reg. no. : question paper code : 421 421 421 - fmcet.infmcet.in/eee/ee6403_auque.pdf · 6. draw the...

Reg. No. :

B.E./B.Tech. DEGREE EXAMINATION, APRIL/MAY 2011.

Fifth Semester

Electronics and Communication Engineering

EC 2302 — DIGITAL SIGNAL PROCESSING

(Common to PTEC 2302 Digital Signal Processing for B.E. (Part-Time) Electronics and Communication Engineering Fourth Semester – Regulation

2009)

(Regulation 2008)

Time : Three hours Maximum : 100 marks

Answer ALL questions.

PART A — (10 × 2 = 20 marks)

1. State the advantages of FFT over DFTs.

2. What is meant by bit reversal?

3. Why do we go for analog approximation to design a digital filter?

4. Give any two properties of chebyshev filters.

5. State the properties of FIR filters.

6. What is meant by Gibbs Phenomenon?

7. What is meant by fixed point arithmetic? Give example.

8. Explain the meaning of limit cycle Oscillator.

9. State the various applications of DSP.

10. What is echo cancellation?

Question Paper Code : 11289

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www.Vidyarthiplus.com


11289 2

PART B — (5 × 16 = 80 marks)

11. (a) With appropriate diagrams describe

(i) overlap-save method (8)

(ii) overlap-add method. (8)

Or

(b) Explain Radix-2 DIF-FFT algorithm. Compare it with DIT-FFT algorithms. (16)

12. (a) Explain in detail butterworth filter approximation. (16)

Or

(b) Explain the bilinear transform method of IR filter design. What is warping effect? Explain the poles and zeros mapping procedure clearly. (16)

13. (a) Realize the system function ( ) 1

3

21

3

2 −

++

= zzzH by linear phase

FIR structure. (16)

Or

(b) Explain the designing of FIR filters using windows. (16)

14. (a) Explain the quantization process and errors introduced due to quantization. (16)

Or

(b) (i) Explain how reduction of product round-off error is achieved in digital filters (8)

(ii) Explain the effects of coefficient quantization in FIR filters. (8)

15. (a) (i) Explain how various sound effects can be generated with the help of DSP. (10)

(ii) State the applications of multirate signal processing. (6)

Or

(b) (i) Explain how DSP can be used for speech processing. (8)

(ii) Explain in detail about decimation and interpolation. (8)

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Reg. No. :

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

Fifth Semester

Electrical and Electronics Engineering


(Regulation 2008)



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?


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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)

Or 421 4

21 4

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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.

—————————

421 4

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Reg. No. :

B.E./B.Tech. DEGREE EXAMINATION, APRIL/MAY 2011

Fifth Semester



(Regulation 2008)


Answer ALL questions

PART A — (10 × 2 = 20 marks)

1. Define sampling theorem.

2. What is known as Aliasing?

3. What is meant by ROC?

4. Obtain the Discrete Fourier series coefficients of wnnx cos)( = .

5. What is the relation between DFT and Z transform?

6. Draw the butterfly diagram for DITFFT.

7. What are the special features of FIR filters?

8. What is meant by prewarping?

9. Mention the features of DSP processor.

10. What is the condition for linear phase in FIR filters?

PART B — (5 × 16 = 80 marks)


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11295 2

11. (a) (i) Check whether the following is linear, time invariant, casual and

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

(ii) Check whether the following are energy or power signals.

(1) )(2

1)( nunx

n

=

(2) njwAenx 0)( = . (8)

Or

(b) (i) Describe in detail the process of sampling and quantization.

Also determine the expression for quantization liner. (10)

(ii) Check whether the following are periodic

(1) )3cos()( nnx π=

(2) )3sin()( nnx = . (6)

12. (a) (i) Determine the Z transform of

(1) 0( ) cos ( )nx n a w n u n= . (5)

(2) )(3)( nunx n= . (3)

(ii) Obtain )(nx for the following :

21 52.052.11

1)(

−− +−=zX

for ROC : | | 1, | | 0.5z z> < , 1||5.0 << z . (8)

Or

(b) (i) Determine the linear convolution of the following sequences

}1,3,2,1{)(1 =nx ↑

−= }1,1,2,1{)(2 nx . (6)

(ii) Obtain the system function and impulse response of the

following system )1()()1(5)( −+=−− nxnxnyny . (10)

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11295 3

13. (a) (i) Explain the following properties of DFT.

