Improving the Realism of the Physical Layer of NS-3 by Considering the PAPR Problem of the IEEE 802.11p Transmitter

Abstract

NS-3 is a network simulator used for the research and development of Vehicular Ad-hoc Networks (VANETs). It allows the IEEE 802.11p standard simulation, which is part of IEEE Wireless Access in the Vehicular Environment (WAVE). One of the limitations of the 802.11p standard in NS-3 is using a simplified theoretical model of the Packet Error Rate (PER). This standard uses for the Physical Layer (PHY) the Orthogonal Frequency Division Multiplexing (OFDM) technique, which suffers from high Peak to Average Power Ratio (PAPR). This high PAPR of the signal causes degradation of the PER when it passes through a non-linear amplifier. In this work, we study the effect of the high PAPR over the PER using a MATLAB implementation of the 802.11p PHY. We also analyze the effect of using the Orthogonal Pilot Sequences (OPS) technique for PAPR reduction. The results show that the high PAPR affects the PER of high data rates, which use 16-QAM and 64-QAM modulation. Finally, these results are extended to NS-3 simulations as a new model of the IEEE 802.11p PHY with high realism since it considers the effect of the non-linear HPA. The NS-3 results show a similar trend compared to the MATLAB simulations.