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






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






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






4. 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 .






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






6. 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.






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






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






9. 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






10. Filter output sample depends on previous input samples and previous filter output samples - these filters always have a feedback component - recursive filters






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






12. Processing of signals by digital means






13. Uses multiplexing - compressions - and echo control






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






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






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






17. Involves music - speech generation - speech recognition






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






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






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






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






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






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






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






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






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






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






28. A projection onto real axis






29. 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






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






31. 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.






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






33. Radar - Sonar - Data Communication






34. 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






35. 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






36. 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






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






38. Echo Location uses: radar - sonar - _______






39. Represented mathematically by an indexed sequence of numbers






40. Imax-Imin / 2^n - 1






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






42. A phasor rotating in negative (clockwise) direction






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






44. 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.






45. 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.






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