SPATIAL AND ANTENNA DIVERSITY SCHEMES FOR ENHANCING CAPACITY OF VEHICULAR ADHOC NETWORKS

Abstract

The domain of vehicular ad hoc networks (VANET) is recent with newlinesignificant contributions made over few years. Considering the broad area of newlinenetwork, VANET is a special area of mobile ad hoc networks (MANET) with newlinepeculiar characteristics, which lay emphasis on considering VANET as a newlineseparate area for research. The underlying aim of VANET to provide newlinevehicular safety, internet accessibility and communication during transit is not newlineeasy to achieve amidst networking challenges posed by it. With the prediction newlineof huge data generation by VANETs in near future, the need for high data newlinerate, large capacity, high reliability and low latency are becoming prime focus newlinefor VANET applications. The area of VANET is still unexplored to large newlineextent and there are various issues such as channel modeling, multipath newlinefading, channel estimation, protocol designing etc., that need to be addressed newlineat different layers to achieve the required performance. newlineIn this thesis, spatial and antenna diversity schemes have been newlinesuggested to enhance VANET performance by mitigating multipaths due to newlinescattering, reflection and diffractions. An extended quasi orthogonal spacetime newlineblock codes (Q-OSTBC) with code rate of 1 has been proposed which is newlinethe core of an antenna diversity scheme. The analysis of results indicates the newlinesignificant reduction in bit error rate (BER) for this scheme as compared to newlineOSTBC thus improving VANET capacity. newlineAnother contribution of this thesis is, multiple input multiple output newline(MIMO) diversity scheme proposed for VANET scenario considering the newlineeffects of vehicular mobility. The performance has been analyzed in terms of newlineimportant metrics for a realistic vehicular scenario on urban and rural/ newlinehighway roads. It has been observed that the performance of MIMO with high newlinediversity order is significantly better than that having lesser diversity.