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Non-data-aided joint time and frequency offset estimation method for OFDM systems using channel order based regression

  • US Patent No. 9083596
  • Issued: July 14, 2015
  • Status: Active
Communications

A system and method involve receiving a plurality of samples of an orthogonal frequency division multiplex (OFDM) signal containing a complete OFDM symbol. The OFDM symbol includes data samples and a cyclic prefix comprising inter-symbol interference (ISI) samples and ISI-free samples. The ISI samples are used to limit the search region of possible symbol time offset (STO) estimates made using the ISI-free samples. This may involve determining a first cost function using the ISI-free samples and using data samples that correspond to the ISI-free samples, determining a second cost function using the ISI samples and using data samples that correspond to the ISI samples, using regression coefficients to determine a set of STOs yielding the smallest second cost function, and determining a joint estimate of STO and carrier frequency offset (CFO) by finding STO and CFO values within the set that result in minimization of the first cost function.

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