  Characterization of the millimeter wave wireless channel is needed to
facilitate fully connected vehicular communication in the future. To study the
multipath-rich, rapidly varying nature of the vehicular propagation
environment, fast millimeter wave channel sounders are required. We present a
channel sounder design capable of covering 360 degrees in azimuth and 60
degrees in elevation with 200 individual beam directions in 6.25 ms by using
four phased arrays simultaneously. The channel measurements are accompanied by
high resolution positioning and video data, allowing channel sounding to be
conducted while either the transmitter, or the receiver, or both are moving.
Channel sounding campaigns were conducted at multiple urban locations with
light traffic conditions in Austin, Texas. Preliminary results show that beam
selection at the receiver can lower the effective pathloss exponent to 1.6 for
line-of-sight and 2.25 for non line-of-sight.
