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- Advanced Digital Signal Processing - ADSP
- 2018
- PYQ
**Biju Patnaik University of Technology BPUT - BPUT**- Electrical Engineering
- B.Tech
**233 Views**- 3 Offline Downloads
- Uploaded 1 year ago

Registration No: Total Number of Pages: 02 B.Tech PEE6J005 6th Semester Regular Examination 2017-18 Advanced Digital Signal Processing BRANCH: Electrical Time: 3 Hours Max Marks: 100 Q.CODE: C434 Answer Part-A which is compulsory and any four from Part-B. The figures in the right hand margin indicate marks. Q1 a) b) c) d) e) f) g) h) i) j) Q2 a) b) c) d) e) f) g) h) i) j) Part – A (Answer all the questions) Answer the following questions: multiple type or dash fill up type Down-sampling is a _________ process. (time-variant/ time-invariant) Multistage implementation of sampling rate conversion ______ the efficiency of the conversion. The noise whitening filter for generating the innovation process for an autoregressive process input is _______ filter (all-pole /all-zero). Welch method is ____method of power spectrum estimation. Levinson-Durbin algorithm is for solving _________. The power density spectrum estimate is better is its variance is _____. A delay of k samples is equivalent to a phase shift of ____. ______ is the maximum frequency that can be uniquely represented at a sampling rate Fs=40 Hz. Convolution of ( ) with ( ) smoothens spectrum of ( ), provided the spectrum of ( ) is _____ compared to ( ). An adaptive linear combiner with 3-weights has a error surface plot of____ dimensions. Answer the following questions: Short answer type Define Wide-sense stationary process. Give the block-diagram representation for down-sampling by a factor D. Mention the frequency response of the filter used. What is a noise whitening filter ? Give the difference equation for an AR process. What is leakage in the context of energy density spectrum estimate? Give the weight updation rule for LMS algorithm, explaining each of the terms in the expression. What is meant by Wold representation of a stationary random process? Explain the terms convergence and stability in reference to an optimisation algorithm. Cite two disadvantages of Least Mean Square algorithm. Justify the words “adaptive” and “linear” in Adaptive Linear Combiner. (2 x 10) (2 x 10)

Part – B (Answer any four questions) Q3 a) Given a signal ( ) ↔ ( ) , such that ( ) = 0 for | | > . The signal is decimated by a factor D=2 to get ( ). Sketch ( ) and ( ) , and justify whether ( ) can be reconstructed from the signal ( ) or not. b) What do you understand by integer-band-positioned discrete time signals? Explain with spectral diagrams, the effect of down-sampling on an even-band-positioned bandpass signal. (10) (5) Q4 a) Explain sub-band coding of speech signal with proper block diagram. b) What do you mean by uniform analysis filer bank? Give the expressions for impulse response, frequency response and system function of such a filter. Draw the frequency response of a 4-component analysis filer bank. (10) (5) Q5 a) Derive the time-domain expression for the output of Forward Linear Prediction Error filter and draw the direct form-1 structure for the filter. Explain what Normal Equations are in reference to this error function expression. b) What is the relationship between Forward Linear Prediction Error Filter system function ( ) and Backward Linear Prediction Error Filter system function ( ) . Determine the reflection coefficients { } of the lattice filter corresponding to the FIR filter described by the system function : 1 H (z) A 2 (z) 1 2 z 1 z 2 3 (10) Q6 a) Discuss Welch method for power spectrum estimation as an modified form of Bartlett method. b) Prove that periodogram is not a consistent estimate of the true power density spectrum. (10) Q7 a) Differentiate between direct method and indirect method of energy density spectrum estimation. Explain the leakage problem encountered in the computation of energy density spectrum from a finite-duration signal. b) Explain the Bartlett method of power spectrum estimation with supporting mathematical expressions. (10) Q8 a) What do you understand by noise cancellation? Explain adaptive noise cancellation with block diagram and supporting mathematical expressions. b) Define mean square error for an adaptive linear combiner. Hence derive the Wiener- Hopf equation for optimum filter coefficients for the same. (10) Q9 a) Derive the relationship between the autocorrelation function ( ) and the filter parameters, if the power spectral density of the stationary random process ( ) is a rational function, and the filter generates the random process by filtering the white noise sequence ( ). b) Explain rational power spectra for a stationary random process. Also explain the three specific cases of rational power spectra? Write the difference equation for each of them. (10) (5) (5) (5) (5) (5)

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