淺談關(guān)于移動(dòng)通信發(fā)展趨勢(shì)_外文翻譯

1、淺談關(guān)于移動(dòng)通信發(fā)展趨勢(shì)_外文翻譯 大連科技學(xué)院畢業(yè)設(shè)計(jì)論文外文翻譯 學(xué)生姓名 李婷 專業(yè)班級(jí) 信息工程09(2)班 指導(dǎo)教師 揚(yáng)揚(yáng) 職 稱 講師 所在單位電氣工程系 教研室主任石桂名 完成日期 2013年4月12日Talkabout the development trend for mobile communicationsOne, introduction:Mobile communication means between the mobile users, or mobile users and fixed communications between.,With the devel

2、opment of electronic technology, particularly semiconductors, sets Development of circuit and computer technology and mobile communications have enjoyed rapid development. With the expansion of its application fields and on improving the performance requirements, allow mobile communication in techno

3、logy and development of the theory to a higher level. Since in the 1980s of the 20th century, the mobile communications have become indispensable in modern communication network and one of the fastest means of communication.Reviewing the development of mobile communications, mobile communications de

4、velopment through several stages of development : the first major cellular mobile communication technology of analog mobile communications, the technical characteristics of Cellular network structure overcome the regional capacity low, restricted the scope of activities of the problem. Second G is t

5、he cellular mobile communications, cellular systems can provide integrated service digital transmission, and other advantages. Main Characteristics of third G is in addition to providing second of mobile communication system own advantages, overcome its shortcomings, but can also provide broadband m

6、ultimedia service can provide high - quality video multimedia integrated services, and global roaming. With most of them are now second technology, third technology is still not very successful. but there are already fourth technology vision. 4G standard with more than third of the fourth mobile com

7、munication system function.。Two. 4G about mobile cfourth the concept of mobile communication technologies as broadband access and distribution network, with asymmetry over 2Mbits data transmission capacity. It consists of fixed broadband wireless access and broadband wireless local area network, mob

8、ile broadband system and interactive broadcasting network. fourth G standards than third standard has more functionality. In different fixed fourth g, wireless platforms and wireless services across different frequency band network, in any place with broadband Internet access, including satellite co

9、mmunication and stratospheric communication to provide orientation of time, data acquisition and remote control, comprehensive functions. In addition, fourth mobile communication systems are integrated broadband mobile communication system of multifunctional are broadband IP system. Currently in dev

10、elopment and research of 4G communications will have the following characteristics :ommunications A communications fasterThe initial study on 4G communications is aimed at enhancing cellular phones and other wireless access the Internet, mobile device rate, so 4G characteristics of communication is

11、it a faster speed of wireless communication. Experts estimated that fourth mobile communications system up to 10 -20Mbits imum reach 100MbitsThe second network spectrum widthTo make 4G communication transmission speed of up to 100 Mbits, operators must be on the basis of 3G communications network to

12、 carry out large - scale improvement, so 4G network on communication bandwidth than 3G network bandwidth much higher. According to the study, each 4G channel will hold the 100 MHz spectrum, equal to 20 times of the W-CDMA3G network.Complete integration of the three servicesPersonal communications, i

13、nformation systems, broadcasting and entertainment businesses such as seamless connection as a whole, meet the various needs of users. 4G should be able to integrate different models of wireless communication to - from indoor wireless local area network and Bluetooth network, cellular signal and rad

14、io and television to satellite communication, mobile users to roam freely from a standard to another standard. Business applications, interconnection between various system platform more convenient, safe, and for different users, more personalized. 4G mobile phone from the point of view of the appea

15、rance and style will have more breakthroughs can think of is, spectacles and watches, cosmetic boxes, sneakers are likely to become 4G terminal.Four intelligent properties of even higherFourth Mobile Intelligent better, not only expressed in the design and operation of 4G communication terminal with

16、 intelligent, but more importantly 4G function of cell phone can implement many unimaginable. For example, 4G mobile phones will be based on the environment, time and other factors to timely to remind the owner of the cell phone.Three, 4G access system in mobile communications4G system for mobile co

17、mmunication access remarkable feature is that intelligent multi - mode terminals multi-modeterminal based on common platform, through a variety of technology, in various network system platform realization of seamless connection and collaboration. In 4G mobile communications, based on a common platf

18、orm for all kinds of special access system, mutual cooperation, in the most optimal manner to meet the communication needs of different users. When terminal access multi - model systems, network adaptive allocation band, give the optimization of routing in order to achieve the best effect of communi

19、cations.。With the development of technology and changes in market demand, new technology will constantly emerging. Different types of access technology designed for different business. therefore, the basis of our access application fields of technology, small mobile radius and working environment, a