(1) Convolution.

(2) Time shifting

(3) Conjugate Symmetry. (10)

(ii) Compute the 4 point DFT of }3,2,1,0{)( =nx . (6)

Or

(b) (i) Explain the Radix 2 DIFFFT algorithm for 8 point DFT. (8)

(ii) Obtain the 8 point DFT using DITFFT algorithm for

↑

= }1,1,1,1,1,1,1,1{)(nx . (8)

14. (a) (i) Realize the following using cascade and parallel form .

21

21

2.01.01

6.06.33)(

−−

−−

−+

++=

zz

zzzH . (12)

(ii) Explain how an analog filter maps into a digital filter in Impulse Invariant transformation. (4)

Or

(b) (i) Using Hanning window, design a filter with

ππ

ππ

≤≤=

≤≤−

= −−

||4

0

44)(

w

weeHd jzwjw

.

Assume 7=N . (12)

(ii) Write a note on need and choice on windows. (4)

15. (a) Explain in detail the architectural features of a DSP processor. (16)

Or

(b) Explain the addressing formats and functional modes of a DSP processor. (16)

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Reg. No. :

B.E./B.Tech. DEGREE EXAMINATION, NOVEMBER/DECEMBER 2010

Fifth Semester

Electronics and Communication Engineering


(Regulation 2008)

Time : Three hours Maximum : 100 Marks


PART A — (10 × 2 = 20 Marks)

1. Obtain the circular convolution of the following sequences ( ) { }1,2,1=nx ;

( ) { }2,2,1 −=nh .

2. How many multiplications and additions are required to compute N-point

DFT using radix-2 FFT?

3. What is prewarping?

4. What is the advantage of direct form II realization when compared to direct

form I realization?

5. Give the equations for Hamming window and Blackman window.

6. Determine the transversal structure of the system function

( ) 321 4321 −−− −−+= zzzzH

7. What is truncation?

8. What is product quantization error?

9. What is decimation?

10. What is sub band coding?


53123 2

PART B — (5 × 16 = 80 Marks)

11. (a) (i) Compute the eight-point DFT of the sequence

( )

= 0,0,0,0,

2

1,

2

1,

2

1,

2

1nx

Using the radix-2 decimation-in-time algorithm. (10)

(ii) Explain overlap-add method for linear FIR filtering of a long

sequence. (6)

Or

(b) (i) Compute the eight-point DFT of the sequence

( ) ≤≤

=otherwise,0

70,1 nnx

By using the decimation-in-frequency FFT algorithm. (10)

(ii) Summarize the properties of DFT. (6)

12. (a) Determine the system function ( )zH of the Chebyshev’s low pass digital

filter with the specifications

dB1=pα ripple in the pass band πω 2.00 ≤≤

=sα 15 dB ripple in the stop band πωπ ≤≤3.0

using bilinear transformation (assume T= 1 sec). (16)

Or

(b) Obtain the direct form I, direct form II, cascade and parallel form

realization for the system

( ) ( ) ( ) ( ) ( ) ( )26.016.3322.011.0 −+−++−+−−= nxnxnxnynyny (16)

13. (a) Design an ideal high pass filter with a frequency response

( )

≤

≤≤=

40

41

πω

πωπ

ω

for

for

eH jd

Find the values of ( )nh for N =11 using hamming window.

Find ( )zH and determine the magnitude response. (16)

Or

53123 3

(b) (i) Determine the coefficients ( ){ }nh of a linear phase FIR filter of

length M =15 which has a symmetric unit sample response and a

frequency response that satisfies the condition (10)

=

==

7,6,5,4for,0

3,2,1,0for,1

15

2

k

kkH r

π

(ii) Obtain the linear phase realization of the system function

( ) 654321

2

1

34

1

3

1

2

1 −−−−−− +1

+++++= zzzzzzzH (6)

14. (a) Discuss in detail the errors resulting from rounding and truncation. (16)

Or

(b) Explain the limit cycle oscillations due to product round off and overflow

errors. (16)

15. (a) Explain the polyphase structure of decimator and interpolator. (16)

Or

(b) Discuss the procedure to implement digital filter bank using multirate

signal processing. (16)

—————————

REG. NO:

