新千年通信趋势

概括地汇总专家对新千年通信趋势的预测,内容包括话音通信、数据通信、图像通信、光纤传输、固定通信网和无线移动通信等。     

Supervisory Communication and Performance in Urban Hospitals

The relationship between the communicative effectiveness of hospital supervisory personnel and their performance as perceived by subordinate workers was examined through use of questionnaire interview. Communicative effectiveness measures included (1) perceived communication behavior, (2) frequency and amount of communication between supervisors and subordinates, (3) employee knowledge of hospital policies and procedures, (4) perceived employee communication satisfaction and (5) perceived use of formal channels of communication by non-supervisory workers. Performance ratings included scales on human relations, administrative and technical skills. Hypotheses predicted positive correlations (1) between communication effectiveness and performance, (2) between amount (and frequency) of communication and performance, (3) between employees’ communication satisfaction and supervisor performance, (4) between employee knowledge of hospital policies (and procedures) and supervisor performance ratings, and (5) between amount of use (by employees) of formal channels of communication and supervisor performance ratings. With noted exceptions, the first three hypotheses were supported. Results are discussed in the context of related studies of supervisory communication and performance in hospitals and in industry.     

基于SCA无线通信系统的安全体系结构研究

采用软件无线电技术和模块化设计思路,构造新一代的无线通信系统,是无线通信发展的趋势。介绍了软件通信体系结构(SCA)的无线通信系统,描述了基于SCA无线通信系统的安全体系结构,详细分析了加密子系统、信息安全子系统和设备安全子系统。这样定义的安全体系结构保证了基于SCA无线通信系统实现不同的安全模式,提供不同的安全级别。     

The evolution of communication vehicles: linear progress andcyclical progress

Examines several aspects of communication methods (`vehicles') and the various types of progress that have been made over the years. Much of the progress we have made in communicating is rooted strongly in our past. Much of the future of our communication vehicles will be rooted in our present and our understanding of our present. In this paper, we focus our discussion on six aspects of communication: (1) communication vehicles for teaching and learning; (2) forums for communication-wide interchange of ideas; (3) vehicles for search-and-retrieval of information; (4) the richness of the communication media set; (5) venues of communication-where we communicate and the tools we use; and (6) the idea of linearity in communication     

Laser satellite communication network-vibration effect and possiblesolutions

A number of serious consortiums develop satellite communication networks. The objective of these communication projects is to service personal communication users almost everywhere on Earth. The intersatellite links in those projects use microwave radiation as the carrier. Free-space optical communication between satellites networked together can make possible high-speed communication between different places on Earth. Some advantages of an optical communication system over a microwave communication system in free space are: (1) smaller size and weight, (2) less transmitter power, (3) larger bandwidth, and (4) higher immunity to interference. The pointing from one satellite to another is a complicated problem due to the large distance between the satellite, the narrow beam divergence angle, and vibration of the pointing system. Such vibration of the transmitted beam in the receiver plane decreases the average received signal, which increases the bit error rate. We review: (1) the present status of satellite networks, (2) developing efforts of optical satellite communication around the world, (3) performance results of vibration effects on different kinds of optical communication satellite networks, and (4) seven approaches to overcome the problems caused by transmitter pointing vibration     

CDMA与GSM基站共址杂散干扰仿真与分析

随着无线通信技术和服务要求的飞速发展，出现了第二代和第三代系统，以及同一代移动通信系统内不同通信标准共存的情况。中国联通的CDMA系统和GSM系统就是一个最具代表性的例子。不同系统营运于同一个电磁环境下，势必会带来系统之间电磁兼容的问题。对电磁兼容中的共址干扰问题中的杂散干扰做了较深入地探讨。     

Exploring the Relationship Between Communication Risk Perception and Communication Portfolio

With the rapid development of information communication technologies (ICT) over the past decade, the nature of how organization members communicate has changed, becoming far more complex and challenging. Communication risks brought about by technology-mediated communication can sometimes be detrimental to the overall organizational function and success. We classify these communication risks into three types: reception, understanding, and action risks. We propose the notion of communication portfolio which refers to a single ICT or a specific combination of lCTs that can be used to manage any perceived risk of communication. Specifically, this study aims to examine the relationship between perceived risks (i.e., risk of reception, risk of understanding, and risk of action) in the communication process and the dimensions (i.e., content, and structuring mechanism) of the communication portfolio used for communication. We also identify communication risk factors that may accentuate the different types of risks. We develop a communication risk perception framework to illustrate the relationship between the communication risk factors, the different types of communication risks, and the communication portfolio. Finally, we illustrate how the communication risk perception framework can be applied in a real-life natural setting by using the shuttle Challenger incident, as an example.     

