Reg. No. :

B.E./B.Tech. DEGREE EXAMINATION, NOVEMBER/DECEMBER 2011.

Fifth Semester

Electrical and Electronics Engineering

EC 2314 — DIGITAL SIGNAL PROCESSING

(Regulation 2008)

Time : Three hours Maximum : 100 marks

Answer ALL questions.

PART A — (10 × 2 = 20 marks)

1. What is a linear time invariant system?

2. State sampling theorem.

3. What is meant by ROC in z-transforms?

4. Write the commutative and distributive properties of convolution.

5. Draw the basic butterfly diagram for Radix 2 DITFFT.

6. Write the DTFT for (a) )()( nuanx n= (b) )1(3)(4)( −== nnnx δδ .

7. What is meant by linear phase response of a filter?

8. Compare bilinear transformation and Impulse invariant method of IIR

filter design.

9. Give the special features of DSP processors.

10. What is pipelining?

Question Paper Code : 66288

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66288 2

PART B — (5 × 16 = 80 marks)

11. (a) (i) Discuss whether the following are energy or power signals

(1) )(2

3)( nunx

n

=

(2) njw

Aenx 0)( = . (10)

(ii) Explain the concept of quantization. (6)

Or

(b) Check whether following are linear, time invariant, causal and stable.

(i) )1()()( ++= nnxnxny . (8)

(ii) )(cos)( nxny = . (8)

12. (a) (i) Obtain the linear convolution of

}2,1,2,3{)( =nx ↑

= }2,1,2,1{)(nh . (6)

(ii) A discrete time system is described by the following equation :

)1(2

1)()1(

4

1)( −+=−+ nxnxnyny

Determine its impulse response. (10)

Or

(b) (i) Obtain the discrete Fourier series coefficients of nwnx 0cos)( = .(4)

(ii) Determine )(nx for the given )2(x with ROC

(1) 2|| >z

(2) 2|| <z

21

1

231

31)(

−−

−

++

+=

zz

zzX . (12)

13. (a) (i) Explain 8 pt DIFFFT algorithm with signal flow diagram. (10)

(ii) Compute the DFT of }0,0,1,1{)( =nx . (6)

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66288 3

(b) (i) Describe the following properties of DFT.

(1) Time reversal

(2) Circular convolution. (10)

(ii) Obtain the circular convolution of

}1,2,2,1{)](1 =nx }1,3,2,1{)(2 =nx . (6)

14. (a) Design a butterworth filter using the Impulse invariance method for

the following specifications.

ππ

π

≤≤≤

≤≤≤≤

weH

WeH

jw

jw

6.02.0)(

2.001)(8.0

Or

(b) Design a filter with desired frequency response

ππ

ππ

≤≤=

≤≤−

= −

||4

3for0

4

3

4

3for)( 3

w

weeHd wjjw

Use Hanning window for 7=N .

15. (a) Explain the addressing modes of a DSP processor.

Or

(b) Describe the Architectural details of a DSP processor.

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