An improved algorithm for peak-to-average power ratio reduction in MIMO-OFDM systems

Subblock Successive Transform (SST) algorithm is an effective method to reduce the PAPR of the MIMO-OFDM signals, and can fully utilize the degrees of freedom in space domain to overcome the shortage of Successive Suboptimal Cross-Antenna Rotation and Inversion (SS-CARI) algorithm. However, the degrees of freedom in frequency domain are not considered in SST algorithm. For this problem, an improved SST (ISST) algorithm is proposed, in which, not only Subblocks are permuted in the same way as SST algorithm in space domain, but also subblocks on the same antenna are successively rotated in frequency domain. So it can fully use the degrees of freedom in both space domain and frequency domain. Simulation results indicate that the effect of PAPR reduction of presented method is obviously better than that of SST algorithm. Furthermore, as the number of Subblocks M increases, this superiority is more obvious.