A new tone reservation method for complex-baseband PAR reduction in OFDM systems

The high peak-to-average power ratio (PAR) in OFDM systems can significantly limit performance. Tone reservation techniques use unavailable or reserved tones to design a peak-cancelling signal that lowers the PAR of a transmit data block. These techniques have been shown to reduce the PAR for real-baseband OFDM signals, such as for ADSL. Our fast-converging real-baseband tone-reservation approach based upon active-set methods is extended to reduce PAR in complex-baseband signals. This new technique converges very quickly toward a minimum-PAR solution at a low cost.