Research On The Application Of Leakey Coaxial Cable In Wireless Communication Of Semi-confined/Confined Area

Leaky coaxial cable (LCX) is also called continuous antenna, and it is the important information carrier to realize the duplex gapless mobile communication in confined zones, which both has the functions of wire and wireless communication in a long distance, so it can make up the disadvantage of the blind zone that is unavoidable in the traditional antenna communication, consequently LCX can be widely used in the mobile communication of many kinds of confined areas such as subway, tunnels, coals and highway, etc.. The radiation characteristics of LCX in every complex electromagnetic environment is analyzed and discussed theoretically in this dissertation, and the transmission characteristics of electromagnetic wave in confined zones are studied by building the exact simulation models, analyzing method and solution scheme. The simulation results of the dissertation provide some worthy theoretical and technological support for the engineering application.Aiming at the blind zone of mobile communication in indoor space, a kind of coupling leaky coaxial cable is presented and desgined, and the field distribution of it is analyzed by using FDTD method, then propagation path of electromagnetic wave in indoor space is traced and forecasted by using ray-tracing method, and the coefficients of reflection, refraction and diffraction are deduced, the feasibility of the designed leaky coaxial cable is verified, and the representative analyzing method and technology of LCX transmission characteristcs in semi-confined zones are obtained.To enhance and consummate the basic theory and analyzing method of LCX in confined zones, take the subway and coal mobile communication system for example, the dissertation analyzes the transmission path and characteristics of LCX in complex electromagnetic environment by the numbers. The radiation characteristics of LCX in the representative confined zones are studied using the hybrid method of FDTD and ray-tracing, and the material analyzing method and solution scheme are presented. For the co-existence of platform and tunnels in subway, a kind of leaky coaxial cable with different radiation directions at different part is designed; for the required wide coverage in coal mine, a kind of omni-direction radiation leaky coaxial cable is designed.Aiming at the highway building problems in the future, an intelligent highway mobile communication system involves leaky coaxial cable is presented, combining the communication function of vehicles on the road, the information transmission between every parts of the communication system is realized, which ensures the electromagnetic wave coverage along the roadside, and the radiation characteristics of leaky coaxial cable at every part of intelligent highway mobile communication system are investigated by using FDTD and ray-tracing method.