问题 问答题 简答题

简述TD-SCDMA系统中动态信道分配DCA的分类及方法?

答案

参考答案:

(1)时域动态信道分配

因为TD-SCDMA系统采用了TDMA技术,在一个TD-SCDMA载频上,使用7个常规时隙,减少了每个时隙中同时处于激活状态的用户数量。每载频多时隙,可以将受干扰最小的时隙动态分配给处于激活状态的用户。(2)频域动态信道分配

频域DCA中每一小区使用多个无线信道(频道)。在给定频谱范围内,与5MHz的带宽相比,TD-SCDMA的1.6MHz带宽使其具有3倍以上的无线信道数(频道数)。可以把激活用户分配在不同的载波上,从而减小小区内用户之间的干扰。

(3)空域动态信道分配

因为TD-SCDMA系统采用智能天线的技术,可以通过用户定位、波束赋形来减小小区内用户之间的干扰、增加系统容量。

(4)码域动态信道分配:

在同一个时隙中,通过改变分配的码道来避免偶然出现的码道质量恶化。

阅读理解

Holidays are often associated with no work and all play. People seek to enjoy their holidays in different ways. Vacation packages (一揽子交易) have been in existence for a long time. ---小题1:--- So now people can choose from the different packages according to their own tastes.

Sky diving, hiking and many other extreme sports are packaged with hotel tours to attract the younger generation. Tour service providers enjoy the benefits of the increase in bookings from hotel tours. Holiday-makers enjoy the exciting experiences without making efforts to look for hotels. ---小题2:---

---小题3:-- These holiday-makers enjoy student discount and packages while learning about history and culture of different places.

Summer vacation packages have never fallen down the rankings. ---小题4:--- Having a warm sunny day at the beach is one of the fast selling vacation packages in the leisure industry.

Safari (游猎) adventures have always attracted some of the modern adventurers. The animals of Africa continue to amaze crowds that have only seen these creatures on educational channels. Many activities like outdoor camping, safari day tours and hiking in protected parks are always welcomed by holiday-makers.

--小题5:--- Alaways try something new or fun to do and your days of relaxation will be always exciting.

A.Picking out a vacation package can keep yourself from boring vacations.

B.Everyone is in a winning situation.

C.You can’t miss vacation packages if you want to have a good vacation.

D.Educational vacation packages are quite suitable for students.E. They are one of the favorite choices for most holiday-makers who like sunny beaches.

F. They are continually being improved to meet people’s demands.

G.  Vacation needs your plan.

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