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1.
第三代移动通信系统中的软件无线电技术   总被引:7,自引:0,他引:7  
软件无线电技术是 90年代新技术之一 ,它已与第三代移动通信系统紧密的结合起来。第三代移动通信系统的研究推动了软件无线电技术的发展 ,而软件无线电技术又促使第三代移动通信系统更加灵活的实现。本文分析了软件无线电技术在第三代移动通信系统中的应用 ,并总结归纳了由于第三代移动通信系统的推动作用 ,软件无线电系统呈现出的一些新的发展趋势。  相似文献   

2.
介绍了国际电联对第三代移动通信系统的要求,及第三代移动通信系统的主要特点,分析了第三代移动通信系统的几项关键技术。  相似文献   

3.
软件无线电在第三代移动通信系统中的应用与新进展   总被引:9,自引:1,他引:8  
第三代移动通信系统的研究推动了软件无线电技术的发展,而软件无线电技术又促使第三代移动通信系统更加灵活地实现。本文分析了软件无线电技术在第三代移动通信系统中的应用。并总结归纳了由于第三代移动通信系统的推动作用,抚线电系统呈现出的一些新的发展趋势。  相似文献   

4.
自1997年以来,第三代移动通信系统逐渐成为移动通信中的重点。本文通过对第三代移动通信系统中业务信息的分析,讨论在第三代移动通信系统步推广下,如何保护移动通信系统的安全性。  相似文献   

5.
关于3G移动通信系统业务模式的探析   总被引:1,自引:1,他引:0  
文章针对第三代移动通信系统探讨了其可承载的业务模式,结合第三代移动通信系统中发展进程和实际应用,分析了第三代移动通信系统业务运营方式和价值链的实现。  相似文献   

6.
首先介绍了第四代移动通信系统(4G)的概念、主要特点,并与第三代移动通信系统的参数进行了对比,然后讨论了第四代移动通信系统的网络架构及其七大关键技术,最后总结了第四代移动通信系统的最新进展。  相似文献   

7.
向第四代移动通信系统演进   总被引:2,自引:0,他引:2  
首先简要介绍移动通信发展的历史和第三代移动通信系统的特点,然后重点介绍第四代移动通信系统的出现和关键技术,最后对第四代移动通信系统作了展望。  相似文献   

8.
对前三代移动通信系统作了简单的介绍,并指出了第三代移动通信系统的不足,对第四代移动通信的主要技术特点及其关键技术进行了探讨.  相似文献   

9.
第三代移动通信是当前业内人士的热门话题,第三代移动通信的引入无疑会对21世纪人类的生活工作方式产生巨大影响,本文简略介绍了第三代移动通信系统及其标准情况,然后从电信运营的角度进行了中国联通为什么要关注第三代移动,以及如何迎接第三代移动通信的到来。  相似文献   

10.
基于第三代移动通信网络的业务管理特性,提出了第三代移动通信网络的SLM的功能体系结构和物理体系结构,设计并实现了一个第三代移动通信网络的SLM原型系统。  相似文献   

11.
In this article Korean development of IMT-2000 is considered. It includes the second-generation digital mobile communications, R&D and standardization activities related to IMT-2000, and the authors' perspectives on IMT-2000 in Korea. In Korea, there are many activities for development of IMT-2000 radio transmission technologies, and the results of these activities will be the submission of technologies to the ITU. However, the Korean telecommunications standardization body (TTA) will make every effort to make a common global standard for IMT-2000. Therefore, the TTA will make a domestic standard for IMT-2000 after the ITU finalizes the related Recommendations. It seems to the authors that difficulties in harmonization in the TTA are very similar to difficulties in harmonization worldwide. The only way of reaching the harmonization of IMT-2000 in Korea is that the key players should have the view from the end users' seat  相似文献   

12.
This article describes the current development of mobile communications in China, including market demand, operators, and technologies. The reasons China put great emphasis on IMT-2000 research and development are discussed. An IMT-2000-related organization structure is given, and their different responsibility and latest progress are also described. Finally, the author gives some viewpoints on IMT-2000  相似文献   

13.
本介绍了第三代移动通信系统IMT-2000的发展、运用及前景。结合云南省移动通信系统的现状,对云南省IMT-2000的应用及采用模式,可能存在的问题进行了探讨。  相似文献   

14.
崔春风  张平 《数字通信》2000,27(2):53-55
简要介绍了国际电联 (ITU)建议的 IMT- 2 0 0 0网络技术方面的特点 ,以及 ITU的相关建议制订情况 ,阐述了IMT- 2 0 0 0家族的概念、网络的兼容和过渡及网络实现的原则和方案。  相似文献   

