通信工程畢業(yè)設(shè)計(jì)外文翻譯

1、<p><b>　　附 錄</b></p><p><b>　　一、英文原文：</b></p><p>　　Goals Of True Broad band’s Wireless Next Wave (4G-5G)</p><p>　　K.R.Santhi,Prof.V.K.Srivastava,G.Senth

2、ilKumaran,Eng. Albert Butare .Kigali Institute of Science Technology and Management (KIST),B.P.3900, Kigali, Rwanda.</p><p><b>　　Abstract</b></p><p>　　As access technology increases,

3、 voice, video,multimedia, and broadband data services are becoming integrated into the same network. Fourth Generation (4G) is the next generation of wireless networks that will replace third Generation (3G) networks som

4、etimes in future. 4G is intended to provide high speed, high capacity, low cost per bit, IP based services.4G is all about an integrated, global network that’s based on an open system approach. The goal of 4G is to “repl

5、ace the current proliferation</p><p>　　Keywords：Wireless, 4G, W-OFDM, MC-CDMA, LAS-CDMA,UWB.</p><p>　　I. INTRODUCTION</p><p>　　While carriers and handset manufacturers obviously hav

6、e their hands full with 3G, some companies are already looking beyond this next generation of wireless technology and networks. 4G is simply an initiative by academic R&D labs to move beyond the limitations and probl

7、ems of 3G which is having trouble getting deployed and meeting its promised performance and throughput .While this 3G has not completely reached researchers and vendors are expressing growing interest in 4G why? Two main

8、 areas are</p><p>　　II. WHY THE LEAP TOWARDS 4G?</p><p>　　3G networks are in a very painful phase of their development, with early trials yielding disappointing results, costs ballooning, techni

9、cal glitches, and network operators being forced to deflate expectations based on unrealistic hype. Despite the hype surrounding the higher-speed 3G mobile networks now under construction, the reasons for the leap toward

10、s 4G are:</p><p>　　A. Performance</p><p>　　Industry skeptics say that users will not be able to take advantage of rich multimedia content across wireless networks with 3G. 4G communications will

11、 feature extremely high-quality video equal to that of high-definition television. In addition, it will enable wireless downloads at speeds exceeding 100 Mbps, about 260 times than 3G wireless network.</p><p&g

12、t;　　B. Interoperability</p><p>　　There are multiple standards for 3G making it difficult to roam and interoperate across networks. We need a global standard that provides global mobility and service portabil

13、ity so that service provider would no longer be bound by single-system vendors of proprietary equipment.</p><p>　　C. Networking</p><p>　　3G are based on primarily a wide-area concept. We need hy

14、brid networks that utilize both wireless LAN (hot spot) concept and cell or base-station WAN design. With 4G,the world would have base stations everywhere, ensuring phone users connection to a high-speed network anywhere

15、, anytime.</p><p>　　D. Bandwidth</p><p>　　We need wider bandwidth and higher bit rates. The 4G technology, with its transmission speeds of more than 20 mbps, would offer high-bandwidth services

16、within the reach of LAN "hotspots," installed in offices, homes, coffee shops ,and airport lounges. Away from these hotspots, customers could connect to souped-up 2G networks for voice and rudimentary data cove

17、rage.</p><p>　　E. Technology</p><p>　　Unlike 3G, 4G will more resemble a conglomeration of existing technologies rather than an entirely new standard. Analysts define 4G as a seamless combinatio

18、n of existing 2G wireless networks with local-area networks (LANs) or Bluetooth.</p><p>　　F. Convergence</p><p>　　Convergence involves more than mere technology; it is a coming together of servi

19、ces and markets.We need all network that utilizes IP in its fullest form with converged voice and data capability,which the 4G will achieve.</p><p><b>　　G. Cost</b></p><p>　　4G syste

20、ms will prove far cheaper than 3G, since they can be built atop existing networks and won't require operators to completely retool and won't require carriers to purchase costly extra spectrum.Also an open system

21、IP wireless environment would probably further reduces costs for service providers by ushering in an era of real equipment interoperability.</p><p>　　H. Scalability</p><p>　　Scalability, or the

22、ability to handle increasing numbers of users and diversity of services, is more challenging with mobile networks."Design for Scalability," includes information that can help you meet changing usage demands .Be

