Metric-Based Symbol Predistortion Techniques for Peak Power Reduction in OFDM Systems

In this paper, we present a novel metric-based symbol predistortion algorithm and describe three variants for peak-to-average power ratio (PAPR) reduction in OFDM transmission. The algorithm consists of predistorting a set of input symbols per block using simple metrics, which measure how much each symbol contributes to the output signal samples of large magnitudes. The symbols to be predistorted in each block are selected as those with the largest positive-valued metrics. Predistortion of input symbols is performed either by scaling only the amplitude or by scaling separately the real and/or the imaginary parts of the selected symbols. The simple metric-based structure of the proposed algorithm gives high flexibility which enables various tradeoffs between performance and complexity. Another important feature is that the algorithm does not require transmitting any side information to the receiver and it does not involve any additional complexity for symbol detection at the receiver side. It is shown by simulations that a considerable improvement can be achieved with these simple techniques, which can be implemented as one-shot or iterative procedures.