问题 问答题 简答题

从收发角度解释智能天线的波束成型带来的好处?

答案

参考答案:

1)从接收角度看,基站利用智能天线对来自移动台的多径电波方向进行波达方向(DOA)估计,并进行空间滤波(也称为上行波束成型),抑制其他移动台和多径干扰。

2)从发送角度看,基站利用智能天线对发射信号下行波束成型,使基站发射信号能够沿着移动台电波的来波方向发送回移动台,从而降低了发射功率,减少了对其他移动台的干扰。

阅读理解

In the United States, when one becomes rich, he wants people to know it. And even if he does not become very rich, he wants people to think that he is. That is what ‘keeping up with the Joneses’ is about, It is the story of someone who tried to look as rich as his neighbours.

The expression was first used in 1913 by a young American called Arthur Momand. He told this story about himself. He began earning $ 125 a week at the age of 23. That was a lot of money in those days. He got married and moved with his wife to a very wealthy neighbourhood outside New York City. When he saw that rich people rode horses, Momand went horseback riding every day. When he saw that rich people had servants, Momand and his wife also hired a servant and gave big parties for their new neighbours.

It was like a race, but one could never finish this race because one was always trying to keep up. The race ended for Momand and his wife when they could no longer pay for their new way of life. They moved back to an apartment in New York City.

Momand looked around him and noticed that many people do things just to keep up with rich life--style of their neighbours. He saw the funny side of it and started to write a series  of short stories, He called it ‘Keeping up with the Joneses’ because ‘Jones’ is a very common name in the United States.’ Keeping up with the Joneses’ came to mean keeping up with rich lifestyle of the people around you. Momand’s series appeared in different newspapers across the country for over 28 years.

People never seem to get tired of keeping up with the Joneses. And there are ‘Jonses’ in every city of the world. But one must get tired of trying to keep up with the Joneses because no matter what one does, Mr. Jones always seems to be ahead.

小题1:Some people want to keep up with the Joneses because they ______.

A.want to be as rich as their neighbours

B.want others to know or to think that they are rich

C.don’t want others to know they are rich

D.want to be happy小题2:It can be inferred from the story that rich people like to ________.

A.live outside New York City

B.live in New York City

C.live in apartments

D.have many neighbours小题3:The underlined word neighbourhood in the second paragraph means ________.

A.a person who lives near another

B.people living in an area

C.an area near the place referred to

D.an area in another town or city小题4: Arthur Momand used the name ‘Jones’ in his series of short stories because’ Jones’ is ________.

A.an important name

B.a popular name in the United States

C.his neighbour’s name

D.not a good name小题5:According to the writer, it is       to keep up with the Joneses.

A.correct

B.interesting

C.impossible

D.good

论述题