Statistical Analysis of Cars Induced Scattering in 60 GHz UWB Outdoor Channels

Millimeter-waves radio technology is attracting great interest because large portions of radio spectrum are available from about 30 to beyond 90 GHz to support modern bandwidth- hungry applications with QoS requirements. Fifth generation of mobile communications is mainly envisaged in the spectrum around 28-40 GHz, whereas 60 GHz band is mostly used for indoor wireless local area networks (WLANs). However, with 7 GHz of available bandwidth, 60 GHz links could play a key role for outdoor backhaul, street lamps hot-spots and video surveillance. Studies of 60 GHz outdoor channels are currently limited. Outdoor channels are usually sparser than indoor channels, but the presence of scatterers like, e.g., cars, in the proximity of the link may induce specific patterns in the multipath composition. In this paper, we provide a statistical analysis of the effect of scatterers with large electromagnetic surface, namely cars, on multipath propagation of 60 GHz ultra- wideband (UWB) signals. The analysis is based on experimental data collected in two parking areas with and without parked cars, where a 60 GHz UWB radio transmits from street lamps towards collector points located in the proximity of a building. The measurements were done at eight carrier frequencies in the region 54-66 GHz, using a tunable sliding correlator, thus results also show the channel behavior vs. frequency.