Reduction of PAPR in OTFS using rooting companding techniques

Peak-to-average power ratio (PAPR) is one of the major limitations of an orthogonal time frequency space (OTFS) system. To reduce the PAPR, this paper proposes three companding techniques, namely, logarithmic rooting companding, rooting companding, and rooting-based μ-law companding. This paper also presents the preferable range of rooting parameter through the analysis of variation of PAPR and bit error rate (BER) with respect to the rooting parameter. To assess the performance of the proposed companding techniques, simulations are carried out by considering various number of delay and Doppler bins. The simulation results reveal that all the proposed techniques provide better PAPR performance than the existing μ-law companding.