Thapar University 2006 B.Tech Electronics and Communications Engineering DIGITAL SIGNAL PROCESSING - Question Paper
Thapar Institute of Engineering & Technology
B.Tech ECE (4thYear)
Final Term exam
EC011 (DIGITAL SIGNAL PROCESSING)
THAPAR INSTITUTE OF ENGINEERING & TECHNOLOGY, PATIALA Electronics and Communication Engineering Department END Semester Examination BE (ECE and EIC) Final Year EC- 011 (Digital Signal Processing)
Max Marks: 72 Instructor: Dr. Kulbir Singh Time allowed: 3Hrs
NOTE : 1. Attempt any FIVE questions.
2. Assume missing data, if any, appropriately.
3. All parts of a question must be done at one place.
4. OVER ATTEMPTED QUESTIONS WILL NOT BE EVALUATED.
1 |
a) |
Determine the response of the LTI system y(n)=5 y(n-l) - y(n-2) + 6 x(n) to the input signal x(n)= 5 (n) - 0.2 S (n-1). |
6 |
b) |
Comment upon the linearity, causality, stability and time invariance propert of the discrete time system and jutify your answer i) y(n) - x(2n) ii) y(n) = x(-n+2) iii) y(n) = x(n) u(n) |
6 | |
c) |
Explain the concept of frequency in continuous and discrete time domain. |
2.4 | |
2 |
a) |
Find the Z-transform of the following: i) x(n) = n2u(n) ii) x(n) = nanu(n) -1 < a <1 iii) x(n) = (l/2)n [u(n)-u(n-10)] |
6 |
b) |
Find the inverse Z-transform of the following: ,>*<- lose-;") - O.SX Hi) X(z). z'+2z" z2 - z + 0.3561 |
6 | |
c) |
Explain the requirement of Region of Convergence (ROC) in Z-transform. |
2.4 | |
3 |
a) |
Calculate the linear convolution, circular convolution, auto correlation and cross correlation of the sequences x(n) = [1,2,3,4] and h(n) = [ 1,2,1,1]. |
6 |
b) |
Compute the 8-point DFT of Hanning window using radix-2 DIT algorithm with the help of neat sketch. |
6 | |
c) |
List the properties of Discrete Fourier transform. |
2.4 | |
4 |
a) |
A filter function h(n)= [2 ,1 ,0,1] is given and it is desired to filter a long data sequence x(n)= [ 1,2, 4, 6, 5, 3,4, 2, 1, 3, 5, 7, 5, 3, 2, 1, 3, 4, 5, 6, 5, 4.......]. Calculate the output of the filter for the given filter function using a method of filtering oflong data sequences. |
6 |
b) |
Using Divide and conquer approach calculate the discrete Fourier transform of signal x(n)=[ 1,2, 1,2, 1,1, 1,1, 0,1, 0,1, 1,2, 3,4] |
6 | |
c) |
What is alias frequency? Explain with suitable example. |
2.4 |
5 |
0 |
Obtain the coefficients of a linear phase FIR filter to meet the specifications given below using the window method. Stopband attenuation 41 dB Passband ripple 0.01 dB Transition width 5 kHz Sampling frcqucncy 100 kHz Ideal cutoff frequency 12 kHz |
6 |
b) |
Using pole-zero placement method, obtain the transfer function, realization and the difference equation of a digital notch filter that meets the following specifications: Notch frequency 50 IIz 3 dB width of notch 5 Hz Sampling Frequency 500 Hz |
6 | |
c) |
Differentiate FIR and HR filters. |
2.4 | |
6 |
a) |
A requirement exists to simulate in a digital computer an analog system with the following normalized characteristics: ms)=- S +S+ 1 Obtain a suitable transfer function using the impulse invariant method. Assume a sampling frequency of 10 kHz and a 3 dB cutoff frequency of 1.5 kHz. | |
*>) |
Determine, using BZT method the transfer function and difference equation for the digital equivalent of resistance- capacitance (RC) filter shown in figure below. Assume a sampling frequency of 150 Hz and cut off of 30 Hz. O o----WV--J-------)(i) Tc |
6 | |
c) |
Discuss the design of an FIR filter using Kaiser window. Also give the required equations. |
2.4 | |
7 |
a) |
Explain in detail the process of conversion of an analog signal to digital signal. |
6 |
b) |
Discuss Butterworth, Chebyshev and Elliptical Filter approximations in detail. |
6 | |
c) |
List various applications of DSP and discuss any one of them in detail with neat sketch. |
2.4 |
Attachment: |
Earning: Approval pending. |