Osmania University (OU) 2006-2nd Sem B.E Electronics & Tele-Communication Engineering 3/4 (E.C.E)(ESTER)SUPPLEMENTARY ,emr, Digital signal processing - Question Paper
B.E 3/4 (E.C.E)(II-SEMESTER)SUPPLEMENTARY EXAMINATION,December,2006
Digital signal processing ..........Jj 1 a fl n *\ *-------
M V S R Engg. CoHtgfc Code No. 11328
HYDERABAD
B.E. 3/4 (ECE) II -Semester Supplementary Examination, December 2006
Subject : Digital Signal Processing
Time: 3 Hours Max. Marks: 75
Note :Answer all questions of Part-A and answer any five questions from Part-B.
Part-A (25 Marks)
1. State the conditions for a system to be stable and causal.
2. Sketch the ROC of the signal.
x (n) *2" u(n) + 3n u (-n-1)
3. Find whether the signal x(n) Sin 3n Is periodic or not. If periodic, find the period.
4. The discrete frequency response of a digital filter is periodic. Is it correct. Justify.
5. Match the following: LIBRARY
M 8 R Engg. CollectTime Signal Its Spectrum HYDERABAD
a) continuous and periodic 1) continuous and periodic
b) discrete and periodic 2) continuous and periodic
c) discrete and aperiodic 3) discrete and periodic
4) discrete and aperiodic
6. Draw the two point Butterfly diagram for the DIF FFT algorithm.
7. Why Gibbs oscillations are developed in rectangular window and how they can be reduced.
8. Match the following :
Window Width of transition band
a) Rectangular 1) 12IT / N
b) Hamming 2) 4111N
c) Blackman 3) 811 / N
9. HR filters can have linear phase characteristics. Is it true. Justify.
10. Sketch tine mapping between S-Plane and Z-Plane under impulse invariant method.
Part -B (50 Marks)
11 .(a) Discuss the merits and demerits of digital fitters over analog filters.
(b) Check whether the following systems are linear, time invariant and stable.
(i) y(n)-x(n2) (ii) y(n) = Ex(k)
12.(a) Sketch the frequency response of the system
y (o) -y (n-l) + 0.24 y (n-2) = 5x(n).
(b) Explain the overlap add method to convolve an infinite sequence with a finite sequence.
13.(a) State and prove the symmetry properties of DFT.
(b) Find the DFT of the sequence x (n), where
(2", osns3 x (n)-n-2n, 4 s ns 7 1 0, otherwise
'A i. '* ",
14.(a) Explain toe DIF FFT algorithm with necessary signal flow graphs for an 8-point sequence.
(b) Hence calculate the DFT Coefficients of the sequence
x (n) [2,3,4,5,4,3,2).
15.(a) effects.
(b) Design a linear phase FIR filter of length 11 to meet the following characteristics.
Cutoff frequency = 100 Hz. Use Hamming Window. ART
Assume suitable sampling frequency WeSti?*
16. (a) Compare FIR and HR filters.
(b) Design a digital tow pass fitter wrtHJ-dB cutoff frequency at 1KHz and an attenuation of atleast 15dB for frequencies larger than iOKHz.
17. (a) Explain the various applications of DSP to speech.
(b) Explain the short time spectrum analysis technique to process the speech signals.
(c) Discuss the merits and demerits of tills method.
|
Attachment: |
| Earning: Approval pending. |
