选择题：CDMA for cellular systems can be described as follows. As with FDMA, each cell i

CDMA for cellular systems can be described as follows. As with FDMA, each cell is Allocated a frequency （　　），which is split into two parts; half for reverse (mobile unit to base station) and half for（　　）(base station to mobile unit). For full-duplex（　　）, a mobile unit uses both reverse and forward channels. Transmission is in the form of direct-sequence spread（　　）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（　　）chipping codes to multiple users, so that the receiver can recover the transmission of an individual unit from multiple transmissions.
问题1选项
A.wave
B.signal
C.bandwidth
D.domain
问题2选项
A.forward
B.reverse
C.backward
D.ahead
问题3选项
A.connection
B.transmission
C.compromise
D.communication
问题4选项
A.structure
B.spectrum
C.stream
D.strategy
问题5选项
A.concurrent
B.orthogonal
C.higher
D.lower