A Low-Complexity PTS Scheme for PAPR Reduction in SFBC MIMO-OFDM Systems

Multiple-input multiple-output orthogonal frequency division multiplexing (MIMO-OFDM) is an attractive technique for high-data-rate wireless communications because of its high spectral efficiency and robustness with respect to multipath fading channels. However, MIMO-OFDM systems have an inherent drawback in that the transmitted signals of various antennas may have a high peak-to-average power ratio (PAPR). In this paper, a low-complexity partial transmit sequences (PTS) scheme is proposed to reduce the PAPR for MIMO-OFDM systems with space- frequency block coding (SFBC). In the proposed PTS scheme, we use the sample powers of subblocks derived from the input data blocks to generate a set of cost functions. We then use the cost functions and the similarity among the subblocks to develop a new method to jointly select the samples to estimate the peak power of candidate signals for various transmitting antennas. Simulation results show that, in SFBC MIMO-OFDM systems, the proposed PTS scheme can achieve a PAPR reduction performance close to that of the conventional PTS scheme, but with much lower computational complexity.