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1.
In Europe, the challenge of the design of third-generation cellular mobile radio systems has been taken numerous research and development activities in this field have been started. The authors try to give an overview of the European activities in this field. The article is organized in two parts. In the first part, the requirements for third-generation cellular mobile radio systems such as Universal Mobile Telecommunications System (UMTS) and Future Public Land Mobile Telecommunications System (FPLMTS), which has been named International Mobile Telecommunications after the year 2000 (IMT-2000) are presented concisely. Also, the importance and challenge of the multiple access design for such third-generation cellular mobile radio systems is explained. In the second part, numerous European research activities with focus on the multiple access design for third-generation cellular mobile radio systems are reviewed  相似文献   

2.
To achieve high capacity and to support high-data-rate services in the terrestrial access network (UTRAN) of the third generation Universal Mobile Telecommunications System (UMTS), it is essential to employ some advanced transceiver techniques at the base stations. Three such techniques are presented: adaptive antennas, multistage parallel interference cancellers and a new hybrid scheme. The operation principles and some simulation results of the techniques are given and some challenging implementation issues are discussed  相似文献   

3.
A novel multiband planar inverted-F antenna (PIFA) covering ten frequency bands has been proposed for personal wireless communications terminals. The design is based on the combination of various techniques that are used for designing multiband/broadband antennas. We used a shorted parasitic patch efficiently coupled to the driven patch, a quarter-wave resonator connected to the feed strip in parallel with the main patch, and four slits in the main radiator to excite various current modes in the antenna structure. The antenna is designed within a volume of 4.0 times 2.0 times 0.8 cm3 and it can be used to serve the following wireless communication systems: Global System for Mobile Communications (GSM-900), Digital Communications System (DCS), Personal Communication Service (PCS), Universal Mobile Telecommunications System (UMTS), WiBro at 2.35 GHz, Bluetooth, Satellite-Digital Multimedia Broadcasting (SDM-B) at 2.65 GHz, WiMAX at 3.5 GHz, and the two bands (5.15-5.35 GHz and 5.725-5.875 GHz) for the wireless Local Area Network (WLAN) standards. A prototype antenna was fabricated and tested for input reflection coefficient and radiation performances. The measured and simulated results have been presented and discussed. Important geometrical parameters determining the multiband performances of the antenna have been explained in the paper.  相似文献   

4.
Johnston  W. 《Spectrum, IEEE》1998,35(10):49-53
Building on the huge success of its homegrown cellular system, Europe is planning a next-generation wireless system to handle data as well as voice, and-it is hoped-lay the foundation for universal roaming. The system being developed in the framework of the European Telecommunications Standards Institute (ETSI) is called UMTS (Universal Mobile Telecommunication System). In parallel, the International Telecommunication Union, based in Geneva, is formulating IMT (International Mobile Telecommunications) 2000, which is to be a family of systems that will let users roam worldwide with the same handset, and which will include UMTS as a subset  相似文献   

5.
UMTS security     
The Universal Mobile Telecommunications System (UMTS) is one of the new 'third generation' mobile cellular communication systems. UMTS builds on the success of the 'second generation' GSM system. One of the factors in the success of GSM has been its security features. New services introduced in UMTS require new security features to protect them. In addition, certain real and perceived shortcomings of GSM security need to be addressed in UMTS. This paper surveys the major security features that are included in the first releases of the UMTS standards.  相似文献   

6.
The paper provides a general overview of the main research activity on the Universal Mobile Telecommunications System (UMTS) and the Mobile Broadband System (MBS) within the European Union's RACE II programme. The main characteristics, innovations and trends with regard to cell types, services, network architectures and radio interfaces are discussed. Evolutionary aspects of interworking with other existing and emerging terrestrial networks are also discussed  相似文献   

7.
Cellular radio started in the early 1980s by using analog technologies. Research in voice coding, modulation, and channel coding resulted in second-generation cellular radio based on digital technologies, which were introduced in the early 1990s. These were all based on advanced time division multiple access technology, resulting in better capacity and lower cost. Today, these digital technologies-based on the Global System for Mobility, digital Advanced Mobile Phone System, and personal digital cellular-have more than 100 million subscribers worldwide. The next step is to introduce wide-band packet services for wireless Internet up to 2 Mb/s. These so-called third-generation systems (Universal Mobile Telecommunications Services, IMT2000) are planned to be introduced in the early 2000s  相似文献   

