A Study on DS/SS Inter Vehicle Communication System Using Array Antenna

Presently, many studies on ITS (intelligent transport systems) have been made in the world. Especially, IVC (inter-vehicle communication) is one of the most important research areas in ITS. In IVC, application of DS/SS (direct sequence spread spectrum) communication scheme is focusing attention. In this paper, the application using the DS/SS CDMA (code division multiple access) scheme is studied. In this system, common PN codes that are known to all vehicles are used in order to perform initial link establishment between vehicles (Kawamagari et al., 2005). However, the packet error rate characteristic sometimes degrades under the influence of the near-far problem situation and the increase of the number of vehicles due to PN code interference. Moreover, the common code interference becomes a severe problem in this scheme while link establishment is being performed. In order to improve this degradation, division of the receiving direction using an array antenna is performed. Moreover, the signal acquisition performance combined with a matched filter is also analyzed. As the result of simulations, performance improvement was confirmed