23、cause an all IP core layer of 4G is easily scalable, it is ideally suited to meet this challenge.</p><p>　　III.EVOLUTION AND COMPARISON OF BROADBAND WIRELESS</p><p>　　1) First Generation (1G): 1

24、G wireless mobile communication systems, was introduced in the early 1980s.1G wireless was analog and supported the first generation of analog cell phones. They include a signaling protocol known as SS7 (Signaling System

25、 7).</p><p>　　2) Second Generation (2G): 2G systems, fielded in the late 1980s, were intended primarily for voice transmission and was all about digital PCS.</p><p>　　3) Third Generation (3G): 3

26、G in wireless will be a deliberate migration to faster, data-centric wireless networks. The immediate goal is to raise transmission speeds from 125kbps to 2M bit/sec.</p><p>　　4) Fourth Generation (4G): In r

27、eality, as of first half of 2002, 4G is a conceptual framework for or a discussion point to address future needs of a universal high speed wireless network that will interface with wire line backbone network seamlessly.&

28、lt;/p><p>　　IV. THE 4G NETWORK THAT THE CELL-HEADS DREAM ABOUT</p><p>　　4G can be imagined of as an integrated wireless system that enables seamless roaming between technologies.A user can be opera

29、ting in cellular technology network and get handed over to a satellite-based network and back to a fixed wireless network, depending upon the network coverage and preference of charging.</p><p>　　A. The Goal

30、s</p><p>　　Open Mobile Alliance’s (OMA) main goal is to make sure different wireless services and devices work together, and across countries, operators, and mobile terminals.Other plans in the group's c

31、harter include:</p><p>　　? Deliver open standards and specifications based on market and customer requirements.</p><p>　　? Create and promote a common industry view on an architectural framework

32、.</p><p>　　? Help consolidate standards groups and work in conjunction with other existing standards organizations and groups.</p><p>　　B. The Composite Vision</p><p>　　? 20 Mbps da

33、ta rates</p><p>　　? Streaming Audio/Video</p><p>　　? Asymmetric Access</p><p>　　? Adaptive Modulation/Coding</p><p>　　? Dynamic packet assignment</p><p>　　

34、? Smart/Adaptive antennas supported</p><p>　　C. 4G Network Architecture</p><p>　　“4G” wireless networks can be realized with an IP-based core network for global routing along with more customize

35、d local-area radio access networks that support features such as dynamic handoff and ad-hoc routing as well as newer requirements such as self-organization,QoS, multicasting, content caching, etc..</p><p>　　

36、In 4G LANs will be installed in trains and trucks as well as buildings, or even just formed on an ad-hoc basis between random collections of devices that happen to come within radio range of one other. Routing in such ne

37、tworks will depend on new architectures, already under development by the IEEE and a European project called Mobile IP Network Developments (MIND).</p><p>　　D. The working Principle </p><p>　　In

38、 4G-style mobile IP, each cell phone is assigned a permanent "home" IP address, along with a "care-of" address that represents its actual location.When a computer somewhere on the Internet wants to co

39、mmunicate with the cell phone, it first sends a packet to the phone's home address.A directory server on the home network forwards this to the care-of address via a tunnel, as in regular mobile IP. However, the direc

40、tory server also sends a message to the computer informing it of the correct care-</p><p>　　V. TECHNOLOGIES THAT SUPPORT 4G</p><p>　　The revolution in 4G will be the optical networking, the new

41、air interface, the portable device etc.</p><p>　　A. The Transmission Protocols</p><p>　　1) OFDM: OFDM is a digital modulation technology in which in one time symbol waveform, thousands of orthog

42、onal waves are multiplexed.This is good for high bandwidth digital data transition.</p><p>　　2) W-OFDM: W-OFDM enables data to be encoded on multiple high-speed radio frequencies concurrently. This allows fo

43、r greater security, increased amounts of data being sent, and the industry’s most efficient use of bandwidth.W-OFDM enables the implementation of low power multipoint RF networks that minimize interference with adjacent

44、networks.This enables independent channels to operate within the same band allowing multipoint networks and point-to-point backbone systems to be overlaid in the same</p><p>　　3) MC-CDMA : MC-CDMA is actuall

