A Rotation-Based Quasi-Orthogonal Space-Time Block Coded OFDM System over Frequency-Selective Channels

In this paper, we apply Quasi-Orthogonal Space - Time Block Code through Constellation rotation (QOSTBC_CR) in OFDM system, construct the QOSTBC_CR-OFDM code and propose the decoder. Since OFDM can combat frequency-selective channels and the QOSTBC_CR have both full rate and full diversity, the QOSTBC_CR-OFDM performs effectively in frequency-selective channels. Simulation results show that QOSTBC_CR-OFDM achieves better tradeoff between transmission rate and diversity gain. This approves the theoretical analysis.