Semi-blind channel estimation for OFDM-STC

A semi-blind method is proposed for estimating the channel responses of OFDM-STC system with three transmit antennas and one receive antenna. Firstly, a subspace-based algorithm is introduced to estimate the channel responses subject to one ambiguity parameter. Secondly, a method is presented to resolve the ambiguity by using optimum sequences. Computation simulations show this semi-blind method outperforms training sequences based non-blind methods for it incorporates the information of both known and unknown transmitted symbols.