Paul Thevenon

Development and validation of an OFDM/DVB-T sensor for positioning

The use of Global Navigation Satellite System (GNSS) for positioning has grown significantly in recent years thanks in particular to the development of several mass-market applications, such as car navigation or mobile positioning. Unfortunately, in difficult environments such as dense urban or indoor areas, GNSS exhibits degraded performances in terms of precision and availability. The use of signals of opportunity is one of the solutions to replace or assist GNSS in those environments. These signals are communication signals that are usually designed to provide a service in dense environment and can thus be used in location where GNSS is unavailable. Several commercial positioning services based on signals of opportunity already exist such as ROSUM with ATSC digital TV signals, or Skyhook with Wi-Fi signals

Positioning principles with a mobile TV system using DVB-SH signals and a Single Frequency Network

Mobile receiver positioning has received a lot of attention, both in research and standardization bodies, due to regulatory (E-911) or commercial (Location-Based Services) incentives. This paper investigates the possibility of self-positioning a mobile receiver using a mobile TV broadcasting system based on the European DVB-SH standard. This OFDM-based standard offers the interesting possibility of using a Single Frequency Network (SFN) of emitters, meaning that the transmitters are synchronized, which is extremely precious for navigation applications based on Time of Arrival measurements. This paper proposes to base our positioning service on the use of the estimation of the channel done by the receiver, in order to use Time Differences of Arrival techniques. In order to detect several emitters in a SFN, it is proposed to introduce artificial delays between adjacent emitters. The impact of this modification is investigated and some particular DVB-SH signal parameters are found to be well-suited to this solution.

Use of OFDM-based digital TV for ranging: Tests and validation on real signals

This article presents results of tests on real signal of a method of positioning using a digital TV DVB-T signal-of-opportunity which is based on an OFDM modulation. OFDM and DVB-T standard are presented and the positioning method using the DVB-T signal is detailed. The result on real signal are analyzed qualitatively and quantitatively in static and dynamic scenarios and indoor and outdoor environments. In static scenarios, the standard deviation of pseudorange error is about 8 cm outdoor and 0.7 m indoor. In dynamic scenarios the pseudorange estimation is considerably disturbed and additional experiments are necessary to quantify the performance in this case.

Regulatory analysis of potential candidate bands for the modernisation of GNSS systems in 2015–2020

With the increase of global satellite navigation systems (GNSS) in a limited number of frequency bands, the current spectrum dedicated to satellite navigation encounters congestion. A possible path to keep modernizing the different GNSS is to find new frequency bands where a satellite radio-navigation service (RNSS) could be provided. This article takes a regulatory approach to identify potential candidate bands, which are then reviewed in detail to assess their usability for a new RNSS deployment. The results of this analysis are: (1) there exist spaces in the spectrum where a RNSS allocation exists or could be added. For example, the option consisting in adding another RNSS allocation into aeronautical radio-navigation service (ARNS) bands. However, such allocation change is not planned and would require important commitment from administrations and long negotiations with the civil aviation community; (2) the use of telecommunication signals of opportunity coming from an hybrid satellite-terrestrial network of emitters. Among these solutions, some would permit to combine navigation and telecommunication services, offering a huge opportunity for mass market application.