Digital Signal Processing

Inverse Systems and Deconvolution

Question 1
Marks : +2 | -2
Pass Ratio : 100%
If h(n) is the impulse response of an LTI system T and h1(n) is the impulse response of the inverse system T-1, then which of the following is true?
[h(n)*h1(n)].x(n)=x(n)
[h(n).h1(n)].x(n)=x(n)
[h(n)*h1(n)]*x(n)=x(n)
[h(n).h1(n)]*x(n)=x(n)
Explanation:
If h(n) is the impulse response of an LTI system T and h1(n) is the impulse response of the inverse system T-1, then we know that h(n)*h1(n)=δ(n)=>[h(n)*h1(n)]*x(n)=x(n).
Question 2
Marks : +2 | -2
Pass Ratio : 100%
If the frequency response of an FIR system is given as H(z)=1-5/2z-1-3/2z-2, then the system is ___________
Minimum phase
Maximum phase
Mixed phase
None of the mentioned
Explanation:
Given H(z)= 1-5/2z-1-3/2z-2
Question 3
Marks : +2 | -2
Pass Ratio : 100%
An IIR system with system function H(z)=\\(\\frac{B(z)}{A(z)}\\) is called a mixed phase if ___________
All poles and zeros are inside the unit circle
All zeros are outside the unit circle
All poles are outside the unit circle
Some, but not all of the zeros are outside the unit circle
Explanation:
For an IIR filter whose system function is defined as H(z)=\\(\\frac{B(z)}{A(z)}\\) to be said a mixed phase and if the system is stable and causal, then the poles are inside the unit circle and some, but not all of the zeros are outside the unit circle.
Question 4
Marks : +2 | -2
Pass Ratio : 100%
If the frequency response of an FIR system is given as H(z)=1-z-1-6z-2, then the system is ___________
Minimum phase
Maximum phase
Mixed phase
None of the mentioned
Explanation:
Given H(z)=1-z-1-6z-2
Question 5
Marks : +2 | -2
Pass Ratio : 100%
What is the causal inverse of the FIR system with impulse response h(n)=δ(n)-aδ(n-1)?
δ(n)-aδ(n-1)
δ(n)+aδ(n-1)
a-n
an
Explanation:
Given h(n)= δ(n)-aδ(n-1)
Question 6
Marks : +2 | -2
Pass Ratio : 100%
An IIR system with system function H(z)=\\(\\frac{B(z)}{A(z)}\\) is called a minimum phase if ___________
All poles and zeros are inside the unit circle
All zeros are outside the unit circle
All poles are outside the unit circle
All poles and zeros are outside the unit circle
Explanation:
For an IIR filter whose system function is defined as H(z)=\\(\\frac{B(z)}{A(z)}\\) to be said a minimum phase,
Question 7
Marks : +2 | -2
Pass Ratio : 100%
If a system is said to be invertible, then?
One-to-one correspondence between its input and output signals
One-to-many correspondence between its input and output signals
Many-to-one correspondence between its input and output signals
None of the mentioned
Explanation:
If we know the output of a system y(n) of a system and if we can determine the input x(n) of the system uniquely, then the system is said to be invertible. That is there should be one-to-one correspondence between the input and output signals.
Question 8
Marks : +2 | -2
Pass Ratio : 100%
What is the inverse of the system with impulse response h(n)=δ(n)-1/2δ(n-1)?
(1/2)nu(n)
-(1/2)nu(-n-1)
(1/2)nu(n) & -(1/2)nu(-n-1)
None of the mentioned
Explanation:
The system function of given system is H(z)=\\(1-\\frac{1}{2} z^{-1}\\)
Question 9
Marks : +2 | -2
Pass Ratio : 100%
What is the inverse of the system with impulse response h(n)=(1/2)nu(n)?
δ(n)+1/2 δ(n-1)
δ(n)-1/2 δ(n-1)
δ(n)-1/2 δ(n+1)
δ(n)+1/2 δ(n+1)
Explanation:
Given impulse response is h(n)=(1/2)nu(n)
Question 10
Marks : +2 | -2
Pass Ratio : 100%
If the frequency response of an FIR system is given as H(z)=6+z-1-z-2, then the system is ___________
Minimum phase
Maximum phase
Mixed phase
None of the mentioned
Explanation:
Given H(z)=6+z-1-z-2