Novel Device Reproduce In-Vehicle Wireless Multipath Radio Channels

This paper describes and evaluates a new test facility able to generate different wireless multipath radiocommunication channels. It is used to recreate various electromagnetic (EM) environments, such as those inside vehicles. This test facility, in the form of a moderate volume metallic chamber, contains apertures, left opened or obstructed as required, and a variable quantity of salt water. Both are used to adjust the EM losses and to control smoothly and accurately the delay spread of the communication channel inside the test facility. A frequency range between 2 and 3 GHz is studied. As a first step, the root-mean-square (rms) delay spread is measured inside a vehicle for several locations of the receiving antenna and for different scenarios including different line-of-sight and non-line-of-sight paths. Then, the test facility is introduced, dimensioned, and evaluated, trying to reproduce the rms delay spread of each previous in-vehicle radiocommunication configuration. A comparison between the measurement data performed both in the vehicle and in the configured test facility is presented. This comparison shows a good agreement between these two sets of measurements. It demonstrates that different static wireless in-vehicle multipath channels, corresponding to various transmitting and receiving antenna configurations, can be reproduced inside the proposed prototype test facility.