B.TECH - Semester 4 digital signal processing Question Paper 2020 (sep)
Practice authentic previous year university questions for better exam preparation.
Sample Questions
- 404 : DIGITAL SIGNAL PROCESSING (AT) (2013 Scheme) Time : 3 Hours Max. Marks : 100 Answer all questions.
- $\mathrm{x}[\mathrm{n}]=[1,1,1,1]$ and $\mathrm{X}[\mathrm{K}]$ is its 4 point DFT . Given that $Y[K]=W_{4}^{2 K} X[K]$. Without computing IDFT, determine the time domain sequence $\mathrm{y}[\mathrm{n}]$.
- What you mean by in place computation in FFT method?
- State time shifting property of DFT.
- Which filter is more stable-FIR or IIR? Justify your answer.
- Write down the condition for linear phase in an FIR filter.
- What do you mean by frequency warping?
- Write down the expression for Bilinear Transformation from analog to digital domain.
- Illustrate an instance of finite word length effects in filters? P.T.O.
- Illustrate direct form realization of an FIR filter. Assume a suitable transfer function.
- Design a system in block level to directly record the audio from a system with sampling frequency 44.1 KHz to a system with sampling frequency 48 KHz . PART - B Answer any one full questions from each Module.
- (a) A signal discretized in time domain is $[1,2,3,4,1,2,3,4, \ldots$.$] For a sampling$ frequency of 100 Hz , Plot amplitude, phase and power spectra of the sequence.
- (b) The 4 pint DFT of a real sequence $x[n]$ is $X[K]=[1, j, 1,-j]$. Find DFT of the following sequences by using the properties of DFT
- (i) $=(-1)^{n} \times[n]$ (ii) $=x((n+1))_{4}$
- Find 8 point DFT of the sequence ( $1,1,1,1,1,1,1,1$ ) using radix 2 FFT method.
- (a) List the steps to be followed in designing an analog Butterworth Filter.
- (b) Design an analog Butterworth Filter that has -2 dB pass band attenuation at $20 \mathrm{rad} / \mathrm{Sec}$ and at least -10 dB stop band attenuation at $30 \mathrm{rad} / \mathrm{Sec}$.
- (a) Prove that a stable analog filter will be mapped to a stable digital filter through impulse invariant transformation.
- (b) Design a third order Butterworth digital filter using impulse invariance method. Given that $H(s)=2 /(s+1)(s+2)$ and $T=1 \mathrm{sec}$.
- (a) Consider an IIR system $y(n)=a y(n-1)+x(n)$. Let the product be quantized to 4 bits (excluding sign bit) by upward rounding and assume $\mathrm{y}^{\prime}(\mathrm{n})=0, \mathrm{n}<0, \mathrm{a}=+1 / 2 \mathrm{x}(\mathrm{n})=(15 / 16) \delta(\ma...
- (b) Obtain direct form-1 and direct form-2 realization of the filter with transfer function $\mathrm{H}(\mathrm{z})=0.5\left(1-\mathrm{Z}^{-2}\right) /\left(1+1.3 \mathrm{Z}^{-1}+0.36 \mathrm{Z}^{-2}\right)$ OR
- (a) Given that $H(z)=1+(13 / 24) Z^{-1}+(5 / 8) Z^{-2}+(1 / 3) Z^{-3}$ Determine its lattice structure.
- (b) Realize the linear phase filter having the frequency response $\mathrm{h}(\mathrm{n})=\delta(\mathrm{n})-(1 / 4) \delta(\mathrm{n}-1)+(1 / 2) \delta(\mathrm{n}-2)+(1 / 2) \delta(\mathrm{n}-3)-(1 / 4) \delta(\mathrm{n}-4) +\delta(\mathrm{n}-5)$.
- Design a three stage decimator where input sampling frequency is $96 \mathrm{KH}_{\mathrm{Z}}$ and output is 1 KHz . The highest frequency of interest after decimation is 450 Hz . Assume an optimal FIR filter with $\delta_{p}=0.01$ and $\delta_{s}=0....
- With neat figures, explain the architecture of TMS320C6713 processor.