Efficient PAPR reduction schemes for MIMO SC-FDMA with space-frequency block codes

Single carrier frequency division multiple access (SC-FDMA), which utilizes discrete Fourier transform (DFT) as a pre-coder of orthogonal frequency division multiple access (OFDMA), has been adopted as the standard for the uplink access scheme in long term evolution (LTE). The DFT pre-coder makes SC-FDMA restoring the low envelope fluctuations of single-carrier (SC) systems and consequently provides a lower peak to average power ratio (PAPR) than OFDMA. The lower PAPR is a very important concern for wireless communication systems, hand-held devices especially. However, conventional space-frequency Bbock coding (SFBC) used in multiple-input multiple-output (MIMO) systems permutes the spectral components of the transmitted signal and causes SC-FDMA losing the low PAPR property. In this paper, we propose a modified SFBC scheme using for 2T2R MIMO SC-FDMA, and a modified QOSFBC and a combination of modified SFBC with FSTD schemes using for 4T4R MIMO SC-FDMA. From the simulation results, our proposed schemes provide a superior PAPR performance with negligible bit block error rate (BLER) degradation.