45、y OFDM with a CDMA overlay.Similar to single-carrier CDMA systems,the users are multiplexed with orthogonal codes to distinguish users in (multi-carrier) MC-CDMA.However in MC-CDMA, each user can be allocated several cod

46、es,where the data is spread in time or frequency.</p><p>　　4) LAS-CDMA：Link Air Communications is developer of LAS-CDMA (Large Area Synchronized Code Division Multiple Access) a patented 4G wireless technolo

47、gy. LAS-CDMA enables high-speed data and increases voice capacity and latest innovative solution, CDD, merges the highly spectral efficient LAS-CDMA technology with the superior data transmission characteristics of TDD.T

48、his resulting combination makes CDD the most spectrally efficient, high-capacity duplexing system available today.</p><p>　　B. The Radio Interface-UWB Radio</p><p>　　To make 4G really work carri

49、es will need to migrate to Ultra Wideband (UWB) technology.UWB radio will deliver essential new wireless and wired bandwidth inexpensively, without using precious and scarce radio frequencies.Instead,digital video, voice

50、 and data are enabled using modulated pulses of energy that peacefully co-exist alongside traditional communications.UWB radio solves the multipath fading issues and is 1,000% more process efficient than CDMA.</p>

51、<p>　　C. The Network-LMDS</p><p>　　Local multipoint distribution system (LMDS) is the broadband wireless technology used to deliver voice ,data, Internet, and video services in the 25-GHz and higher sp

52、ectrum (depending on licensing).The acronym LMDS is derived from the following:</p><p>　　L (local)—denotes that propagation characteristics of signals in this frequency range limit the potential coverage are

53、a of a single cell site;</p><p>　　M (multipoint)—indicates that signals are transmitted in a point-to-multipoint or broadcast method;</p><p>　　D (distribution)—refers to the distribution of sign

54、als, which may consist of simultaneous voice, data, Internet, and video traffic;</p><p>　　S (service)—implies the subscriber nature of the relationship between the operator and the customer.</p><p

55、>　　VI. POTENTIAL APPLICATIONS OF 4G</p><p>　　1) Virtual Presence: 4G system gives mobile users a "virtual presence" -- for example, always-on connections that keep people involved in business ac

56、tivities regardless of whether they are on-site or off.</p><p>　　2)Virtual navigation:A remote database contains the graphical representation of streets, buildings, and physical characteristics of a large me

57、tropolis.Blocks of this database are transmitted in rapid sequence to a vehicle, where a rendering program permits the occupants to visualize the environment ahead.</p><p>　　3) Tele-medicine: 4G will support

58、 remote health monitoring of patients.For e.g. the paramedic assisting the victim of traffic accident in a remote location must access medical records and may need video conference assistance from a surgeon for an emerge

59、ncy intervention.The paramedic may need to relay back to the hospital the victim's x-rays taken locally.</p><p>　　4)Tele-geoprocessing applications:The combination of geographical information systems (GI

60、S),global positioning systems (GPS), and high-capacity wireless mobile systems will enable a new type of application referred to as tele-geoprocessing.Queries dependent on location information of several users, in additi

61、on to temporal aspects have many applications.</p><p>　　5) Crisis-management applications:Natural disasters can affect the entire communications infrastructure is in disarray.Restoring communications quickly

62、 is essential.With wideband wireless mobile communications Internet and video services, could be set up in hours instead of days or even weeks required for restoration of wireline communications.</p><p>　　6)

63、 Education :Educational opportunities available on the internet, for individuals interested in life-long education, will be unavailable to client in remote areas because of the economic unfeasibility of providing wideban

64、d wireline internet access.4G wireless communications provides a cost-effective alternative in these situations.</p><p>　　VII. ROLE OF THE WIRELESS INDUSTRY RECOMMENDATIONS</p><p>　　We are bring

65、ing to the attention of professionals following issues and problems that must be analyzed and resolved:</p><p>　　1)Standardization: Standardization of wireless networks in terms of modulation techniques, swi

66、tching schemes and roaming is an absolute necessity for 4G. We must pay more attention to general meaning advanced technologies.</p><p>　　2) Lower Price Points Only Slightly Higher than Alternatives: The bus

67、iness visionaries should do some economic modeling before they start 4G hype. They should understand that 4G data applications like streaming video must compete with very low cost wireline applications.</p><p&

