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Ryo Takai Shoya Uchida Akihiro Sato Mamiko Inamori Yukitoshi Sanada 《Wireless Personal Communications》2014,77(1):553-569
Overlapped FFT based energy detection has been proposed as a signal detection scheme in dynamic spectrum access. The overlapped FFT scheme increases the number of FFT frames to reduce the variance of squared noise and improve the detection probability. This paper evaluates the performance of the energy detection with overlapped FFT through experiments. In the experiments, different from the assumption in computer simulation of previous researches, a fixed distortion component caused by a direct current offset is observed. It is shown that the overlapped FFT scheme also works effectively under the existence of the fixed distortion. Numerical results obtained through the experiments show that the overlapped FFT scheme improves the detection probability by up to 0.15 with the noise and the fixed distortion component. The variance of the squared noise also reduces with the overlapped FFT scheme as it is expected in theoretical analysis when the fixed distortion is negligible. 相似文献
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In this paper, we investigate the Multiple-Input Multiple-Output (MIMO) channel capacity in indoor Ricean channels based on MIMO channel measurements at 2.45 GHz. The measured data is analysed using a super resolution parameter estimation algorithm. Our results demonstrate that the line-of-sight (LOS) component in a Ricean scenario influences indoor MIMO performance through increased spatial correlation between array elements. We found that indoor channels with higher values of Ricean K factor have smaller numbers of effective multipath components and increased spatial correlation. Measurement results also showed that, the effect of varying antenna height on indoor MIMO capacity is also due to the spatial correlation of multipath propagation and has a close relationship with the separation between the transmitter and receiver.
Zhongwei Tang is currently with the Wireless Technologies Laboratory at CSIRO. He was with Microwave and Wireless Technology Research Laboratory (MWTRL), Information and Communication Group, Faculty of Engineering of the University of Technology Sydney, Australia, where he pursued his Ph.D. Degree. His current research interests include RF propagation, MIMO Space-Time channel measurements, characterization and channel modelling, smart antennas, MIMO systems and array signal processing.
Ananda S. Mohan is currently a member of the Faculty of Engineering, University of Technology, Sydney (UTS), Australia where he leads research on antennas, microwaves, wave propagation, and wireless technology. He received a Ph.D. degree in electrical communication engineering from the Indian Institute of Technology, Kharagpur, India and was a Scientist and Senior Scientist at the Research and Training Unit for Navigational Electronics, Hyderabad, India. At UTS, he directed the Sydney microwave design resource centre and was the associate program leader of the co-operative research centre for satellite systems. He currently directs the microwave and wireless technology research laboratory and a core member of the university research centre on health technologies. His current teaching and research interests include wireless mobile communications, microwaves and antennas, smart antennas and applications of microwave and wireless technology in medicine and has obtained many competitive research grants in these areas. Dr. Mohan was a co-recipient of the Priestly memorial award from the Institute of Radio and Electronic Engineers (IREE), Australia. He was a member of the organizing and technical Program Committees of the IEEE Globecom'98, APMC 2000, and International Symposium on Wireless Systems and Networks, 2003 and IASTED International Conference on Antennas, Radar, and Wave Propagation, for 2004 and 2005. 相似文献
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该文针对星基定位接收机导航信号捕获的干扰问题,提出一种非完备空际间叠干扰信号模型。首先对提出的干扰模型以及非完备空际间叠引起的干扰裂变效应进行了阐述分析与推究证明,而后推导计算出了星基定位接收机输出信干噪比(SINR)与空际间叠长度的函数式,论证了两者函数单调性关系。仿真实验表明星基定位接收机输出信干噪比为空际间叠长度的单调增函数,短空际间叠长度干扰可抑制3维频码域相关峰突起,降消星基定位接收机捕获性能。
相似文献5.
