Performance Evaluation of Vehicular Ultra-Wideband Radio Channels

Ultra-wideband impulse-radio (UWB-IR) channel with omni-directional antenna was experimentally investigated inside a vehicle body with passengers where the interference power out-radiated from the vehicle is also discussed. From the result, the RMS delay spread and average delay, which are considerably degraded as compared with the use of directional antenna, are likely to decrease in proportion with the number of passengers in either channel of line-of-sight (LOS) and non-LOS. Also remarkable difference was not seen for the channel bandwidth. And the interference power is found to depend on the antenna height as well as antenna directivity. For example, the attenuations at 3 m away are approximately 80 dB and 60 dB for the antenna height of 0.8 m (below the window) and 1 m (above the window) respectively.