面向光纤通信的大气激光应急通信系统设计

应急通信是指在突发事故造成通信中断或通信阻塞情况下的临时通信。结合应急通信的特点,给出一个面向光纤的大气激光应急通信系统,较为详细地说明了该系统中应急数字光端机的各模块功能,分析了PPM调制和锁相环原理和作用,最后指出了应急通信系统的应用前景。     

Intellicise communication system: model-driven semantic communications

As one of the critical technologies for the 6th generation mobile communication system (6G) mobile communication systems, artificial intelligence (AI) technology will provide complete automation for connecting the virtual and physical worlds. In order to construct the future ubiquitous intelligent network, people are beginning to rethink how mobile communication systems transmit and exploit intelligent information. This paper proposes a new communication paradigm, called the Intellicise communication system: model-driven semantic communication. Intellicise communication system is built on top of the traditional communication system and innovatively adds a new feature dimension on top of the traditional source coding, which enables the communication system to evolve from the traditional transmission of bit to the transmission of “model”. Like the semantic base (Seb) for semantic communication, the model is considered as the new feature obtained from the joint source-channel coding. The sink node can re-construct the original signal based on the received model and the encoded sequence. In addition, the performance evaluation metrics and the implementation details of the Intellicise communication system are discussed in this paper. Finally, preliminary results of model-driven image transmission in the Intellicise communication system are presented.     

流星余迹通信信道统计特性及模型仿真

流星余迹通信不同于传统的通信,它是低速率通信,具有突发、不连续以及不定时的特性。流星余迹通信的复杂性要求有必要对其通信信道进行研究。可用流星率、占空比、平均持续期、等待时间和通信通过量是影响流星余迹通信信道性能的重要参数。根据偶发流星日心空间和地心空间的几何关系,得到了流星突发通信信道参数预测模型;并对流星通信链路观测的数据进行统计分析,得到流星余迹通信信道的各参数,预测结果和通信链路观测结果比较一致,为流星通信系统的建立提供了技术支持。     

Review of vehicular ad hoc network communication models including WVANET (Web VANET) model and WVANET future research directions

The most ever growing research field is vehicular ad hoc network. This prominent research field has the widely known communication models such as RoadSide Unit Communication, Vehicle to Vehicle Communication, and Cluster based Communication models. In addition to that M. Milton Joe and B. Ramakrishnan et al. have proposed a new communication model known as WVANET (Web VANET) for vehicular ad hoc network communication. The authors portray that WVANET will be the everlasting research field in future. This WVANET (Web VANET) communication model is fundamentally different from other communication models as it makes use of web signals to disseminate the messages among vehicles. Of course, each communication model in VANET will have its own various pros and cons. This paper provides the overall review of all the existing communication models in VANET and in addition to that WVANET (Web VANET) communication model is also presented. Further this paper discusses the various future research that can be done in WVANET (Web VANET) communication model.     

Toward a Reconceptualization of Communication

The study of communication as a focus on messages or on symbolic transmission is challenged as unrealistically narrow. In addition, it is suggested that the communication scholar must recognize the influences of (1) man's changing contexts, (2) man's interdependence with his environment, (3) man's limited ability to control for error, (4) interaction effects in communication, and (5) the effects of choices of communication behaviors attributed to others. Thus, it is argued, communication should be defined as the study of the ways by which men affect each other and the interactions of those systems of influence.     

2010年通信技术和业务概貌预测──AT＆T贝尔研究院John Mayo院长演讲笔记

本文是贝尔研究院ＪｏｈｎＭａｙｏ院长１９９４年７月１１日在上海所作学术报告的听讲笔记。报告预测２０１０年通信技术和业务十大方面的概貌：（１）微电子集成芯片；（２）光子逻辑控制；（３）光纤传输容量；（４）语音信号处理；（５）传真和可视通信；（６）通信网结构进化，（７）个人无线通信；（８）计算机处理能力；（９）通信软件生产率；（１０）多媒体信息终端。     

基于高阶累积量的近场通信波达方向估计算法

通过对近场通信波达方向准确估计,提高目标信源的定位能力.传统方法中对近场源通信信源的波达方向估计采用多普勒估计方法,由于近场通信的空间信源为窄带信号,多普勒估计会导致DOA估计频谱失真.提出一种基于高阶累积量的近场通信波达方向估计算法.采用均匀间隔线列阵构建近场通信的信号模型,进行近场源目标特征构建,提取近场源通信信号的斜度和峰度等特征,采用高阶累积量特征提取方法,分别求得对应近场通信信源的方位角、频率和距离三维参数,使得每个信源的参数自动配对,提高了近场通信DOA波达方向估计的效率和精度,实现近场源通信信号的波达方向估计算法改进.仿真实验结果表明,采用该方法进行近场方法波达方向估计的精度较高,对信源方位的定位准确,性能优越于传统方法,在近场通信中具有较好的应用价值.     

