A Method For Fine Resolution Frequency Estimation From Three DFT Samples

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Candan C.

IEEE SIGNAL PROCESSING LETTERS, vol.18, no.6, pp.351-354, 2011 (SCI-Expanded) identifier identifier

  • Publication Type: Article / Article
  • Volume: 18 Issue: 6
  • Publication Date: 2011
  • Doi Number: 10.1109/lsp.2011.2136378
  • Journal Name: IEEE SIGNAL PROCESSING LETTERS
  • Journal Indexes: Science Citation Index Expanded (SCI-EXPANDED), Scopus
  • Page Numbers: pp.351-354
  • Keywords: Frequency estimation, fine doppler estimation, radar signal processing, DFT, PARAMETERS
  • Middle East Technical University Affiliated: Yes

Abstract

The parameter estimation of a complex exponential waveform observed under white noise is typically tackled in two stages. In the first stage, a coarse frequency estimate is found by the application of an N-point DFT to the input of length N. In the second stage, a fine search around the peak determined in the first stage is conducted. The method proposed in this paper presents a simpler alternative. The method suggests a nonlinear relation involving three DFT samples already calculated in the first stage to produce a real valued, fine resolution frequency estimate. The estimator approaches Jacobsen's estimator for large N and presents a bias correction which is especially important for small and medium values of N.