Selected Mapping Algorithm for PAPR Reduction of Space-Frequency Coded OFDM Systems Without Side Information

Selected mapping (SLM) is a well-known technique for peak-to-average-power ratio (PAPR) reduction of orthogonal frequency-division multiplexing (OFDM) systems. In this technique, different representations of OFDM symbols are generated by rotation of the original OFDM frame by different phase sequences, and the signal with minimum PAPR is selected and transmitted. To compensate for the effect of the phase rotation at the receiver, it is necessary to transmit the index of the selected phase sequence as side information (SI). In this paper, an SLM technique is introduced for the PAPR reduction of space-frequency-block-coded OFDM systems with Alamouti coding scheme. Additionally, a suboptimum detection method that does not need SI is introduced at the receiver side. Simulation results show that the proposed SLM method effectively reduces the PAPR, and the detection method has performance very close to the case where the correct index of the phase sequence is available at the receiver side.