20、nd to access technology for layers. Distribution layer : mainly by the stratospheric communications, satellite communication and broadcasting and TV communication, and the scope of service coverage. Cellular layer : mainly by 2G, 3G communication systems, services covering larger. Hot cell layer is

21、mainly composed of WLAN network services to focus on the campus, communities, meeting center, mobile communication ability is very limited. Personal network layer : mainly used in the home, Office and other places, the service scope of coverage is very small. Mobile Communications Limited ability, b

22、ut through Internet access systems of other network layer. Fixed Network : Double strands, coaxial cable, fiber composition of fixed communication system. Network access system in a very important position in the entire mobile networks. To improve network performance, access system of high - level a

23、greements and Research Network self - optimization and automatic reconfiguration technology and dynamic spectrum allocation and resource allocation technology, network management and cooperation between different access system. Improving and extending the application of IP technology in mobile netwo

24、rk, strengthening the software radio technology and optimization of radio transmission technologies such as supporting real - time and non - real - time business, seamless connectivity and network security.Four, 4G key technology of mobile communication systemA positioning technology Positioning mob

25、ile terminal location method for measuring and calculating methods. It is mainly based on mobile terminal location, location based on mobile network location or mixed three ways. 4G mobile communication systems, mobile terminal in mobile communication between different system platforms. therefore, f

26、or mobile terminal location and tracking, is the realization of mobile terminal in seamless connections between different system platforms and systems prerequisite of high - speed and high - quality mobile communications and protection.The second handover technology Switch technology for mobile term

27、inal in different mobile community between communication between different frequencies or signal to reduce channel selection, and so on. Switch Technology is the future of mobile terminal in many of the communication system, mobile community between solid foundation and an important technology in mo

28、bile communications. It is mainly soft - switching and hard handoff. 4G communication system, switching technique is more extensive scope, and in soft - switching and combination of hard handoff direction of development. Three software radio technology 4G mobile communication systems, software will

29、become very complicated. To this end, The experts suggested the introduction of software radio technology, as the mobile communications to third from second, and fourth bridges in mobile communications. Software radio technology to close as possible to the process of digital analog signal antenna, A

30、D and DA converter soon as possible to RF Front - End using DSP channel separation, modulation and demodulation and channel decoding and so on. It aims to establish a communication platform, platform software system to realize multi - channel, multi - level and multi - mode wireless communications.

31、therefore, the application of software radio technology, a mobile terminals can be achieved between the different systems and platforms, unimpeded. There are more mature software radio technology parameter control software radio system. Four smart antenna technology Smart Antenna with inhibition of

32、signal interference and automatic tracking and intelligence features such as digital beam adjustment, can meet the data center, mobile IP network performance requirements. Smart Antenna beam in the space field suppression of mutual interference and to enhance the special scope of signal, this techno

33、logy can improve the quality of signal increase transmission capacity. Five mutual Interference suppression and multiuser detection Development of interactive Interference suppression and multiuser detection technology should become part of the 4G, they use interactive Interference suppression metho

34、d introduction to the base stations and mobile phone system, elimination of unnecessary nearby and co - channel user interaction interference, to ensure the high quality of receiver signal reception. This combination will meet the needs of more user capacity, but also can increase the coverage. Mutu

35、al Interference suppression and multiuser detection combination of two technology will significantly reduce the deployment of network infrastructure, ensure the improvement of service quality. Signal Transmission and modulation of six new technology High - speed mobile communications, will face seve

36、re frequency selection fading frequency-selectivefading. To improve the signal performance, research and development of intelligent modulation and demodulation techniques, to effectively curb the decline. For example, the Orthogonal Frequency Division Multiplexing OFDM, adaptive equalizer. meanwhile

37、, the TPC, Rake Spread Spectrum receive, hopping, FEC such as AQR and Turbo coding technology, to get a better signal - noise ratio of energy.Five. conclusions Now people, 4G communication of the future looks very mysterious, Many people think that the fourth wireless communication network system is

38、 the most complex technical system in the history of mankind. All in all, smooth and comprehensively implement 4G communications, also may encounter some difficulties. first, people in the future 4G communication transmission speed of the demand was that it will greatly improve, theoretically highes

39、t reaching 100 Mbits, but the rate of mobile phones will be limited by the capacity communications systems. According to analysis by experts concerned, 4G mobile phones will be difficult to achieve the theory of speed. secondly, 4G development of the market will face great pressure. Some experts pre

40、dict that, after 10 years, 2G multimedia services will enter third stage of development, which covers 3G global network has been basically completed, more than 25 of the world's population uses 3G, by that time, the whole industry is absorbing third technology, to accept 4G technology also needs

