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混沌激光具有宽频谱、类噪声、低相干等特性,在保密光通信、高速随机数、混沌激光雷达、混沌光时域反射仪和分布式光纤传感等领域具有重要的应用价值。光子集成混沌激光器是混沌激光应用的核心器件,具有体积小、性能稳定、成本低等优点。综述了近十年来光子集成混沌半导体激光器的进展及其主要应用。首先介绍了混沌半导体激光器的集成方式;接着介绍了光子集成混沌半导体激光器的分类,根据其扰动方式讨论了直腔单反馈、多腔反馈、环形腔反馈、二维外腔反馈、互注入等结构,并对比分析了各自的优势与输出特性;然后介绍了光子集成混沌半导体激光器在光时域反射仪、保密光通信和高速随机数产生等方面的应用;最后,讨论了光子集成混沌激光器的关键集成技术、时延特征抑制及间歇混沌的特性。 相似文献
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混沌激光具有宽频谱、类噪声、低相干等特性,在通信、雷达、传感等领域有广泛的应用。本文介绍了混沌半导体激光器的3种主要工作机制,分别为光反馈、光注入和光电反馈;重点研究典型混沌半导体激光器的频谱带宽、时延特征,以及复杂度等性能及其研究进展;进一步论述光子集成混沌半导体激光器的发展趋势;最后介绍混沌半导体激光器在保密光通信、随机数生成器、激光雷达、分布式光纤传感、混沌光时域反射计等领域的应用现状。本文可为高带宽、低时延混沌半导体激光器的发展和应用前景提供借鉴。 相似文献
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以超混沌电感电容(LC)振荡电路模型为对象,提出了一种线性和非线性混合反馈同步通信方案。通过设计李雅普诺夫函数对系统同步的稳定性进行了理论分析,得出了稳定状态下系统反馈强度的临界值。同时,基于线性和非线性混合反馈同步方式,研究了信号的注入式混沌保密通信方法。该方法不仅增强了通讯的保密性,而且对噪声有较强的鲁棒性,因而具有较好的工程应用价值。 相似文献
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激光混沌保密通信是近年来新兴的一个领域,它通常利用半导体激光器产生混沌,再将传输信号隐藏于混沌信号中,从而达到保密通信的目的。由于每个学者方式取向不同从而衍生出多种产生混沌的方式,本文参考大量文献,综合各种常用方式,将产生混沌的方式进行系统分类。首先分为反馈混沌和注入混沌;其中把反馈型混沌按反馈物质的不同又分为光反馈混沌和光电反馈混沌,而光反馈又有两种类型:反馈相干光和反馈非相干光,最近,更有学者在此基础上提出了双光反馈;然后分别阐述各种混沌类型的系统模型、理论模型及优缺点,将这个新兴领域的理论系统化、完整化。 相似文献
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相位共轭反馈半导体激光器混沌动力学 总被引:5,自引:0,他引:5
本文研究了相位共轭反馈对半导体激光器的动力学行为的影响。结果表明,在弱反馈条件下,系统处于稳态;增加反馈量,系统由周期经周期三、周期四进入混沌。当相位共轭反馈量一定时,通过改变注入电流的大小,可以达到所期待的周期或混沌状态。 相似文献
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Fei-Hu Hsieh Yen N.-Z. Juang Y.-T. 《Circuits and Systems II: Express Briefs, IEEE Transactions on》2005,52(2):77-81
This work presents an optimal design approach for the pulsewidth modulation switching control of a buck DC-DC converter by modeling the converter as a stochastic linear system with noise of uncertain load. Firstly, we temporarily assume that the stochastic system is available with complete state, and then derive an optimal state feedback control for the optimal noise regulation in steady state. Secondly, from the steady-state viewpoint, the optimal state feedback control is transferred into an equivalent error-driven servo controller, and then the designed optimal control law is implemented using a phase lead-lag controller. A distinctive advantage of this approach is that the optimal controller's parameters are actually independent of the statistics of the assumed uncertain load noise, so the benefit of optimal noise regulation is assured for global operation. Furthermore, the optimal controller is easily implemented. As a matter of fact, by just using the simplest possible operation amplifier circuits, the controller can be implemented. 相似文献
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LQR 即线性二次型调节器,其对象是现代控制理论中以状态空间形式给出的线性系统,而目标函数为对象状态和控制输入的二次型函数。LQR的最优解可以写成统一的解析表达式, 且可导致一个简单的状态反馈控制律。线性二次型控制理论已成为反馈设计系统的一种重要工具, 其特点是:为多变量反馈系统的设计提供了一种有效地分析方法;它可以适应于时变系统;它可以处理扰动信号和测量噪声问题;它可以处理有限和无限的时间区间。在处理可精确数学描述的对象时取得了很大的成功。对研究无人机的自动飞行控制技术具有十分重要的现实意义。 相似文献
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A partial-state and an output feedback control system synthesis method with feed-forward compensation, which doesn't make use of the state observer procedure, are proposed. These are applied to an efficiency-optimized speed control system of a dc motor system. This leads to a decrease in the number of current detectors of the motor system and the channel of the A/D converter. Although they are useful in practice, these control systems are, to some extent, susceptible to noise due to the inclusion of high-order difference actions in the controller. It is inevitable that the transient response becomes slow if the weighting factors in the