S12 BITS系统在通信网中的应用

Ｓ１２ＢＩＴＳ系统在通信网中的应用无锡邮电局王颖张建清Ｎｏ．７信令网和ＳＤＨ环型自愈网、数字数据网等的广泛应用，通信设备的不断增加，带来了一个新的问题，即面对众多对时钟要求很高的设备，时钟同步网如何组织。如果在每个设备点上都建大楼时钟同步系统（ＢＩＴ...     

宽带ISDN与ATM交换技术──第一讲 ATM的基本概念和B－ISDN标准

本文讨论了宽带ＩＳＤＮ的产生和发展，介绍了ＡＴＭ的基本概念和原理，并给出了ＩＴＵ－Ｔ关于Ｂ－ＩＳＤＮ／ＡＴＭ的有关标准。     

宽带ISDN与ATM交换技术

本文讨论了宽带ＩＳＤＮ的生产和发展，介绍了ＡＴＭ的基本概念和原理，并给出了ＩＴＵ－Ｔ关于Ｂ－ＩＳＤＮ／ＡＴＭ的有关标准。     

关于尽快采用同步状态信息的建议

介绍了同步状态信息（ＳＳＭ）的概念，ＩＴＵ—Ｔ相关建议对ＳＳＭ的规定，以及目前同少数字体系（ＳＤＨ）设备和数字同步网中综合定时供给设备（ＢＩＴＳ）的ＳＳＭ功能情况；提出了当前急需采取相应技术措施的建议。     

一种新型电子节能灯用晶体管——双极型静电感应晶体管

本文简要叙述了开发和研制ＢＳＩＴ的市场背景和技术现状，对ＢＳＩＴ器件模型进行了理论分析，对ＢＳＩＴ器件的设计和制作工艺进行了探讨，并分析了ＢＳＩＴ器件的工作原理和特性；介绍了ＢＳＩＴ器件的应用和上灯试用情况。     

华为的又一支柱

1996年,华为第一套ＳＤＨ光同步传输网在重庆地区顺利开通,标志着中国在光同步传输领域的长足进步。随后华为的ＳＤＨ设备ＳＢＳ155/622陆续进入山东、吉林、甘肃、贵州、江西、河南、河北等省,经受了通信网上实际运行的考验,得到了使用者的普遍认可和信赖。华为的ＳＤＨ产品的成功,源于其质量和性能。ＳＤＨ产品ＳＢＳ155/622及/ＳＢＳ622/2500是从如下几个方面为用户服务的:(1)标准化。完全遵循ＩＴＵＴ的ＳＤＨ标准及国标设计。(2)兼容性。ＳＢＳ155/622、ＳＢＳ622/2500两个系列兼容。与不同厂商的设备也兼容。(3)组网灵活。可满足网络…     

激光制备多层薄膜及铁电性能的研究

利用脉冲准分子激光淀积（ＰＬＤ）方法，在Ｓｉ基片上制备了ＢＩＴ／Ｓｉ〔１００〕、ＰＺＴ／ＢＩＴ／Ｓｉ〔１００〕和ＢＩＴ／ＰＺＴ／ＢＩＴ／Ｓｉ〔１００〕铁电薄膜。用ＸＲＤ分析了多层铁电薄膜的晶相结构；用Ｓａｗｙｅｒ－Ｔｏｗｅｒ电路研究了这些单层和多层铁电薄膜的铁电性能。结果表明，单层ＢＩＴ的矫顽场Ｅｃ为４ｋＶ／ｃｍ，剩余极化强度为３．４μＣ／ｃｍ２；ＰＺＴ／ＢＩＴ的矫顽场Ｅｃ为８２ｋＶ／ｃｍ，剩余极化强度Ｐｒ为３６μＣ／ｃｍ２；ＢＩＴ／ＰＺＴ／ＢＩＴ夹层铁电薄膜的矫顽场Ｅｃ为５７ｋＶ／ｃｍ，剩余极化强度Ｐｒ为２９μＣ／ｃｍ２。最后讨论了薄膜的铁电性能与多层结构的关系     

