Exploiting the pilot pattern orthogonality of OFDMA signals for the estimation of base stations number of antennas

In a recent work [1, 2], we proposed a GLR (Generalized Likelihood Ratio) test dedicated to the identification of OFDM systems. In the present paper, we show that the proposed technique can be extended for the estimation of the number of antennas used by a base station. This extension is made possible thanks to the orthogonality property that exhibits the pilot pattern associated to the different antennas. Thanks to a multi-hypothesis testing we show that the number of transmitting antennas is estimated using only one antenna at the receiver and without any knowledge of the pilot sequence.