Wednesday, October 28, 2009
DIGITAL SIGNAL PROCESSING |
PART A – (10 X 2 = 20 marks) |
1. What is meant by aliasing? How can it be avoided? |
2. Is the system y(n) =In{x9n)} is linear and time invariant? |
3. Define DFT pair.4. Differentiate b/w DIT and DIF FFT algorithms. |
5. Find the transfer function for normalized Butterworth filter of order 1 bydeterming the |
pole values. |
6. What does ‘frequency warping’ mean? 7. State the advantages of FIR filter over FIRfilter? |
8. List out the different forms of structural realizations available for realizing a FIRsystem |
9. Bring out the difference between fixed point and floating point arithmetic. |
10. How will you avoid cycle oscillations due to overflow in addition? |
PART B – (5 X 16 = 80 marks) |
11. (i) With a neat diagram , explain the analysis and synthesis part of a vocoderin detail. |
11 (ii) The system is characterized by the difference equationy(n) = 0.75 y(n1)+ 5x(n) . |
The input signal x(n) has a range of 6vto +6vrepresented by 8 bits. Find the quantization |
step signal, variance of the errorsignal, variance of the error signal and variance of the |
quantization noise at theoutput. |
12.(a) (i)Find the output response of the system given the input signal |
12.(a) (ii) Define correlation and bring out the difference between convolution |
andcorrelation. |
12.(b).(i) Determine the Ztransform of the signal. ) 1 ( ) ( ) ( - - - = n u b n u a n x n n |
b>aand plot the ROC. |
12.(b)(ii) Find the steady state value given. |
12.(b)(iii) Find the system function of the system described by y(n) = 0.75y (n1)+0.125 y |
(n2)= x (n) –x(n1)and plot the poles and zeros of H(z). |
13.(a)(i) Using DFTIDFTmethod, perform circular convolution of the twosequences x(n) = { |
1, 2, 0, 1} and h(n) = {2, 2, 1, 1 }. |
13.(a) (ii) State & prove the circular convolution property of DFT. |
13.(b)(i) Determine the number of complex Multiplications and additions involved |
inNpointRadix 2 and Radix4FFTTAlgorithm . |
13.(b)(ii) Compute the 8pointDFT of the given data sequence{ } 0 , 0 , 0 , 0 , 21 , 21 , 21 , |
21 ) ( = n x using radix 2decimation in Time FFTAlgorithm. |
14.(a) (i)Connect the analog Filter with systemfunction. [ { } 9 ) 1 . 0 ( / ) 1 . 0 ( ) ( 2 + + |
+ = S S S H a into a digital IIR filter usingimpulse invariance method.(Assume T=0.1 sec) |
14.(a) (ii) Obtain the direct form I, canonic form and parallel form realizationstructures |
for the system given by the difference equation. |
14.(b) Design and realize a digital Butterworth filter using bilinear transformation to |
meetthe following requirements.1 ) ( 707 . 0 £ £ jw e H 2 0 p w £ £2 . 0 ) ( £ jw e H p w p |
£ £ 2 3 |
15. (a) (i) Determine the filter coefficient h(n) of length M=15 obtained by sampling |
itsfrequency response as . |
15.(a)(ii) Obtain the transversal and linear phase relazation for a filter given byh(n) ={0.5, |
2.88, 3.404, 2.88, 0.5}H(z) = 0.5+2.88Z 1 |
15.(b) Design a digital filter with p p £ £ = w e H jwd 21 ) (o otherwiseusing Hamming |
Window with N=7. Draw the frequency response |
http://www.ziddu.com/download/7201563/DIGITALSIGNALPROCESSING.pdf.html