Gray coded constellation shifting scheme with low complexity in MB-OFDM UWB systems

Abstract

Multi-band orthogonal frequency division multiplexing (MB-OFDM) with a dual carrier modulation (DCM) is a promising technique for ultra wideband (UWB) communication systems. However, it suffers from high peak-to-average power ratio (PAPR) at the transmitter because of the fundamental feature of the orthogonal frequency division multiplexing (OFDM). In this paper, we propose a new shifting scheme of a gray coded 16-quadrature amplitude modulation (QAM) constellation in the DCM mapping process that considerably reduces the PAPR. The PAPR reduction performance and computational complexity of the proposed scheme are compared to the existing PAPR reduction scheme. The simulation results show that the proposed scheme can reduce the PAPR and computational complexity effectively.