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

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

Answer briefly :

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

1 | M-71164

(S2)-2073

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

2 | M-71164

(S2)-2073

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

NOTE : Disclosure of Identity by writing Mobile No. or Making of passing request on any

page of Answer Sheet will lead to UMC against the Student.

3 | M-71164

(S2)-2073

This post was last modified on 04 November 2019