利用高阶累积量实现数字调制信号的自动识别

通信信号的自动调制识别在截获信号处理方面是一个十分重要的课题。本文针对数字调制信号的识别问题，提出了一种基于高阶累积量的分类特征，该特征有效地抑制高斯白噪声的影响，能实现对2ASK、4ASK、4PSK、2FSK、4FSK等五种数字调制信号的识别。论文进行了理论推导，并用仿真实验和实际采集数据进行了验证。     

利用幅度特性对数字信号调制方式进行识别

数字调制方式的识别对于通信信号分析有着重要的作用。针对数字信号（2ASK,4ASK,2PSK,4PSK,2FSK和4FSK）的调制方式,本文提出了一种只利用调制信号瞬时幅度特性便可以对调制信号进行识别的新算法,利用特征参数提取与决策树分类器结合对以上6种数字信号进行调制识别。首先提出了使用希尔伯特变换和解析函数对数字信...     

基于决策论的数字调制信号识别方法

以决策论为基础提出了一种改进的数字调制信号识别方法,该方法仅需4个相对简单的特征参数,就能识别2ASK、4ASK、2FSK、4FSK、2PSK、4PSK和16QAM这7种数字调制信号。仿真结果表明,该方法复杂度较低,识别正确率有较大提高,尤其对于2ASK、4ASK、MPSK/MFSK及16QAM的识别,在信噪比较低的情况下,具有较好的识别效果。     

基于高阶累积量和神经网络的数字调制识别

针对数字调制信号的识别问题,提出了一种基于高阶累积量的分类特征,该特征有效地抑制高斯白噪声的影响,能实现对2ASK、4ASK、4PSK、2FSK、4FSK等五种数字调制信号的识别。分类器采用了多层组合的神经网络分类器,不需要设定判决门限,而且在收敛速度、训练时间以及识别率方面都有很大改进。仿真结果表明,在信噪比大于7 dB时,系统的正确识别率可达95%以上。     

基于瞬时幅度与小波分析相结合的数字调制制式的自动识别

本文提出了一种基于信号瞬时幅度与小波分析相结合的数字调制制式的自动识别新算法。该算法计算简单、实时性强,能够成功识别2ASK、4ASK、2FSK、4FSK及2PSK5种信号。仿真结果表明,该算法具有较高的识别率。     

利用高阶累积量实现数字调制信号的识别

文中提出一种基于高阶累积量识别多种数字调制信号的算法。首先推导计算各信号的八阶累积量,从二、八阶累积量中提取一个特征参数,实现以更少参数识别更多信号的目的;然后,为提高MFSK的识别率,从微分后MFSK信号的四、六阶累积量中提取一个特征参数完成识别。仿真结果显示,通过利用这两个参数可以实现2 ASK/BPSK、4 ASK、8 ASK、QPSK、8 PSK、2 FSK、4 FSK、8 FSK、16 QAM、64 QAM等多种数字调制信号的识别。     

差分运算在数字调制制式识别中的应用

随着数字通信技术的发展，数字信号调制制式的识别成为近年来的研究热点，本文将差分运算应用到数字调制制式的自动识别当中，设计了一种新的算法，能够成功识别2ASK，4ASK，2FSK，4FSK及2PSK五种信号。仿真结果表明，该算法具有较高的识别率。     

基于循环谱和高阶累积量的联合模式识别方法

为完全识别当前卫星通信采用的主要调制方式,结合循环谱和高阶累积量两种信号调制识别方法的特点,提出了一种联合识别算法。该算法将循环谱特征加入到高阶累积量识别法中,联合多种特征参数判决构建识别器,首先利用循环谱完成ASK、FSK、PSK信号的类间识别以及FSK信号的类内识别,在此基础上利用高阶累积量方法完成FSK、PSK信号的类内识别。仿真结果表明,该算法能够完全区分卫星通信中主要的调制模式{ASK、2ASK、2FSK、4FSK、BPSK、QPSK},在信噪比高于5 d B时识别率达88%以上。     

基于BP神经网络的数字调制信号样式自动识别

针对2ASK，4ASK，2FSK，4FSK，BPSK和QPSK六种数字调制信号，给出了对他们进行识别的5种特征参数的定义，提出了基于BP神经网络利用较少样本分3步进行训练，来实现对数字信号调制样式自动识别的方法，最后得到了在信噪比≥8dB时较高的正确识别率。     

特征提取及其在数字调制方式识别中的应用

通信信号调制识别技术在军事和民用领域都具有重要的应用前景,而特征参数的提取是调制方式识别的首要问题。本文提出了两个新的特征参数,并结合这两个新的特征参数在统计模式识别的基础上构造了一组新的特征集参数,该特征集无需任何先验知识。随后,本文针对2PSK、QPSK、8PSK、16QAM、2FSK、4FSK、8FSK、2ASK、4ASK等9种调制类型,采用了分层结构的神经网络分类器进行自动识别。大量仿真表明,在待识别的信号信噪比大于5dB时,该识别系统的正确识别率达97%以上,且识别的稳定性好。     

Cost-effective test solutions for smart card and other integrated flash applications

From its emergence in the late 1980s as a lower cost alternative to early EEPROM technologies, flash memory has evolved to higher densities and speedsand rapidly growing acceptance in mobile applications.In the process, flash memory devices have placed increased test requirements on manufacturers. Today, as flash device test grows in importance in China, manufacturers face growing pressure for reduced cost-oftest, increased throughput and greater return on investment for test equipment. At the same time, the move to integrated flash packages for contactless smart card applications adds a significant further challenge to manufacturers seeking rapid, low-cost test.     

