IMT-Advanced技术研究进展

简要介绍了B3G技术的市场背景，以及世界主要国家和组织对B3G技术的研究进展．其中包括欧洲、日本、韩国，美国和中国。     

IMT-Advanced技术研究进展

简要介绍了B3G技术的市场背景,以及世界主要国家和组织对B3G技术的研究进展,其中包括欧洲、日本、韩国、美国和中国.     

IMT-Advanced信道建模探讨

作为第四代移动通信技术,高级国际移动通信（IMT-Advanced,International Mobile Telecom Advanced）相比于第三代移动通信技术（IMT-2000,International Mobile Telecom System-200）,能够提供更高的数据速率和更好的用户体验。为了适应新的无线传播特性,国际电信联盟（ITU,International Telecommunications Union）提出了相关的测试环境和评估场景,这对开展相关技术研究,系统评估和测试具有重要的意义。IMT-Advanced信道模型的建立,相比与早期的模型更加完善,也更加准确,适于在不同场景下对无线传播特性进行分析和研究。     

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。     

8通道TD-LTE系统优势分析

通过介绍LTE标准演进,说明了TD-LTE和LTEFDD两种制式的由来,并在此基础上对两种制式由于本身特点带来的天线技术选择上的差异进行了剖析。通过相同且合理的仿真条件下仿真结果的对比说明了使用多天线的TD-LTE系统的优势所在。     

Requirements and Algorithms for Cooperation of Heterogeneous Radio Access Networks

This paper defines the requirements for cooperation of heterogeneous radio access networks (RANs) and proposes a novel radio resource management (RRM) framework for support of mobility and quality of service (QoS) in a heterogeneous communication environment comprising IMT-Advanced and legacy systems. The reference IMT-Advanced system is the one developed within the IST project WINNER (IST-2003-507581 Project Wireless Initiative New Radio, ). The RRM mechanisms are evolved from traditional ones to comply with the requirements imposed by a simplified new (RAN) architecture as proposed for IMT-Advanced systems. The RRM mechanisms are evaluated for the scenario of intra-RAN and inter-RAN user mobility. The RRM framework incorporates as novelty improved triggering mechanisms, a network-controlled mobility management scheme with policy enforcement on different levels in the RAN architecture, and a distributed handover and admission control mechanism for fast decision polling at different levels of the RAN. The RRM framework is further enhanced with computational intelligence based on fuzzy logic algorithms to enhance the process of handover. The RRM framework has been evaluated in terms of reduced user blocking probabilities.

TD-LTE／TD-LTE-Advanced技术

作为TD—SCDMA技术的演进。TD—LTE／TD—LTE-Advanced是下一代移动通信系统IMT-Advanced的主流候选技术之一。与第三代移动通信系统采用CDMA技术不同,TD—LTE采用OFDM和MIMO作为基本技术,大量采用了目前移动通信领域最先进的技术和设计理念。本文介绍了TD—LTE／TD—LTE—Advanced技术的标准化进程、技术特点以及系统性能评估情况。     

Indoor channel characteristics based on wideband MIMO measurements at 5.25 GHz

Extensive indoor channel measurements were conducted in Beijing with wideband multiple-input multiple-output （MIMO） sounder at 5.25 GHz. Both line-of-sight （LOS） and non-line-of-sight （NLOS） propagation were measured in the indoor office and hotspot scenarios. On the basis of measured data, statistical channel characteristics are presented in this article, including the empirical path loss （PL） models, three excess delay parameters, circular azimuth spread （CAS）, and circular elevation spread （CES）. Comparative analysis of different propagation mechanisms in two scenarios is conducted. These values are significant for indoor coverage and technical research of MIMO and orthogonal frequency division multiplexing （OFDM） for the international mobile telecommunications-advanced （IMT-Advanced） system.     

OFDMA TDD WMAN标准化历程及其特性

文章介绍了OFDMA TDD WMAN(WiMAX)成为ITU国际移动通信系统最新标准的历程,分析了其主要技术特性。     

Secure Personal Networks for IMT-Advanced Connectivity

The challenge to deliver the next generation of ubiquitous and converged network and service infrastructures for communication, computing and media, has forced research into innovative new directions. New infrastructures must overcome the scalability, flexibility, dependability and security bottlenecks of current ones in order to permit the emergence of dynamic and, pervasive and robust new communication technologies. This paper promotes secure personal networks (PNs) as a key IMT-Advanced technology candidate, in particular, contributing to fulfilling the requirement for global connectivity for IMT-Advanced communications. Advanced PN concepts, such as the PN-Federation can support a number of requirements related to connectivity for the successful adoption of IMT-Advanced systems and services. Introducing intelligence for managing, protecting, processing, and delivering information of mobile communication systems has been identified as the way towards ubiquitous, converged and secure communications. One way to do this is through cognition. This paper discusses an approach and application of intelligence in the context of achieving ubiquitous, converged, and secure communications. Namely, we apply cognitive radio to personal networks for improving IMT-Advanced system and service connectivity. Further, the paper provides an understanding of how best to combine cognition with the current mobile communication systems.