FDTD Propagation Analysis of 720MHz and 5.8GHz Bands at Intersection Surrounded by Light-weight Concrete Walls in Residential Area

摘要

近年,交差点における自動車衝突事故防止のため,車車間通信を用いた衝突防止システムの研究が進められている.特に家屋塀で囲まれた道幅の狭い住宅地交差点では,その効果が期待されている.現在,車車間通信用の周波数帯として720MHz帯及び5.8GHz帯の利用が検討されている.本研究では軽量コンクリート家屋塀で囲まれた住宅地交差点における720MHz帯及び5.8GHz帯での電波伝搬特性解析を行った.種々の塀厚み及び送信側自動車位置に対する伝搬損失特性を明らかにした.また,電波の伝搬メカニズムを明らかにするため電力遅延プロファイル特性解析を行った.尚,電磁界解析手法としてFDTD法を用いた.Recently, inter-vehicle communication system to prevent car crush at an intersection has been proposed. In the system, the use of 720MHz and 5.8GHz bands have been considered. In Japan, there are many intersections surrounded by light-weight concrete walls at residential area, which have poor visibility. It is important to know the propagation characteristics at these intersections in each frequency band. In this paper, the propagation analyses of 720MHz and 5.8GHz bands at an intersection in residential area are carried out using the FDTD method. The propagation characteristics for both various locations of wave source and wall thickness were investigated. The azimuthal power delay profiles were obtained by using the direction of arrival estimation method.