B—ISDN和ATM与宽带通信业务

本文首先通过对宽带业务发展情况，ＡＴＭ标准，ＡＴＭ适配层的分析引出了ＡＴＭ对Ｂ－ＩＳＤＮ发展的作用及向Ｂ－ＩＳＤＮ过渡的步骤，并指出工发具ＳＭＤＳ和ＦＲ业务接口的ＡＴＭ交换机，对实现Ｎ－ＩＳＤＮ向Ｂ－ＩＳＤＮ过渡具有积极现实意义，其次介绍和分析了ＩＴＵ－Ｔ，日本ＮＴＴ及欧洲各国关于ＡＴＭ和Ｂ－ＩＳＤＮ的标准化活动，应用试验等情况。     

配置采、编、播设备应注意系统性

在与一些有线台和企事业电教部门合作中,发现部分单位在配置采、编设备时比较乱,几个厂家甚至几种格式的设备并存。如果是老台,由于历史原因造成这种现象尚可理解,但一些新台配置设备也是如此。笔者认为应引起重视。应该说,采、编设备的格式不统一会给用户带来极大的麻烦。在模拟时代,视频设备格式百花齐放,但却苦了用户,如果用户自己不注意统一格式,就会更加麻烦。现在正向数字化过渡,目前数字化设备的格式更是五花八门,如ＤＩＧＩＴＡＬＢＥＴＡＣＡＭ,ＢＥＴＡＣＡＭＳＸ,ＤＶＣＰＲＯ,ＤＶＣＡＭ,ＤＩＧＩＴＡＬＳ等等,…     

DBASEⅢ与PASCAL语言的数据交换

由于ＰＡＳＣＡＬ接收的数据文件是以空格作为隔符，而在ＤＢＡＳＥⅢ下用ＤＥＬＩＭＩＴＥＤ ＷＩＴＨ ＢＬＡＮＫ复制数据文件时将字符型字段的后面空格全部删除，所以，编程时要注意这一点。     

Narrow bus encoding for low-power DSP systems

High levels of integration in integrated circuits often lead to the problem of running out of pins. Narrow data buses can be used to alleviate this problem provided that the degraded performance due to wait cycles can be tolerated. We address bus coding methods for low-power core-based systems incorporating narrow buses. We show that transition signaling combined with bus-invert coding, which we call BITS coding, is particularly suitable for the data patterns of typical DSP applications on narrow data buses. The application of BITS coding to real circuit design is limited by the extra bus line introduced, which changes the pinout of the chip. We propose a new coding method, which does not require the extra bus line but retains the advantage of BITS     

电信企业信息化统一模型构建策略

电信企业信息化的实质就是赋予电信企业精细化的企业资源整合能力，本以此认识为出发点，通过定义基本的信息化业务元素，需求参数和基本信息处理机制，构建出带有行业共性的电信企业信息化统一模型，该模型针对目前电信企业信息化中常见的和潜在的问题提供了有效的解决措施。     

Bipolar transistor selected P-channel flash memory cell technology

A novel BIpolar Transistor Selected (BITS) P-channel flash memory cell is proposed, where a bipolar transistor embedded in the source region of the cell amplifies cell-read-current and acts as a select transistor. With this cell, not only a very low 1.5 V non-word-line-boosting read operation, but also a sector-erase operation are successfully achieved with only a small cell-size increase over the conventional NOR cell. Moreover, this cell technology maintains all the advantages of the P-channel DIvided-bit-line NOR (DINOR) flash memory     

相位数据分析在同步网管系统中的应用

提出了同步时钟设备的相位性能数据分析对同步网监控管理的重要性，详细介绍了在同步网管系统中对楼内综合定时供给单元(BITS)相位性能数据分析采用的方法及分析结果对判断网络和设备性能提供的辅助作用，并指出同步网管中相位性能数据分析还有待解决的一些问题。     

有线数字电视前端系统的同步研究和实现

随着有线电视数字化的全面推行，时钟同步问题成为前端播出的一项新的课题和挑战。本文对数字电视前端各种同步方式进行了研究和比较，阐述各自特点和局限性，建设了一套高精度、安全可靠、可扩展的时钟同步系统。     