B.E./B.TECH. DEGREE EXAMINATION, MAY/JUNE 2012

FIFTH SEMESTER

ELECTRONICS AND COMMUNICATION ENGINEERING

EC 2302 / EC52 – DIGITAL SIGNAL PROCESSING

(REGULATION 2008)

TIME: THREE HOURS MAX: 100 MARKS

ANSWER ALL THE QUESTIONS

PART A – (10 X 2 = 20)

1. WHAT IS TWIDDLE FACTOR?

2. HOW MANY STAGES OF DECIMATIONS ARE REQUIRED IN THE CASE OF A 64 POINT RADIX

2 DIT FFT ALGORITHM?

3. WHY IS THE BUTTERWORTH RESPONSE CALLED A MAXIMALLY FLAT RESPONSE?

4. WHAT IS FREQUENCY WARPING?

5. WHAT ARE THE FEATURES OF FIR FILTER DESIGN USING THE KAISER’S APPROACH?

6. DRAW THE DIRECT FORM IMPLEMENTATION OF THE FIR SYSTEM HAVING DIFFERENCE

EQUATION.

y(n) = x(n) – 2x(n-1) + 3x(n-2) – 10x(n-6)

7. WHAT ARE LIMIT CYCLE OSCILLATIONS?

8. WHAT IS DEAD – BAND OF A FILTER?

9. WHAT IS DECIMATION?

10. FIND THE EXPRESSION FOR THE FOLLOWING MULTIRATE SYSTEMS.

PART B – (5 X 16=80)

11. (a) (i) DIFFERENTIATE DFT FROM DTFT. (4)

(ii) COMPUTE AN 8 POINT DFT OF THE SEQUENCE x(n) (1,0,1,-1,1,-1,0,1)

(12)

QUESTION PAPPER CODE: 11332

4 24 4

[OR]

(b) (i) PROVE THAT FFT ALGORITHM HELPS IN REDUCING THE NUMBER OF

COMPUTATIONS INVOLVED IN DFT COMPUTATION. (6)

(ii) COMPUTE A 8 POINT DFT OF THE SEQUENCE USING DIT – FFT ALGORITHM

X(n) =(1,2,3,2,1,0) (10)

12. (a) (i) EXPLAIN THE PROCEDURE FOR DESIGNING ANALOG FILTERS USING THE

CHEBYSHEV APPROXIMATION. (6)

(ii) CONVERT THE FOLLOWING ANALOG TRANSFER FUNCTION IN TO DIGITAL USING

IMPULSE INVARIANT MAPPING WITH T = 1 sec . (10)

[OR]

(b) (i) DESIGN A DIGITAL SECOND ORDER LOW – PASS BUTTERWORTH FILTER WITH

CUT-OFF FREQUENCY 2200 Hz USING BILINEAR TRANSFORMATION . SAMPLING RATE IS

8000 Hz. (8)

(ii) DETERMINE THE CASCADE FORM AND PARALLEL FORM IMPLEMENTATION OF

THE SYSTEM GOVERNED BY THE TRANSFER FUNCTION

(1 + Z - 1)(1 – 5Z - 1 – Z - 2)

H(Z)= (1 +2Z - 1 + Z - 2)(1 + Z - 1 + Z - 2) (8)

13. (a) DESIGN AN FIR LOW PASS DIGITAL FILTER BY USING THE FREQUENCY SAMPLING

METHOD FOR THE FOLLOWING SPECIFICATIONS

CUTOFF FREQUENCY = 1500Hz

SAMPLING FREQUENCY = 15000 Hz

ORDER OF THE FILTER : N = 10

FILTER LENGTH REQUIRED L = N + 1 = 11 (16)

[OR]

(b) (i) EXPLAIN WITH NEAT SKETCH THE IMPLEMENTATION OF FIR FILTERS IN THE

(1) DIRECT FORM

(2) LATTICE FORM (6)

(ii) DESIGN A DIGITAL FIR BAND – PASS FILTER WITH LOWER CUT-OFF FREQUENCY

2000 Hz AND UPPER CUT-OFF FREQUENCY 3200 Hz USING HAMMING WINDOW OF

LENGTH N = 7. SAMPLING RATE IS 10000 Hz.

