A modified Low PAPR space-frequency block coding scheme for SC-FDMA

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 Third Generation Partnership Project Long Term Evolution (3GPP-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, handheld devices especially. However, conventional Space-Frequency Block 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 low PAPR SFBC scheme for SC-FDMA systems. Simulation results show that with a slight degradation in the Bit Block Error Rate (BLER) performance our proposed scheme can benefit PAPR reduction around 2 dB for Quadrature Phase Shift Keying (QPSK) modulation and 1.5 dB for 16-Quadrature Amplitude Modulation (16-QAM) comparing with conventional SFBC, respectively.