Exploiting input cyclostationarity for blind channel identification in OFDM systems

Transmitter-induced cyclostationarity has been explored recently as an alte rnative to fractional sampling and antenna array methods for blind identifi cation of FIR communication channels. An interesting application of these i deas is in OFDM systems, which induce cyclostationarity due to the cyclic p refix. In this correspondence, we develop a novel subspace approach for bli nd channel identification using cyclic correlations at the OFDM receiver. E ven channels with equispaced unit circle zeros are identifiable in the pres ence of any nonzero length cyclic prefix with adequate block length. Simula tions of the proposed channel estimator along with its performance in OFDM systems combined with impulse response shortening and Reed-Solomon coding a re presented.