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1.
一种用于数字QAM接收机的盲均衡器实现   总被引:1,自引:1,他引:0  
许玲  蒋文军 《电视技术》2003,(12):15-17
提出了一种适用于数字QAM接收机的自适应盲均衡器实现方案。该均衡器采用多模算法(MMA)和最小均方算法(LMS),称为MMA—LMS算法结合判决反馈结构(DFE),即采用前向滤波器和反馈滤波器两级滤波器组实现,提高了信道的适应性能和降低均衡器的阶数。仿真结果表明,该均衡器比一般采用恒模算法(CMA)的横式均衡器有更好的性能,更易于硬件实现。  相似文献   

2.
短波信道的时变性可导致数据通信产生严重的码间串扰,必须选择合适的自适应均衡器,以便最大限度地降低码间串扰的影响;从而降低数据通信的误码率.通过比较选择适用于短波信道的自适应均衡器结构及其自适应算法,并通过仿真验证了采用平方根卡尔曼算法和判决反馈结构均衡器的性能.  相似文献   

3.
赵文斌  张长春  张桄华  董舒路 《微电子学》2021,51(5):666-671, 677
基于65 nm CMOS工艺,设计了一种25 Gbit/s带有一个无限冲激响应抽头的自适应判决反馈均衡器。该均衡器中关键路径采用堆叠式选择器和锁存器组成的半速率预测式结构,以减小环路反馈延时。自适应模块采用改进的最小均方算法,以改善抽头系数的收敛性。输出缓冲采用改进的fT倍增结构,以提升带宽并具有预加重功能。仿真结果表明,当信号速率为25 Gbit/s时,该均衡器能够自适应地实现最高20 dB衰减量的补偿,输出抖动小于10 ps。1.2 V电源供电时,整体电路在不同工艺角下的平均功耗约为120.5 mW。  相似文献   

4.
提出了一种具有较强抗突发干扰能力的非单点模糊径向基函数(Radial Basis Function,RBF)网络判决反馈均衡器.该方法将具有前置滤波特性的非单点模糊化技术引入RBF网络,利用梯度下降法自适应调整参数.通过仿真实验,并与基于径向基函数网络的判决反馈均衡器(Radial Basis Function Network-Decision Feedback Equalizer,RBFN-DFE)和传统判决反馈均衡器(Decision Feedback Equalizer,DFE)进行比较,结果证明该方法抗突发干扰能力强,误码性能好.  相似文献   

5.
本文设计了一种适用于高清晰数字电视(HDTV)接收芯片的全数字正交幅度调制器(QAM)的均衡器。该均衡器由前馈滤波器、误差判别电路和系数更新电路以及后馈滤波器构成。该均衡器采用了常模算法(CMA)和判决导引最小均方算法(DD-LMS)相结合的算法。重点给出了均衡器的VLSI实现、两种算法间切换的依据、步长的选择以及抽头系数的确定。同时在电路上采用了逻辑简化、重编码、电路时分复用等简化和优化方法来实现性能、面积和功耗的折衷。  相似文献   

6.
张明科  胡庆生 《电子学报》2017,45(7):1608-1612
本文介绍了应用于背板通信系统中均衡器的设计与实现.该均衡器采用连续时间线性均衡器(Continuous Time Linear Equalizer,CTLE)和2抽头判决反馈均衡器(Decision Feedback Equalizer,DFE)的组合结构来消除信道码间干扰中的前标分量和后标分量.在设计中,CTLE采用双路均衡器结构补偿信道不同频率的损耗,减小了电路的面积和功耗;DFE采用半速率预处理结构来缓解传统DFE结构中关键反馈路径的时序限制,并采用模拟最小均方(Least Mean Square,LMS)算法电路控制DFE系数的自适应.电路采用IBM 0.13μm BiCMOS工艺设计并实现,测试结果表明对于经过18英寸背板后眼图完全闭合的24Gb/s的信号,均衡后的眼图水平张开度达到了0.81UI.整个均衡器芯片包括焊盘在内的芯片面积为0.78×0.8mm2,在3.3V的电源电压下,功耗为624mW.  相似文献   

