PAPR reduction scheme in SFBC MIMO-OFDM based on transformation

Partial Transmit Sequence (PTS) is one of promising techniques to reduce the high peak-to-average power ratio (PAPR) in orthogonal frequency division multiplexing (OFDM) systems. The PTS scheme can be directly applied to a space-frequency block coding (SFBC) multiple-input multiple-output OFDM (MIMO-OFDM) system, selecting the transmitted sequence with lowest average PAPR over all transmitting antennas. However, the computational complexity increases in proportion to the number of sub-blocks and antennas. In this letter, a novel scheme, called as the polyphase circular shift and conjugate (PCSC), is proposed. The proposed method uses properties of Fast Fourier Transform (FFT) and employs the character of multiple antennas. Simulation results of the proposed method can provide good performance compared to PTS in the case of the same number of sub-blocks, phase weighting factors and antennas.