41、 a process of gradual transition. therefore, when the construction of 4G communication network system, carriers will consider direct 3G communications network infrastructure, with the gradual introduction of the method to make mobile communications from 3G gradual transition to 4G.淺談關(guān)于移動(dòng)通信發(fā)展趨勢(shì)引言? 移動(dòng)

42、通信是指移動(dòng)用戶之間,或移動(dòng)用戶與固定用戶之間的通信。移動(dòng)通信是指移動(dòng)用戶之間,或移動(dòng)用戶與固定用戶之間的通信。隨著電子技術(shù)的發(fā)展,特別是半導(dǎo)體、集 成電路和計(jì)算機(jī)技術(shù)的發(fā)展,移動(dòng)通信得到了迅速的發(fā)展。隨著其應(yīng)用領(lǐng)域的擴(kuò)大和對(duì)性能要求的提高,促使移動(dòng)通信在技術(shù)上和理論上向更高水平發(fā)展。20世紀(jì)80年代以來,移動(dòng)通信已成為現(xiàn)代通信網(wǎng)中不可缺少并發(fā)展最快的通信方式之一?；仡櫼苿?dòng)通信的發(fā)展歷程,移動(dòng)通信的發(fā)展大致經(jīng)歷了幾個(gè)發(fā)展階段:第一代移動(dòng)通信技術(shù)主要指蜂窩式模擬移動(dòng)通信,技術(shù)特征是蜂窩網(wǎng)絡(luò)結(jié)構(gòu)克服了大區(qū)制容量低、活動(dòng)范圍受限的問題。第二代移動(dòng)通信是蜂窩數(shù)字移動(dòng)通信,使蜂窩系統(tǒng)具有數(shù)字傳輸所能提供

43、的綜合業(yè)務(wù)等種種優(yōu)點(diǎn)。第三代移動(dòng)通信的主要特征是除了能提供第二代移動(dòng)通信系統(tǒng)所擁有的各種優(yōu)點(diǎn),克服了其缺點(diǎn)外,還能夠提供寬帶多媒體業(yè)務(wù),能提供高質(zhì)量的視頻寬帶多媒體綜合業(yè)務(wù),并能實(shí)現(xiàn)全球漫游?，F(xiàn)在用的大多是第二代技術(shù),第三代技術(shù)還不太成功,但已有了第四代技術(shù)的設(shè)想。第四代移動(dòng)通信系統(tǒng)(4G)標(biāo)準(zhǔn)比第三代具有更多的功能。 二、4G移動(dòng)通信簡(jiǎn)介?第四代移動(dòng)通信技術(shù)的概念可稱為寬帶接入和分布網(wǎng)絡(luò),具有非對(duì)稱的超過2Mbit/s的數(shù)據(jù)傳輸能力。它包括寬帶無線固定接入、寬帶無線局域網(wǎng)、移動(dòng)寬帶系統(tǒng)和交互式廣播網(wǎng)絡(luò)。第四代移動(dòng)通信標(biāo)準(zhǔn)比第三代標(biāo)準(zhǔn)擁有更多的功能。第四代移動(dòng)通信可以在不同的固定、無線平臺(tái)和跨

44、越不同的頻帶的網(wǎng)絡(luò)中提供無線服務(wù),可以在任何地方用寬帶接入互聯(lián)網(wǎng)(包括衛(wèi)星通信和平流層通信),能夠提供定位定時(shí)、數(shù)據(jù)采集、遠(yuǎn)程控制等綜合功能。此外,第四代移動(dòng)通信系統(tǒng)是集成多功能的寬帶移動(dòng)通信系統(tǒng),是寬帶接入IP系統(tǒng)。目前正在開發(fā)和研制中的4G通信將具有以下特征: (一)通信速度更快? 由于人們研究4G通信的最初目的就是提高蜂窩電話和其他移動(dòng)裝置無線訪問Internet的速率,因此4G通信的特征莫過于它具有更快的無線通信速度。專家預(yù)估,第四代移動(dòng)通信系統(tǒng)的速度可達(dá)到10-20Mbit/s,最高可以達(dá)到100Mbit/s。? (二)網(wǎng)絡(luò)頻譜更寬? 要想使4G通信達(dá)到100Mbit/s的傳輸速度,

