A Novel Broadband Ultrasonic Location System

Indoor ultrasonic location systems provide fine-grained position data to ubiquitous computing applications. However, the ultrasonic location systems previously developed utilize narrowband transducers, and thus perform poorly in the presence of noise and are constrained by the fact that signal collisions must be avoided. In this paper, we present a novel ultrasonic location system which utilizes broadband transducers. We describe the transmitter and receiver hardware, and characterize the ultrasonic channel bandwidth. The system has been deployed as a polled, centralized location system in an office. Test results demonstrate that the system can function in high levels of environmental noise, and that it has the capability for higher update rates than previous ultrasonic location systems.