(10)

14. (a) (i) WHAT IS QUANTIZATION OF ANALOG SIGNALS? DERIVE THE EXPRESSION FOR

THE QUANTIZATION ERROR .

(ii) EXPLAIN COEFFICIENT QUANTIZATION IN IIR FILTER.

[OR]

(b) (i) HOW TO PREVENT LIMIT CYCLE OSCILLATION ? EXPLAIN.

(ii)WHAT IS MEANT BY SIGNAL SCALING? EXPLAIN.

15. (a) (i) EXPLAIN SAMPLING RATE CONVERSION BY A RATIONAL FACTOR AND DERIVE

INPUT OUTPUT RELATION IN BOTH TIME AND FREQUENCY DOMAIN.

(10)

(ii) EXPLAIN THE MULTISTAGE IMPLEMENTATION OF SAMPLING RATE

CONVERSION. (6)

[OR]

(b) (i) EXPLAIN THE DESIGN OF NARROW BAND FILTER USING SAMPLING RATE

CONVERSION. (8)

(ii) EXPLAIN THE APPLICATION OF SAMPLING RATE CONVERSION IN SUB – BAND

CODING. (8)

Reg. No. :

B.E./B.Tech. DEGREE EXAMINATION, NOVEMBER/DECEMBER 2010

Fifth Semester



(Regulation 2008)

Time : Three hours Maximum : 100 Marks


PART A — (10 × 2 = 20 Marks)

1. What are even and odd signals?

2. Define aliasing effect.

3. Mention the relation between, Z transform and Fourier transform.

4. Give any two properties of linear convolution.

5. Calculate DFT of ( ) { }2,2,1,1 −−=nx .

6. Differentiate between DIF and DIT.

7. What are the advantages of FIR filter?

8. Mention the significance of Chebyshev’s approximation.

9. Define warping.

10. What is BSAR instruction? Give an example.

Question Paper Code : 53129 4

21 4

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53129 2

PART B — (5 × 16 = 80 Marks)

11. (a) (i) What do you mean by Nyquist rate? Give its significance. (6)

(ii) Explain the classification of discrete signal. (10)

Or

(b) (i) Explain in detail the Quantization of digital signals. (8)

(ii) Describe the different types of sampling methods used. (8)

12. (a) (i) Explain the properties of Z-transform. (8)

(ii) Find the impulse response given by difference equation.

( ) ( ) ( ) ( ) ( )122413 −+=−−−− nxnxnynyny (8)

Or

(b) (i) Test the stability of given systems. (8)

(1) ( ) ( )( )nxny cos=

(2) ( ) ( )2−−= nxny

(3) ( ) ( )nxnny =

(ii) Find the convolution. (8)

( ) { }2,2,1,1 −−=↑

nx , ( ) { }75.0,2,1,1,5.0 −=↑

nh

13. (a) An 8-point sequence is given by ( ) { },1,1,1,1,2,2,2,2=nx . Compute

8-point DFT of ( )nx by radix DIT--FFT method also sketch the

magnitude and phase. (16)

Or

(b) Determine the response of LTI system when the input sequence is

( ) { }1,1,2,1,1 −−=nx using radix 2 DIF FFT. The impulse response is

( ) { }1,1,1,1 −−=nh . (16)

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53129 3

14. (a) Design a low pass filter using rectangular window by taking I samples of

( )nω with cut off sequence of 1.2 radians/sec also draw the filter. (16)

Or

(b) The specification of defined low pass filter is :

( )

( ) πωπω

πωω

≤≤≤

≤≤≤≤

32.0;2.0

2.00;0.18.0

H

H

Design Chebyshev’s digital filter using bilinear transformation. (16)

15. (a) (i) With a neat diagram explain Von-Neumann architecture. (8)

(ii) What is MAC unit? Explain its functions. (8)

Or

(b) Explain the architecture of TMS320C50 with a neat diagram. (16)

–––––––––––––

421 4

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www.cset

ube.

in

www.csetube.in

www.csetube.in

http://www.csetube.in/



http://www.csetube.in

Reg. No. :

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

Fifth Semester



(Regulation 2008)



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?


421 4

21 4

21



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)

Or 421 4

21 4

21



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.

—————————

421 4

21 4

21



reg. no. : question paper code : 421 421 421 - fmcet.infmcet.in/eee/ee6403_auque.pdf · 6. draw the...

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