8.
The paper reviews the findings of work completed in RACE Mobile Telecommunications Project 1043 on the suitability of packet access mechanisms for mixed services in the Universal Mobile Telecommunication System. A first order comparison of random and scheduled access is provided and conditions under which these mechanisms provide an attractive alternative to channel allocation for call duration are specified. It is concluded that packet reservation multiple access (PRMA) is an attractive candidate for mixed services over a range of cell sizes as it can accommodate fixed channel access, reserved channel access and random channel access  相似文献   

9.
Upcoming mobile technologies like the Universal Mobile Telecommunications System (UMTS) or Voice-Over-IP/IP Multimedia Subsystem (VoIP/IMS) offer new possibilities but also threats. Consequently, operators and vendors need to adopt appropriate technology and business principles. This article focuses on the concept of Service Platforms to allow flexible and fast service development, and enablers for Location Based Services.  相似文献   

10.
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.  相似文献   

11.
This paper deals with the use of a CDMA-based radio interface in third generation mobile systems (Universal Mobile Telecommunications System – UMTS, and Future Public Land Mobile Telecommunications System – FPLMTS). The paper is not intended as a detailed analysis of the radio interface performance, but as an overview of the main issues arising in a typical CDMA-based mobile system, discussing the different available technical solutions. First of all, the basic requirements of the radio interface in a third generation mobile system are outlined. In particular, the support of variable bit rate transmission, the adaptability to the different propagation and service environments and the flexibility are felt to be important topics to be discussed. Then, the main characteristics of the CDMA access technique are depicted, in relation with the above mentioned requirements, focusing in particular on the DS-CDMA radio interface designed within the RACE II – CODIT Project. In that context the paper describes some of the technical solutions proposed for the provision of advanced features such as macrodiversity, multibearer transmission and variable bit rate services. This revised version was published online in June 2006 with corrections to the Cover Date.  相似文献   

12.
Faggian  N. Hua  T. 《IEEE network》1998,12(4):11-18
New telecommunications services tend to consider fixed network subscribers' requirements as well as mobile network subscribers' requirements. On one hand, subscribers of fixed networks would like to benefit from the mobility offered in mobile networks. On the other hand, mobile subscribers would like to access to services inherent in fixed networks. Personal communications services (PCS) meet this trend while allowing fixed and mobile convergence. In this environment, the application of intelligent networks (INs) to fixed and mobile networks is very convenient to realize PCS. Thus, the natural advancement of telecommunications systems (fixed and mobile) consists in the definition of new telecommunications architectures which take into account technologies from both fixed and mobile environments. This article studies how the IN is used to support mobility and interworking for PCS. Although mobility management already exists in cellular networks like GSM, it is desirable to use the IN concept to introduce flexibility. In addition, the IN allows the introduction of new supplementary services in PCS. Furthermore, the IN concept can be utilized to provide necessary networking functions for the integration of fixed and mobile networks. This article also highlights the involvement of IN in the definition of the global communications systems such as Telecommunication Information Networking Architecture (TINA), Universal Mobile Telecommunications System (UMTS), and International Mobile Telecommunications in the year 2000 (IMT2000)  相似文献   

13.
At present time it is broadly recognized the existence of three generations of mobile telephone systems. In this work it is analysed the evolution of the three generations systems in terms of the services provided in each generation, focusing in the entity known as CAMEL (Customized Applications for Mobile Networks Enhanced Logics), which is an important platform influencing the evolution of 2G and 3G and beyond mobile telephony systems. This work starts with a general overview of mobile telephone systems, their architectures and services platforms, going further into the evolution of CAMEL that occurs together with the evolution of third generation system UMTS (Universal Mobile Telecommunications System) and would play an important role when the “all-IP” network and multimedia applications become part of everyday use by million of subscribers part of the mass market. CAMEL evolution is important as it is the evolution of 3G into 4G networks such as Ambient Networks, where CAMEL will be a fundamental element in order to make it easy the creation, control, and establishment of advanced and personalized services to subscribers, wherever they would be, and whenever they require the services, with full mobility and service portability, independently of the radio-access technology, the networks and the operators.  相似文献   

