Phase-difference ambiguity resolution for a single-frequency signal

Tarig Ballal*, Chris J. Bleakley

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

33 Scopus citations


In this letter, we propose a novel method to disambiguate the phase-difference of a single-frequency signal observed between a pair of spatially separated sensors, with inter-sensor spacing exceeding half the wavelength (λ/2) of the signal. We mathematically prove that, in a noiseless case, the true phase-difference can unambiguously be estimated utilizing a third collinear sensor, provided that the absolute difference between the two smaller inter-sensor spacings is less than λ/2. The performance of the method is characterized by estimating the probability of failure in noisy cases.

Original languageEnglish (US)
Pages (from-to)853-856
Number of pages4
JournalIEEE Signal Processing Letters
StatePublished - 2008
Externally publishedYes

Bibliographical note

Funding Information:
Manuscript received April 30, 2008; revised July 23, 2008. This work was supported by Science Foundation Ireland (SFI). The associate editor coordinating the review of this manuscript and approving it for publication was Prof. Yimin Zhang.


  • Phase-difference unwrapping
  • Sensor arrays
  • Time-delay estimation

ASJC Scopus subject areas

  • Signal Processing
  • Applied Mathematics
  • Electrical and Electronic Engineering


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