On Fixed-Mobile Network Convergence

As the convergence in digital industry takes shape, the digital networks, both wireline and wireless, are also converging to offer seamless services and enhanced experience to the user. With the arrival of the mobile Internet the mobility is also moving into new areas, e.g., imaging, games, video, multimedia, and across different types of networks. In this paper we explore why, what, and how of the network convergence, and identify how the industry viewpoints align and differ. We also identify the key barriers to achieving true network convergence. We then discuss the role of the Internet Protocol (IP) as the common thread that enables network convergence, and the key industry and standards initiatives to actually provide solutions and the equipment to implement a cost-efficient and high performance converged network. Sudhir Dixit joined Nokia Research Center in 1996, where he is currently a Research Fellow and works on next generation wireless networks. From 1996 to 2003 he was a Senior Research Manager, focusing on IP/ATM, wireless, content networks, and optical networks. Prior to that he worked at NYNEX Science & Technology (now Verizon), GTE (now Verizon), Codex Motorola, Wang, Harris, and STL (now Nortel Europe Labs). He has published or presented over 150 papers, published three books, and holds 14 patents. He is on the Editorial Board of the IEEE Communications Magazine, Springer's Wireless Personal Communications Journal, and KIC's Journal of Communications and Networks. He received a B.E. degree from MANIT, Bhopal, India, an M.E. degree from BITS, Pilani, India, a Ph.D. degree from the University of Strathclyde, Glasgow, Scotland, and an M.B.A. degree from Florida Institute of Technology, Melbourne. He is a Fellow of IEE (UK) and IETE (India). He represents Nokia on the Steering Board of the Wireless World Research Forum, and is also Chair of the SIG on Self-Organization of Wireless World Systems.     

A new derivation of least-squares-fitting principle for OFDM channel estimation

Many channel estimation and data detection algorithms of the orthogonal frequency division multiplexing (OFDM) system have been proposed. Some of these algorithms are based on the principle of linear minimum mean-square error (LMMSE) estimation, which is theoretically optimal. There are also some algorithms developed based on the least-squares-fitting (LSF) principle, which finds a regression polynomial to fit a block of tentative channel estimates in the least-squares sense. The LSF principle is a non-statistical approach, while the LMMSE algorithm is statistical and it needs to known or estimate the channel statistics like correlation matrices and signal-to-noise ratio (SNR). This letter proposes a novel viewpoint of the LSF principle. We show that the non-statistical LSF principle can be derived alternatively from the statistical LMMSE principle by eigenvector approximation. This constructs a link between these two principles. The mean-square estimation error (MSEE) analysis shows that there are common terms in the MSEE expressions of these two principles. This further validates the constructed link. Based on the derived link and MSEE analysis, we also give some characteristics and discussions of the LSF principle.     

The Variational Principle for Non-Self-Adjoint Electromagnetic Problems

A systematic and intuitive procedure is proposed to derive the variational (or stationary) principle for non-seff-adjoint electromagnetic problems with various boundary conditions. Several physical interpretations of this principle in terms of generalized reactions, time-average stored energy, and reactive powers, respectively, are discussed in detail. This general variational principle which makes the generalized reactions a stationary value is actually an extension of the least action principle in physics. The applications of the principle to establish the variational expressions for a waveguide, a cavity resonator, and a Ioasy one-dimensional inhomogeneous slab are presented.     

DTMB单频网组网概述

就地面数字电视国标(DTMB)单频网(SFN)组网的概念、系统构成单频网同步原理、激励器原理以及实验室测试方法等作了系统介绍。同时通过对实际组网中可能遇到的问题以及需注意的事项给出分析和解决办法。     

A novel tunable-complexity turbo-soft detector for high-throughputHDSL applications over ISI channels with crosstalk

We present a novel iterative (turbo) receiver with tunable complexity for reliable detection of (uncoded) payload data transmitted over long intersymbol interference (ISI) channels affected by crosstalk, as those typically encountered in emerging HDSL2 services standardized by ANSI T1.418 recommendation. The proposed receiver combines in an original way "minimum mean square error (MMSE) estimation principle," "turbo-processing principle" and "crosstalk-prediction principle" for achieving both suboptimal maximum a posteriori probability channel equalization and reliable soft-mitigation of ISI tail plus crosstalk. More in detail, according to the turbo-processing principle, at each iteration suitable extrinsic information is extracted from the equalizing and interference-canceling modules and used as "a priori information" for the next iteration. Several simulation results on typical HDSL-like test-loops confirm the superiority of the proposed turbo-detector (TD) over current solutions based on conventional MMSE decision-feedback equalizers and precoders (such as the Tomlinson-Harashima precoder). The numerical tests also point out that performance of the presented TD on typical high bit-rate digital subscriber lines (HDSL) is not limited by error-floor phenomena, even at error-probabilities below 10^-7