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1.
Wireless mobile communications at the start of the 21st century   总被引:8,自引:0,他引:8  
At the start of the 21st century, the wireless mobile markets are witnessing unprecedented growth fueled by an information explosion and a technology revolution. In the radio frequency arena, the trend is to move from narrowband to wideband with a family of standards tailored to a variety of application needs. Many enabling technologies including wideband code-division multiple access, software-defined radio, intelligent antennas, and digital processing devices are greatly improving the spectral efficiency of third-generation systems. In the mobile network area, the trend is to move from traditional circuit-switched systems to packet-switched programmable networks that integrate both voice and packet services, and eventually evolve toward an all-IP network. Furthermore, accompanied by wireless mobile location technology, wireless mobile Internet is expected to revolutionize the services that can be provided to consumers in the right place and at the right time. Wireless mobile communications may not only complement the well established wireline network; it may also become a serious competitor in years to come. We review the history of the wireless mobile communications, examine the current progress in standards and technologies, and discuss possible trends for wireless mobile solutions  相似文献   

2.
The forthcoming mobile communication systems are expected to provide a wide variety of services, from high-quality voice to high-definition videos, through high data rate wireless channels anywhere in the world. The high data rate requires broad frequency bands, and sufficient broadband can be achieved in higher frequency bands such as microwave, Ka-band, and millimeter-wave. Broadband wireless channels have to be connected to broadband fixed networks such as the Internet and local area networks. The future-generation systems will include not only cellular phones, but also many new types of communication systems such as broadband wireless access systems, millimeter-wave LANs, intelligent transport systems, and high altitude stratospheric platform station systems. Key to the future generations of mobile communications are multimedia communications, wireless access to broadband fixed networks, and seamless roaming among different systems. This article discusses future-generation mobile communication systems.  相似文献   

3.
Antenna systems for broadband wireless access   总被引:6,自引:0,他引:6  
Broadband wireless access along with evolving mobile Internet and multimedia services are driving the surge of research and development activities for future wireless communication systems. We provide an overview of antenna systems for broadband wireless communications and introduce some of the important issues surrounding them. The approach we use is to first provide a general framework of how antenna systems may be utilized in wireless communication systems and then describe the antenna systems themselves. In particular, we consider antenna systems for the base station, mobile station, and then finally multiple-input multiple-output antenna systems where antenna systems are utilized at both the base and mobile stations  相似文献   

4.
Broadband wireless access   总被引:4,自引:0,他引:4  
This article reviews the technologies and potential markets, applications, and architectures for broadband wireless access. The emergence of wireless communications for cellular systems is presented, together with its projected future evolution to mobile wideband systems. The field of broadband access systems, services, and network architectures is also covered, and then systems for broadband wireless communications for indoor local area networks and outdoor public fixed access networks are discussed. Broadband wireless access systems are emerging as a new and growing area of telecommunications, since the ability to provide access without extensive installation of copper or fiber infrastructures make wireless technology well suited for broadband services. Finally, some of the key enabling technologies, such as adaptive antennas and video compression, and the future architectural directions of broadband wireless networks are presented  相似文献   

5.
Willie W. Lu 《中国通信》2009,6(2):134-143
This paper relates to an advanced open mobile communication system and method of integrating the mobile communications, wireless access systems and wired communications into one common platform architecture for China's 4th generation mobile communications, supporting costeffective broadband voice, data and video services in wireless, mobile and wired environment with one single integrated mobile terminal device. The paper includes new architecture in the integrated mobile device and converged network access, and minimum modification in the existing mobile telecommunication infrastructures. This paper introduces the long-term evolution strategy for China's TDD system platform towards China's future 4G mobile communications.  相似文献   

6.
Sun  Y. 《Signal Processing, IET》2009,3(6):431-432
Wireless and mobile communications have developed rapidly in recent years due to the endless demand for broadband multimedia Internet access and wireless connection anywhere and any time. Several 4G standards have been proposed such as WiMax, LTE and IEEE 802.11n. Signal processing plays a key role in the evolution of wireless and mobile communications. With the emergence of various 4G enabling technologies, advanced signal processing has become ever increasingly important for low complexity, low power and efficient physical implementations of future multimedia communication systems. Multi-antenna, multi-frequency, multi-user and cooperative technologies have emerged as powerful enablers for high date rate and highly reliable broadband communications. To harvest the benefits of these technologies maximally, both excellent opportunities and significant challenges are present in the research of signal processing. The aim of this special issue was to publish some most recent advances in the signal processing aspects of these wireless and mobile communication technologies. Five papers have been selected for the special issue. These papers cover various multi-antenna topics including MIMO detection, spacetime equalization, MIMO channel prediction and estimation, and space-time coding. Some papers also consider cooperative relay communications, OFDM, and multiuser systems.  相似文献   

