电子与通信技术专业英语Unit 3 lesson 18

1、PART1 4G is the fourth generation of wireless communications currently being developed for high speed broadband mobile capabilities. It is characterized by higher speed of data transfer and improved quality of sound. Although not yet defined by the ITU (International Telecommunications Union), the i

2、ndustry identifies the following as 4G technologies: WiMAX (Worldwide Interoperability for Microwave Access) 3GPP LTE (3rd Generation Partnership Project Long Term Evolution) UMB (Ultra Mobile Broadband) Flash-OFDM (Fast Low-latency Access with Seamless Handoff Orthogonal Frequency Division Multiple

3、xing) The 4G technology is being developed to meet QoS (Quality of Service) and rate requirements that involve prioritization of network traffic to ensure good quality of services. These mechanisms are essential to accommodate applications that utilize large bandwidthLesson 18 4G NetworkTextNew word

4、NotesExercisesTranslationVocabulary PART1Lesson 18 4G Network such as the following (as shown in Fig.18-1): Wireless Broadband Internet Access, MMS (Multimedia Messaging Service), Video Chat, Mobile Television, HDTV (High Definition TV), DVB (Digital Video Broadcasting), Real Time Audio, High Speed

5、Data Transfer. The goal set by ITU for data rates of WiMAX and LTE is to achieve 100Mbps when the user is moving with high speed relative to the base station, and 1Gbps for fixed positions. The industry moves towards expansion of the number of 4G compatible devices. It is set to find its way to tens

6、 of different mobile devices not restricted to 4G phones or laptops, such as Video Camera, Gaming Devices, VendingTextNew wordNotesExercisesTranslationVocabulary Fig.18-1 4G networkPART1Lesson 18 4G NetworkMachines, and Refrigerators. The trend is to provide wireless internet access to every portabl

7、e device that could supply and incorporate the 4G embedded modules. The 4G technology could not only provide internet broadband connectivity but also a high level of security that is beneficial to devices that incorporate financial transactions such as vending machines and billing devices.The follow

8、ing key features can be observed in all suggested 4G technologies: MIMO: to attain ultra-high spectral efficiency by means of spatial processing including multi-antenna and multi-user MIMO. Frequency-domain-equalization, for example, multi-carrier modulation (OFDM) in the downlink or single-carrier.

9、 Frequency-domain-equalization (SC-FDE) in the uplink: To exploit the frequency selective channel property without complex equalization.TextNew wordNotesExercisesTranslationVocabulary PART1Lesson 18 4G Network Turbo principle error-correcting codes: to minimize the required SNR at the reception side

10、. Channel-dependent scheduling: to use the time-varying channel. Link adaptation: adaptive modulation and error-correcting codes. Mobile-IP utilized for mobility. IP-based femtocells (home nodes connected to fixed Internet broadband infrastructure).TextNew wordNotesExercisesTranslationVocabulary PAR

11、T2New words and phrases:interoperability intr,prbilti n. 互通性，互操作性latency leitnsi n. 潜伏时间；延迟时间seamless si:mlis adj. 无缝的；不停顿的handoff hndf n. 切换accommodate kmdeit vt. 使适应，容纳relative reltiv adj. 相对的compatible kmptibl adj. 兼容的incorporate ink:preit v. 包含；使并入transaction trnzkn n. 交易spectral efficiency spek

12、trl ifinsi 频谱效率adaptive modulation dptiv ,mdjulein 自适应调制femtocell femtusel n. 家庭基站TextNew wordNotesExercisesTranslationVocabulary PART2New words and phrases:Phrases and Expressions4G 第四代移动电话通信标准ITU 国际电信联盟WiMAX 全球微波互通存取3GPP 第三代合作伙伴项目LTE 长期演进技术UMB 超移动宽带OFDM 正交频分复用技术MMS 多媒体短信服务HDTV 高清电视DVB 数字视频广播MIMO (

13、Multi-input Multi-output) 多输入多输出技术SC-FDE 单载波频域均衡SNR or S/N (signal-to-noise ratio) 信噪比Spectral efficiency 频谱效率adaptive modulation 自适应调制TextNew wordNotesExercisesTranslationVocabulary PART3Notes:1.4G is the fourth generation of wireless communications currently being developed for high speed broadban