68、gt;　　3) More Coordination Among Spectrum Regulators Around the World: We must demand almost free spectrum NOT necessarily unlicensed Spectrum regulation bodies must get involved in guiding the researchers by indicating w

69、hich frequency band might be used for 4G.</p><p>　　4) Regulatory frameworks: Policy and Regulatory Environment which Provides Transparency, Certainty and a Level Playing Field are necessary. The most importa

70、nt thing is that we should recognize that regulatory framework is as much an evolving matter as technology, and be prepared to meet changes with an open-minded and pragmatic attitude, always keeping the interests of the

71、industry and consumers in mind.</p><p>　　5) More Academic Research: Universities must spend more effort in solving fundamental problems in radio communications (especially multiband and wideband radios, inte

72、lligent antennas and signal processing).</p><p>　　6) Voice-independent Business Justification Thinking: Business and Technology executives should not bias their business models by using voice channels as eco

73、nomic determinant for data applications. Voice has a built-in demand limit - data applications do not.</p><p>　　7) Integration Across Different Network Topologies: Network architects must base their architec

74、ture on hybrid network concepts that integrates wireless wide area net works, wireless LANS (IEEE 802.11a, IEEE 802.11b,IEEE 802.11g, IEEE 802.15 and IEEE 802.16), Bluetooth with fiber-based Internet backbone. Broadband

75、wireless networks must be a part of this integrated network architecture.</p><p>　　8) Non-disruptive Implementation: Upgrading from 3G to 4G is expected to be seamless to end-users with no device upgrades re

76、quired.</p><p>　　VIII. DEVELOPMENTS IN 4G</p><p>　　AT&T is combining W-OFDM and EDGE technologies, to provide broadband mobile downlink access at peak rates of up to 10 Mbps while EDGE offer

77、s uplink access at 384 Kbps with an 800KHz bandwidth in a high-mobility environment.</p><p>　　Sun Microsystems Laboratories are building 4G wireless technologies that promise to integrate voice and web data

78、in an IP-based mobile communications.</p><p>　　The Government of Karnataka in India has signed a MoU with Charmed Technologies Inc from Beverly Hills, California and Software Technology Parks of India in Kar

79、nataka to develop 4G wireless technology. The project plan to use wireless technology based on the IEEE802.11a and IEEE802.11b standards for wireless LAN for the underlying network is designed to support a data rate of u

80、p to 11Mbps and 54Mbps respectively. The goal is to get 6 billion people connected to the wireless Internet by 2010.</p><p>　　NTT DoCoMo and Hewlett-Packard Company &MOTO media collaboration will explore

81、 new mobile service concepts in which people, places and things will be able to interact, thereby bridging the real and the cyber world. MOTO-media is expected to enable high performance streaming of multimedia content t

82、o mobile users. DoCoMo and HP aim to nish the shared study of basic technology by 2003 and hope to push for 4G in 2006.</p><p>　　IX. SUGGESTIONS</p><p>　　We would like to give the following sugg

83、estions for the development of 4G mobile technologies:</p><p>　　1. Technologies like 4G must be developed to integrate into a more flexible network that grow within the network so that we don't have to s

84、carp the old network to implement the next generation, the generations to come.</p><p>　　2. The very big challenge for developing a technology is proper human resource for building high quality systems .Big

85、organization, which is engaged in software and system development, should rapidly go for tie-ups with educational institutes for better manpower and knowledge management.</p><p>　　3. We talk about mobile mul

86、timedia that 4G will support but in reality people are not going to watch TV while they walk down the street. Likewise people will not buy Coca Cola at vending machines with a cell phone. Quit often services conjured up

87、by the engineering side of the vendor organizations has little to do with the reality. So wireless industry should ponder well about market demand and invest money so that they will not be at loss.</p><p>　　

88、X.CONCLUSION</p><p>　　4G should make a significant difference and add perceived benefit to an ordinary person’s life over 3G.We should drop the 2.5G, 3G, 4G speak altogether where an additional “G” means mer

89、ely an increase in capacity. What really means something for the users are new services, integration of services, applications etc. Our goal is to struggle to get a “G”eneration of standards so that we can take our phone

