Theoretical Analysis of PAPR Companding Techniques for FBMC Systems

Wireless Personal Communications - The offset quadrature amplitude modulation (OQAM) with filter bank multicarrier (FBMC) has turn on considerable interest in last decades over orthogonal frequency...     

Design and Performance Analysis of a New Soft Handoff Scheme for CDMA Cellular Systems

In this paper, a new soft handoff scheme for CDMA cellular systems is proposed and investigated. It is pointed out that some handoff calls unnecessarily occupy multiple channels with little contribution to the performance of handoffs in IS95/CDMA2000-based handoff schemes or systems. To alleviate performance degradation due to channel resource shortage during soft handoff, a new concept of channel convertible set (CCS), which contains several types of handoff calls that unnecessarily occupy extra channels by considering the relative mobility of the calls in the handoff area is introduced. A new scheme that reallocates those extra channels in the CCS to new handoff calls when there is no available free channel in the system is proposed. Furthermore, according to the variation of the CCS, the proposed scheme dynamically adjusts the number of guard channels reserved exclusively for handoff. Then, the feasibility and implementation issues of the proposed scheme are discussed. To evaluate and compare performance indexes of different soft handoff schemes, continuous-time Markov chain models are constructed. Automated generation and solution of the underlying Markov chains are facilitated by stochastic reward net models, which are specified and solved by stochastic Petri net package. Numerical results show that this scheme can significantly decrease both the number of dropped handoff calls and the number of blocked calls without degrading the quality of communication service and the soft handoff process.     

数字系统的诊断技术分析

文章讨论了故障诊断技术的产生,发展和存在的一些问题,并对一些故障诊断方法进行了分析,评价;最后,对故障诊断和ＡＩ技术的结合进行了探讨。     

Two New Techniques Integrated for Energy-Efficient TLB Design

The translation lookaside buffer (TLB) is an essential component used to speed up the virtual-to-physical address translation. Due to frequent lookup, however, the power consumption of the TLB is usually considerable. This paper presents an energy-efficient TLB design for the embedded processors. In our design, we first propose a real-time filter scheme to facilitate the block buffering to eliminate the redundant TLB accesses without comparator delay. By modifying the address registers to be sensitive to the contents variation, the proposed real-time filter can distinguish the redundant TLB access as soon as the virtual address is generated. The second technique is a banking-like design, which aims to reduce the energy consumption per TLB access in case of block buffer miss. To alleviate the performance penalty introduced by the conventional banking technique, we develop two adaptive variants of the banked TLB. Both variants can achieve the high energy efficiency as the banked TLB while maintaining the low miss ratio as the nonbanked TLB. The experimental results show that by filtering out all the redundant TLB accesses and then minimizing the energy consumption per access, without any performance penalty our design can effectively improve the Energy^* Delay product of the TLB, especially for the data TLB with poor locality     

Analysis of FSO Systems with SISO and MIMO Techniques

Wireless Personal Communications - The capacity of the radio link can be improved a lot by using modern wireless technologies like Multiple Input and Multiple Output (MIMO) technology. Successful...     

WDM-PON接入技术及其最新进展

本文首先从时分复用无源光网络（TDM—PON）的不足引入波分复用无源光网络（WDM—PON）,接着介绍了ONU波长固定和可调WDM—PON,随后阐述了ONU无色和无光源WDM—PON。鉴于目前WDM-PON难以推广使用的现状,上行用TDMA替代WDMA会使WDM—PON看起来更加现实,所以本文也介绍了混合使用WDM和TDM的HPON。最后对WDM—PON与功率分配PON（PS—PON）的技术进行了比较。     

