更多“CDMA (Code Division Multiple Acc”相关问题
  • 第1题:

    Circuit-switching technology is used in Publish Switched Telephone Network(PSTN), Global System for Mobile Communications(GSM) and code Division Multiple Access (CMDA) .It is a ( ) information transfer mode.

    A.connection oriented

    B.connectionless

    C.high bandwidth utilization

    D.poor real-time


    正确答案:D

  • 第2题:

    Dense Wavelength Division Multiplexing (DWDM) is an important innovation in optical networks.Which two descriptions best define DWDM?()

    A. optical technology for transmitting up to 32 channels over multiple fiber strands

    B. optical technology for transmitting up to 16 channels over multiple fiber strands

    C. a WDM system that is compatible with EDFA technology

    D. a technology for transmitting more closely packed optical signals using more sophisticated transceiver designs than CWDM .


    参考答案:C, D

  • 第3题:

    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 forwardchannels.Transmission is in the form of direct-sequence spread(本题),which uses a chipping code to increase the data rate of the transmission,resulting inan 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.

    A.structure
    B.spectrum
    C.stream
    D.strategy

    答案:B
    解析:
    见下题

  • 第4题:

    根据《2GHzTD-SCDMA数字蜂窝移动通信网工程验收暂行规定》,WCDMA(Wideband Division Multiple Access)意思是()。

    • A、宽带码分多址接入
    • B、码分多址接入
    • C、时分多址接入
    • D、时分同步码分多址接入

    正确答案:A

  • 第5题:

    Dense Wavelength Division Multiplexing (DWDM) is an important innovation in optical networks.Which two descriptions best define DWDM?()

    • A、optical technology for transmitting up to 32 channels over multiple fiber strands
    • B、optical technology for transmitting up to 16 channels over multiple fiber strands
    • C、a WDM system that is compatible with EDFA technology
    • D、a technology for transmitting more closely packed optical signals using more sophisticated transceiver designs than CWDM .

    正确答案:C,D

  • 第6题:

    CDMA中用到的扩频序列是()

    • A、Walsh code
    • B、Short PN code
    • C、Long PN code
    • D、Turbo code

    正确答案:A,B,C

  • 第7题:

    OFDM的英文全称是()

    • A、Orthogonal Frequency Division Multiplexing
    • B、Outstanding Frequency Division Multiplexing
    • C、Overwhelming Frequency Division Multiplexing
    • D、Orthogonal Frequency Division Modulation

    正确答案:A

  • 第8题:

    WDM与()本质是相同的。

    • A、OFDM(optical frequency division multiplexing)
    • B、OTDM(optical time division multiplexing)
    • C、CDM(code division multiplexing)
    • D、EDFA(erbium doped fiber amplifier)

    正确答案:A

  • 第9题:

    单选题
    TDD表示的含义()。
    A

    transfer control protocol

    B

    time division duplex

    C

    time division synchronous CDMA

    D

    time division multiple access


    正确答案: A
    解析: 暂无解析

  • 第10题:

    填空题
    ()是码分多址的英文缩写(Code Division Multiple Access),它是在数字技术的分支,扩频通信技术上发展起来的一种崭新而成熟的无线通信技术。

    正确答案: CDMA
    解析: 暂无解析

  • 第11题:

    填空题
    WCDMA英文全称是Wideband Code Division Multiple Access,其系统带宽、码片速率分别是(),()。

    正确答案: 5MHz,3.84Mbps
    解析: 暂无解析

  • 第12题:

    名词解释题
    CDMA (Code Division Multiple Access)

    正确答案: 又称码分多址,是在无线通讯上使用的技术,CDMA允许所有的使用者同时使用全部频带(1.2288Mhz),并且把其他使用者发出的讯号视为杂讯,完全不必考虑到讯号碰撞(collision)的问题。CDMA的优点包括:CDMA中所提供的语音编码技术,其通话品质比目前的GSM好,而且可以把用户对话时周围环境的噪音降低,使通话更为清晰。CDMA利用展频的通讯技术,因而可以减少手机之间的干扰,并且可以增加用户的容量,而且手机的功率还可以做的比较低,不但可以使使用时间更长,更重要的是可以降低电磁波辐射对人的伤害。CDMA的带宽可以扩展较大,还可以传输影像呢,这是第三代手机为什么选用CDMA的原因。就安全性能而言,CDMA不但有良好的认证体制,更因为其传输的特性,用码来区分用户,防止被人盗听的能力大大地增强。目前CDMA系统正快速发展中。WidebandCDMA(WCDMA.宽带码分多址传输技术,为IMT-2000的重要基础技术,将是第三代数字无线通信系统的标准之一。
    解析: 暂无解析

