Design of interleaved sequences for joint channel estimation and PAPR reduction

Abstract

In a series of previous related works, a joint Channel Estimation and Peak-to-Average Power Ratio (PAPR) (CEPR) based on shifted and superimposed sequences (FS-CEPR) for Orthogonal Frequency Division Multiplexing (OFDM) has been addressed by some authors of this paper. While the FS-CEPR techniques have proven its efficiency in terms of PAPR reduction, the channel estimation requires an additional processing at the receiver side. In this paper, we propose a novel implementation algorithm of the sequences. Instead of superimposing them, we propose to implement an interleaving process which allows a simple PAPR reduction technique, but also, a simple channel estimation scheme. To realize this target, we propose to uniformly distribute the sequences chips over the whole spectrum (i.e. over the set of subcarriers at the input of Inverse Fast Fourier Transform IFFT) and to apply, as for the CEPR technique, a multiplicative law between the chips of these sequences. To reduce multiple peaks, different sequences will be interleaved at the input of the IFFT. Finally, we show that the fast interleaved-CEPR technique (FI-CEPR) is efficient in terms of PAPR reduction value and channel estimation.