulation)调制技术组合起来,可构成一种新的组合调制的脉冲超宽带信号,即DS-PAM-TH-PPM-PSM-UWB(Direct Spread-Pulse Amplitude Modulation-Time Hopping-Pulse Position Modulation-Pulse Shape Modulation-Ultra Wideband)信号.利用对数正态阴影模型分析其传输性能,在单频干扰信号条件下分析其抗干扰性能,利用模糊函数分析其测量性能.仿真结果表明,相比于传统的DS-PAM-UWB信号和TH-PPM-UWB信号,该组合信号具有良好的传输性能、抗干扰性能和测量性能,为脉冲超宽带信号应用于航天测控领域提供了更多的选择. 相似文献
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《Comptes Rendus Physique》2019,20(3):218-227
In the automotive domain, Cooperative Localization (CLoc) is a new promising paradigm that aims at outperforming conventional Global Navigation Satellite Systems (GNSS) in terms of positioning accuracy, robustness, and service continuity, by relying on Vehicle-to-Vehicle (V2V) communications and hybrid data fusion. However, the growing number and the variety of the sensors aboard vehicles raise unprecedented challenges, especially in the context of distributed fusion approaches. This paper thus compares parametric and nonparametric Bayesian data fusion engines (e.g., based on cooperative variants of the Extended Kalman Filter (EKF) and Particle Filter (PF), respectively), while validating a CLoc scheme suitable to Vehicular Ad Hoc Networks (VANETs). More particularly, absolute position information from both onboard GNSS receiver and ITS-G5 V2V messages, as well as relative distance measurements based on the Impulse Radio–Ultra-Wideband (IR–UWB) technology, are combined into a single location solution that is hopefully more robust and more accurate than that of standalone GNSS. First, we investigate V2V ranging accuracy on a highway under real mobility conditions. In the same environment, we then provide offline validations of CLoc positioning, confirming significant performance gains through cooperation over conventional GNSS, even in case of poor initialization. In this specific context, the PF solution is thus shown to yield even better accuracy in comparison with EKF, thanks to its fine robustness against faced non-linear dynamics and non-Gaussian noise processes. Finally, we illustrate the resilience of the proposed solution under temporary GNSS denial. 相似文献
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本文提出了一种用于脉冲式超宽带接收机的低抖动,低杂散多相输出锁相环。为了同时满足低抖动、低功耗和输出多相时钟这些需求,该锁相环基于一个环形振荡器结构。为了提高多相时钟的时间精度和相位噪声性能,设计了一个改善了噪声和匹配特性的压控振荡器。在设计中,通过良好的匹配电荷泵和仔细选择环路滤波器带宽来抑制参考频率杂散。测试结果表明,当载波频率为264 MHz时,1 MHz失调频率下的相位噪声为-118.42 dBc/Hz,均方根抖动为1.53 ps,参考频率杂散为-66.81 dBc。该芯片采用0.13 µm CMOS工艺制造,1.2 V电源电压下功耗为4.23 mW,占用0.14 mm2的面积。 相似文献
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基于时域射线追踪技术(TD-Ray)和时域有限差分方法(FDTD),提出了一种可以对穿墙传播环境中的组合尺寸结构进行快速电磁散射建模的混合计算方法。混合方法针对冲激/脉冲超宽带(IR-UWB)信号时域极窄的特点,利用TD-Ray技术来计算电大尺寸的规则墙体结构及室内空间的传播过程,避免了FDTD方法在电大结构和空间传播上过于精细的网格划分,提高了计算效率并减少内存需求。混合方法同时又结合FDTD方法对室内较小尺度的复杂损耗结构进行计算,可以解决TD-Ray技术在复杂损耗结构电磁建模上存在的困难,从而保证了电磁散射的计算精度。通过应用算例验证了该方法在电大电小组合结构电磁散射建模上的有效性,对比表明该方法得到的穿墙人体目标平均雷达散射截面(RCS)计算结果与实测数据吻合较好。 相似文献