Adding signal for peak-to-average power reduction and predistortion in an orthogonal frequency division multiplexing context
Résumé
In this study, the authors look into digital predistortion and its combination with the peak-to-average power ratio (PAPR) reduction technique in the case of orthogonal frequency division multiplexing (OFDM)-based systems. First of all, the authors propose a new predistortion methodology which uses the addition of signals. Two different algorithms are investigated for the predistortion signals generation. The first one is based on the traditional predistortion method, where an estimation of the power amplifiers (PAs) characteristics is needed in the first place. The second algorithm to generate the predistortion signal does not need a priori PA estimation. It is based on an iterative compensation of the error between the amplified signal and the OFDM signal. Then, the authors combine this latter algorithm with the tone reservation PAPR reduction method in order to have a global adding signal expression. Two combination scenarios of PAPR reduction and predistortion obtained by means of adding a signal are proposed. The first one combines both of them in series while the second one is parallel. Performances of the proposed predistortion algorithms and the combination scenarios are compared thanks to simulations based on IEEE802.il a/g standards for a memoryless solid state PA.