Tunnel Propagation Channel Characterization for DSRC Applications

The propagation channel characteristics of a transportation tunnel for DSRC applications is discussed. One problem in DSRC applications is that the received power in the adjacent (non-coverage) zone can be higher than the maximum allowed threshold. To identify its cause, a wideband directional channel sounding was conducted inside the tunnel. From the sounding data, the propagation path parameters are estimated by a multidimensional maximum likelihood estimation algorithm and scatterers are identified based on the angle-of-arrival and delay information. These propagation paths together with simulated DSRC application antennas are then used to predict the probability of the received power in the adjacent zone. The power contribution of the scatterers are calculated and the dominant scatterers are found to be from ground and sidewalk scatterers.