A new space-time-frequency MIMO-OFDM scheme with cyclic delay diversity

In traditional multiple input multiple output-orthogonal frequency division multiplexing (MIMO-OFDM) system, cyclic delay can increase frequency selectivity of the channel seen by the receiver, which results in cyclic delay diversity (CDD) and achieves spatial diversity. Space frequency coded scheme is another effective method to improve bit error performance of the whole wireless system. While both cyclic delay diversity and space frequency coded technology is put into traditional MIMO-OFDM system, a new space-time-frequency MIMO-OFDM scheme with cyclic delay diversity is proposed in this paper. Spatial diversity is achieved by cyclic delay diversity and frequency diversity is exploited by space frequency coded method in our scheme. Tests show that the new scheme can achieve excellent diversity gains and bit error performance. The new scheme also has obvious advantages on its simple and flexible structure.