7.
一种T/4分数间隔预测判决反馈盲均衡算法   总被引:2,自引:0,他引:2  
为了消除由深衰落信道引起的严重码间干扰,本文给出一种基于改进双模式多模算法的 T/4 分数间隔预测判决反馈均衡器.该均衡器采用改进的双模式多模算法独立优化前向、反馈滤波器,前向滤波器采用 T/4 分数间隔,反馈滤波器采用预测结构,仍为符号速率.在两种深衰落信道条件下仿真实验表明,本文给出的均衡器能够避免传统判决反馈均衡器的误收敛情况;同时其稳态均方误差小于基于常模算法的 T/4 分数间隔均衡器、基于常模算法的 T/4 分数间隔判决反馈均衡器,以及基于双模式多模算法的 T/4 分数间隔预测判决反馈均衡器,更适合处理 QAM 信号.  相似文献   

8.
欧阳缮  方惠均 《通信学报》1997,18(11):14-19
对于自适应非线性均衡问题,当非线性信道的传输函数可由二阶Volterra级数表征时,可以作为广义多道滤波问题来处理。本文提出了一种无方根广义多道Givens格型算法来实现该非线性信道均衡器,研究了该均衡器消除由于信道非线性衰落引起的码间干扰的性能。实验结果表明:该自适应非线性均衡器具有快速收敛性能,对非线性信道的均衡效果优于LS格型判决反馈均衡器。  相似文献   

9.
在无线通信中,由于信道的不完善性和多径衰落等因素,使得数据在无线信道上传输时码间干扰严重,基于LMS(最小均方)算法的自适应判决反馈均衡器因其实现复杂度小可以广泛应用,文章对其原理和结构进行了分析并通过Matlab对该均衡器性能进行了计算机仿真,结果表明:在接收端采用该自适应均衡器可以大大降低误比特率,在工程上具有一定参考价值。  相似文献   

10.
本文研究了一种基于自适应步长LMS算法的自适应判决反馈均衡器算法,此算法通过对前向滤波器、后向滤波器和锁相环参数分别进行实时的、自适应步长的调整,在均衡时变多径的同时高精度地锁定接收信号相位,因此适用于相干通信系统。仿真结果表明在相同多径条件下,该方法比基于固定步长LMS算法的判决反馈均衡器输出误码率低1-7倍。  相似文献   

11.
DUV lithography, using the 248 nm wavelength, is a viable manufacturing option for devices with features at 130 nm and less. Given the low kl value of the lithography, integrated process development is a necessary method for achieving acceptable process latitude. The application of assist features for rule based OPC requires the simultaneous optimization of the mask, illumination optics and the resist.Described in this paper are the details involved in optimizing each of these aspects for line and space imaging.A reference pitch is first chosen to determine how the optics will be set. The ideal sigma setting is determined by a simple geometrically derived expression. The inner and outer machine settings are determined, in turn,with the simulation of a figure of merit. The maximum value of the response surface of this FOM occurs at the optimal sigma settings. Experimental confirmation of this is shown in the paper.Assist features are used to modify the aerial image of the more isolated images on the mask. The effect that the diffraction of the scattering bars (SBs) has on the image intensity distribution is explained. Rules for determining the size and placement of SBs are also given.Resist is optimized for use with off-axis illumination and assist features. A general explanation of the material' s effect is discussed along with the affect on the through-pitch bias. The paper culminates with the showing of the lithographic results from the fully optimized system.  相似文献   

12.
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.  相似文献   

13.
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.  相似文献   

14.
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.  相似文献   

15.
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.  相似文献   

16.
This paper presents a new method to increase the waveguide coupling efficiency in hybrid silicon lasers. We find that the propagation constant of the InGaAsP emitting layer can be equal to that of the Si resonant layer through improving the design size of the InP waveguide. The coupling power achieves 42% of the total power in the hybrid lasers when the thickness of the bonding layer is 100 nm. Our result is very close to 50% of the total power reported by Intel when the thickness of the thin bonding layer is less than 5 nm. Therefore, our invariable coupling power technique is simpler than Intel's.  相似文献   

17.
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.  相似文献   

18.
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.  相似文献   

19.
It is well known that adding more antennas at the transmitter or at the receiver may offer larger channel capacity in the multiple-input multiple-output(MIMO) communication systems. In this letter, a simple proof is presented for the fact that the channel capacity increases with an increase in the number of receiving antennas. The proof is based on the famous capacity formula of Foschini and Gans with matrix theory.  相似文献   

20.
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  相似文献   

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