7.
The tremendous growth rates of the Internet as well as the area of mobile communications give rise to the chance that the mobile Internet is most promising by combining both the Internet and mobile communications. These prospects are the motivation for the European research project BRAIN (Broadband Radio Access for IP‐based Networks), which is developing an open architecture for a broadband wireless mobile access network offering an integrated communication platform across heterogeneous networks and, thus, goes beyond current third generation systems and towards the mobile Internet. The project covers three major technical areas: support of seamless service provision in a mobile environment; the design of an IP‐based access network that will support non‐cellular technologies such as wireless LANs; and requirements of a broadband air interface suitable for hot spots. BRAIN is going to integrate HIPERLAN/2 with UMTS by means of an IP access network. The work is guided by a user‐centric top‐down approach ensuring that user functionality is the key driver of the project. This article will focus on that part of the BRAIN work which specifies the main interfaces of the BRAIN architecture and deals with aspects related to the support of Quality of Service and mobility. Copyright © 2001 John Wiley & Sons, Ltd.  相似文献   

8.
个人通信的研究发展和面临的新挑战   总被引:2,自引:0,他引:2  
朱近康 《电信科学》2001,17(2):18-20
本文应国家“863”计划通信技术主题的个人通信高技术研究发展,特别是无线接入技术、CDMA通信技术、第三代移动通信技术、高空平台移动通信方式和第二代移动通信新技术的突出研究成果,和在个人通信发展中的作用和地位进行论述,并对21世纪我国个人通信面临的新挑战和发展策略进行讨论。  相似文献   

9.
During the last 10 years, wireless communications can be considered as the fastest growing segment of telecommunications. In fact, mobile telephones have become an everyday accessory for hundreds of million people, and they are increasingly being used in the most developed and many developing countries in the world. Current forecasts indicate that demands for wireless access will exceed the number of fixed access lines by year 2010. This paper examines the technological developments, as well as the worldwide social-economic impacts of wireless mobile communications. More specifically, it gives an overview on the technological developments of wireless mobile communications, describes the evolution towards the next-generation systems, analyzes the reasons for the growth rate of subscribers, and the related social development. As a conclusion, it suggests several solutions in response to dangerous behaviour generated by wireless terminals.  相似文献   

10.
Rapid progress in research and development of wireless networking and communication technologies have created different types of wireless systems (e.g., Bluetooth, IEEE 802.11, UMTS, and satellite networks). These systems are envisioned to coordinate with each other to provide ubiquitous high-data-rate services to mobile users. In this article, the architecture for ubiquitous mobile communications (AMC) is introduced that integrates these heterogeneous wireless systems. AMC eliminates the need for direct service level agreements among service providers by using a third party, a network interoperating agent. Instead of deploying a totally new infrastructure, AMC extends the existing infrastructure to integrate heterogeneous wireless systems. It uses IP as the interconnection protocol. By using IP as the gluing protocol, transparency to the heterogeneities of the individual systems is achieved in AMC. Third-party-based authentication and billing algorithms are designed for AMC. New mobility management protocols are also developed to support seamless roaming between different wireless systems.  相似文献   

11.
With the advances in wireless communications and low-power electronics, accurate position location may now be accomplished by a number of techniques which involve commercial wireless services. Emerging position location systems, when used in conjunction with mobile communications services, will lead to enhanced public safety and revolutionary products and services. The fundamental technical challenges and business motivations behind wireless position location systems are described, and promising techniques for solving the practical position location problem are treated  相似文献   

12.
无人机自组网技术研究   总被引:1,自引:0,他引:1  
在无人机系统中,编组和协同作战能力对提高无人机作站效能和生存能力具有重要意义。无线自组网是一种特殊结构的无线通信网络,其通信依靠节点之间的相互协作,以无线多跳方式完成,因此网络不依赖于任何固定设施,具有自组织和自管理的特性,这种特殊的组网方式使得无线自组网非常适用于无人机系统。介绍了无线自组网的原理,分析了无线自组网应用于无人机系统主要面临的关键技术:路由技术和安全问题。介绍了无线自组网的发展情况和在无人机领域的研究情况。  相似文献   