90、 anywhere in the world and access any service or communicate with any other user any way we wan</p><p><b>　　二、英文翻譯：</b></p><p>　　下一代無線寬帶的目標(biāo)（4G—5G）</p><p>　　摘要：隨著接入技術(shù)的增長，

91、語音、視頻、多媒體和寬帶數(shù)據(jù)業(yè)務(wù)正在集成到同一個(gè)網(wǎng)絡(luò)中去。第三代移動(dòng)通信網(wǎng)絡(luò)（3G）將在不遠(yuǎn)的將來被下一代無線網(wǎng)絡(luò)——第四代移動(dòng)通信網(wǎng)絡(luò)（4G）所取代。4G技術(shù)基于IP的服務(wù)，其目標(biāo)是提供高速率，大容量，低每比特消耗的網(wǎng)絡(luò)。4G的是一個(gè)基于開放的系統(tǒng)方法綜合的全球的網(wǎng)絡(luò)。4G的目標(biāo)是“以一個(gè)基于IP的控制、視頻、分組數(shù)據(jù)和VoIP標(biāo)準(zhǔn)蜂窩網(wǎng)絡(luò)，取代現(xiàn)有的的增殖核心蜂窩系統(tǒng)網(wǎng)絡(luò)。不過，雖然尚未真正到達(dá)的3G時(shí)代，研究人員仍然希望2010年

92、左右能為他們?cè)O(shè)想到的一個(gè)尚未定論的“無線世界”的發(fā)展作出貢獻(xiàn)，讓它最終可以投入使用。本論文著眼于從基本法則和問題上討論網(wǎng)絡(luò)、技術(shù)、頻譜問題、標(biāo)準(zhǔn)、終端，和4G服務(wù)的相關(guān)愿景——網(wǎng)絡(luò)運(yùn)營商和服務(wù)供應(yīng)商對(duì)第四代移動(dòng)通信系統(tǒng)的演化的追尋以及從他們的角度來看未來的研究長遠(yuǎn)需求在何處？</p><p>　　關(guān)鍵詞：無線 第四代移動(dòng)通信 正交頻分多工 多載波碼分多址 大區(qū)域同步碼分多址技術(shù) 超寬帶</p>&l

93、t;p><b>　　1、前言</b></p><p>　　運(yùn)營商和手機(jī)制造商顯然有自己全面應(yīng)對(duì)3G的策略，與此同時(shí)一些企業(yè)已經(jīng)把目光投向了這種下一代無線技術(shù)和網(wǎng)絡(luò)。4G單純是學(xué)術(shù)研發(fā)實(shí)驗(yàn)室想要主動(dòng)超越關(guān)于3G部署方面所遇到麻煩局限和問題，滿足其承諾的性能和吞吐量的問題的努力。雖然這還沒有完全達(dá)到3G的但為什么研究人員和廠商仍然都對(duì)4G表現(xiàn)出了越來越大的興趣？兩個(gè)主要領(lǐng)域是處理這一問題的

94、舉措分別包括：增大無線通信鏈路的容量，以及在異構(gòu)無線接入網(wǎng)絡(luò)的無縫移動(dòng)率。第2節(jié)討論內(nèi)容是在3G技術(shù)創(chuàng)造有利4G技術(shù)發(fā)展條件的問題。第3節(jié)關(guān)于技術(shù)發(fā)展演變的過程和比較，第4節(jié)描述4G的目標(biāo)和遠(yuǎn)景，第5節(jié)對(duì)4G技術(shù)作出了一些闡釋，而在之后的其他章節(jié)中，對(duì)4G技術(shù)發(fā)展的研究和有關(guān)的其他問題進(jìn)行了討論。</p><p>　　無線寬帶的演化和比較</p><p>　　3G網(wǎng)絡(luò)正處于發(fā)展過程中一個(gè)非

95、常痛苦的階段，隨著初期試驗(yàn)帶來的令人失望的結(jié)果、成本膨脹、技術(shù)故障，網(wǎng)絡(luò)運(yùn)營商被迫通過不切實(shí)際的炒作緊縮最初的期望。盡管現(xiàn)在圍繞著興建中的更高速度的3G移動(dòng)網(wǎng)絡(luò)炒作層出不窮，但是邁向4G的飛躍的原因還是有一下幾點(diǎn)：</p><p><b>　　性能</b></p><p>　　工業(yè)懷疑論者表示，用戶將不能夠通過3G無線網(wǎng)絡(luò)利用豐富的多媒體資源。4G通信將采用有極高品質(zhì)

