Download GTU BE/B.Tech 2018 Winter 7th Sem Old 171704 Digital Signals And Systems Question Paper

Download GTU (Gujarat Technological University) BE/BTech (Bachelor of Engineering / Bachelor of Technology) 2018 Winter 7th Sem Old 171704 Digital Signals And Systems Previous Question Paper

1
Seat No.: ________ Enrolment No.___________

GUJARAT TECHNOLOGICAL UNIVERSITY

BE - SEMESTER ?VII (OLD) EXAMINATION ? WINTER 2018
Subject Code: 171704 Date: 29/11/2018

Subject Name: Digital Signals & Systems

Time: 10:30 AM TO 01:00 PM Total Marks: 70

Instructions:

1. Attempt all questions.

2. Make suitable assumptions wherever necessary.

3. Figures to the right indicate full marks.

Q.1 (a) What do you understand by aliasing? How will you control aliasing? 07
(b) What do you mean by sampling process? State the sampling theorem and explain
the concept of sampling.
07

Q.2 (a) Define periodic signal and fundamental period and Determine the signal
X(t) = 2 cos (6?t ? ?/3) + 4 sin (10 ?t) is periodic ? If so find its fundamental
period.
07
(b) For a given
(i) x(n
2
)
(ii) x(2n + 5)
(iii) nx(n)
discrete time systems, check whether they are: (1) Static or dynamic (2) Linear
or non-linear (3)Shift invariant or shift-varying (4)Causal or non-causal (5)
Stable or unstable.
07
OR
(b) Find homogeneous solution of a given system difference equation:
y(n) ? 3y(n-1) ? 4y(n-2) = x(n)
y(-1) = 5 ; y(-2) = 0
07

Q.3 (a) Find the Z transform of x(n)=n
2
u(n) by the help of differentiation property. 07
(b) List out properties of z transform. 07
OR
Q.3 (a) Draw and explain block diagram of DSP. 07
(b) Explain Low pass and High pass filter. 07

Q.4 (a)
Obtain the linear convolution by graphical method of following sequences.
x(n) = {1, 4, 3, 2, 1} and h(n) = { 1,2,1,2,1}
07
(b) Compute the cross-correlation between x(n) = {1,2,3,4} and y(n) = {1,2,1,2} 07
OR
Q.4 (a)
Draw parallel realization of IIR filter having transfer function
H(Z) = (1 ? Z
-1
)/(1 ? 0.2Z
-1
? 0.15Z
-2
)
07
(b) Explain direct form ?I and direct form ?II structure of IIR filter. 07




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1
Seat No.: ________ Enrolment No.___________

GUJARAT TECHNOLOGICAL UNIVERSITY

BE - SEMESTER ?VII (OLD) EXAMINATION ? WINTER 2018
Subject Code: 171704 Date: 29/11/2018

Subject Name: Digital Signals & Systems

Time: 10:30 AM TO 01:00 PM Total Marks: 70

Instructions:

1. Attempt all questions.

2. Make suitable assumptions wherever necessary.

3. Figures to the right indicate full marks.

Q.1 (a) What do you understand by aliasing? How will you control aliasing? 07
(b) What do you mean by sampling process? State the sampling theorem and explain
the concept of sampling.
07

Q.2 (a) Define periodic signal and fundamental period and Determine the signal
X(t) = 2 cos (6?t ? ?/3) + 4 sin (10 ?t) is periodic ? If so find its fundamental
period.
07
(b) For a given
(i) x(n
2
)
(ii) x(2n + 5)
(iii) nx(n)
discrete time systems, check whether they are: (1) Static or dynamic (2) Linear
or non-linear (3)Shift invariant or shift-varying (4)Causal or non-causal (5)
Stable or unstable.
07
OR
(b) Find homogeneous solution of a given system difference equation:
y(n) ? 3y(n-1) ? 4y(n-2) = x(n)
y(-1) = 5 ; y(-2) = 0
07

Q.3 (a) Find the Z transform of x(n)=n
2
u(n) by the help of differentiation property. 07
(b) List out properties of z transform. 07
OR
Q.3 (a) Draw and explain block diagram of DSP. 07
(b) Explain Low pass and High pass filter. 07

Q.4 (a)
Obtain the linear convolution by graphical method of following sequences.
x(n) = {1, 4, 3, 2, 1} and h(n) = { 1,2,1,2,1}
07
(b) Compute the cross-correlation between x(n) = {1,2,3,4} and y(n) = {1,2,1,2} 07
OR
Q.4 (a)
Draw parallel realization of IIR filter having transfer function
H(Z) = (1 ? Z
-1
)/(1 ? 0.2Z
-1
? 0.15Z
-2
)
07
(b) Explain direct form ?I and direct form ?II structure of IIR filter. 07




2

Q.5 (a) Compute 4 point DFT of x(n) = {1,2,3,4} 07
(b) List out properties of DFT. 07
OR
Q.5 (a) Explain forward DCT with necessary equations 07
(b) Explain lattice structure of FIR filter 07


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