Blockwise Space-Frequency Code Design for Noncoherent MIMO OFDM Systems

Two noncoherent space-frequency block coding schemes for MIMO OFDM are proposed and corresponding ML detection rules are derived. Both schemes have high flexibility and merely a linear growth in complexity with the number of OFDM subcarriers. One scheme shows a decrease in the diversity order with increasing number of subcarriers. It performs still better than the original code from (H. Boleskei et al., 2005), which is used as a basis for blocks, if the channel delay greatly exceeds the delay the code is designed for. The second scheme is a unitary blockwise design and it achieves full diversity order. It has the same performance as the original code if there is a channel delay design-mismatch.