14.
One challenge of wireless networks integration is to provide ubiquitous wireless access abilities and seamless handover for mobile communication devices between different types of technologies (3GPP and non-3GPP), such as Global System for Mobile Communication, Wireless Fidelity, Worldwide Interoperability for Microwave Access, Universal Mobile Telecommunications System and Long Term Evolution. This challenge is critical as mobile users are becoming increasingly demanding for services regardless of the technological complexities associated with them. To fulfil these requirements for seamless vertical handover (VHO) two main interworking frameworks have been proposed by IEEE Group and 3GPP for integration between the aforementioned technologies; namely, Media Independent Handover IEEE 802.21 and IP Multimedia Subsystem, where each of them requires mobility management protocol to complement its work, such as Mobile IP and Session Initiation Protocol, respectively. Various VHO approaches have been proposed in the literature based on these frameworks. In this paper, we survey the VHO approaches proposed in the literature and classify them into four categories based on these frameworks for which we present their objectives and performances issues.  相似文献   

15.
16.
Satellites are no longer seen as an alternative to a terrestrial mobile telecommunications system or the (optical-fibre-based) integrated broadband communications network. Instead they are now being considered as one of the components of the Universal Mobile Telecommunications System being developed within the European Union's RACE Programme for the next century and as a component of the broadband ISDN. This paper discusses the role played by satellites in these systems and the issues which have to be addressed  相似文献   

17.
将GPS接收机嵌入到手机硬件中,GPS接收频率将与手机中其它射频源共存.这些射频源包括GSM,UMTS,WLAN和Bluetooth.指出这些射频源对GPS接收信号的干扰程度,以明确哪种射频源对GPS接收机的阻塞影响最大,成为提出相应的解决方案是关键.验证方法主要是由Texas Instrument提供的GPS评估板接收来自GPS卫星模拟器发出的GPS信息,由具备GSM,UMTS,WLAN,Bluetooth功能的手机分别对GPS评估板发出不同的射频传导信号.结果证明:主要验证了UMTS1 900 MHz作为手机发射源时,对GPS接收机的阻塞影响最大,对改善GPS接收机带通滤波器的性能,为抑制UMTS信号起到很好的作用.  相似文献   

18.
In cellular mobile radio systems, the directional inhomogeneity of the mobile radio channel can be exploited by smart antennas to increase the spectral efficiency. In this paper, a novel smart antenna concept applying receiver antenna diversity at the uplink receiver is investigated for a time-slotted code-division multiple-access (CDMA) mobile radio air interface termed time-division CDMA (TD-CDMA), which has been selected by the European Telecommunications Standards Institute (ETSI) in January 1998 to form part of the Universal Mobile Telecommunications System (UMTS) air interface standard. First, a combined direction-of-arrival (DOA) and joint channel estimation scheme is presented, which is based on DOA estimation using the Unitary ESPRIT algorithm and maximum likelihood estimation of the channel impulse responses associated with the estimated DOA's, which can also be used as an input for advanced mobile positioning schemes in UMTS. The performance of the combined DOA and joint channel estimation is compared with the conventional channel estimation through simulations in rural and urban propagation environments. Moreover, a novel joint data detection scheme is considered, which explicitly takes into account the signal DOA's and the associated channel impulse responses. The link level performance of a TD-CDMA mobile radio system using these novel schemes is evaluated by Monte Carlo simulations of data transmission, and average bit error rates (BER's) are determined for rural and urban propagation environments. The simulation results indicate that, depending on the propagation environment, the exploitation of the knowledge of the directional inhomogeneity of the mobile radio channel can lead to considerable system performance enhancements  相似文献   

19.
Telecommunication Systems - Mobile communication networks have entered a new age by introducing fifth-generation technologies (5G). The International Union of Telecommunications (IUT) proposes new...  相似文献   

20.
Location estimation that is based on the mobile phone network has drawn considerable attention in the field of wireless communications. Among the different mobile location estimation methods, the one that estimates a mobile station location with reference to a wave propagation model is shown to be effective and is applicable to different kinds of cellular networks, including Global System for Mobile Communications (GSM), cdmaOne, CDMA2000, and the Universal Mobile Telecommunications System. We have designed a train-once approach for location estimations using the directional propagation model (DPM). The DPM is an improved model that is based on the traditional free-space wave propagation model with the directional gain and environmental factors integrated in the estimation. The train-once approach works because we observe that different types of antennas are designed for different types of environments. Thus, a parameter estimation is related to the antenna type and, in turn, related to the environment. In this paper, we report our study of the train-once approach with the DPM for location estimations. We have tested our model with 192 177 sets of real-life data that have been collected from a major mobile phone operator in Hong Kong. Experimental results show that the train-once approach with the DPM is practical and outperforms the existing location estimation algorithms in terms of accuracy, stability among different types of terrains, and success rates.  相似文献   

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