15.
Several countries are keenly interested in the research and development of novel wireless communication systems using high altitude platform stations (HAPS) because of their great potential benefits. In June and July 2002, we carried out the world's first experiment on International Mobile Telecommunication 2000 (IMT-2000) by radio relay via transponders onboard an unmanned solar powered aircraft at an altitude of 20 km. This experiment demonstrated for the first time the feasibility of applying the IMT-2000 system using a HAPS and a compact cellular phone designed for terrestrial cellular systems. Two experiments were carried out over Kauai Island in Hawaii, USA. In the first experiment, we were unable to establish an IMT-2000 link connection via the aircraft at 20 km because the onboard transponder for the reverse link received unexpected signals from a terrestrial cellular system in commercial use 200 km away on Oahu Island. However, we managed to establish the link by connecting a high gain external antenna to the cellular phone. After the first flight experiment, we developed an onboard receiving antenna with a low sidelobe level to suppress interference signals. In the second experiment, we successfully achieved IMT-2000 video communication with a cellular phone. This paper presents the experimental results and analysis of these IMT-2000 communication experiments.  相似文献   

16.
This article provides an overview of the current IMT-2000 standardization activities in Japan. This article includes three main points, namely a guideline for introducing IMT-2000 into the Japanese market, radio transmission technology and an outline of the proposal to ITU-R, and key issues of network aspects  相似文献   

17.
Satellite UMTS/IMT2000 W-CDMA air interfaces   总被引:1,自引:0,他引:1  
The third-generation IMT-2000 initiative of the International Telecommunication Union is aiming at the provision of a limited family of global standards providing worldwide multimedia wireless services in a host of environments encompassing indoor picocells to satellite megacells. The ITU IMT-2000 initiative has been supported by several regional standardization bodies such as the European Telecommunication Standard Institute with its Universal Mobile Telecommunication System. In this article a few air interface proposals for the satellite component of UMTS/IMT-2000 based on adaptation of the emerging terrestrial wideband CDMA standards are reviewed. In particular, S-UMTS requirements are examined together with W-CDMA applicability to the satellite environment. It is shown that with minor adaptations, the terrestrial W-CDMA air interface provides an efficient solution for the satellite UMTS component. This commonality will certainly help in the realization of low-cost low-size dual-mode user terminals encompassing both terrestrial and satellite components  相似文献   

18.
王靖宇 《世界电信》2003,16(6):42-46
超3G在ITU—R范围内的各项研究工作还刚刚开始.基本上还处于制定工作计划的阶段。但目前关于对超3G频率需求计算方法的研究.已经有一些国家提出了自己的建议,主要是日本和德国。超3G研究工作。特别是频谱计算、业务预制、新的无线接入和核心网技术方面研究工作的开展,对我国的研究机构、相关公司和高校都是一个继续赶超世界先进通信技术.获取成果的绝好机会。  相似文献   

19.
The 3GPP proposal for IMT-2000   总被引:7,自引:0,他引:7  
Market expectations for third-generation mobile radio systems (IMT-2000) show an increasing demand for a wide range of services from voice to low, high, and advanced data rate services to support mobile multimedia. This leads to technical requirements for IMT-2000 which are currently being standardized worldwide. Circuit- and packet-oriented services will be supported. These systems will operate in all radio environments to provide service to anyone, anytime, anywhere. The ITU has identified spectrum for the allocation of IMT-2000. However, these frequency bands are currently not available worldwide. In different regions research activities on IMT-2000 have been initiated to support the international consensus building process and standardization activities. Based on these activities system proposals have been submitted to ITU TG 8/1. In particular, the newly formed Third Generation Partnership Projects 3GPP and 3GPP2 have the objective of harmonizing similar proposals and defining detailed standards. Proposals from Europe, Japan, Korea, and the United States are very similar. The evolution and migration of second-generation systems to the third generation takes into account the deployed investment to save today's investment where useful and necessary. This article focuses on market and technical requirements and, in particular, the technical approach of 3GPP based on the big footprint of the GSM system  相似文献   

20.
A penetration rate of portable phones became more than 50% in Japan andpeople are getting to expect new kinds of services provided by new generation systems. 3rd generation IMT-2000 commercial service is to be started in the second quarter of 2001 and 4th generation systems became new research target. This paper describes new services that will be provided by IMT-2000 systems in Japan and a concept of the 4th generation system. Major technologies for 4G systems are also presented.  相似文献   

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