Nonlinear companding transform for PAPR reduction of OTFS signals

Peak-to-Average Power Ratio (PAPR) is one of the major limitations of an Orthogonal time frequency space (OTFS) signals. To reduce the PAPR, a simple non-linear companding transform is proposed in this paper. The proposed companding transform mainly compresses the large amplitudes and slightly enhances the small amplitudes such that the peak power reduces but the average power remains unaltered. To validate the proposed companding transform, we compare the our proposed companding with the orthogonal frequency division multiplexing (OFDM), normalized μ- law, and clipping methods. Simulations demonstrate that, the proposed companded OTFS transform provides better PAPR than the proposed companded OFDM, μ- law companded OTFS and clipping methods. © 2022 Walter de Gruyter GmbH, Berlin/Boston 2022.