Gonzalez-Hernandez, JuanJuanGonzalez-HernandezBleakley, Chris J.Chris J.Bleakley2015-09-162015-09-162007 IEEE2007-10-05http://hdl.handle.net/10197/7039IEEE International Symposium on Intelligent Signal Processing (WISP), Madrid, Spain, 3 - 5 October, 2007This paper proposes a novel hybrid Time of Arrival (ToA) and Angle of Arrival (AoA) based system for 3D indoor location using ultrasonic spread spectrum signals. The proposed system differs from previously proposed hybrid systems in several ways - the mobile devices determines its own position, the consequent orientation problem is solved and the system uses spread spectrum techniques to improve robustness to noise and multipath. The system uses an inclinometer to allow the mobile to determine its own position. This paper compares the performance of the proposed hybrid system with that of a conventional ToA- only system. The hybrid system is found to reduce the number of base stations needed for 3D location of the mobile device, from three to two, and to provide more accurate location estimates under conditions of typical noise and room reverberation.en© © 2007 IEEE. Personal use of this material is permitted. Permission from IEEE must be obtained for all other uses, in any current or future media, including reprinting/republishing this material for advertising or promotional purposes, creating new collective works, for resale or redistribution to servers or lists, or reuse of any copyrighted component of this work in other works.Spread spectrumTime of arrivalAngle of arrivalImage methodUltrasonicLocation systemsConference Publication10.1109/WISP.2007.44476072015-09-04https://creativecommons.org/licenses/by-nc-nd/3.0/ie/