CDMA for cellular systems can be described as follows．As with FDMA，each cell is allocated a frequency (71)，which is split into

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问题 CDMA for cellular systems can be described as follows．As with FDMA，each cell is allocated a frequency (71)，which is split into two parts，half for reverse(mobile unit to base station)and half for (72) (base station to mobile uni0．For full—duplex (73) ，a mobile unit uses both reverse and forward channels．Transmission is in the form of direct—sequence spread (74)，which uses a chipping code to increase the data rate of the transmission，resulting in an increased signal bandwidth．Multiple access is provided by assigning (75) chipping codes to multiple users，SO that the receiver can recover the transmission of an individual unit from multiple transmissions．
(72)

选项 A、forward
B、reverse
C、backward
D、ahead

答案A

解析

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本试题收录于：网络工程师上午基础知识考试题库软考中级分类

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