2020 移动通信（陈万通）(中国民航大学) 最新满分章节测试答案

文章目录[隐藏]

Chapter 1- History of Mobile Communications and Cellular systems 第一章测验
【作业】Chapter 1- History of Mobile Communications and Cellular systems 单元测验
Chapter2： Wireless Channel 第二章测验
【作业】Chapter2： Wireless Channel 第二章作业
【作业】Chapter 1- History of Mobile Communications and Cellular systems 第一章作业
Chapter3：DigitalModulation 单元测验
【作业】Chapter3：DigitalModulation 单元作业
Chapter 4： Multiple Division Techniques and CDMA-DSSS 单元测验
【作业】Chapter 4： Multiple Division Techniques and CDMA-DSSS 单元作业

本答案对应课程为:点我自动跳转查看
本课程起止时间为:2020-02-18到2020-07-15
本篇答案更新状态:已完结

Chapter 1- History of Mobile Communications and Cellular systems 第一章测验

1、问题:In OFDM, the chosen subcarrier frequencies are spaced apart by the inverse of the symbol time, and the spectrum of each subchannel may overlap to fully utilize the available bandwidth.
选项：
A:正确
B:错误
答案: 【正确】

2、问题:In a cellular structure, a MS needs to communicate with the BS of the cell where the MS is currently located, and the BS acts as a gateway to the rest of the world.
选项：
A:正确
B:错误
答案: 【正确】

3、问题:A BS consists of a base transceiver system (BTS) and a BSC. Both tower and antenna are a part of the BTS, while all associated electronics are contained in the BSC.
选项：
A:正确
B:错误
答案: 【正确】

4、问题:HLR is located at the MSC where the MS is registered and where the initial home location for billing and access information is maintained.
选项：
A:正确
B:错误
答案: 【正确】

5、问题:The third and most promisingCDMAtechnique utilizes a wider frequency band for each user. As the transmission frequency is distributed over the allocated spectrum, this technique is also known as spread spectrum.
选项：
A:正确
B:错误
答案: 【正确】

【作业】Chapter 1- History of Mobile Communications and Cellular systems 单元测验

1、问题:A new wireless service provider decided to employ a cluster of 19 cells as the basic module for frequency reuse. (a) Can you identify one such cluster structure? (b) Repeat (a) for N = 28. (c) Can you get an alternative cluster structure for part (a)? (d) What is the reuse distance for the system of part (c)? (e) Can you find the worst-case co-channel interference in such a system
评分规则: 【每个小题10分
】

2、问题:The size and shape of each cluster in a cellular need to be designed carefully so as to cover adjacent spoke in a non-overlapped manner. Define such patterns for the following cluster sizes: (a) 4-cell (b) 9-cell (c) 13-cell (d) 37-cell? （e）7-cell?
评分规则: 【每个小题10分
】

Chapter2： Wireless Channel 第二章测验

1、问题:In link-level simulations, only multi-path fading is considered, and no need to consider （） and shadowing
答案: 【(以下答案任选其一都对)path-loss;
path loss】

2、问题:Small delay spread indicates （） coherence bandwidth and hence correlated fading.
答案: 【(以下答案任选其一都对)larger;
bigger】

3、问题:A carrier transmitted on a single frequency will receive multiple reflections and each reflection will arrive at the receiver shifted in frequency by a different amount. The difference between the highest shift and the lowest shift gives the ( ) spread.
答案: 【(以下答案任选其一都对)Doppler;
doppler】

4、问题:Delay spread and coherence bandwidths are parameters which describe the ( ) dispersive nature of the channel in a local area.
答案: 【time】

5、问题:Propagation in free space does not have any obstacles and hence it characterizes the most ideal situation for propagation. Whereas, radio propagation on land may take place close to obstacles which cause reflection, diffraction, and ( ).
答案: 【scattering】

6、问题:Two frequencies that are larger than the coherence bandwidth and fade independently. This concept is used in ( ) reception.
答案: 【diversity】

7、问题:Inter-symbol interference (ISI) is caused by time delayed multipath signal, where in the second multipath signal is delayed such that it is received during the ( ) symbol.
答案: 【next】

8、问题:Coherence time is the time domain dual of Doppler spread and is used to characterize the time varying nature of the ( ) dispersiveness of the channel in the time domain.
答案: 【frequency】

9、问题:If the reciprocal bandwidth of the baseband signal is ( ) than the coherence time of the channel, then the channel will change during the transmission of the baseband message, thus causing distortion at the receiver.
答案: 【(以下答案任选其一都对)greater;
larger;
bigger】

10、问题:Propagation in free space does not have any ( ) and hence it characterizes the most ideal situation for propagation.
答案: 【(以下答案任选其一都对)obstacles;
obstacle】

【作业】Chapter2： Wireless Channel 第二章作业

1、问题:A wireless receiver with an effective diameter of 250 cm is receiving signals at 20 GHz from a transmitter that transmits at a power of 30 mW and a gain of 30 dB. (a) What is the gain of the receiver antenna? (b) What is the received power if the receiver is 5 km away from the transmitter?
评分规则: 【每问25分
】

2、问题:The transmission power is 40 W, under a free-space propagation model, (a) What is the transmission power in unit of dBm? (b) The receiver is in a distance of 1000 m; what is the received power, assuming that the carrier frequency fc = 900 MHz and Gt = Gr = 1? (c) Express the free space path loss in dB.
评分规则: 【第一问和第二问各15分，第三问20分
】

【作业】Chapter 1- History of Mobile Communications and Cellular systems 第一章作业

1、问题:Exercise 1A new wireless service provider decided to employ a cluster of 19 cells as the basic module for frequency reuse. (a) Can you identify one such cluster structure? (b) Repeat (a) for N = 28. (c) Can you get an alternative cluster structure for part (a)? (d) What is the reuse distance for the system of part (c)? (e) Can you find the worst-case co-channel interference in such a system
评分规则: 【 Exercise 2The size and shape of each cluster in a cellular need to be designed carefully so as to cover adjacent spoke in a non-overlapped manner. Define such patterns for the following cluster sizes: (a) 4-cell (b) 9-cell (c) 13-cell (d) 37-cell? (e）7-cell?