问题 问答题 简答题

载波聚合是什么?与MIMO有什么区别?

答案

参考答案:

载波聚合是在LTE增强版本Release10中引入的新功能,通过多个载波的捆绑使用来提升传输的速率,特别是峰值速率。该功能与LTE基础版本兼容(Release8/9),即:不支持载波聚合的终端(Release8/9)可接入载波聚合的基站(Release10/11);支持载波聚合的终端(Release10/11)也可接入不支持载波聚合的基站(Release8/9)。

对于不支持载波聚合的Release8/9终端1/2/3,最多能使用20MHz的传输资源;而对于支持载波聚合的Release10终端4/5,最多可使用40MHz甚至更高带宽的传输资源。因此,相比终端1/2/3,终端4/5的速率可获得数倍提升。

载波聚合是聚合频率资源提升数据传输速率,MIMO是通过充分利用空间维度提升数据传输速率。载波聚合与MIMO之间没有任何的必然联系,二者的共同点是均可成倍提升用户速率,网络侧可根据用户实际需求,灵活配臵用户使用MIMO和载波聚合技术。终端1/2/3仅可使用MIMO技术,但终端4/5可同时使用MIMO和载波聚合技术,以获得更高峰值速率。

单项选择题 B型题
阅读理解

Being able to multitask---doing several things at the same time---is considered a welcome skill by most people. But if we consider the situation of the young people aged from eight to eighteen, we should think again.

What we often see nowadays is that young people juggle an ever larger number of electronic devices as they study. While working, they also surf on the Internet, send out emails, answer the telephone and listen to music on their iPods. In a sense, they are spending a significant amount of time in fruitless efforts as they multitask.

Multitasking is even changing the relationship between family members. As young people give so much attention to their own worlds, they seem to have no time to spend with the other people around them. They can no longer greet family members when they enter the house, nor can they eat at the family table.

Multitasking also affects young people’s performance at university and in the workplace. When asked about their opinion of the effect of modern gadgets on their performance of tasks, many young people gave a positive response. However, the response from the worlds of education and business was not quite as positive.

Educators feel that multitasking by children has a serious effect on later development of study skills. They believe that many college students now need help to improve their study skills. Similarly, employers feel that young people entering the job market need to be taught all over again, as modern gadgets have made it unnecessary for them to learn special skills to do their work.

小题1:What does the underlined word “juggle” in Paragraph 2 most probably mean?

A.Want to buy.

B.Take the place of.

C.Use at the same time.

D.Seek for information from.小题2:In Paragraph 3, the author points out that  ________.

A.family members do not eat at the family table.

B.family members do not greet each other.

C.young people live happily in their families

D.young people seldom talk with their family members小题3:What is the main idea of the last paragraph?

A.multitasking is harmful to young people’s development.

B.Young people benefit a lot from modern gadgets.

C.Multitasking is an important skill to young people.

D.Yong people must learn skills for future jobs.小题4:The author develops the passage mainly by ________.

A.providing typical examples

B.following the natural time order

C.comparing opinions from different fields

D.presenting a cause and analyzing its effects