Doppler shift signature for BPSK in a vehicular Network: IEEE 802.11p

The emergence of the Intelligent Transportation System (ITS) has given new hope and an unprecedented number of promising benefits to the transportation industry. However, these benefits are accompanied with inherent challenges that are due to the higher mobility of the vehicular nodes. One of the major problems faced is the induced Doppler Shift (DS) in the carrier frequency of the transceiver node. This paper attempts to decrypt the effect of the DS impact in a Vehicle-to-Vehicle (V2V) or Vehicle-to-Infrastructure (V2I) communication based system. Mobile nodes moving at a relative speed of 25 to 250 km/h are considered. Using a fixed modulation code scheme, the degradation effect in term of Bit Error Rate (BER) is analysed under variable signal strength condition. Using the principle of Monte-Carlo, intense simulations are carried with a 95% Confidence Interval (CI). The results obtained from simulations prompted the derivation of a mathematical model. Considering the BER threshold limit defined by the standard, multiple simulation results are optimized to develop the composite result called the DS signature. The final product is then presented as the mathematical model of the DS signature accounting for all channel realisations when the MCS BPSK rate 3/4 is used in a Vehicular Adhoc Network (VANET).