2021 Digital Signal Processing(Nanjing University of Posts and Telecommunications) 最新满分章节测试答案

本答案对应课程为:点我自动跳转查看
本课程起止时间为:2021-03-08到2021-06-21

1st Week： Unit 1 Introduction Unit Test for Unit 1

1、 问题:If you want to digitize the speech signal for subsequent processing, the speech signal must be passed through:
选项：
A:anti-aliasing analog filter
B:D / A conversion
C:digital filter
D:A / D conversion
答案: 【anti-aliasing analog filter;
A / D conversion】

2、 问题:The digital signal is a discrete-time signal with discrete-valued amplitudes.
选项：
A:正确
B:错误
答案: 【正确】

2nd Week： Unit 2 Discrete-Time Signals in the Time Domain Unit Test for Unit 2

1、 问题:
选项：
A:5
B:10
C:
D:10/3
答案: 【10】

2、 问题:Express    as a linear combination of delayed unit sample sequences.
选项：
A:
B:
C:
D:
答案: 【】

3、 问题:
选项：
A:
B:
C:
D:
答案: 【】

4、 问题:The length of the sequence obtained by linear convolution of length-M and length-N signals is
选项：
A:M + N
B:M + N -1
C:M + N +1
D:M * N
答案: 【M + N -1】

5、 问题:
选项：
A:
B:
C:
D:
答案: 【】

6、 问题:Regarding the unit step sequence, the correct descriptions are
选项：
A:finite length sequence
B:causal sequence
C:infinite length sequence
D:right-sided sequence
答案: 【causal sequence;
infinite length sequence;
right-sided sequence】

3rd Week： Unit 3 Discrete-Time Signals in the Frequency Domain Unit Test for Unit 3

1、 问题:
选项：
A:
B:
C:
D:
答案: 【】

2、 问题:For a discrete time sequence x[n], its DTFT must satisfy
选项：
A:
B:
C:
D:
答案: 【】

3、 问题:
选项：
A:
B:
C:
D:
答案: 【】

4、 问题:Let  denote the DTFT of the sequence then 
选项：
A:0
B:-3
C:-5
D:uncertain
答案: 【-3】

5、 问题:Let  denote the DTFT of the sequencethen 
选项：
A:3
B:11
C:31
D:uncertain
答案: 【31】

6、 问题:The DTFT of discrete time signal h[n] is then h[n] =
选项：
A:
B:
C:
D:
答案: 【】

7、 问题:
选项：
A:正确
B:错误
答案: 【错误】

8、 问题:The sequence x[n] has the same magnitude spectrum as its delayed sequence x[n-5].
选项：
A:正确
B:错误
答案: 【正确】

4th Week： Unit 4 Sampling and Recovery of Analog Signal Unit Test for Unit 4

1、 问题:When sampling a continuous-time signal with a maximum frequency , to satisfy the Nyquist criterion of the sampling theorem,  the range of the sampling interval T is
选项：
A:
B:
C:
D:
答案: 【】

2、 问题:Sampling two continuous-time sinusoidal signals with frequencies of  and   at the sampling frequency , if the two sequences obtained after sampling are equal, they need to meet
选项：
A:
B:
C:
D:No requirements for   and
答案: 【】

3、 问题:Consider the continuous-time signal  ,  is in units of seconds, and the discrete-time sequence is obtained after sampling, then the sampling frequency is
选项：
A:4000 Hz
B:1/8000 Hz
C:8000 Hz
D:2000 Hz
答案: 【8000 Hz】

4、 问题:A continuous-time signal xa(t) is composed of a linear combination of sinusoidal signals of frequencies 300Hz, 500Hz, 1.2kHz, 2.15kHz and 3.5 kHz. The signal xa(t) is sampled at a 3 kHz rate, and the sampled sequence is then passed through an ideal lowpass filter with a cutoff frequency of 900 Hz, generating a continuous-time signal ya(t). What are the frequency components present in the reconstructed signal ya(t)?
选项：
A:300 Hz
B:850 Hz
C:1200 Hz
D:500 Hz
答案: 【300 Hz;
850 Hz;
500 Hz】

5、 问题:The cut-off frequency of the reconstruction filter used to recover the analog signal is the sampling angular frequency.
选项：
A:正确
B:错误
答案: 【错误】

6、 问题:Anti-aliasing filtering is only required before sampling an analog signal of unlimited bandwidth.
选项：
A:正确
B:错误
答案: 【错误】

5th Week： Unit 5 z-Transform Unit Test for Unit 5

1、 问题:The region of convergence of z-transform of the sequence must not include:
选项：
A:zero
B:pole
C:origin