TOA Estimation using Music Super-Resolution Techniques for an Indoor Audible Chirp Ranging System

An indoor TOA-based ranging system which uses an audible spread spectrum signal is presented. The indoor acoustic environment is modeled with a dense multipath propagation channel whose characteristics are very different from those of outdoor environments. The complexity and site-specific nature of indoor acoustic propagation, when using traditional correlation techniques, often lead to the creation of undetectable direct-line-of-sight (DLOS) situations. It is shown that by using an LFM signal and MUSIC super-resolution techniques, namely the root-MUSIC, the substantial TOA errors can be reduced significantly and the range accuracy improved by a factor of at least 3.