A pulse design paradigm for ultra-wideband communication systems

A novel paradigm is proposed to design time-limited pulse shapes for ultra-wideband communication systems. Pulses can be designed using the new paradigm that not only conform to spectral emission constraints, but also achieve good bit error rate performance in multiple access interference environments. Compared with previously proposed pulses, the novel pulses provide the same multiple access performance as the Gaussian monocycles yet have advantages over them in terms of power spectrum and spectral emission constraints. Our pulse design paradigm provides a flexible and effective method for designing suitable pulses for ultra-wideband communication applications that comply with frequency emission constraints.     

设计UWB脉冲的算法研究

本文依据Rayleigh脉冲的特征提出了一种设计UWB脉冲的新算法,它不仅简单而且适用于各国的频谱模板.理论分析表明这种脉冲的性能明显优于超宽带脉冲无线电中广泛使用的高斯脉冲.     

Physics-based pulse distortion for ultra-wideband signals

Pulse distortion is difficult to model by the state of the art statistical measurements. In this paper, we propose a physics-based deterministic model for urban environments consisting of high rise buildings. We first derive the channel impulse response of the renowned Wolfisch-Bertoni model in closed form. This model captures many properties that are not available in the existing statistical models such as the IEEE 802.15.4a model. The closed form time domain solutions are in good agreement with the inverse fast Fourier transform (IFFT)-based frequency domain solutions. These solutions are important to understanding the system principle.     

A new ultra-wideband, ultra-short monocycle pulse generator withreduced ringing

We introduce a new ultra-wideband (UWB), ultra-short, step recovery diode monocycle pulse generator. This pulse generator uses a simple RC high-pass filter as a differentiator to generate the monocycle pulse directly. The pulse-shaping network employs a resistive circuit to achieve UWB matching and substantial removal of the pulse ringing, and rectifying and switching diodes to further suppress the ringing. An ultra-short monocycle pulse of 300-ps pulse duration, -17-dB ringing level, and good symmetry has been demonstrated. Good agreement between the measured and calculated results was achieved     

Channel estimation technique for ultra-wideband pulse transmitters

Multipath fading channel significantly modifies the shape of pulses in ultra-wideband (UWB) communications and makes it difficult to distinguish between different pulse shapes. Hence, channel effects must be compensated for. A technique is introduced to extract and estimate the UWB channel impulse response from the distorted signal.     

A novel approach for the design of pulse shaping filters

In this work, we propose a new class of pulses for PAM type digital signals. The pulses are designed based on minimization of a figure of merit that is the product of the Cramer-Rao bound of the timing jitter variance and the mean eye closure rate. The new pulses are seen to yield significantly better performances as compared to the classical ones.     

一种简易的超宽带纳秒级脉冲发生器设计

为了得到超宽带纳秒级窄脉冲信号,在对UWB脉冲产生方法分析总结的基础上,提出了一种基于数字逻辑器件的简单脉冲产生电路。对实际制做的电路进行了测试,能够得到重复频率为10 MHz,脉冲宽度约为4ns,幅度约为500mV的窄脉冲。该电路成本低,结构简单,易于制作,工程实用性较强。     

A novel algorithm to estimate the pulse pressure variation index deltaPP

We designed a new methodology to estimate the pulse pressure variation index (deltaPP) in arterial blood pressure (ABP). The method uses automatic detection algorithms, kernel smoothing, and rank-order filters to continuously estimate deltaPP. The technique can be used to estimate deltaPP from ABP alone, eliminating the need for simultaneously acquiring airway pressure.     

Photonic method for ultra-wideband monocycle pulse frequency upconversion

A novel optical method for frequency upconversion in ultra-wideband (UWB) system application is proposed and demonstrated. A UWB monocycle pulse can be generated by cross-polarsation modulation combined with carrier-suppressed modulation, and after an O/E detector, it can be converted to 32 GHz band. After electrical downconversion, the UWB monocycle pulse has a fractional bandwidth of 144% and fits UWB applications.     

