Journal of Theoretical and Applied Information Technology
In this paper, the authors present a new approach to achieve Optimal Training Sequences (OTSs) in terms of minimizing the mean-square channel estimation error for spectrally efficient MIMO OFDM systems. It is shown that the OTS are equi-powered, equi-spaced and position orthogonal. However, in special cases they can find that required conditions to achieve optimal pilot design are not satisfied, this means the optimum pilot is unachievable. In this paper, an algorithm is proposed to achieve suboptimum pilot design under time varying channels.