PAPR Reduction Technique for OFDM Signals Using Unused Tones with Phase Information

A major drawback of orthogonal frequency division multiplexing (OFDM) is the high peak-to-average power ratio (PAPR) of the transmit signal which can significantly impact power efficiency and performance. In this paper we present a PAPR reduction technique which exploits the phase of the signal in the frequency domain. When used to extend a previous PAPR reduction technique developed by the authors, a PAPR reduction of up to 5 dB can be obtained with this technique giving extremely low out-of-band distortion as well as lower in-band distortion than windowing and clipping methods. There is also no need for side information to be transmitted to the receiver.