Wedding……

兄弟结婚了，朋友结婚了，朋友的朋友结婚了；男的结婚了，女的结婚了，不男不女的也结婚了；有感情的结婚了，没感情的结婚了，认识不认识的结婚已经无所谓了……     

乱

江湖最近挺乱. 金融海啸了,经济危机了;奥巴马当选了,杨致远下课了;三聚氰胺走了又来了,"林书记"来了又走了;百度乱卖广告被央视曝光了,首富黄光裕涉嫌违法被拘查了;国家开始上万亿的花钱了,央行敢于一百零八个基点的降息了!     

临界连续模式功率因数校正器的高频数字控制研究

本文提出了一种无需检测电感电流及其过零点的简单数字控制方案，实现了临界连续模式功率因数校正器的控制。取得了功率开关管的ZVZCS，消除了整流二极管和快恢复二极管的反向恢复带来的损耗，提高了变换器的效率和可靠性；另外，数字控制器克服了模拟IC控制器的开关频率限制问题，消除了输入电流的低频畸变，提高了功率因数；同时，也降低了输入电感的值，降低了成本的同时提高了功率密度。为实现中小功率数字控制功率因数校正器的产品化提供了一个良好的解决方案。     

基于nRF905的无线通信的设计与实现

针对采用芯片nRF905的LED屏无线通信,分别给出了上位机和下位机的系统框图,分析了系统的功耗,比较了无线模块和串口通信的通信速率,验证了系统的可行性,设计了串口通信协议,为保证数据质量,设计了数据通信协议,针对串口数据的nRF905分包转发,设计了无线芯片通信协议,例举了状态机的5种状态,介绍了状态间的转换条件,巧妙地编程设计了通信数据的定时器检查,论述了基于状态机的嵌入式单片机软件编程。     

干扰电子通信的要素以及应对策略的探讨

在当今的社会中,人们已经离不开电子通信了,其作为了一个新兴产业,并得到了良好的应用,对各行各业起到了促进作用,同时,传统的产业收到了冲击。我国的电子通信发展较快,达到了先进的水平,不过,由于发展时间较短,存在很多不足之处,拉低了整体水平。特别是干扰问题,严重影响了电子通信的发展。本文对电子通信进行了概述,探讨了干扰要素,并且,提出了相关的应对策略。     

铝电解电容器技术的新进展

详细讨论了电子技术的发展对铝电解电容器的性能要求,提出了其技术对策,分析了存在的技术瓶颈,找出了它的技术出路,探讨了它的技术难点,给出了当前我国铝电解电容器行业的技术现状,指出了未来发展方向。     

ATM原理概论

介绍了ATM技术的框架，详细描述了ATM的协议栈；介绍了ATM的信元结构，描述了信元边界判定算法，指出了特殊信元的结构；叙述了常用的ATM适配层协议AAL1－AAL5；简单介绍了ATM的维护功能；最后指出了影响ATM性能的重要参数。     

加法器结构的大功率固态脉冲调制器的研究

介绍了大功率固态调制器电路常用的拓扑结构,讨论了开关直接串联与加法器叠加两种拓扑结构的特点.设计了基于绝缘栅双极性晶体管的加法器结构的大功率固态脉冲调制器,探讨了该类型大功率调制器的关键技术,介绍了调制器系统参数,并与国内外大功率调制器进行了对比.重点阐述了调制器实验,给出了实验结果,并对实验结果进行了分析.最后探讨了加法器结构的大功率固态脉冲调制器的优势及应用潜力.     

