PAPR reduction of BF-OFDM waveform using DFT-Spread technique

Abstract

For actual (4G) and future (5G) wireless systems, multicarrier modulations (MCM) have been widely used because of their low implementation complexity and their simple equalization in frequency selective channels. For 4G and 5G, Cyclic Prefix Orthogonal Frequency Division Multiplexing (CP-OFDM) has been chosen. Nevertheless, because of the poor spectral containment of CP-OFDM, many MCM schemes with better frequency localizations have been developed in the past few years. These waveforms (WF) are classically named as post-OFDM WFs. In this paper, we will focus on Block-Filtered OFDM (BF-OFDM) waveform which has a very good frequency localization because of its prototype filter, which allows sharp filtering of subcarrier blocks and has the same classical receiver as CP-OFDM. Nevertheless, like any Multicarrier modulation, BF-OFDM has a high peak to average power ratio (PAPR) of the same order as that of the OFDM. In this paper, we propose a DFT spread technique to BF-OFDM for the uplink and compare the performances in terms of PAPR reduction with DFT spread CP-OFDM named SC-OFDM or SC-FDMA. We show that the performances obtained in PAPR reduction with DFT spread BF-OFDM are very close to those obtained with SC-FDMA.