A New Weighted Tone Reservation Method for PAPR Reduction in OFDM Systems

Abstract

The tone reservation (TR) technique is an efficient method to reduce the peak-to-average power ratio (PAPR) in orthogonal frequency division multiplexing (OFDM) systems. Although the weighted tone reservation (WTR) approach has been proposed as a potentially promising way to reduce the peak power, it suffers from high peak regrowth in the non-peak region of the transmitted signal. In addition, so far the effective selection of the weights is still an open problem. In this paper, we propose a new weighted tone reservation method that offers two contributions. The first is a reformulation of the traditional weighted least squares optimization that seeks to deeply suppress the peak regrowth of the transmitted signal in the low energy portion while reducing the peak power. The second is a careful study of the optimal weight selection. We provide the general guidelines and propose a class of suitable weights that are easy to implement. Then from this class we find the empirically optimal weights. Simulation results show that the proposed method has much improved performance in terms of both PAPR reduction and bit error rate (BER) than the existing clipping-based TR methods, which represent the state-of-the-art PAPR reduction solutions.  Index Terms-Orthogonal frequency division multiplexing (OFDM), peak-to-average-power ratio (PAPR), weighted least squares (WLS), tone reservation (TR), clipping control I.

An Overview of Peak-to-Average Power Ratio Reduction Techniques for OFDM Signals

“…Both of them overcame shortcomings in CC-TR method, and had a better performance in PAPR reduction and computational complexity. In [75], authors proposed a new method based on the optimal prototype signal and least squares approximation algorithm, which were used to approximate the clipping noise just in the time domain by circularly shift and scale to reduce the PAPR of OFDM signals. In [76], an improved TR method based on the maximum likelihood estimate (MLE), called the MLE-TR algorithm, was proposed.…”