Test your basic knowledge |

DSP: Digital Signal Processing

Subject : it-skills
Instructions:
  • Answer 46 questions in 15 minutes.
  • If you are not ready to take this test, you can study here.
  • Match each statement with the correct term.
  • Don't refresh. All questions and answers are randomly picked and ordered every time you load a test.

This is a study tool. The 3 wrong answers for each question are randomly chosen from answers to other questions. So, you might find at times the answers obvious, but you will see it re-enforces your understanding as you take the test each time.
1. Filter output sample depends on previous input samples and previous filter output samples - these filters always have a feedback component - recursive filters






2. States any periodic waveform can be approximated by a sum of harmonically related sinusoids






3. A formal mathematical operation - takes two signals and produces a third signal






4. Processing involves improving quality a signal- e.g. image enhancement - data compressions - noise reduction - ________ - filtering - etc.






5. A phasor rotating in negative (clockwise) direction






6. Uses a relatively low frequency message signal to modulate or vary the frequency of a relatively high frequency carrier signal






7. The negative half cycle of the function waveform is the same shape as the positive half - except inverted - Both sine and cosine functions have this - Functions with this have only odd harmonics.






8. Equivalent to the principle of superposition - if the input is the sum of two or more scaled sequences - we can find the output of each sequence acting alone - then add (superimpose) the separate scaled output






9. If an input is delayed (shifted) by n0 - then the output is delayed by the same amount






10. Signal comprised of a continuous set of values; -not digital or discrete






11. Description of how one parameter is related to another - ex. voltage which varies with time is common in analog electronics






12. Varying quantity that is a function of time; time is continuous - then the value of the signal can be found at any point in time; - not discrete






13. A phenomenon of sinusoids changing frequency during sampling; sinusoid assumes a frequency other than its own






14. Uses multiplexing - compressions - and echo control






15. Imax-Imin /4*( 2^n - 1)






16. A projection onto real axis






17. For any sinusoidal signal with fundamental frequency f 0 - there exists an infinite number of ________frequencies or frequencies which are integer multiples of f 0 .






18. Processing of signals by digital means






19. A special case of amplitude modulation - When two sinusoids of different frequencies are multiplied






20. Two separate units - one for tracking targets - one for illumination of targets for weapons guidance (SAMs etc)






21. Obtained by recording the values of x(t) at equally spaced time instants - the result is a sequence of numbers whose individual values are samples of the analog signal






22. Radar - Sonar - Data Communication






23. Occur frequently in nature - sound waves - electromagnetic radiation - any type of periodic waveform can be constructed from this signal






24. Two properties lead to simplifications of mathematical analysis: - __________ - time-invariance






25. Use only the current and past input samples to calculate the current output sample; -no feedback -non recursive filters






26. Waveform is symmetrical about the origin or f(x) = -f(-x); - Sine is this function - only sine terms and no constant term.






27. Waveform is symmetrical about the vertical axis or f(x) = f(-x); - Cosine is this function - only have cosine terms and may have a constant.






28. Echo Location uses: radar - sonar - _______






29. Used in medical fields - space - commercial imaging products






30. Uses a process called the Discrete Fourier Transform or DFT - used to determine the frequency content of a continuous signal






31. Imax-Imin / 2^n - 1






32. DSP Applications: - radar and sonar - oil exploration - space exploration - _______






33. Industry Apps / Major Areas: Telecommunications - Audio Processing - ___________ - Image processing






34. Involves music - speech generation - speech recognition






35. The conversion of analog or continuous signals to digital or discrete signals - referred to as analog-to-digital conversion - value of signal is sampled at discrete time intervals; time intervals are usually uniform






36. Used for detection and tracking of underwater acoustic signals - consists of a dry end and a wet end - dry end;






37. Type of decomposition relies on the use of a function known as the delta function or unit _____function






38. Uses a signal that has been quantized into discrete values rather than a continuous signal






39. Used for two general purposes: (1) separation of signals that have been combined - and (2) restoration of signals that have been distorted in some way.






40. Controls how much the carrier frequency varies around its unmodulated value.






41. Means that sample number zero has a value of one - while all other samples have a value of zero -delta function is frequently called the unit impulse.






42. Process of multiplying a (relatively) low frequency message signal by a high frequency sinusoid






43. Graphical representation of the frequency content of a signal - allows us to quickly and easily see the relationship between different frequency components and their amplitudes






44. Measurement at regular intervals of the amplitude of a varying waveform (in order to convert it to digital form)






45. Represented mathematically by an indexed sequence of numbers






46. Refers to what we are familiar with as the signal itself - with amplitude values plotted against time values