A Novel ZCS-Clipping Precoding Technique for PAPR Reduction using DCT-OFDM in Vehicular Channels

IEEE 802.11p defines an international standard for wireless access in vehicular environments. It is normally designed for operating at high user mobility. Thus, decreasing the signal bandwidth to 10 MHz in IEEE 802.11p makes the communication more efficient for the vehicular channel. Furthermore, the Orthogonal Frequency Division Multiplexing (OFDM) methodology is commonly used to mitigate the InterSymbol Interference (ISI) occurred over a wireless channel. However, the OFDM suffers from certain drawbacks including higher system complexity due to the generation of the peak to average ratio (PAPR). The objective of this study is to reduce the high PAPR resulted from adapting the OFDM system to vehicular networks. In this paper, we propose a novel precoding Zadoff-Chu Sequence (ZCS) combined with the Clipping technique for PAPR reduction in OFDM based on the Discrete Cosine Transform (DCT). The proposed technique which is based on precoding the constellation symbols of the vehicular channels with DCT succeeds to decrease the PAPR ratio up to 4dB for 64 subcarriers.