Abstract
In this thesis, we propose a peak-to-average power ratio (PAPR) reduction scheme based on tone reservation and tone injection for orthogonal frequency-division multiplexing systems. In the first step of the proposed scheme, we evaluate the peak-reduction capability of each of the reserved tones (or subcarriers) by computing the corresponding metrics. Based on the resulting metrics, we determine the transmitted values of each reserved tone. In the second step, we apply a constellation extension technique, tone injection, to the data subcarriers for further PAPR reduction, where each extendable constellation point is with only one possible extended constellation point. We compute new metrics of all extendable frequency-domain data samples for measuring their contributions to the corresponding time-domain peak samples, and then select the data sample with the largest metric for tone injection. The second step is repeated unless the PAPR value is lower than a predetermined threshold or the maximum number of injected tones has been reached. The proposed scheme does not need to transmit any side information to the receiver. As compared with the combined tone reservation and active constellation extension scheme adopted in the DVB-T2 standard, the proposed one can achieve better PAPR reduction performance with lower transmitted power.