Tone Reservation for Peak-to-Average Power Ratio Reduction in OFDM under Different Optimization Constraints

The high peak-to-average power ratio (PAR) of the transmit signal is considered to be one major drawback of orthogonal frequency-division multiplexing (OFDM) systems. This paper analyzes the tone reservation (TR) technique for PAR reduction. It is shown that the good performance of TR is paid with an increase in average transmit power. Therefore, an extension of the TR scheme is considered, which limits the average power. This increase of power efficiency comes along with a decrease of PAR reduction; a trade-off is possible. In addition to that, the TR scheme is compared with selected mapping (SLM), another popular PAR reduction technique. Simulations show that SLM outperforms TR in terms of PAR reduction and power efficiency. Finally, a combined approach of TR and SLM is proposed. Although, this scheme does not offer the PAR reduction capabilities of pure TR it has lower complexity.