常见的无线电干扰及其规避措施探讨

无线电干扰查处工作,是无线电管理工作中的一项重要的任务,作为无线电管理工作者对监测设备的工作原理、功能、技术性能、指标要深刻领会理解,要求掌握电磁环境随地形、频率、天气、距离等外部条件的变化规律。掌握各类干扰的成因及其规避措施,是有效降低无线电干扰发生率的主要途径。如何科学有效地规避频率间的干扰,介绍常见的无线电干扰类型、特征、危害性及其抑制干扰采取的措施。     

GSM与GPRS无线网络协调优化分析

GPRS无线网络以GSM无线网络作为其承载网,这决定了GPRS网络优化具有与GSM网络优化相互关联、相互制约的特点.本文介绍GPRS无线网络优化的主要流程和内容,综合考虑对现有GSM无线网络的影响,合理利用现有无线网资源,以效益最大化为目标,实现两个网络的优化平衡.     

无线电气象学研究进展与展望(特邀文章)

气象条件会导致无线电信号折射、衰减和超视距传播等电波传播效应.无线电气象学是研究气象环境特性及其对电波传播影响机理的一门交叉学科,是电波传播研究的重要领域.无线电气象学随着电波传播、气象和相关信息技术的发展而不断取得新的研究进展,为电波传播的更可靠预测和无线电系统的应用提供了可靠的数据和机理支撑.本文对全球数字地图、无线电参数遥感和短期预报等方面的研究进展进行了综合论述,并对无线电气象相关方向的发展给予了展望.     

一种基于CR的无线通信侦察体系结构

在分析认知无线电思想的基础上,定义了基于认知无线电的无线通信侦察分析的概念,设计了一种基于认知无线电的无线通信侦察分析的体系结构,为无线通信侦察技术研究提供参考。     

网络技术在广播电视工程中的应用

随着网络技术的不断发展和普及,广播电视工程领域也在逐步应用网络技术,以提高广播电视行业的效率和服务质量。文中论述了网络技术与广播电视工程的联系、网络技术在广播电视传输中的应用、网络技术在广播电视制作中的应用、网络技术在广播电视服务中的应用以及网络技术在广播电视工程中的未来应用方向,旨在全面探讨网络技术在广播电视工程中的应用情况,为广播电视工程的发展提供参考。     

软件无线电分层体系结构

介绍一种用来设计可重构平台的软件无线电体系结构,叫做软件无线电分层体系结构。这种结构引入了软件无线电的所有特征,并使复杂的问题简单化,是一个开放的、统一的、正式的体系结构,适合于软件无线电系统的标准化,有利于软件无线电体系结构的统一。     

SCA电台与高保障IP加密机的一体化设计研究

SCA电台的安全设计可以基于SCA安全附录的要求来实现,与传统电台不同的是,它需要实现架构上的红黑物理隔离、硬件的可编程,以及软件与安全策略的可加载.为了满足基于IP的新型宽带无线组网波形的安全需要,有必要把用于保护飞地网络安全的新型高保障IP加密,即HAIPE机制也融入到SCA电台中来.文中探讨了SCA电台安全设计思路,研究了HAIPE的设计原理,提出了SCA电台与HAIPE的一体化设计方案,展望了电台安全架构设计未来的发展方向.     

Radio Astronomy and Spectrum Management: The Impact of WARC-79

As a valid use of the radio spectrum and an official radio service, radio astronomy was very much a part of the 1979 World Administrative Radio Conference (WARC-79). The allocation of frequency bands is vitally important for the sustained health of the science. WARC-79 provided first the impetus for astronomers, worldwide, to examine the allocation requirements of radio astronomy and then the opportunity to communicate those needs to the regulatory community. The characteristics of radio astronomy, the criteria for interference-free operation, possibilities for sharing with other radio services, and the need for frequency-band allocations are discussed because all bear directly on an evaluation of the Conference. The Final Acts of WARC-79 are examined from the viewpoint of their impact on radio astronomy.     

认知无线电技术及应用

认知无线电技术是目前无线传输领域的主要研究热点之一。对认知无线电的不同定义进行了讨论,并从认知无线电系统组成及认知无线电与其他无线电(特别是自适应无线电和智能无线电)的关系2方面分析了其内涵,重点介绍了无线频谱感知、智能资源管理、自适应传输和跨层设计等认知无线电系统主要关键技术;最后给出了认知无线电可能的应用场景。     

广播电视编辑业务创新与发展探讨

当下,广播电视媒体行业正处于转型发展时期,广播电视台一定要与时俱进,不断创新和发展新媒体时代的广播电视编辑业务,以保证广播电视节目的可持续发展。首先论述了当前新媒体时代下广播电视编辑中存在的问题,其中包括:广播电视新闻时效性不够高、广播电视新闻内容比较单调、广播电视新闻节目缺乏主动性等;并以此为依据,提出新媒体时代下广播电视编辑业务创新与发展的对策,包括对新媒体技术进行充分利用、对广播电视新闻内容进行不断丰富等,具有重要意义。     

移动通信系统中的软件无线电技术

软件无线电是在通用的、开放的硬件平台上采用软件技术来实现无线通信系统的各种功能的通信技术。本文介绍了软件无线电的基本概念、主要特点，分析了实现软件无线电的关键技术及其在第三代移动通信系统中的应用前景。     

