Amplifier-Coupled Tone Reservation for Minimization of OFDM Nonlinear Distortion

Nonlinear distortion of an orthogonal frequency division multiplexing signal is a serious problem when it comes to energy-efficient power amplifier (PA) utilization. Typically, peak-to-average power ratio reduction algorithms and digital predistortion algorithms are used independently to fight the same phenomenon. This paper proposes an amplifier-coupled tone reservation (AC-TR) algorithm for the reduction of nonlinear distortion power, utilizing knowledge on the predistorted PA characteristic. The optimization problem is defined. Its convexity is proved. A computationally-efficient solution is presented. Finally, its performance is compared against two state-of-the-art TR algorithms by means of simulations and measurements. The results show the proposed solution is advantageous, both in terms of nonlinear distortion power and the required number of computations.