MIMO-based spatial diversity scheme in VANET scenario

Designers of Vehicular Adhoc Network (VANET) systems face challenge to achieve high data rate and improved performance within the available bandwidth. Due to random and unpredictable nature of wireless channels, signal undergoes reflection, scattering and shadowing, resulting in attenuation of signal. The multiple signal thus at receiver, which are varying in time and phase, are destructive or constructive superposition of actual transmitted signal, hence it becomes very difficult to correctly detect the transmitted signal. In such fading channels, these effects can be presented statistically as multiplicative random factor variable. In case of VANET, fading needs to be overcome, as reliability for safety applications is of utmost importance. To improve the performance over wireless fading channel, diversity schemes have been proposed; which has underlying principle of providing multiple, original signal replicas to receiver to achieve reliability. Antenna or spatial diversity is one such scheme, wherein multiple antennas are employed either at the transmitter or receiver or on both sides, to achieve quality signal at receiver with maximum bandwidth efficiency. Antenna Diversity scheme which is basis of Multiple Input Multiple Output (MIMO) can help in overcoming detrimental effects of multipath fading in VANET. In this work, we have evaluated the performance of multi-hop vehicular ad hoc networks with antenna diversity schemes in highway and urban road scenario. The simulation results indicate the improvement in the metrics - delay, packet delivery ratio (PDR) and throughput.