Verification of CDMA and accuracy on echo ranging system using spread spectrum ultrasonic signals

This paper proposes the echo ranging system with spread spectrum ultrasonic signals for automobile robots. The spread spectrum signals have noise-proof property and an ability of code division multiple access (CDMA). To verify them on reflected waves, an experimental system for indoor echo ranging dealing with spread spectrum modulations was installed on original PCI hardware connected PC, and experiments for verification of CDMA and measurement accuracies were conducted. Results of the experiments indicated usefulness of the echo ranging system with spread spectrum ultrasonic signals.