Selected mapping (SLM) is considered as a practical probabilistic PAPR reduction method for OFDM systems. A problem of this technique is its high computational complexity due to multiple inverse Fourier transform. We suggest a decimation in frequency IFFT scheme together with an interleaverbutterfly ensemble to generate multiple candidates. Orthogonality in the frequency domain is kept and better PAPR reduction performance is achieved without additional complex multiplication. Moreover, we obtain a better error rate over both the AWGN channel and the frequency selective fading channel.