| This paper presents an ultra-wideband (UWB) testbed and its application to characterize channels for intra-vehicle automotive sensor networks. A received pulse width of 300 ps is achieved both in laboratory environment and outdoor over 60 m. Channel characteristics are thoroughly measured for a car. Different settings are investigated, including UWB signal propagation from rear wheels to the engine compartment area, within the engine compartment, and from within the engine compartment to the passenger compartment. The study found: (a) communications between a transceiver at the bottom of the engine compartment and rear wheel speed sensors can be achieved at 330 mega-pulses per second using UWB technology without inter-symbol interference; (b) When the hood is shut, UWB communications within the engine compartment can achieve 476 mega-pulses per second when there is a line-of-sight, or 50 mega pulses per second when there is no line-of-sight; (c) The received signals for UWB communications within the vehicle are very stable, and have negligible fading. Pulses traveled through different paths are distinct in the received signals. In other words, the UWB technology has resolved mutipath. Therefore, UWB can provide sufficiently high data rate for hundreds of wireless sensors in future automotive vehicles. The negligible fading in the received signals makes it much easier to design transceivers with low cost and low complexity. |