Downlink frequency-selective fading channel blind estimation for space-time coded MIMO MC-CDMA systems

Due to inherent characteristic of blind channel estimation algorithm based on subspace method, there exists an ambiguous complex coefficient between estimated channels and real channels. In this paper, we focus on the downlink frequency-selective fading channel estimation problem of the space-time coded multiple-input multiple-output (MIMO) MC-CDMA systems. Based on subspace decomposition technique and the subspace orthogonality property, we derive a blind accurate estimation of downlink frequency-selective fading channels using the finite alphabet. Thus, we generalize the blind identification method of ambiguous complex coefficient from single carrier systems to multicarrier MIMO systems. Monte Carlo simulations show that when the SNR is low, the error of channel estimation is relatively small.