一个紧凑型超宽带微带带通滤波器

设计制作了一种紧凑型超宽带微带带通滤波器。该滤波器采用两对由1/4波长型SIR谐振器和1/4波长终端短路谐振器构成的枝节线对与微带低通滤波器相联而成。在ADS软件上对该滤波器进行仿真验证,然后制作实物。结果表明,该滤波器相对带宽达到112%,阻带带宽超过4 GHz,通带范围内插入损耗小于1 d B,回波损耗大于10 d B,阻带范围回波损耗大于20 d B;滤波器尺寸为14.22 mm×9.65 mm。     

一种新的基于脉冲超宽带系统的发送分集方案

本文针对UWB信道特点,提出了预瑞克(Pre-RAKE)与空时块码(STBC)结合的新的发送分集方案,采用了基于最小均方误差准则(MMSE)的Pre-RAKE参数估计算法.最后仿真结果表明,基于MMSE算法的发送分集方案对系统误码率性能有较大改善,尤其是多径衰落严重而且存在符号间干扰(ISI)和窄带干扰(NBI)的非视距(NLOS)信道性能改善明显.     

Design of novel ultra-wideband antenna with individual SRR

A novel small ultra-wideband antenna (UWB) design using an individual split-ring resonator and coupled microstrip line structure is proposed. The radiation property of the antenna is numerically simulated and experimentally measured. The absolute frequency band, where S11 is less than 210 dB, is found to be across the entire UWB spectrum from 3.6 to 14.6 GHz. The gain at every frequency for the antenna is larger than 2.4 dBi.     

A 2/spl times/2 antennas ultra-wideband system with biorthogonal pulse position modulation

The Golden code is a 2/spl times/2 space-time code that achieves the best known performance with all constellations carved from /spl Zopf/[i]. In this letter, we present the construction of a new coding scheme for 2M-ary biorthogonal pulse position modulations (BPPM) with M/spl ges/4. The proposed code satisfies all of the construction constraints of the Golden code and it has the additional advantage of being totally real making it suitable for low cost carrier-less ultra-wideband terminals. Namely, this totally real construction achieves full rate and full diversity with the best known coding gain and without any shaping losses for 2M-BPPM with M/spl ges/4.     

一种新型的高增益超宽带低噪声放大器

文中提出了一种采用增益提高技术的超宽带低噪声放大器(LNA)。为了通过提高电路的输出阻抗,进而实现改善电路增益的目的,该LNA包含了两级共射共基放大器电路,并在共基晶体管基极引入电感。基于0.13μm SiGe BiCMOS工艺对其进行设计,实现了超宽的31GHz~42GHz的工作频率,增益为20.1dB~30.7dB,噪声系数为1.19dB~1.31dB,并且在1.8V单电源电压供电情况下,消耗的功耗为13.2mW。     

基于缺陷接地结构的超宽带带通滤波器的设计

介绍了一种将阶梯阻抗耦合谐振器和开口谐振环缺陷接地结构相结合的新的超宽带带通滤波器。利用3D场仿真软件,分析了电路的不同支节尺寸对滤波器宽带特性和频率特性的影响,最后给出了一款超宽带滤波器的仿真和实验结果。     

A study of the ultra-wideband wireless propagation channel and optimum UWB receiver design

The paper addresses a crucial point in ultra-wideband (UWB) radio wave propagation, which is the spatial-temporal resolution of scattering objects into multiple frequency-dependent scattering centers. The effect contributes to the widely observed temporal dispersion of pulse-shaped transmit signals and their distortion, respectively. Particularly the latter is explained by (multiple) diffraction of the incident wave, leading to (multiple) band-limited impulse responses with characteristic frequency content, which in turn causes signal distortion and a degradation of the signal-to-noise ratio in a correlation receiver. We presented a new approach on UWB propagation modeling and optimum design of correlation receivers.     

超宽带低噪声放大器仿真设计

采用负反馈技术和集总参数匹配技术,选用VMMK-1218低噪声E-PHEMT晶体管,利用ADS进行仿真优化,设计了一种微波超宽带低噪声放大器。仿真结果显示,在0.5~4.5GHz范围内,放大器增益大于14.2 dB,平坦度小于1.1 dB,噪声系数小于0.85 dB,输入输出反射系数均小于-11 dB。设计结果可应用于各种宽带微波通信及雷达等领域。