performance index are chosen so that the influence of noise is decreased. The feed-forward compensation is useful for improvement on the transient response of the control system. But, the feed-forward compensation method for the partial-state or the output feedback control system has not been proposed until now. In this paper, the feed-forward compensation method, which can be applied to all the control systems, is proposed and the effectiveness is examined experimentally. Also, the influence of noise for each control system and the improvement of the efficiency are investigated experimentally. 相似文献
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Petros Bithas Athanasios Rontogiannis 《Wireless Communications and Mobile Computing》2016,16(16):2700-2713
A new user selection strategy is investigated and analyzed in a multiuser relaying environment in the presence of co‐channel interference. The proposed selection scheme aims at avoiding unnecessary feedback load processing, in cases where a target threshold, in the received instantaneous signal‐to‐noise ratio, is exceeded. Assuming that perfect channel state information is available, closed‐form lower bound expressions are derived for the cumulative distribution function of the output signal to interference plus noise ratio. Moreover, the impact of outdated channel state information on the system's performance is also investigated. In addition, under the assumption of high signal‐to‐noise ratio conditions, simplified approximated expressions are also provided for the cumulative distribution functions of the output signal to interference plus noise ratio, which are employed to study the outage probability and bit error probability performance of the system. It is shown that with the proposed approach, a significant reduction in feedback load processing is achieved, with only a slight loss in performance. Copyright © 2016 John Wiley & Sons, Ltd. 相似文献
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对主动噪声控制系统的前馈型、反馈型和混合型3种控制方式进行了比较,利用Simulink设计了实现FxLMS算法的模块,并进行仿真。结果表明,前馈型控制方式可降低与参考信号相关的噪声;反馈型控制方式可降低可预测的噪声;而混合型控制方式可同时降低这2种噪声。 相似文献
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m序列即最长线性反馈移位寄存器序列,其随机特性与白噪声特性最为接近,是一种常用的信号形式,在信号分析和信号处理中具有重要的价值。为了产生随机性能良好的伪随机序列,进而生成较为理想的白噪声信号,满足一般通信系统的测试要求,文中从m序列的原理和构造方法出发,应用周期性变更线性反馈移位寄存器的反馈连接和初始状态的方法,提出了一种基于VHDL生成的具有更长周期m序列的新方案。给出了原理分析、系统设计及算法的仿真结果。 相似文献
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Ho-Seop Jeong Chong-Won Lee 《Mechatronics, IEEE/ASME Transactions on》1997,2(3):161-168
A time delay controller with state feedback is proposed for azimuth motion control of the frictionless positioning device which is subject to the variations of inertia in the presence of measurement noise. The time delay controller, which is combined with a low-pass filter to attenuate the effect of measurement noise, ensures the asymptotic stability of the closed-loop system. It is found that the low-pass filter tends to increase the robustness in the design of the time delay controller, as well as the gain and phase margins of the closed-loop system. Numerical and experimental results support that the proposed controller guarantees a good tracking performance, irrespective of the variation of inertia and the presence of measurement noise 相似文献
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为了降低半导体抽运固体激光器的弛豫振荡噪声,提高其输出功率的稳定性,采用光电负反馈的方法来抑制半导体抽运的固体激光器的强度噪声,并对激光器强度噪声的理论特性进行了分析。根据理论分析结果设计了比例-积分-微分反馈控制电路,通过运用该反馈电路对激光器进行强度噪声抑制实验,得到了比较理想的实验数据,即当抽运功率为700mW、弛豫振荡峰频率为300kHz时,弛豫振荡峰值处和低频区域强度噪声分别降低了45dB和15dB;当抽运功率为550mW、弛豫振荡峰值为250kHz时,弛豫振荡峰值处和低频区域强度噪声分别降低了40dB和10dB。结果表明,该反馈控制电路能够有效地降低半导体抽运固体激光器的强度噪声,提高激光器输出功率的稳定性。 相似文献