Only one asymptotic training design for a special case of channel correlation was proposed in the literature for spatially correlated multiple-input multiple-output with orthogonal frequency-division multiplexing (MIMO-OFDM) systems. To fill this gap, this letter applies tractable semi-definite programming (SDP) to obtain the optimal superimposed training signals for the general case of channel correlation. For a more efficient computation, two approximate designs are also proposed. Simulation results demonstrate the efficiency of our approach and its advantage over the asymptotic design.
Nguyen Nam Tran, Hoang Duong Tuan, Ha H. Nguyen