13.
The rapid growth of multimedia wireless communications services forces the development of advanced digital wireless systems with high reliability and high speed as well as flexibility for varying traffic conditions. To achieve such advanced wireless systems. New system design concepts different from the conventional ones aiming at increasing system capacity for voice transmission would be required. Since multimedia wireless communications require high quality, high speed, and high flexibility as well as temporary and spatial control of traffic under severe fading environments, the so-called conventional system design concept will be insufficient. New system design concepts and techniques for achieving highly reliable and high-capacity multimedia wireless communications are discussed using both time division multiple access (TDMA) and code division multiple access (CDMA) systems. The demands for high-speed and high-reliability mobile, personal, and multimedia wireless communications services strongly require matching with the trunk network constructed by a broadband optical fiber system or wired system  相似文献   

14.
冯宇  于竹林 《电子科技》2009,22(7):66-68
无线通讯系统是移动机器人的一个重要组成部分,在机器人自主能力有限的情况下,借助上位机与机器人进行无线通信是控制机器人的一种可行方案。文中以轮式移动机器人作为控制平台,利用nRF905无线射频收发模块,实现了移动机器人的无线通讯系统。文中详细阐述了机器人无线通信系统的硬件及软件设计,该系统具有成本低、实时性强、通信可靠等特点。  相似文献   

15.
IPv6 for Future Wireless Networks   总被引:5,自引:0,他引:5  
The functionalities of the next generation Internet protocol, IPv6, havebecome increasingly interesting due to the current merging of the traditionalcellular mobile communications and the traditional data-communications intothe future wireless systems, as e.g., UMTS. IPv6 provides several enhancedfunctionalities requested for the future mobile systems. In this article thelargest advantages in relation to mobile systems are presented. Variousaspects of introducing IP throughout the entire mobile network (core, accessand termainals) are also presented along with an illustration of the abilitiesof the future wireless network.  相似文献   

16.
常冬友  封颖 《电子工程师》2011,37(6):8-12,23
分析公众电话网、移动通信、互联网、城市应急通信等系统及有线与无线、固定与移动通信网络系统,并就这些典型公共通信系统的技术现状与发展趋势,展望下一代互联网IPV6协议的规划以及物联网的基本概念及发展趋势,展望物联网的应用前景,总结其应用特点。  相似文献   

17.
对当前无线通信中的热点问题,如无线拉入系统,第三代移动通信系统,双向寻呼移动通信系统,数字集群通信系统以及蓝牙技术等,就它们对频率使用的有关问题进行了综述。  相似文献   

18.
王立军  姚琨  石元兵  曹宝 《通信技术》2010,43(6):132-134
随着通信技术的迅猛发展,移动宽带化和宽带移动化是通信网发展的必然趋势。WiMAX城域网无线宽带接入技术,可提供大范围及高速率无线接入,同时支持视距传输和非视距传输,能提供面向互联网的高速无线连接。WiMAX可作为线缆和用户数字线的无线扩展技术,实现无线宽带接入。首先简要介绍WiMAX的应用模式,然后重点分析其点对点应用中上行链路和下行链路的通信容量,提供相关工程技术人员进行方案设计的参考。  相似文献   

19.
5G无线通信网络物理层关键技术   总被引:1,自引:0,他引:1       下载免费PDF全文
倪善金  赵军辉 《电信科学》2015,31(12):40-45
信息社会日益增长的需求,促使着无线通信技术的不断发展。计划于2020年进入商业运营的5G无线通信技术,尚在探索和研究阶段。从无线通信的发展历程出发,介绍了当前国内外的无线通信发展的最新趋势,然后从频谱资源紧缺、系统容量亟需提高的角度,着重介绍了两个关键的物理层技术——毫米波通信技术和大规模MIMO技术,以应对未来无线通信的发展要求。此外,还概括性地介绍了5G无线通信系统的应用场景以及未来的发展趋势。  相似文献   

20.
A Survey of Energy Efficient Network Protocols for Wireless Networks   总被引:30,自引:0,他引:30  
Wireless networking has witnessed an explosion of interest from consumers in recent years for its applications in mobile and personal communications. As wireless networks become an integral component of the modern communication infrastructure, energy efficiency will be an important design consideration due to the limited battery life of mobile terminals. Power conservation techniques are commonly used in the hardware design of such systems. Since the network interface is a significant consumer of power, considerable research has been devoted to low-power design of the entire network protocol stack of wireless networks in an effort to enhance energy efficiency. This paper presents a comprehensive summary of recent work addressing energy efficient and low-power design within all layers of the wireless network protocol stack.  相似文献   

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