# PTU B.Tech Automation Robotics ECE-EIE 6th Semester May 2019 71164 DIGITAL SIGNAL PROCESSING Question Papers

PTU Punjab Technical University B-Tech May 2019 Question Papers 6th Semester Automation Robotics ECE-EIE

Roll No.
Total No. of Pages : 03
Total No. of Questions : 09
B.Tech.(Electronics & Computer Engg.) (2011 Onwards) (Sem.?6)
DIGITAL SIGNAL PROCESSING
Subject Code : BTEC-502
M.Code : 71164
Time : 3 Hrs. Max. Marks : 60
INSTRUCTIONS TO CANDIDATES :
1.
SECTION-A is COMPULSORY consisting of TEN questions carrying T WO marks
each.
2.
SECTION-B contains FIVE questions carrying FIVE marks each and students
have to attempt any FOUR questions.
3.
SECTION-C contains T HREE questions carrying T EN marks each and students
have to attempt any T WO questions.

SECTION-A
1

a) What are the advantages of digitial signal processing?
n
1

b) Calculate DTFT of the sequence x (n)
U (n 2).

3

c) What is the z-transform of the sequence x(n) = A (n ? m + p), where n, m and p are
integers?

d) Match the following for the window functions.

Window function
Peak of the sidelobe

Rectangular
-58dB

Hamming
-32dB

Hanning
-43dB

Bartlett
-27dB

Blackman
-13dB
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e) Define infinite impulse response and finite impulse response filters and compare.

f) What are the limitations of impulse invariant method ?

g) What is frequency warping? How it will arise?

h) Find the frequency response of a rectangular window.

i) What are the advantages of DSP processors over conventional processors?

j) List the status register bits of TMS320C5X and their functions.

SECTION-B
2.
An FIR filter has the unit impulse response sequence h (n) = {1, ?3, 1}. Determine the
output sequence in response to the input sequence x (n) = {1, 3, 4, ?7, ?1, 1, 4, ?5, 4, 2,
?9, 3, 4} using overlap add method.
3.
Determine the 8-point DFT of the signal x (n) = {1 1 1 1 1 1}.
4.
Determine the z-transform of the following sequences :
n 1

1 1

a) x(n)
n
U (n 1)

2 3

b) x (n) = ? nU(?n ?3)
6

7
z
z
5.
Determine the causal signal x(n) if its z-transform X(z) is given by X(z)
.
1
1 z
6.
A low-pass filter is to be designed with the following desired frequency response :
2 jw

e
,
for
w

4
4
Hd(ejw)

0,
for
| w |

4

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Determine the filter coefficients h (n) if the window function is defined as :
1,
0 n 4
(
w n)

0,
otherwise

SECTION-C
7.
Consider an FIR filter with system function

(z) = 1 + 2.88z?1 + 3.4048 z?2 + 1.74 z?3 + 0.4 z?4

Sketch the direct-form and lattice realizations of the filter and determine in detail the
corresponding input-output equations.
8.
a) What is bilinear transformation technique? Obtain the mapping formula and discuss
the stability for this transformation technique.

b) Transform the analog filter with the transfer function H(s) into a digital filter using
backward difference for the derivative technique.
1
H(s) =

(s 2) (s 3)
9.
Write short notes on :

a) Goertzel algorithm

b) Region of convergence

c) Effect of round off noise in digital filters

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