Rotation matrices for OFDM transmission

摘要

We consider signal space diversity based on Complex Rotation Matrices (CRM) known to provide good performance gains over uncorrelated Rayleigh fading channels. OFDM/OFDMA signals based on LTE-A parameters are combined with CRM, spatial multiplexing (MIMO), Turbo or LDPC codes. It is shown that CRM outperform RRM (Real Rotation Matrix), as well as HM (Hadamard Matrices). The gains are especially high for the uncoded case, but we still have noticeable gains in the coded case, especially for high code rates.