96、幾乎等同于高清晰度電視的視頻通信。此外，它將能用比3G無線網(wǎng)絡(luò)快約260倍超過100 Mbps的速度無線下載網(wǎng)上的東西。</p><p><b>　　互操作性</b></p><p>　　3G的多種標(biāo)準(zhǔn)使網(wǎng)間漫游和互操作有一定困難。我們需要一個(gè)全球標(biāo)準(zhǔn)來提供全球性的流動(dòng)性和可攜性服務(wù)，使服務(wù)提供商不再受單一系統(tǒng)供應(yīng)商的專有設(shè)備的約束。</p><p

97、><b>　　組網(wǎng)</b></p><p>　　3G的主要是基于一個(gè)廣域的概念。我們需要混合網(wǎng)絡(luò)，它能同時(shí)利用無線局域網(wǎng)（熱點(diǎn)）的概念和信元或基站廣域網(wǎng)的設(shè)計(jì)。有了4G技術(shù)，世界各地將有基站，確保手機(jī)用戶隨時(shí)隨地連接到高速網(wǎng)絡(luò)。</p><p><b>　　帶寬</b></p><p>　　我們需要更大帶寬和更高的比

98、特率。4G技術(shù)被安裝在辦公室、居民區(qū)、咖啡店、機(jī)場貴賓室，擁有超過20 Mbps的傳輸速度，將以覆蓋局域網(wǎng)內(nèi)“熱點(diǎn)”區(qū)域提供高帶寬的服務(wù)。遠(yuǎn)離這些熱點(diǎn)，客戶可以連接到加大馬力的2G的語音和數(shù)據(jù)網(wǎng)絡(luò)覆蓋范圍。</p><p><b>　　技術(shù)</b></p><p>　　與3G不同的是，4G技術(shù)將更加類似于現(xiàn)有的技術(shù)的集合，而不是一個(gè)全新的標(biāo)準(zhǔn)。分析家定義4G為一個(gè)現(xiàn)有

99、的2G網(wǎng)絡(luò)與本地區(qū)域網(wǎng)絡(luò)（局域網(wǎng)）或藍(lán)牙無線網(wǎng)絡(luò)的無縫結(jié)合的網(wǎng)絡(luò)。</p><p><b>　　趨同性</b></p><p>　　趨同性牽涉了超過單純的技術(shù)，它是一個(gè)未來的共同服務(wù)和市場。我們需要這樣的網(wǎng)絡(luò)，它能以最充分的形式利用IP地址融合的語音和數(shù)據(jù)的能力，而4G技術(shù)將實(shí)現(xiàn)。</p><p><b>　　成本</b>

100、</p><p>　　4G系統(tǒng)將被證明比3G便宜得多，因?yàn)樗鼈兛梢越F(xiàn)有網(wǎng)絡(luò)之上，并沒有要求經(jīng)營者完全更新設(shè)備，不需要運(yùn)營商購買昂貴的設(shè)備來提供額外頻譜。此外一個(gè)開放系統(tǒng)的IP無線環(huán)境可能進(jìn)一步降低服務(wù)供應(yīng)商的設(shè)備成本，而使我們迎來真正的互操作性時(shí)代。</p><p><b>　　可擴(kuò)展性</b></p><p>　　可擴(kuò)展性，或者說能夠處理

101、越來越多用戶和更多元化的服務(wù)，給移動(dòng)網(wǎng)絡(luò)提供了更多的挑戰(zhàn)?！霸O(shè)計(jì)可擴(kuò)展性”，包含的信息可以幫助您滿足不斷變化的使用需求。由于4G的全I(xiàn)P核心層是容易擴(kuò)展，它非常適合迎接這一挑戰(zhàn)。</p><p>　　無線寬帶的演化和比較</p><p>　　第一代移動(dòng)通信系統(tǒng)（1G）：1G的無線移動(dòng)通信系統(tǒng)，在20世紀(jì)80年代初并研發(fā)出。1G的無線是模擬，并支持第一代模擬手機(jī)。它們包括信令協(xié)議被熟知為七號(hào)