  • 第13题:

    CDMA for cellular system can be described as follows. As with FDMA, each cell is allocated a frequency (71) , when is split into two parts, half for reverse (mobile unit to base station) and half for (72) (base station to mobile unit). For full-duplex (73) , a mobile unit both reverse and forward channels. Transmission is in the form. of direct-sequence spread (74) , which used a chipping code to increase the data rate of the transmission, resulting is 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.

    A.ware

    B.signal

    C.bandwidth

    D.domain


    正确答案:C
    用于蜂窝系统的CDMA技术可以描述如下。就像FDMA一样,每一个小区被分配了一个频带,该频带划分为两半,一半用于反向信道(从移动终端到基站),一半用于正向信道(从基站到移动终端)。在全双工通信中,移动终端使用了反向和正向两个信道。传输以直接序列扩频方式进行,用一个码片来增加传输的数据速率,同时也产生了额外的信号带宽。通过把正交的各个码片指定给不同的用户就可以实现多路访问,这样接收者就能够从多个传输中提取并恢复需要的传输单元。

  • 第14题:

    Circuit-switching technology is used in Public Switched Telephone Network(PSTN), Global System for Mobile Communications(GSM) and Code Division Multiple Access(CDMA). It is a ( ) information transfer mode.

    A.Connection oriented
    B.connectionless
    C.High bandwidth utilization
    D.Poor-real-time

    答案:A
    解析:
    电路交换技术用于PSTN、GSM和CDMA,它是一种(72)信息传输模式。

  • 第15题:

    WCDMA英文全称是Wideband Code Division Multiple Access,其系统带宽、码片速率分别是(),()。


    正确答案:5MHz;3.84Mbps

  • 第16题:

    码分复用(Code Division Multiplexing,CDM)中,各路信号码元在频谱上和时间上都是()的,但是不同用户传输的信号是靠各自不同的(正交)编码序列来区分的。


    正确答案:重叠

  • 第17题:

    FDM的英文是()

    • A、Overload Frequency Division Multiplexing 
    • B、Orthogonal Frequency Division Multiplexing 
    • C、Overwhelming Frequency Division Multiplexing 
    • D、Outstanding Frequency Division Multiplexing

    正确答案:B

  • 第18题:

    CDMA移动通信系统中,Sych信道使用Walsh code(),其用于()

    • A、32;同步
    • B、16;同步
    • C、1;广播 
    • D、7;寻呼

    正确答案:A

  • 第19题:

    Acceptance of deliverables to multiple locations requires which type of sign off?()

    • A、Design Acceptance
    • B、Code Acceptance
    • C、Module Acceptance
    • D、Site Acceptance

    正确答案:D

  • 第20题:

    单选题
    Circuit-switching technology is used in Publish Switched Telephone Network(PSTN), Global System for Mobile Communications(GSM) and code Division Multiple Access (CMDA) . It is a ( ) information transfer mode.
    A

    connection oriented

    B

    connectionless

    C

    high bandwidth utilization

    D

    poor real-time


    正确答案: C
    解析: 暂无解析

  • 第21题:

    单选题
    In order to link data centers, a customer is evaluating the installation of fiber optic cable between buildings that are 400 meters apart. The installation will require multiple patch panels and cables. Which of the following is the most critical factor to consider for this installation?()
    A

    I/O rate

    B

    bandwidth

    C

    signal loss

    D

    Dense Wavelength Division Multiplexing (DWDM)


    正确答案: D
    解析: 暂无解析

  • 第22题:

    单选题
    WCDMA的英文全称是Wideband Code Division Multiple Access,即宽带码分多址。其系统带宽是5MHz,码片速率为()。
    A

    1.2288Mbps

    B

    1.28Mbps

    C

    3.84Mbps


    正确答案: C
    解析: 暂无解析

  • 第23题:

    填空题
    码分复用(Code Division Multiplexing,CDM)中,各路信号码元在频谱上和时间上都是()的,但是不同用户传输的信号是靠各自不同的(正交)编码序列来区分的。

    正确答案: 重叠
    解析: 暂无解析