Power Spectrum Estimation

Perhaps one of the more important application areas of digital signal processing (DSP) is the power spectral estimation of periodic and random signals. Speech recognition problems use spectrum analysis as a preliminary measurement to perform speech bandwidth reduction and further acoustic processing. Sonar systems use sophisticated spectrum analysis to locate submarines and surface vessels. Spectral measurements in radar are used to obtain target location and velocity information. The vast variety of measurements spectrum analysis encompasses is perhaps limitless and it will thus be the intent of this article to provide a brief and fundamental introduction to the concepts of power spectral estimation. Since the estimation of power spectra is statistically based and covers a variety of digital signal processing concepts, this article attempts to provide sufficient background through its contents and appendices to allow the discussion to flow void of discontinuities. For those familiar with the preliminary background and seeking a quick introduction into spectral estimation, skipping to Sections 6.0 through 11.0 should suffice to fill their need. Finally, engineers seeking a more rigorous development and newer techniques of measuring power spectra should consult the excellent references listed in Appendix D and current technical society publications.