根据雷达信号的时宽带宽乘积为常量,不能兼顾作用距离和距离分辨率的原理,使含有噪声的Chirp信号经过匹配滤波器加以检测,并对其进行了MATLAB仿真. 相似文献
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主要研究AWGN信道下,残余频偏对重叠时分复用(OvTDM)信号接收的性能影响;同传统的QAM技术相比,OvTDM是一种可以获得高频谱效率的传输技术,它通过引入符号码间串扰,并利用符号间互扰的约束特性来实现更高传输速率。在一个实际通信系统中,接收信号不可避免的会受到系统载波频偏的影响,从而影响信号的接收性能。因此,分析了系统残余频偏对OvTDM的性能影响,对比了相同条件下QAM信号性能,研究结果表明,在相同的信噪比和残余频偏条件下,OvTDM信号具有更好的误码性能。 相似文献
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本文深入探讨了FFT算法的特点,并对FFT算法在DSP上的实现方法进行了详细的分析.通过分析阐述并总结了利用DSP实现FFT算法的步骤及规律. 相似文献
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This paper proposes a robust signal detection procedure based on generalised patterns in time-frequency space. The paper derives a non-linear time domain correlation process which is equivalent to a time-frequency based detection scheme. The performance of this robust detection scheme in the additive white Gaussian noise case is evaluated with the aid of receiver operating curves. Some examples are given which show that the proposed procedure under nominal conditions does not perform as well as standard detection scheme (ie matched filter) but gives better performance when the measured signal deviates from its nominal model. 相似文献
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In Hwan Park Yoon Hyun Kim Jae Sang Cha Yeong Min Jang Jin Young Kim 《Wireless Personal Communications》2011,60(3):533-545
In this paper, effects of reader-to-reader interference are investigated for LED identification (LED-ID) system in a multi-reader
environment. The LED-ID readers typically use different channels to avoid collision between readers. However, in-channel collision
usually happens in terms of interrogation range. A reader-to-reader interference scenario is proposed, and nominal interrogation
range of a desired reader is derived from this model. In order to evaluate the LED-ID reader-to-reader interference quantitatively,
an efficient detection scheme is proposed and simulated by employing spreading sequence. The spreading sequence is inserted
between each user’s frame formats. In the receiver, the desired signal is detected by using correlation among inserted spreading
sequences. From simulation results, it is confirmed that the proposed scheme is very effective to enhance reliability of LED-ID
communication systems. 相似文献
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二维FFT算法在LFMCW雷达信号处理中的应用及其性能分析 总被引:3,自引:0,他引:3
LFMCW在动目标检测上存在一定难度,利用二维FFT处理技术对目标回波信号相位信息进行提取,可有效地抑制固定杂波,对动目标进行检测,该文就LFMCW的差频相位进行了分析和仿真,对二维FFT的具体应用约束和算法的复杂度作了分析. 相似文献
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This paper examines the performance of a modified Advanced Time Division Multiple Access (ATDMA) protocol when supporting mixed voice and bursty data users in an indoor propagation environment. The performance analysis was performed by a Monte Carlo simulator, the accuracy of which was verified by a simplified Markov model analysis. The system model includes Rice fading, log-normal shadowing, distance dependent pathloss and co-channel interference. The system model also considers preferential channel access based on the capture effect. The results suggest the necessity of modifying the ATDMA frame from the traditional structure and indicate that the ATDMA frame structure could be adaptively modified based on the traffic loading in the system. 相似文献
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针对矿井复杂环境下无线信道的衰落动态变化时,离线模型的线上检测表现会遭遇性能下降的问题,该文研究了基于迁移学习的自适应信号检测网络(ADN)。ADN的主要改进是使用并行网络对动态信道离散化以提高网络泛化能力;对线上接收端信号采取域对抗训练神经网络(DANN)的无监督学习方式,从而将离线训练知识迁移到线上矿井复杂环境中并且实时调整网络参数以适应信道的变化,从而实现矿井复杂环境下的自适应信号检测。实验表明对正交相移键控(QPSK)和正交幅度调制(QAM)信号,在动态变化的矿井Nakagami-m衰落信道中,随着离散信道的增加,ADN获得信道间的分集效益,性能逐渐提高。在高信噪比(SNR)时,其性能接近卷积神经网络(CNN),低信噪比时显著提高深度检测网络的鲁棒性和线上检测效果。 相似文献
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《无线电工程》2018,(2):116-120
在导航系统信号体制设计过程中,广泛引入了单频波多信号分量的设计思想,信号体制的检测性能评估是信号体制设计中不可缺少的环节。基于上述考虑,分析评估了单频波多信号分量信号体制对导航信号检测性能的影响。以时分Alt BOC(TD-Alt BOC)为例,采用理论模型和蒙特卡罗仿真分析了采用1~4个信号分量联合捕获时的检测概率、接收机工作特性(ROC)曲线和平均捕获时间(MAT)。试验结果表明,多信号分量联合检测是一种较好的单载波多信号分量导航信号的检测策略,相对于单信号分量的检测性能,可提高检测灵敏度3~6 d B,降低平均捕获时间5%~30%。 相似文献
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Scott Geoffrey C. Bogen Daniel K. Korostoff Edward 《IEEE transactions on bio-medical engineering》1987,(6):424-429
Contamination of signals by noise degrades the performance of fast Fourier transform (FFT) analysis of biological systems. Thus, we have developed simulation techniques to investigate the effects of noise on FFT computations. Continuous and discrete representations of forcing-noise and response-noise signals are derived. The FFT is used to estimate magnitude and phase of noisy digital signals constructed using the discrete representations. The estimates are then compared to the estimates obtained from the noise-free digital signals. The following factors are shown to have an important influence on estimation accuracy: the inclusion of noninteger as well as integer harmonic noise, the signal series length, the relative noise-to-forcing and response signal magnitude ratios, and the degree of noise signal cross correlation between the forcing and response signals. We demonstrate that the FFT estimation accuracy of magnitude and phase is similar for integer and noninteger noise harmonics, it varies directly with signal series length, and inversely with the noise-to-forcing and response signal magnitude ratios. 相似文献