Current IMT-2000 R&D status and views in Korea

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     

WCDMA标准化进展及在中国的产业化现状

本首先概述了IMT—2000的目标，比较了三种主流模式WCDMA、cdma2000和TD-SCDMA的技术特点，然后阐述了WCDMA的标淮进展情况，最后总结了中国在WCDMA方面的产业化进展和成果。     

超3G研究的最新进展

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。     

Experiments on IMT-2000 Using Unmanned Solar Powered Aircraft at an Altitude of 20 km

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.     

云南省第三代移动通信系统应用的探讨

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。     

IMT—2000系统网络概述

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。     

TD-LTE-Advanced国际标准历程

2000年5月,中国提交的TD-SCDMA技术被国际电联接受为IMT-2000（3G）的国际标准;2010年10月,国际电联WP5D工作组确认中国提交的TD-LTE-Advanced技术成为IMT-Ad-vanced（4G）国际标准。从TD-SCDMA到TD-LTE-Advanced,10年时间里中国已经打造了比较完整地TD产业链,并在积极推动移动通信产业的发展。     

IMT—2000的研究进展

本文就第三代移动通信系统ＩＭＴ－２０００研究的一些最新进展，特别是模式间融合的情况作了简要介绍。     

The 3GPP proposal for IMT-2000

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     

IMT-2000的融合、演进新进展

论述了有关IMT-2000的融合、演进新进展。     

Satellite UMTS/IMT2000 W-CDMA air interfaces

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     

TD-SCDMA──中国的IMT-2000RTT方案

简要介绍了第三代移动通信系统的研究开发情况,并对我国第三代移动通信系统无线传输技术IMT－2000RTT方案（时分-同步码分多址）作了深入探讨。     

Future Mobile Communications Systems in Japan

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.     

The current situation of IMT-2000 standardization activities inJapan

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     

Design of small and broad-band internal antennas for IMT-2000mobile handsets

The objective of this paper is to design some small broad-band internal antennas for third-generation International Mobile Telecommunications-2000 (IMT-2000) mobile handsets. By introducing substrates of low dielectric constants and electromagnetically coupling two shorted microstrip patch elements, of either rectangular or semidisc shape, both compactness and broad bandwidth can be achieved. These novel internal antennas for IMT-2000 mobile handsets incorporate only one single probe feed in a driven patch element, white the broad-band feature is obtained by realizing dual-frequency operation. The typical impedance behavior and far-field radiation pattern characteristics of eight different antenna configurations are discussed theoretically and experimentally     

An overview of CDMA evolution toward wideband CDMA

Third-generation mobile radio networks, often dubbed as 3G, have been under intense research and discussion recently and will emerge around the year 2000. In the International Telecommunications Union (ITU), third generation networks are called International Mobile Telecommunications-2000 (IMT-2000), and in Europe, Universal Mobile Telecommunications System (UMTS). IMT-2000 will provide a multitude of services, especially multimedia and high-bit-rate packet data. Wideband code division multiple access (CDMA) has emerged as the mainstream air interface solution for the third-generation networks. In Europe, Japan, Korea, and the United States, wideband CDMA systems are currently being standarized. This article provides a comprehensive introduction to wideband CDMA. It also provides a review of the wideband CDMA air interface proposals including WCDMA in Europe and Japan, cdma2000 in the United States, and wideband CDMA in Korea.     

IMT-Advanced标准发展分析

IMT-Advanced为具有超过IMT-2000能力的新一代移动通信系统,本文围绕IMT-Advanced的发展进行详细分析,主要包括IMT-Advanced的基本要求、IMT-Advanced的频谱需求、IMT-Advanced的业务特征、IMT-Advanced的提案分析、IMT-Advanced的标准化进程等,这对我国开展相关技术研究、系统评估、设备开发和产业发展具有重要的参考价值。     

An HTS 21-pole microstrip filter for IMT-2000 base stations with steep attenuation

We developed a 21-pole high-temperature superconductor thin-film microstrip filter with steep attenuation. This filter is applicable in the International Mobile Telecommunications-2000 (IMT-2000) base station receiver system, where high selectivity is needed to avoid interference from signals in the personal handyphone system (PHS) band just below the IMT-2000 band. The out-of-band rejection of this filter 1 MHz below the passband edge is more than 40 dB. Owing to the improvements of the design and the fabrication processes, we also eliminated the need for a tuning process in the fabrication processes in order to reduce the production costs and the turnaround time.     

第三代移动通信系统及WCDMA容量的分析

简单介绍了ＩＭＴ＿２０００第三代移动通信系统,对ＷＣＤＭＡ的基本特点进行了分析,提出了容量分析的原理和方法。     

26 GHz频段IMT-2020(5G)系统与卫星间业务频率共用分析方法研究

根据国际电信联盟(International Telecommunication Union,ITU)的相关建议和报告以及技术特性,提出了一种用于分析26 GHz频段IMT-2020(5G)系统与卫星间业务(Inter-Satellite Service,ISS)兼容共存性的方法.方法将全球较大面积部署的国际移动通信系统(International Mobile Telecommunications,IMT)基站合理地建模为一定数量的中心站,从时间和空间两个维度开展分析.其中,时间分析以全球范围的IMT-2020(5G)基站为对象; 空间分析以中国大陆范围的IMT-2020(5G)基站为对象,还考虑了实际的城市人口数量.分析结果表明,在26 GHz频段部署IMT系统,与卫星间业务具有兼容共存的空间.