数字信号处理（全英文）答案2023秋

第三章测试

1.There is a one-to-one correspondence between a discrete time signal and its Fourier transform .（ ）
A:对 B:错
答案:A
2.The spectrum of a sequence can be graphed by magnitude frequency characteristics and phase frequency characteristics.（ ）
A:错 B:对 3.The DTFT of a sequency is a periodic and discrete function of .（ ）
A:错 B:对 4.If ，then .（ ）
A:错 B:对 5.The below figure is one of the ways to compute the linear convolution of x (n) and h (n). Which Fourier transform property does it follow? （ ）
A:Time Shifting Theorem B:Time-Domain Convolution Theorem C:Frequency Shifting Theorem D:Frequency-Domain Convolution Theorem 6.For the following sequence types, whose Fourier transform is conjugate-symmetric? （ ）
A:a real-valued sequence B:an imaginary-valued sequence C:a complex-valued sequence D:a conjugate-symmetric sequence 7.If the DTFT of a sequency is expressed as ，then is referred to as （ ）.
A:fundamental component B:harmonic component C:direct current component D:energy 8.As for understanding on the development and role of Fourier transform，which are correct for the following statements？ （ ）
A:FFT improves the efficiency of DFT and meet the needs of real-time processing in engineering practice. B:All other options are correct. C:DFT provides a method of approximate estimation of signal spectrum by digitization. D:FT realizes the conversion of signals from time domain to frequency domain theoretically. 9.For a sequence with a period of N, its DFS is not necessarily a sequence with a period of N.（ ）
A:对 B:错 10.The Z-transform together with its ROC determines a sequence uniquely.（ ）
A:错 B:对 11.As for understanding on the physical meaning of frequency response，which are correct for the following statements？（ ）
A:The magnitude response shows that how the system affects amplitude attenuation of each frequency component in the input signal. B:The phase response shows that how the system affects time delay of each frequency component in the input signal. C:For a complex exponential input signal with single frequency, the output of an LTI system is also a complex exponential signal of the same frequency. D:For a complex exponential input signal with single frequency, the output of an LTI system is a complex exponential signal of the different frequency. 12.For the transfer function of a causal and stable system, which are correct for the following statements？（ ）
A:If the pole is located on the unit circle, then the value of magnitude frequency response of the system is equal to infinity. B:The closer the pole location approaches to the unit circle, the greater the value of magnitude frequency response of the system will be. C:The closer the pole location approaches to the unit circle, the smaller the value of magnitude frequency response of the system will be. D:If the pole is located on the unit circle, then the value of magnitude frequency response of the system is equal to zero.