A study of inter vehicle communication scheme allocating PN codes to the location on the road

In this paper, improving performance of the PN code allocation scheme for inter-vehicle communication system using spread spectrum communication that we have already proposed [Y. Shiga et al., Nov 2000] is discussed. In the proposed system, a road is divided into small areas and different PN code is assigned to each area. All vehicles on the road share the unique PN code map and they decide on their own PN code used in IVC according to their position on the road by referring the PN code map. By binding PN code to the absolute location, each vehicle can determine its PN code easily and no complex PN code allocation protocol is necessary. In this paper, performance of the proposed system is discussed under more actual and practical situations than the conventional analyses. Here, each vehicle makes a communication randomly while each vehicle is making a communication at constant intervals. As a result of computer simulations, better performance of the proposed scheme were confirmed as compared to the conventional scheme.