Comparative Performance Analysis of Time Local Positioning Architectures in NLOS Urban Scenarios

Abstract

Autonomous navigation has meant a challenge for traditional positioning systems. As a consequence, ad-hoc deployments of sensors for addressing particular environment characteristics have emerged known as Local Positioning Systems (LPS). Among LPS, those based on temporal measurements present an excellent trade-off among accuracy, availability, robustness and costs. However, the existence of different Time-Based Positioning architectures - Time of Arrival (TOA), Time Difference of Arrival (TDOA) and Asynchronous Time Difference of Arrival (A-TDOA)- with different characteristics in clock and signal path noise uncertainties has supposed that it does not exist any preferred a priori architecture for urban NLOS complex scenarios. As a consequence, in this paper, we propose a general framework for the optimization of the node deployments of each architecture in urban scenarios based on accuracy, availability and robustness. This framework allows us to compare the performance of the TBS architectures in the urban scenario proposed as a novel methodology for the deployment of LPS time architectures in urban environments. Results in the proposed scenario have shown the preeminence of the A-TDOA architecture in primary and emergency conditions which supposes and outstanding remark for future high-demanded accuracy applications in urban environments.

Keywords

• A-TDOA
• clock errors
• Cramér-Rao bounds
• genetic algorithm
• localization
• local positioning systems