An improved parallel thinning algorithm with two subiterations

The parallel thinning algorithm with two subiterations is improved in this paper. By analyzing the notions of connected components and passes, a conclusion is drawn that the number of passes and the number of eight-connected components are equal. Then the expression of the number of eight-connected components is obtained which replaces the old one in the algorithm. And a reserving condition is proposed by experiments, which alleviates the excess deletion where a diagonal line and a beeline intersect. The experimental results demonstrate that the thinned curve is almost located in the middle of the original curve connectivelv with single pixel width and the processing speed is high.     

Theoretical analysis of the relationship between the Brillouin gain coefficient and the strain in the optical-fiber sensors

The relation between the power of the Brillouin signal and the strain is one of the bases of the distributed fiber sensors of temperature and strain. The coefficient of the Bfillouin gain can be changed by the temperature and the strain that will affect the power of the Brillouin scattering. The relation between the change of the Brillouin gain coefficient and the strain is thought to be linear by many researchers. However, it is not always linear based on the theoretical analysis and numerical simulation. Therefore, errors will be caused if the relation between the change of the Brillouin gain coefficient and the strain is regarded as to be linear approximately for measuring the temperature and the strain. For this reason, the influence of the parameters on the Brillouin gain coefficient is proposed through theoretical analysis and numerical simulation.     

Novel fiber-optical interferometer with miniaturized probe for in-hole measurements

Today, micro-system technology and the development of new MEMS （Micro-Electro-Mechanical Systems） are emerging rapidly. In order for this development to become a success in the long run, measurement systems have to ensure product quality. Most often, MEMS have to be tested by means of functionality or destructive tests. One reason for this is that there are no suitable systems or sensing probes available which can be used for the measurement of quasi inaccessible features like small holes or cavities. We present a measurement system that could be used for these kinds of measurements. The system combines a fiber optical, miniaturized sensing probe with low-coherence interferometry, so that absolute distance measurements with nanometer accuracy are possible.     

Teleportation of an arbitrary unknown N-qubit entangled state under the controlling of M controllers

A new quantum protocol to teleport an arbitrary unknown N-qubit entangled state from a sender to a fixed receiver under M controllers(M < N) is proposed. The quantum resources required are M non-maximally entangled Greenberger-Home-Zeilinger (GHZ) state and N-M non-maximally entangled Einstein-Podolsky-Rosen (EPR) pairs. The sender performs N generalized Bell-state measurements on the 2N particles. Controllers take M single-particle measurement along x-axis, and the receiver needs to introduce one auxiliary two-level particle to extract quantum information probabilistically with the fidelity unit if controllers cooperate with it.     

Diode-end-pumped Nd:YVO4/LBO lasers with 4.2W continuous-wave output at 457 nm

A continuous-wave (CW) 457 nm blue laser operating at the power of 4.2 W is demonstrated by using a fiber coupled laser diode module pumped Nd: YVO4 and using LBO as the intra-cavity SHG crystal With the optimization of laser cavity and crystal parameters, the laser operates at a very high efficiency. When the pumping power is about 31 W, the output at 457nm reaches 4.2 W, and the optical to optical conversion efficiency is about 13.5% accordingly. The stability of the out putpower is better than 1.2% for 8 h continuously working.     

Call for Papers

正Wireless Body-area Networks The last decade has witnessed the convergence of three giant worlds:electronics,computer science and telecommunications.The next decade should follow this convergence in most of our activities with the generalization of sensor networks.In particular with the progress in medicine,people live longer and the aging of population will push the development of wireless personal networks     

Call for Papers—Feature Topic,Vol.12,No.7,2015

正Information Centric Networking Information-Centric Networking(ICN) is an emerging direction in Future Internet architecture research,gaining significant tractions among academia and industry.Aiming to replace the conventional host-to-host communication model by a data-centric model,ICN treats data content as the first     

JOURNAL OF ELECTRONICS(CHINA)

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NEXT GENERATION WIRELESS NETWORKS–ESPECIALLY THE USE OF MILLI-MICROWAVE BANDS

The global bandwidth shortage of wireless communications has motivated the exploration of the naillimeter wave （ram-wave） frequency spectrum for the next generation wireless communications. Recent advances in RF CMOS technology and high speed baseband signal processing technologies have enabled tile extensive research and development of turn-wave wireless communications. The multi gigabit per second data rate of ram-wave system will lead to applications in many important scenarios, such as WPAN, WLAN,back-haul for cellular system. And the frequency bands include 28 GHz, 38 GHz, 45GHz, 60GHz, E-BAND and even beyond 100 GHz. The propagation and the imitation of the RF circuits design in these frequency bands make the directional antennas be inevitable for mm-wave communications.