PAPR Reduction in OFDM-IM Using Multilevel Dither Signals

TL;DR

This paper proposes a multilevel dither signal approach to reduce PAPR in OFDM-IM, improving performance by exploiting the amplitude distribution of active subcarriers, with simulation confirming its effectiveness.

Contribution

It introduces a novel multilevel dither signal method for PAPR reduction in OFDM-IM, surpassing previous single-level approaches.

Findings

Significant PAPR reduction demonstrated in simulations.

Multilevel dithering offers greater flexibility and effectiveness.

Improved in-band and out-of-band performance.

Abstract

Orthogonal frequency division multiplexing with index modulation (OFDM-IM) is a novel multicarrier scheme, which uses the indices of the active subcarriers to transmit data. OFDM-IM also inherits the high peak-to-average power ratio (PAPR) problem, which induces in-band distortion and out-of-band radiation when OFDM-IM signal passes through high power amplifier (HPA). In this letter, dither signals are added in the idle subcarriers to reduce the PAPR. Unlike the previous work using single level dither signals, multilevel dither signals are used by exploiting that the amplitudes of the active subcarriers are variously distributed for different subblocks. As a result, the proposed scheme gives the dither signals more freedom (a larger radius of dithering) in average. Simulation results show that the proposed scheme can achieve better PAPR reduction performance than the previous work.