A Low Complexity Transmitter Architecture and Its Application to PAPR Reduction in SFBC MIMO-OFDM Systems

Recently, multiple-input multiple-output (MIMO) orthogonal frequency division multiplexing (OFDM) system with space-frequency block coding (SFBC) has attracted substantial attention because of its robustness toward time selective fading channel. However, SFBC MIMO-OFDM system needs the same number of inverse fast Fourier transforms (IFFTs) as the number of antennas at the transmitter and the computational complexity is extremely high. In addition, it also inherits the disadvantage of a high peak-to-average power ratio (PAPR) from OFDM technique. In this paper, a low-complexity transmitter architecture is proposed for SFBC MIMO-OFDM systems with a general encoding matrix and an arbitrary number of transmitter antennas. The proposed scheme fully exploits the time-domain signal properties and requires only one IFFT. Then, a PRPR reduction scheme is presented by using the proposed transmitter architecture. The PAPR reduction performance of the proposed scheme is slightly worse than that of the traditional selected mapping (SLM) scheme. However, the proposed scheme achieves a substantially lower computational complexity.