国家通信网使用IP与WDM的倾向

本文简单说明国家通信网计划时应考虑的关键问题：（１）国际上通信业务量的增长趋势,（２）现代通信技术研究成就的进展方向。（３）国家通信网结构设计的重心转移。文中建议不能单纯以Ｂ－ＩＳＤＮ为目标,而要慎重考虑ＩＰ／ＡＴＭ和ＩＰ／ＷＤＭ。     

基于LDPC码和BPPM的无线光通信系统性能研究

为了克服光在弱湍流大气条件传输时,光强闪烁造成的突发错误,在已知信道衰落信息(CSI)和未知信道衰落信息(NCSI)条件下,研究了基于低密度奇偶校验(LDPC)码和二进制脉冲位置调制(BPPM)的无线光通信系统性能,论述了BPPM光通信信道对称性的特点,并与基于LDPC码和OOK调制的光通信系统性能进行了比较。结果表明,在NCSI和CSI情况下,基于LDPC码和BPPM的光通信系统相对于基于LDPC码和OOK调制的系统均有更优异的差错性能;在NCSI情况下,基于LDPC码和BPPM的光通信系统的性能相对于CSI情况下的系统性能损失并不大;且采用LDPC码BPPM相对于LDPC码OOK调制的光通信系统,随着湍流强度的增大系统性能损失较小。因此,基于LDPC码和BP-PM的光通信系统在不需要信道衰落信息估计的情况下,能获得较大的编码增益,便于工程实现,在无线光通信中将有一定的应用前景。     

High-speed real-time visible light communication system based on InGaN/GaN-base multi-quantum well blue micro-LED

Visible light communication (VLC) technology is a new type of wireless communication technology, which employs a light source as the carrier of information to realize illumination and communication simultaneously. This paper adopts a single InGaN/GaN-base multi-quantum well blue micro-light emitting diode (LED) as the light source, designs pre-emphasis circuit, LED driver circuit, impedance matching network, etc., and builds a high-speed real-time VLC system. It has been verified that the LED achieves a 3 dB modulation bandwidth of 450 MHz or more; and the real-time communication rate reaches over 800 Mbit/s at a distance of 2 m. The communication bit error rate (BER) is as low as at a communication rate of 622 Mbit/s. Experimental indicators including 3 dB bandwidth, communication rate, and communication BER are all taken into account. Therefore, this VLC system supports high-quality high-speed real-time communication.     

适合中国的卫星通信组网的星座方案

针对我国地域分布的实际情况及通信业务量各时段的差异,提出适合中国的卫星无线光通信系统星座方案,利用3颗中轨卫星和16颗低轨卫星组成的通信系统能够覆盖我国区域,满足通信要求。     

机间紫外光通信网络MAC层分段运行退避算法研究

对飞机编队内部和飞机编队之间的紫外光通信网络工作模式以及相应的MAC层协议进行研究.为保证编队内所有飞机的信息共享与交互,编队内部采用非直视通信NLOS(a)模式;为保证通信距离和质量,编队之间采用NLOS(c)模式进行通信.机间紫外通信组网MAC层协议以原IEEE802.11 DCF协议为基础,对传统二进制指数退避算法进行改进,提出了一种基于分段思想的动态退避算法并进行了仿真研究,仿真结果表明:该算法与传统算法相比具有时延短,吞吐量大的特征,更适用于机间紫外通信网络.     

一种CPFSK信号调制指数估计方法

随着通信技术与通信方式的快速发展,通信信号调制方式与通信系统越来越复杂。复杂通信信号连续相位频移键控(CPFSK)由于其频谱利用率高,大量用于卫星通信等领域。针对复杂信号CPFSK的参数估计问题,提出一种基于李雅普诺夫指数的CPFSK信号调制指数估计方法。通过CPFSK信号李雅普诺夫指数与调制指数的数学关系模型,提取李雅普诺夫指数估计信号调制指数。仿真验证了算法性能,得到CPFSK调制指数估计均方根误差随信噪比的变化曲线。此方法计算复杂度低且实现简单,适用于CPFSK信号与常规频移键控(FSK)信号的调制指数估计。