A Second Order Statistics Based Algorithm for Blind Recognition of OFDM Based Systems

An opportunistic radio is a radio able to detect the spectrum unused bands, and to adapt its transmission parameters in order to transmit within these free bands. An opportunistic terminal has also to be able to detect opportunistic access points and to recognize their used standards. As most standards are now based on OFDM modulation with distinct intercarrier spacing, this parameter can be estimated to build standard recognition algorithm. We hence propose in this paper an algorithm for blind estimation of the intercarrier spacing of an OFDM modulation based on the second order statistics of the received signal. The algorithm construction is explained in detail. Some theoretical results are derived and numerical simulations show the gain in regard to the state of art methods.