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Non-coherent ultra-wideband (UWB) receivers offer an attractive low-complexity solution to ranging with UWB radios. They use
a simple receiver architecture that can operate at very low sampling rates compared to the Nyquist rate. In this paper, time-of-arrival
(TOA) estimation performances of two different searchback algorithms for non-coherent impulse radio UWB systems are analyzed:
jump back and search forward (JBSF) and serial backward search (SBS). Average ranging errors for both algorithms are formulated
using noise-based ranging thresholds and at sub-Nyquist sampling rates. For JBSF, a lower bound on the average ranging error
is obtained using an error-minimizing threshold. Also, a semi-analytic technique for the selection of the searchback window
length is presented. For SBS, noise-based threshold selection for both single-cluster and multi-cluster channels are introduced.
Computer simulations in IEEE 802.15.4a channels provide insights on the selection of some of the critical parameters for accurate
ranging. The simulation results show that JBSF typically performs better than SBS if the inter-cluster delay parameter (K) is not selected appropriately for SBS. In both cases, it is shown that even at sampling rates much smaller than the Nyquist
rate, ranging accuracies on the order of 33 cm can be obtained using a non-coherent UWB receiver.
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H. ArslanEmail: |
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针对相参雷达和非相参雷达的概念进行阐述。通过详细分析两种体制雷达在应用上的主要区别,侧重介绍相参雷达的优点。相参性方面重点介绍多普勒效应具有的特性,从信号接收和信号处理上重点讨论了相参性雷达拥有的速度测量功能,在速度模糊和距离模糊上详细比较了两者的差别。通过实践证明,相参雷达的应用范围比非相参雷达的范围广阔得多,但价格不菲。 相似文献
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Wu Zhigang Zhang Weigang Wang Zhi Kai Guiyun Yuan Shuzhong Dong Xiaoyi Utaka Katsuyuki Wada Yasuo 《半导体学报》2006,27(2):328-335
报道了一个新的基于锥形多模干涉的相干光波合波器.对锥形多模波导中的模式行为给出了完整的理论分析,并给出了该锥形合波器在不同结构下的输出特性.在一个绝缘体上硅的基板上实现了该器件.鉴于无后向反射,容易扩展为多口配置,对实验误差有大的允许度和尺寸紧凑等优点,这种锥形多模干涉的合波器是大型光子集成中所用的相干光波合波器的理想选择. 相似文献
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Geyer J.C. Hauske F.N. Fludger C.R.S. Duthel T. Schulien C. Kuschnerov M. Piyawanno K. van den Borne D. Schmidt E.-D. Spinnler B. de Waardt H. Lankl B. Schmauss B. 《Photonics Technology Letters, IEEE》2008,20(10):776-778
A robust in-service estimation of fiber channel parameters from equalizer parameters of a polarization diverse coherent receiver is presented. The equations used for estimation are evolved from a theoretical fiber channel model. The theory is validated based on simulations and data from transmission experiments. 相似文献
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《Photonics Technology Letters, IEEE》2009,21(3):137-139
This letter presents a hardware-efficient phase estimation algorithm that can replace the common complex estimators for a coherent quadrature phase-shift keying transmission system. 相似文献
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Vgenis A. Petrou C.S. Papadias C.B. Roudas I. Raptis L. 《Photonics Technology Letters, IEEE》2010,22(1):45-47
Adaptive electronic equalizers using the constant modulus algorithm (CMA) algorithm often converge to a singular coefficient matrix that produces the same signal at multiple outputs. We address this issue in the context of optical communications systems with polarization-division multiplexing and coherent receivers. We study, by computer simulation, the performance of multiuser CMA equalizer, an enhanced CMA equalizer initially proposed for use in wireless multiuser and later multiple-input/multiple-output communications systems. We show that the proposed adaptive electronic equalizer does not exhibit singularities and, therefore, is superior to the commonly used CMA equalizer. 相似文献
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《Lightwave Technology, Journal of》2008,26(13):1823-1834
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无线相干光通信空间分集接收合并技术 总被引:4,自引:2,他引:2
空间分集接收能补偿大气湍流造成的信道衰落。在给出相干检测分集接收的系统模型和晴朗大气信道模型的基础上,考虑子孔径间信号相关性,分析了等增益合并分集和最大比合并分集的误码率性能,并就中断概率与选择分集进行了比较。分析结果表明,空间分集接收能够明显改善相干光通信系统的性能,并且接收信号间的空间相关性越小分集接收的性能越好,其中最大比合并分集性能相对其他两种合并方式优势明显,选择分集性能最差,但它与等增益合并分集的差距不大,同时选择分集实现相对容易,在工程应用中要综合考虑实现的难易程度和性能。 相似文献
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Carena A. Curri V. Poggiolini P. Forghieri F. 《Photonics Technology Letters, IEEE》2008,20(15):1281-1283
Recently, coherent polarization-multiplexed quadrature-phase-shift keying has attracted considerable interest. Enabled by progress in ultrafast digital signal processing electronics, it can carry 4 bits per symbol and has been proposed for 100-Gb/s transmission at a reduced 25-GBaud line rate. Several different receiver structures are possible, whose performance, complexity, and design issues are varied. In this letter, we concentrate on a receiver employing single-ended, rather than balanced, detection. We analyzed its performance and found that, by properly tailoring its design parameters, the single-ended receiver may closely approach the performance of the more expensive balanced receiver, over a practically relevant received-signal dynamic range. 相似文献
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《Lightwave Technology, Journal of》2009,27(3):224-232
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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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由于非合作接收等因素的影响,相对于通信信号而言,干扰具有一定随机性。本文在研究干扰存在条件下MSK相干解调输出误码率时,将干扰建模成随机参量信号,并推导了针对MSK相干解调的干扰生效条件。讨论了合成矢量图法和数值计算法两种方法,并采用Matlab编程,实现了数值计算法,比较了不同模型下几种干扰样式的优劣。 相似文献
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适用于不同相参体制的雷达数字中频接收机 总被引:2,自引:1,他引:1
介绍了一种功能完备的雷达数字中频接收机,其具有数字中频处理,数字定相,发射脉冲频谱分析及功率校正,AFC控制等功能。其可用于常规磁控管雷达多普勒改造或提升模拟中频相参多普勒系统性能,也适用于全相参系统接收机中频数字化改造或进一步的性能提升。采用该数字接收机,典型磁控管整机系统的改善因子限制可达40dB以上。该数字接收机性能高,集成度高,适用性广。 相似文献
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相参雷达系统下的非相干积累检测方法,可以提高雷达的目标检测速度,达到实时处理的要求。然而,相参雷达系统下的非相干积累检测方法对参考单元数、脉冲积累数、杂波散斑协方差矩阵以及海杂波模型的形状参数均是非恒虚警(CFAR)的。该文基于块白化的海杂波预白化方法,提出预白化单元平均恒虚警(PWCA-CFAR)检测方法和预白化单元中值恒虚警(PWCM-CFAR)检测方法,并使用了匹配于参考单元数、脉冲积累数、形状参数的自适应门限,确保提出检测方法的恒虚警特性。实验结果表明,当存在异常单元时,PWCM-CFAR检测方法的检测性能优于PWCA-CFAR检测方法。
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