紫外通信综合实验平台信号源设计

阐述了紫外通信的优劣性,分析了紫外通信综合实验平台信号源设计的必要性,设计了紫外通信实验平台的系统结构方案,分析了各部分功能,给出了信号源设计的要求,选用了信号产生芯片MAX038与ICL8038,探讨了两者工作原理,对比了两者的优劣性,根据系统信号源参数要求设计了MAX038外围器件工作参数,最后使用OrCAD Pspice完成了电路的仿真,并通过2个结果分析验证了电路的可行性,这对系统的构建具有十分重要的指导意义。     

一种采用电容共用技术的DC-DC开关电源软启动电路

开关电源DC-DC转换器已经在各种电子设备中取得了广泛的应用。软启动电路保证了DC-DC转换器的正常启动,防止了器件的损坏。从理论上分析了软启动电路原理,设计了一种新型的开关电源软启动电路,该电路引入了电容共用方法,通过与频率补偿电容共用节省了软启动电容,降低了应用成本。并给出了具体电路实现,Spectre仿真结果验证了这种电路的可行性。     

量子反馈控制研究进展

量子反馈控制理论将反馈的思想引入量子系统的主动控制中,已开始在量子光学、原子物理和量子信息学等领域发挥越来越重要的作用.考虑到各种反馈策略的差异性,综述了量子反馈控制理论的研究进展,分析和阐述了马尔可夫量子反馈、贝叶斯量子反馈、含时延非马尔可夫量子反馈和相干量子反馈,并对四种量子反馈策略进行了简单比较.     

Performance analysis of discrete feedback schemes for downlink multiuser diversity in OFDMA systems

This paper analyzes discrete feedback of various feedback schemes for multiuser diversity in a multiple subchannel environment. In these schemes of full feedback, fixed feedback, adaptive feedback, and threshold-based feedback, users report a quantized discrete value to indicate their modulation and coding scheme instead of feeding back the full values of the channel state. A closed-form expression of the sum-rate capacity is developed to evaluate the feedback schemes. By comparing the feedback schemes in terms of the sum-rate capacity and the feedback load, this paper provides guidance for the selection of a feedback scheme. Additionally, a mixed-feedback scheme is proposed to reduce the amount of allocated feedback resources in the threshold-based feedback scheme, where the base station adjusts the capacity-feedback tradeoff by controlling two parameters, namely the number of subchannels and a threshold.     

对反馈放大电路类型判定方法的研究

反馈放大电路由基本放大电路和反馈网络组成,反馈桥梁是反馈网络的一部分或全部。反馈放大电路类型的判定方法是：反馈桥梁的一端连接在输出电压的＂上端＂（或＂下端＂）就形成电压（或电流）反馈,反馈桥梁的另一端连接输入信号的＂前端＂（或＂后端＂）就形成并联（或串联）反馈,再利用瞬时极性法确定使净输入量减小（或增大）的反馈为负反馈（或正反馈）。此方法能快速地判定出反馈放大电路的类型。     

Opportunistic Scheduling in Multiuser OFDM Systems with Clustered Feedback

This paper proposes a random access based feedback protocol for multiuser orthogonal frequency division multiple access (OFDMA) systems with clustered feedback, where users are assigned to clusters of subcarriers based on the feedback of channel state information to the base station. To reduce feedback requirements, the proposed protocol employs a contention channel with a fixed number of feedback minislots to carry feedback for each cluster. Users send a feedback message with some probability in the appropriate feedback slot if their average channel quality on a cluster is above a threshold. Both arithmetic and geometric averages are used and compared as channel quality measures. The threshold and feedback probability are jointly adjusted to maximize the estimated average sum rate of all users based on two different limited feedback information. Numerical simulations illustrate that it is possible to achieve multiuser diversity gain despite collisions in the feedback channel and with only a few feedback opportunities.     

一种改进的DL-CoMP-MU有限反馈方案

为提高现有的 CoMP下行链路的反馈能力,降低反馈开销,利用匹配滤波器原理、采用认知的思想方法来判断使用合理的协作传输结构,同时利用基于信号干扰噪声比(SINR)反馈开销方案代替CQI信息以降低信息的反馈量,从而进一步减少反馈信息量化误差。仿真结果证明,改进后的反馈开销方案相比传统方案,在提升反馈信息精确度的基础上,进一步减小了反馈开销。     

The optimal loop gain design for the spectral linewidth reductionin an electrical feedback semiconductor laser

