Finite-alphabet and decision-feedback based channel estimation for space-time coded OFDM systems

A novel blind channel estimation scheme is presented for space-time coded OFDM (STC-OFDM) systems. This scheme is composed of coarse channel estimation by exploiting the finite-alphabet property of information signals and fine channel estimation by using decision-directed method, which employs the priori knowledge of the transmitted signals other than the finite-alphabet property of mapping constellation. At the cost of a little more computational complexity, it achieves better performance than the competitive one. The scheme is tested with simulations and also compared with the subspace-based channel estimation