Semi-blind Channel Estimation for OFDM Systems

In this paper, we propose a semi-blind channel estimation method based on first-order statistics of OFDM systems. The transmitter superimposes periodic pilot sequences on information sequences, where there is no loss in information rate but a controllable increase in transmission power. Employing the first-order statistics, it enables a closed-form channel estimation method to estimate the frequency-selective fading channel. Then, a mean square error (MSE) bound is derived to evaluate the proposed channel estimator. Computer simulations have been provided to compare the MSE performances of the proposed method with the LS estimation method based PSAM and the subspace method