Accession Number : ADA264208


Title :   Scientific and Engineering Studies, Compiled 1989. Signal Processing Studies


Corporate Author : NAVAL UNDERWATER SYSTEMS CENTER NEW LONDON CT


Personal Author(s) : Nuttall, A H


Full Text : https://apps.dtic.mil/dtic/tr/fulltext/u2/a264208.pdf


Report Date : Jan 1989


Pagination or Media Count : 532


Abstract : The properties and behavior of the Wigner Distribution Function (WDF) are investigated both analytical and by means of a number of simple informative examples. The lack of local temporal averaging when obtaining the instantaneous correlation function, and the lack of weighting the longer delay values when transforming to the instantaneous spectrum are shown to be the causes of the deleterious interference effects that are Inherent to the WDF. The equivalence of short-term spectral estimation to the smoothed WDF offers an attractive alternative with guaranteed positive distribution values and no interference effects. The performance of a processor which estimates the WDF of a signal waveform in the presence of additive noise is investigated in terms of the output mean, bias, and variance. Dependence on filtering the input and time- weighting is allowed and included in the analysis. Numerical application to a particular example is carried out.


Descriptors :   *SIGNAL PROCESSING , *CORRELATION , *DISTRIBUTION FUNCTIONS , *UNDERWATER COMMUNICATIONS , *STATISTICAL ANALYSIS , INPUT , OUTPUT , SIGNALS , DELAY , MEAN , FILTRATION , BIAS , NOISE , BEHAVIOR , INTERFERENCE , WAVEFORMS , ESTIMATES , TIME


Subject Categories : Physical and Dynamic Oceanography
      Statistics and Probability
      Non-radio Communications


Distribution Statement : APPROVED FOR PUBLIC RELEASE