PTS Peak Power Reduction of OFDM Signals with Low Complexity IFFTs

Partial transmit sequence (PTS) is a distortionless technique used to reduce the peak-to-average power ratio (PAPR) of an orthogonal frequency division multiplexing (OFDM) signal. However, it has a relatively high computational complexity due to the computation of multiple inverse fast Fourier transforms (IFFTs). We reduce this complexity by using a radix FFT that computes multiple IFFTs with low computational complexity. Signals at the middle stages of an N-point radix-r FFT using decimation in frequency (DIF) are employed for PTS subblocking. Performance results are presented which show that PAPR reduction similar to other techniques such as ordinary PTS (O-PTS) is achieved.