问题 问答题 简答题

TD-SCDMA的功率控制主要包括哪些?它们都有什么特点?

答案

参考答案:

TD功率控制只要包括:开环功率控制、闭环功率控制;闭环功率控制又可划分为内环功率控制和外环功率控制。

开环功率控制:通过测量接收特殊信道的信号功率大小和有关信息,调整自己的发射功率的功率控制方法。

内环功率控制:根据接收到的信噪比与目标信噪比进行比较,产生功率控制命令TPC,发射端根据TPC进行功率调整。

外环功率控制:根据接收数据的质量参数BLER/BER/FER等,调整内环功控所需的目标SIR,以克服信道慢衰落的影响。

阅读理解

Taking away a city’s rubbish is a big job. Every day trucks come into a city to collect it. Most rubbish is made up of things we can’t eat or use. If we kept these things we would soon have a mountain of rubbish.

In some cities the rubbish is collected and taken outside of the city to a dump(垃圾站). Often the city dump is placed where the ground is low or there is a big hole. The kitchen rubbish is broken into small pieces and sent into the sewage system. The sewagesystem takes away the used water from toilets, bathtubs(澡盆) and other places.

To keep mice and flies away, some earth is used to cover the newly dumped rubbish. Later, grass may be planted on the rubbish-filled land. Finally, a house or a school may be built there, and then you’d never know that this had once been an old rubbish dump.

In other cities the rubbish is burnt in special places. The fire burns everything but the metal. Sometimes the metal can be used again in factories where things are made of metal. The food parts of rubbish are put in special piles where they slowly change into something called humus(腐殖土), which looks like black earth. It is rich with kinds of things that feed plants and help make them grow.

小题1:You can most probably read the passage in _______.

A.a history book

B.a TV guide

C.a science book

D.a telephone book小题2:The underlined word “sewage” in the passage means_______.

A.排污

B.染色

C.洗涤

D.吸尘小题3:According to the passage, the food parts of rubbish can be used again_______.

A.to feed animals

B.to feed plants

C.to build a house

D.to make machines小题4:How should we take care of a used metal box according to the passage?

A.By burning it off.

B.By putting it in water.

C.By throwing it away.

D.By reusing and recycling it.

单项选择题