Floating OFDM-SNM for PAPR and OOBE reduction

Abstract

The novel orthogonal frequency division multiplexing with subcarrier number modulation (OFDM-SNM) transmission scheme offers high spectral and energy efficiency compared to the conventional OFDM; this is due to the extra information bits loaded over the active subcarriers. However, the OFDM-SNM scheme has a high and comparable peak-to-average power ratio (PAPR) performance to the classical OFDM. Besides the high PAPR in OFDM-SNM, out-of-band emission (OOBE) often happens between the adjacent blocks. To address the above-mentioned problems, we introduce an enhanced version of the classical OFDM-SNM, where the active subcarriers' positions are cleverly placed to reduce the PAPR and OOBE values. Power spectral density (PSD) and complementary cumulative distribution function (CCDF) of PAPR are used as performance metrics to assess the PAPR and OOBE performances of the proposed scheme. The obtained simulation results exhibit improved PAPR and OOBE performances of the proposed scheme along with almost similar bit error rate (BER) performance as compared to the classical OFDM.