A Parallel Combinatory OFDM System with Weighted Phase Subcarriers

Abstract

Orthogonal Frequency Division Multiplexing (OFDM) is usually regarded as a spectral efficient multicarrier modulation technique, yet it suffers from a high peak-to-average power ratio (PAPR) problem. Among all the existing PAPR reduction techniques in OFDM systems, side information based PAPR reduction techniques such as partial transmit sequence (PTS) and selective mapping (SLM) schemes, have attracted the most attention. However, the transmission of side information results in somewhat spectral loss and this does not significantly improve the bit error rate (BER) performance. Parallel combinatory (PC) OFDM yields higher spectral efficiency (SE) and better BER performance on Gaussian channels,while is a little but not obvious PAPR improvement over the ordinary OFDM system. This investigation aimed to design a 'perfect' OFDM system. We introduce the side information to rotate the subcarrier phases of our novel PC-OFDM system structure, and call this new system the SIPC(Side information based Parallel Combinatory)-OFDM system. The proposed system achieves better PAPR and SE performance. In addition, considering the tradeoff of system parameters, the proposed system also has the properties of a higher BER.

Overlapped Segmental Clipping for the PAPR Reduction of the OFDM-OQAM system

“…Orthogonal frequency division multiplexing (OFDM) is one of the most popular multicarrier modulation scheme which has been widely used in many broadband communication systems [1]. However, the OFDM system uses rectangular pulse shaping on each subcarrier, which leads to relatively serious out-of-band radiations.…”