Integration of GPS with a WiFi high accuracy ranging functionality |
| |
Authors: | Khalid Nur Shaojun Feng Cong Ling Washington Ochieng |
| |
Institution: | 1. Centre for Transport Studies, Department of Civil &2. Environmental Engineering, Imperial College London, London, SW7 2AZ, UK.khalid.nur@imperial.ac.uk;4. Environmental Engineering, Imperial College London, London, SW7 2AZ, UK.;5. Department of Electrical &6. Electronic Engineering, Imperial College London, London, SW7 2AZ, UK. |
| |
Abstract: | High accuracy seamless positioning is required to support a vast number of applications in varying operational environments. Over the last few years, the global positioning system (GPS) has become the de facto technology for positioning applications. However, its performance is limited in indoor and dense urban environments due to multipath as well as signal attenuation and blockage. A number of techniques integrating GPS with other positioning technologies have been developed to address the limitations of standalone GPS in these difficult environments. While most of the developed techniques cover the outages of GPS in such environments, they do not provide acceptable performance, in terms of positioning accuracy, especially for some mission-critical (e.g. safety) applications. This paper proposes a tightly coupled (i.e. in the measurement domain) GPS/WiFi integration method which, in addition to addressing GPS outages, improves the overall positioning accuracy to the meter-level, thus satisfying the requirements of a number of location based services and intelligent transport systems applications. The performance of the proposed GPS/WiFi integration method is assessed for a number of scenarios in a simulation environment for an identified dense urban area in London, UK. |
| |
Keywords: | GPS integration time estimation WiFi Improved FOCUSS for Arrival Time Estimation (IFATE) Time Difference of Arrival (TDOA) WLAN IEEE802 11g |
|
|