TU Wien:Verarbeitung Stochastischer Signale VU (Matz, Winkelbauer)/Oral exam 04.08.2016

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Written exam: 42/70 Exercise points: 43/49

Random processes: ~10 minutes:

  • Stationarity
    • Conditions (WSS: mean constant, autocorrelation function time lag only)
  • Autocorrelation function of stationary processes
    • Definition
    • Properties (even, real for real processes, maximum at origin = mean power)
  • PSD
    • Definition (Fourier transformations explicit in both directions)
    • Properties (periodic, non-negative, even & real for real processes)
    • Meaning of Power in PSD (m=0 in inverse Fourier transform)

Whitening ~10 minutes:

  • Explanation (transform into a new random variable with unit variance (covariance matrix = identity matrix)
  • Is new random variable SI? (not necessarily, unless it's Gaussian)
  • How to calculate A? (Eigenvalue decomposition)
  • Are there other ways? (infinitely many, but only a few are feasible)

Made a few minor mistakes. Written part was lower end of G2 (2-), oral on the upper end of G2 (2+)

Result -> G2