The design of the optimal feedback loop gain for the spectral linewidth reduction in a semiconductor laser with electrical feedback is presented using a model of self-heterodyne type electrical feedback. The results show that the feedback loop gain must be suitably chosen to satisfy the requirement of narrowing linewidth. Due to the influence of AM noise in the feedback process, there is an optimal value for the feedback loop gain to reduce the linewidth for a given feedback condition. The influence of other feedback parameters on the linewidth reduction is also presented     

OFDM中继系统中减少反馈的节能方法研究

针对正交频分复用（OFDM）中继系统中上行反馈负荷过多和两跳链路能量消耗过大的问题,提出了一种减少系统上行反馈的节能方案（RFSE）。首先,根据用户的反馈中断概率,分别为中继和基站设置反馈门限;然后,通过信道的状态变化动态调整反馈门限,以达到减少系统反馈量的同时保证系统反馈量的稳定。最后,根据中继系统两跳链路中速率不匹配的规律,调整基站和中继处的发射功率,以达到减少系统能耗的目的。仿真结果表明,与减少信道反馈信息的分布式调度（RRFD）方案相比较,RFSE方案在减少系统反馈的同时,不仅保证了系统反馈量的稳定性,而且能够极大程度地减少系统能耗。      

Using High Frequency Operational Amplifiers for Low Noise Design

In this paper we present a comprehensive noise and stability analysis of both the current feedback and the voltage feedback op-amp when connected as transimpedance amplifiers with capacitive current sources. It is generally assumed that the current feedback op-amp is noisier than the voltage feedback op-amp; we show how external component values play an important role in determining the total equivalent input noise current spectral density and show that the voltage feedback op-amp may, in certain cases, be noisier than the current feedback op-amp. Both amplifier types are compared in terms of stability, noise and bandwidth; we find that the current feedback op-amp is particularly suited for operation as a transimpedance amplifier. Theoretical analysis is confirmed by simulations of equivalent circuits of the current feedback op-amp and the voltage feedback op-amp, and simulations of the macro models of two high performance commercially available op-amps, namely the Elantec EL2260 current feedback op-amp and the Elantec EL2244 voltage feedback op-amp.     

基于信道反馈的MIMO-OFDM系统多用户分集研究

利用包含信道质量的反馈信息,多用户分集能显著提高无线通信系统的性能。然而,在多载波多天线(MIMO-OFDM)的架构下, 反馈所有用户的所有信道质量信息(CQI)将占据大量的无线资源,从而降低了频谱效率,因此各种有限信道反馈算法被提出来减少系统的反馈开销。该文主要研究了基于两种典型的有限信道反馈的多用户分集增益,并与理想反馈进行了对比。系统平均频谱效率数学表达式的推导考虑了可选调制方式有限的特性,更符合实际。仿真用于评估各种反馈算法下的多用户分集性能,其结果与理论分析相当匹配。并且只要恰当地选取反馈参数,有限信道反馈算法可以在不损失多用户分集增益的前提下,极大的降低反馈开销,这为设计实际系统的信道反馈提供了参考。     

Limited feedback schemes for downlink OFDMA based on sub-channel groups

In a downlink orthogonal frequency division multiple access (OFDMA) system, optimally allocating sub-channels across mobile users can require excessive feedback of channel state information (CSI). We consider an OFDMA model in which the feedback overhead is explicitly taken into account, given a fixed feedback rate and finite coherence time. The tradeoff between feedback rate and sum capacity is studied for two limited feedback schemes: a sequential scheme in which the users send compressed feedback bits over consecutive time slots, and a contention scheme in which users send their feedback via a random access protocol. For both schemes each feedback bit indicates a request for a group containing multiple subchannels. We show that the sum capacity for both schemes with optimized sub-channel groups grows linearly with the number of sub-channels N, and that the associated constant increases as the log of the normalized feedback rate measured in bits per coherence time per sub-channel. We also compare the asymptotic (large N) performance of the two limited feedback schemes as a function of the feedback rate and load (users per sub-channel). The sequential scheme performs best with moderate to large feedback rates, or small loads, whereas the contention scheme performs best with small feedback rates or large loads.