A peak-to-average power ratio (PAPR) reduction based on adaptive all-pass filters (AAPFs) for multiple-input single-output orthogonal frequency division multiplexing systems with space-frequency block coding is proposed. The AAPF creates phase rotation to reduce the PAPR. With the scattered pilot pattern, the AAPF enables data recovery without side information (SI). The PAPR reduction performance and the BER performance with considered system parameters are comparable to those of the blind SLM (B-SLM) scheme and the low complexity SLM (LC-SLM) scheme with SI. The computational complexity is much lower than that of the B-SLM scheme and comparable to that of the LC-SLM scheme.