DSP Lab - viva questions

DSP Lab - viva questions

1.            What is MATLAB?

2.            What are the applications of MATLAB?

3.            State sampling theorem.

4.            What is meant by Nyquist rate and Nyquist criteria?

5.            Explain scaling and superposition properties of a system.

6.            What is meant by linearity of a system and how it is related to scaling and superposition?

7.            What is impulse function?

8.            What is meant by impulse response?

9.            What is energy signal? How to calculate energy of a signal?

10.        What is power signal? How to calculate power of a signal?

11.        Differentiate between even and odd signals.

12.        Explain time invariance property of a system with an example.

13.        What is memory less system?

14.        When a system is said to have memory?

15.        What is meant by causality?

16.        Explain linear convolution and circular convolution.

17.        What is the length of linear and circular convolutions if the two sequences are having the length n1 and n2?

18.        What are Fourier series and Fourier transform?

19.        What are the advantages and special applications of Fourier transform, Fourier series, Z transform and Laplace transform?

20.        Differentiate between DTFT and DFT. Why it is advantageous to use DFT in computers rather than DTFT?

In DTFT, frequency appears to be continuous. But, in DFT, frequency is discrete. This property is useful for computation in computers.

21.        How to perform linear convolution using circular convolution?

If two signals x (n) and y (n) are of length n1 and n2, then the linear convoluted output z (n) is of length n1+n2-1. Each of the input signals is padded with zeros to make it of length n1+n2-1. Then circular convolution is done on zero padded sequences to get the linear convolution of original input sequences x (n) and y (n).

22.        What is meant by correlation?

Correlation is the measure of similarity between two signal/waveforms. It compares the waveforms at different time instants.

23.        What is auto-correlation?

It is a measure of similarity of similarity of a signal/waveform with itself.

24.         What is cross-correlation?

25.        What are the advantages of using autocorrelation and cross correlation properties in signal processing fields?

26.        How auto-correlation can be used to detect the presence of noise?

27.        Differentiate between IIR filters and FIR filters.

28.        What is the procedure to design a digital Butterworth filter?

29.        What is the difference between Butterworth, Chebyshev I and Chebyshev II filters?

30.        What are difference equations and differential equations?

31.        What is non real time processing?

32.        What is meant by real time processing?

• Ability to collect, analyze, and modify signals in real-time
• Real-Time:  As these signals are occurring
• We can analyze and process signals while collecting them, not at a later time.

33.        What is a Digital Signal Processor (DSP)?

Microprocessor specifically designed to perform fast DSP operations (e.g., Fast Fourier Transforms, inner products, Multiply & Accumulate)

• Good at arithmetic operations (multiplication/division)
• Mostly programmed with Assembly and C through Integrated Development Environment (IDE)

34.        Differentiate between RISC and CISC architectures.

RISC	Emphasis on software	Single-clock, reduced instruction only	large code size	Better C compilers
CISC	Emphasis on hardware	Includes multi-clock complex instructions	Small code sizes	Poor C compilers

35.        Differentiate between General purpose MPU(Micro Processor Unit) and DSP Processor

MPU are built for a range of general-purpose functions such as:

Data manipulation

Math calculations

Control systems

They run large blocks of software

They are used in real-time and in unreal-time systems

DSPs are single-minded, dedicated to:

Perform mathematical calculations

Small blocks of software

Have a predictable execution time

Real-time only

Could assist a general-purpose host MPU

36.        What is pipelining?

37.        What is parallel processing?

38.        What is MAC?

39.        What is barrel shifter? Why it is advantageous to use it in DSP processor?

40.        Differentiate between floating point DSP and fixed point DSP.

41. Fixed Point/Floating Point
• fixed point processor are :

                                                              i.      cheaper

                                                            ii.      smaller

                                                          iii.      less power consuming

                                                          iv.      Harder to program

1.      Watch for errors: truncation, overflow, rounding

                                                            v.      Limited dynamic range

                                                          vi.      Used in 95% of consumer products

• floating point processors

                                                              i.      have larger accuracy

                                                            ii.      are much easier to program

                                                          iii.      can access larger memory

                                                          iv.      It is harder to create an efficient program in C on a fixed point processors than on floating point processors

42.        What is code composer studio?

43.        Explain Von-Neumann and Harvard architectures

• Von Neumann Architecture : Single memory shared by both the program instructions and data

• Harvard Architecture : Two separate memories, a program memory (PM) for instructions, and a data memory (DM) for data

44.        What are Line-in, Line-out, Mic-in, Mic-out?