Cognitive Radio for Flexible Mobile Multimedia Communications

Wireless multimedia applications require significant bandwidth, some of which will be provided by third-generation (3G) services. Even with substantial investment in 3G infrastructure, the radio spectrum allocated to 3G will be limited. Cognitive radio offers a mechanism for the flexible pooling of radio spectrum using a new class of protocols called formal radio etiquettes. This approach could expand the bandwidth available for conventional uses (e.g., police, fire and rescue) and extend the spatial coverage of 3G in a novel way. Cognitive radio is a particular extension of software radio that employs model-based reasoning about users, multimedia content, and communications context. This paper characterizes the potential contributions of cognitive radio to spectrum pooling and outlines an initial framework for formal radio-etiquette protocols.     

Frequency bands for optimum propagation of complex signals through shortwave radio channels

A radio-engineering approach based on the dispersion characteristic and impulse response of a radio channel is proposed to describe the dispersion distortion of complex shortwave radio signals propagating through ionospheric radio channels. The impulse response of a wideband ionospheric radio channel is investigated using the polynomial representation of the dispersion characteristics, which are determined from oblique sounding of the radio channel by ultrawideband chirp signals. Frequency bands for optimal propagation of complex signals over radio links 3600 to 5700 km long are estimated.     

我国无线电导航发展的回顾与对策建议

在过去的五十年里,我国的无线电导航技术获得了突飞猛进的发展和进步,无线电导航的事业也在不断壮大,由初期的一片空白逐步的发展到了如今的系统工程,无线电导航为我国的航空、航海、国防、经济等方面的发展都做出了巨大的贡献.本文对我国的无线电导航系统的发展进行了深入的探讨和分析,并针对我国的无线电导航提出了相关的建议和对策,同时也对未来的无线电导航的进一步发展做出了展望和期许.     

基于软件无线电和云计算技术的无线电监管体系

文章提出了运用软件无线电、有线及无线高速网络、云计算等技术等3项新技术相结合的全新的无线电监测系统的设想、框架及应用模式,一改传统无线电监测基础思想和模式,为新一代的无线电监管技术及体系的发展提供参考。     

Diversity protections for digital radio-summary of ten-yearexperiments and studies

A summary is presented of a series of critical experiments that led to recent discoveries of large improvement factors for digital radio performance by antenna pattern diversity, antenna angle diversity, frequency diversity, and space diversity. The measured diversity improvement factors for digital radio against multipath dispersive fading are larger than those predicted by the existing analog radio model by at least one order of magnitude. Applications of these findings will lead to substantial savings in the cost for diversity protections for digital radio routes. These discoveries stimulated the development of new models of diversity improvement factors for digital radio and the development of the DRDIV computer program for engineering digital radio routes. Background information is given on multipath fading and diversity concepts, and a glossary of terms is included     

虚拟无线电技术及其应用

近年来软件无线电技术已成为无线电通信领域的技术热点。文中首先介绍软件无线电的基本概念、体系结构及其关键技术 ,在此基础上着重探讨软件无线电的发展新趋势虚拟无线电 (virtualradio)技术 ,通过与传统软件无线电技术的比较 ,分析其优势所在 ,并以SpectrumWare系统为例 ,提出了采用虚拟无线电技术实现GSM收发信基站的软件模块设计方法。     

无线电短波通信在信息化时代的应用

社会科技信息化的全面发展,为当前的无线电波领域创新提供了强有力的支撑,其被广泛应用于各个领域,为人们提供了优质的服务。基于此,文中以当前的无线电波通信行业发展为基础,探索了无线电短波通信的特点,明确了信息化时代无线电短波通信的应用技术,分析了无线电波通信行业的发展前景,旨在为当前行业发展提供良好的参考。     

Slant-path microwave radio propagation through distorted raindrops

Attenuation and phase coefficients are evaluated for microwave radio propagation through oblate spheroidal raindrops on slant radio paths. From these coefficients, it is evident that the resultant crosspolarisation for linearly or circularly polarised waves should be significantly less on satellite radio paths than on horizontal radio paths.     

Opportunistic channel allocation decision making in cognitive radio communications

The global spread of wireless devices with mobile Internet access and the increasing demand of multimedia‐based applications are fueling the need for wireless broadband networks. IEEE 802.16 and 802.20 are standards for a broadband wireless access with promising cognitive radio features to support mobile Internet access. However, because of the fast changing radio environment and the demand for dynamic spectrum allocation mechanisms, these standards must continuously readjust different radio parameters. The cognitive radio makes decisions based on its built‐in inference engine, which also in time can adapt itself to different situations through the process of learning from experience. In this paper we present an automated opportunistic decision making and learning process for cognitive radio based on uncertainty reasoning algorithms. This novel approach is well suited in fast changing wireless environments with vague, incomplete, and heterogeneous information. Theory and simulations prove that decision making and learning of the cognitive radio based on the proposed approach cope with the changes in the radio environment. In this work we use fuzzy logic for the learning and decision making of the cognitive radio. Simulation also show that our approach provides accurate and precise decisions on allocating spectrum to mobile Internet users even in fast varying radio conditions. Copyright © 2012 John Wiley & Sons, Ltd.