(PDF, Unknown) - Tejas Engineers Academy
Transcription
(PDF, Unknown) - Tejas Engineers Academy
IPU/DSP/1 DSP TejasAcademy.in DIGITAL SIGNAL PROCESSING (ETIT-308) Question 1. (a) Let x n 2d n 2 d n 1 3d n d n 1 2d n 2 . Evaluate (i) X e jw w 0 (ii) p X e jw d w (iii) X e jw w 2p without explicitly finding X e jw . 6 p (b) Find the state variable matrix A,B,C,D for the input output relation given by the equation : y n 2 y n 1 3 y n 2 x n 2 x n 1 3x n 2 . 5 (c) Derive the relationship between DFT (i) Z transform (ii) Fourier Transform of a periodic sequence. 4 (d) Discuss the design of digital resonator. (e) Derive the input and output relation for a system function h(t) if the input signal x n is random. 5 5 Solution. UNIT-1 Question 2. (a) Perform the convolution of the following two sequence graphically h n 1/ 2 n 0 n 2 0 (b) ,x n d n d n 1 4d n 2 . Find the 'Z' transform the following sequence: x n 6.5 otherwise 6 n n 1/ 2 u n 2 Question 3. (a) Find the inverse 'Z' transform. (i) X z 1 1/ 4Z 1 1/ 2Z (ii) X z (b) 6 1 1 2 ,Z 2 1 1/ 4Z 1 1 5 / 6Z 1 1/ 6 Z 2 ,Z 1/ 2 Compute the DTFT of the following : (i) x n (iii) y n u n (ii) x n 3/ 4 y n 1 1/ 8 y n 2 6.5 Cosw 0 n with w 0 2p / 5. x n. UNIT-II Question 4. Tejas Engineers Academy, A premier Institute B.Tech / LEET / GATE / PSUs Contact 9999070890, 9971614745, visit TejasAcademy.in IPU/DSP/1 DSP TejasAcademy.in (a) Perform the circular convolution and linear convolution for the input sequence x1 n 1, 2,3,1, 2 , x2 1, 2,3, 4 . Discuss the result. (b) Determine the DFT of the given data sequence x n algorithm. 1, 2, 3, 4,9, 20,12,6 using DIT Question 5. (a) Prove the following properties of DFT when X k is the N point DFT: (i) If x n is real and odd. (ii) If x n is purely imaginary and odd. (b) Calculate the IDFT for the given coefficient X k {38, 5.828 j 6.07, j 6, 0.172 j8.07, j 6, 5.828 j8.07, 10, 0.172 j 6.07} using DIF structure. 6.5 UNIT-III Question 6. (a) For the following causal linear H Z H Z in form H min Z H ap Z . (i) H z (ii) H Z (b) shift invariant system factorize 1 3Z 2 1 0.5Z 1 0.75Z 5 Z 1 1 7 5Z 1 1/1Z 1 1 1 . Consider the random process X t variables i.e. E Y , Z EY E Z ySin n0t Z cos n0t Y and Z are uncorrelated random 0, with zero mean and variance s 2 . (i) Find mean of X t (ii) Auto correlation of X t . 6.5 Question 7. (a) Explain the sampling theorem in the frequency domain. Discuss the design of zero order hold circuit. 8.5 (b) Consider a linear shift invariant system with system function H Z Z 1 a* |a | 1. 1 aZ 1 (i) Find a linear difference equation to implement this system. (ii) Show that this system is an all pass system. Solution. Tejas Engineers Academy, A premier Institute B.Tech / LEET / GATE / PSUs Contact 9999070890, 9971614745, visit TejasAcademy.in IPU/DSP/1 DSP TejasAcademy.in UNIT-IV Question 8. Z2 1 realize H Z as (i) Z 1/ 2 Z 1/ 3 Z 1/ 4 parallel form (ii) cascade form (iii) cononic form. (a) Give the system transfer function H Z (b) Design the digital butter worth filter satisfying the constraint given below T=1 using bilinear transformation 1/ 2 | H e jw | 1 for 0 w p / 2 | H e jw | 0.2 for 3p / 4 w p Question 9. (a) Discuss the properties of Chebyshev polynomial. (b) Design a high pass filter where the desired frequency response is given below with t 3 and wC 2 rad/S using a window with stop band attenuation 53dB, H d e jw e jw z w C |w | p 0 otherwise Tejas Engineers Academy, A premier Institute B.Tech / LEET / GATE / PSUs Contact 9999070890, 9971614745, visit TejasAcademy.in