14、d mobile capabilities.译文：4G是目前正在开发的具有高速移动宽带能力的第四代无线通信技术。“being developed”为分词结构作定语修饰主语4G。2.The 4G technology is being developed to meet QoS (Quality of Service) and rate requirements that involve prioritization of network traffic to ensure good quality of services.译文：正在开发的4G技术可以满足QoS（服务质量）和网络流量优先化的速率

15、要求，以保证良好的服务质量。meet: 满足，常与requirement，standard，need等搭配。如：(1) How can we best meet the needs of all the different groups?(2) I cannot possible meet that deadline.TextNew wordNotesExercisesTranslationVocabulary PART33.The goal set by ITU for data rates of WiMAX and LTE is to achieve 100Mbps.译文：由ITU为WiM

16、AX和LTE设定的目标是：当用户高速相对于基站移动时，数据速率达到100Mbps。“set by ”为分词作定语修饰goal。4.The 4G technology could not only provide internet broadband connectivity but also a high level of security that is beneficial to devices that incorporate financial transactions such as vending machines and billing devices.译文：4G技术不仅可以提供

17、宽带互联网连接而且具有更高级别的安全性，有利于包含金融交易的设备，如自动售货机和计费装置。(1) not only but (also) :不仅而且，如：They not only talked but also shouted and laughed. (2) that is beneficial和that incorporate为定语从句分别修饰a high level of security和devices.Notes:TextNew wordNotesExercisesTranslationVocabulary PART4Exercises:1.Write T (True) or F

18、(False) beside the following statements about the text.a. 4G is characterized by higher speed of data transfer and improved quality of sound. b. Flash-OFDM is regarded as one of 4G technologies. c. 4G technologies are developed for the applications that require large bandwidth. d. When the user is i

19、n a fixed position, the data rates of WiMAX should achieve 100Mbps in a 4G network. e. 4G compatible devices only refer to 4G phones or laptops. f. The 4G technology is beneficial to devices that incorporate financial transactions because it provides a high level of security. 2.Fill in the missing w

20、ords according to the text.a.4G is currently developed for high speed _.b.4G technologies mentioned in the text are _, _, _, _.c.ITU set a goal for data rates of WiMAX and LTE is to _ when the user is _ relative to the base station, and 1Gbps for_.d.The 4G technology could provide _ and a high level

21、 of _ _that is beneficial to devices which_.TextNew wordNotesExercisesTranslationVocabulary 1.Write T (True) or F (False) beside the following statements about the text.a. 4G is characterized by higher speed of data transfer and improved quality of sound. b. Flash-OFDM is regarded as one of 4G techn

22、ologies. c. 4G technologies are developed for the applications that require large bandwidth. d. When the user is in a fixed position, the data rates of WiMAX should achieve 100Mbps in a 4G network. e. 4G compatible devices only refer to 4G phones or laptops. f. The 4G technology is beneficial to dev

23、ices that incorporate financial transactions because it provides a high level of security. 2.Fill in the missing words according to the text.a.4G is currently developed for high speed _.b.4G technologies mentioned in the text are _, _, _, _.c.ITU set a goal for data rates of WiMAX and LTE is to _ wh

24、en the user is _ relative to the base station, and 1Gbps for_.d.The 4G technology could provide _ and a high level of _ _that is beneficial to devices which_.PART4Exercises:3.Translate the following paragraphs into Chinese.The 4G technology is being developed to meet QoS (Quality of Service) and rat

25、e requirements that involve prioritization of network traffic to ensure good quality of services. These mechanisms are essential to accommodate applications that utilize large bandwidth.The trend is to provide wireless internet access to every portable device that could supply and incorporate the 4G

26、 embedded modules. The 4G technology could not only provide internet broadband connectivity but also a high level of security that is beneficial to devices that incorporate financial transactions such as vending machines and billing devices.TextNew wordNotesExercisesTranslationVocabulary PART5Translation第18课 4G网络 4G是目前正在开发的具有