On the optimal cyclic delay value in cyclic delay diversity

In this paper, we propose a method to determine the optimal cyclic delay value of cyclic delay diversity (CDD) in orthogonal frequency division multiplexing (OFDM) systems. As the cyclic delay value increases, we can get signal to interference and noise ratio (SINR) gain by the diversity effect, while SINR loss increases because of channel estimation errors. If the optimal cyclic delay value obtained by the proposed method is applied to a CDD scheme, we can minimize the required SINR for a given frame error rate (FER) under the above-mentioned trade-off.