Simple and Robust Method for OFDM Performance Improvement with Nonlinear Amplification

This work proposes a new technique to be used in orthogonal frequency division multiplexing (OFDM) systems subject to nonlinear power amplification, aiming to obtain better bit error rate (BER) performance with reduced computational complexity and low peak-to-average power ratio (PAPR). The core of the proposed technique is a new metric to choose a modified OFDM symbol to be transmitted among several alternatives with the aim of reducing the deleterious effects of nonlinear amplification. The proposed metric is independent of a power amplifier model and may be associated with different approaches to generate the modified OFDM symbols. Simulation results are presented, using a Partial Transmit Sequence (PTS) approach, which show that the proposed scheme provides BER performance similar to other known techniques at a significantly lower computational cost (about 33% less real multiplications and 66% less real additions). Estimates of the PAPR complementary cumulative distribution function (CCDF) are also presented and show that the proposed method does not degrade this performance index substantially compared to those techniques.