45、通信運(yùn)營(yíng)商必須在3G通信網(wǎng)絡(luò)的基礎(chǔ)上對(duì)其進(jìn)行大幅度的改造,以便使4G網(wǎng)絡(luò)在通信帶寬上比3G網(wǎng)絡(luò)的帶寬高出許多。據(jù)研究,每個(gè)4G信道將占有100MHz的頻譜,相當(dāng)于W-CDMA3G網(wǎng)絡(luò)的20倍。 (三)多種業(yè)務(wù)的完整融合個(gè)人通信、信息系統(tǒng)、廣播、娛樂等業(yè)務(wù)無縫連接為一個(gè)整體,滿足用戶的各種需求。4G應(yīng)能集成不同模式的無線通信?從無線局域網(wǎng)和藍(lán)牙等室內(nèi)網(wǎng)絡(luò)、蜂窩信號(hào)、廣播電視到衛(wèi)星通信,移動(dòng)用戶可以自由地從一個(gè)標(biāo)準(zhǔn)漫游到另一個(gè)標(biāo)準(zhǔn)。各種業(yè)務(wù)應(yīng)用、各種系統(tǒng)平臺(tái)間的互聯(lián)更便捷、安全,面向不同用戶要求,更富有個(gè)性化。而且4G手機(jī)從外觀和式樣上看將有更驚人的突破,可以想象的是,眼鏡、手表、化妝盒、旅游鞋都

46、有可能成為4G終端。? (四)智能性能更高?第四代移動(dòng)通信的智能性更高,不僅表現(xiàn)在4G通信的終端設(shè)備的設(shè)計(jì)和操作具有智能化,更重要的是4G手機(jī)可以實(shí)現(xiàn)許多難以想象的功能。例如,4G手機(jī)將能根據(jù)環(huán)境、時(shí)間以及其他因素來適時(shí)提醒手機(jī)的主人。 三、4G移動(dòng)通信的接入系統(tǒng)?4G移動(dòng)通信接入系統(tǒng)的顯著特點(diǎn)是,智能化多模式終端(multi-modeterminal)基于公共平臺(tái),通過各種接技術(shù),在各種網(wǎng)絡(luò)系統(tǒng)(平臺(tái))之間實(shí)現(xiàn)無縫連接和協(xié)作。在4G移動(dòng)通信中,各種專門的接入系統(tǒng)都基于一個(gè)公共平臺(tái),相互協(xié)作,以最優(yōu)化的方式工作,來滿足不同用戶的通信需求。當(dāng)多模式終端接入系統(tǒng)時(shí),網(wǎng)絡(luò)會(huì)自適應(yīng)分配頻帶、給出最優(yōu)化

47、路由,以達(dá)到最佳通信效果。目前,4G移動(dòng)通信的主要接入技術(shù)有:無線蜂窩移動(dòng)通信系統(tǒng)(例如2G、3G);無繩系統(tǒng)(如DECT);短距離連接系統(tǒng)(如藍(lán)牙);WLAN系統(tǒng);固定無線接入系統(tǒng);衛(wèi)星系統(tǒng);平流層通信(STS);廣播電視接入系統(tǒng)(如DAB、DVB-T、CATV)。隨著技術(shù)發(fā)展和市場(chǎng)需求變化,新的接入技術(shù)將不斷出現(xiàn)。 不同類型的接入技術(shù)針對(duì)不同業(yè)務(wù)而設(shè)計(jì),因此,我們根據(jù)接入技術(shù)的適用領(lǐng)域、移動(dòng)小區(qū)半徑和工作環(huán)境,對(duì)接入技術(shù)進(jìn)行分層。 分配層:主要由平流層通信、衛(wèi)星通信和廣播電視通信組成,服務(wù)范圍覆蓋面積大。 蜂窩層:主要由2G、3G通信系統(tǒng)組成,服務(wù)范圍覆蓋面積較大。 熱點(diǎn)小區(qū)層:主要由WLAN網(wǎng)絡(luò)組成,服務(wù)范圍集中在校園、社區(qū)、會(huì)議中心等,移動(dòng)通信能力很有限。 個(gè)人網(wǎng)絡(luò)層:主要應(yīng)用于家庭、辦公室等場(chǎng)所,服務(wù)范圍覆蓋面積很小。移動(dòng)通信能力有限,但可通過網(wǎng)絡(luò)接入系統(tǒng)連接其他網(wǎng)絡(luò)層。 固定網(wǎng)絡(luò)層:主要指雙絞線、同軸電纜、光纖組成的固定通信系統(tǒng)。 網(wǎng)絡(luò)接入系統(tǒng)在整個(gè)移動(dòng)網(wǎng)絡(luò)中處于十分重要的位置。未來的接入系統(tǒng)將主要在以下三個(gè)方面進(jìn)行技術(shù)革新和突破:為最大限度開發(fā)利用有限的頻率資源,在接入系統(tǒng)的物理層,優(yōu)化調(diào)制、信道編碼和信號(hào)傳輸技術(shù),提高信號(hào)處理算法、信號(hào)檢測(cè)和數(shù)據(jù)壓縮技術(shù),并在頻譜共享和新型天線方面做進(jìn)一