光学和光电子系统用的微机械加工技术

回顾了微机械加工技术的最新进展, 介绍了自由空间微型光学试验平台和光预对准的概念以及微机械加工的光学器件实例。     

防空体系光电对抗技术应用分析

光电对抗技术在军事上的广泛应用,使战争的进程和结局产生极速变化。从宏观的角度分析了防空体系预警系统的组成,并对光电对抗技术在防空中的应用作了介绍。     

Reliability Prediction Techniques for Complex Systems

As electronic systems continue to evolve into more and more complex structures, the search for better and more efficient reliability prediction techniques naturally takes on added momentum. Needed are not only systematic methods of mathematical model building that will simplify the procedures involved but also noncomplex ways of obtaining solutions to many practical problems. This paper illustrates the applicability of transition diagram in describing the state space of a complex system, repairable or nonrepairable, and shows the methodology of writing the set of first-order linear differential equations representing the system performance by inspection of the transition diagram. A discussion of some applicable properties of linear signal-flow graphs is included. Methods of solving problems by inspection techniques are clearly explained and specific examples are given to illustrate the concepts. The mean time Tm for a system to pass for the first time from its initial state to a failed state is usually a statistic of prime interest. Certain properties of Laplace transform are used to illustrate how Tm of a general complex system, repairable or nonrepairable, can be obtained by solving a set of simultaneous algebraic equations. Flow graph techniques of solution by inspection are shown to be a valuable tool in obtaining analytical solutions for Tm of many practical systems.     

高能效系统的功耗优化技术

本本将叙述了各种系统选择方案及其对系统功耗的影响,全面介绍了处理器电源管理功能,并讨论总系统功耗的一些重要促进因素。本文网络版地址：http：//www.eepw.com.cn/article/164395.htm     

DSP系统电源管理技术

电源效率既取决于硬件设计与组件选择,又取决于基于软件的电源管理技术。文章讨论了嵌入式系统的电源管理技术,介绍了如何将其集成到DSP的RTOS 中,并以TI的DSP/BIOS操作系统为例,给出了电源管理软件技术的实施方法。     

Design and Analysis of Data Communication Systems

A network can promote collaboration between many different and widely dispersed groups of workers. Expanding network capabilities and information flow throughout a business organization can help to improve quality, responsiveness, reaction time and, ultimately, sales and profits.     

液相外延温控系统与真空系统的全新设计

对液相外延温控系统和真空系统进行了全新的设计,温控系统运用单相可控硅过零触发技术,解决了移相触发技术中使系统电压畸变,功率因数下降的问题.并配以日本神港程序控制器,使得温度精度达到±0.1 ℃,且重复性和稳定性也相应地得到提高.真空系统加入了冲洗气体保护装置,有效地解决了以往冷阱变暖使油蒸汽反流的问题.     

矿用RFID标签天线的分析与设计

本文提出了一种用于矿井人员定位系统的结构紧凑的Hilbert分形倒F标签天线.通过HFSS软件仿真,分别给出了普通倒F天线和Hilbert分形倒F天线的回波损耗、方向图及天线增益.仿真结果表明,这2种天线性能相当,但Hilbert分形倒F天线具有更小的尺寸,更符合矿用RFID标签天线小尺寸、低功耗的要求.制作的Hilbert分形天线经测试,在2.425 GHz的中心频率下,回波损耗为-38.28 dB,带宽为190 MHz.     

融合地址薄系统的设备安全管理技术

为了方便用户搜索和共享联系人信息,保持多种端的地址簿同步,获得联系信息同步更新,发送邀请信息,开放式移动联盟（0MA）提出了融合地址簿研究项目。针对终端丢失或被窃导致数据泄露的问题,基于OMA的设备管理（DM）技术提出了锁定和擦除管理对象（LAWMO）,并给出了在CAB系统实现具体流程。     

Disturbance Response Techniques for Digital Control Systems

An adequate disturbance response is important to obtain good regulation in automatic control systems. This paper considers the form of the disturbance response for variable digital control systems with proportional-plus-integral feedback, and derives the relationship between the system responses to both reference and disturbance signals. The choice of optimum parameters is considered, and it is shown that good system response for both reference and disturbance signals can readily be obtained for the case of closed-loop control with complete feedback.     

多进制数字调相系统分析与设计方法的探讨

对数字通信中MPSK系统的调制与解调问题进行了较为的分析,并以8PSK和循环码16PSK系统为例,阐述其调制器电路的逻辑设计方法。在此基础上给出了8PSK系统调制与解调的一种方案,讨论了循环码和自然二进制码16PSK系统的调制器的具体设计过程,该设计方法可应用于一般MPSK系统的逻辑设计。     

Filter-Bank Modulation Based Signal Design and Transmission Techniques for Intensity Modulated MIMO Visible Light Communication Systems

Wireless Personal Communications - Current research in wireless communication undoubtedly points towards the tremendous advantages of using visible light as a spectrum for significantly boosting...