ISSN : 1796-2021
Volume : 2    Issue : 3    Date : May 2007

Blind CFO Estimators for OFDM/OQAM Systems With Null Subcarriers
Tilde Fusco and Mario Tanda
Page(s): 17-23
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This paper deals with the problem of blind carrier-frequency offset (CFO) estimation in OFDM
systems based on offset quadrature amplitude modulation (OFDM/OQAM) with null subcarriers.
Specifically, by assuming that the number of subcarriers is sufficiently large, the received signal is
modeled as a complex Gaussian random vector (CGRV). Since the OFDM/OQAM signal results to
be a noncircular (NC) process, by exploiting the generalized probability density function for
NC-CGRVs, the unconditional maximum likelihood (ML) algorithm for CFO estimation in non
dispersive channel is proposed. Moreover, a modified version of the unconditional ML CFO
estimator is considered. The performance of the derived algorithms, assessed via computer
simulation, is compared with that of recently proposed estimators exploiting the second-order
cyclostationarity and with the Gaussian Cramer-Rao bound.

Index Terms
Blind estimation, carrier-frequency offset, null subcarries, OFDM/OQAM systems.