A second demonstration session took place in Luxembourg on the 19th November 2013. The project team participated at the public event, Salon Index 2014, organised by the Paperjam Business Club at the Abbaye Neumünster.

More than 500 people participated in the event. More information can be found on the event website.

The project team presented a technology for indoor navigation based on Bluetooth. An accuracy better than 2 meters was achieved. Below are some pictures of the application running on a smartphone.

As explained during the event, indoor positioning using Galileo technology which is the basis of the i-GOing project has significant advantages over the technologies that are currently on the market. We can mention here seamless navigation between outdoor and indoor, and increased accuracy.

The first demonstration session of the technology developed in the i-GOing project took place at the Pau airport located in the south of France.

Below is a plan of the airport. Two pairs of antennas (in red) have been placed in the main hall. The test area is delimited in green.

Time of arrival of direct path signal is classically based on correlation process. The correlation process consists in multiplying and accumulating received signal (combination of N PRN) with a local PRN after down-converting received PRN signal into baseband. For reasons of complexity and resources the local signal is an ideal NRZ waveform without modelling of the filter effect.  That limits the number of bits needed to store the accumulation value as the FPGA blocs required to multiply the received signal with the local signal. The impact of multipath on time of arrival measurement in harsh indoor environment implies to have some flexibility in correlator position and to be able to have a high resolution of the correlation function (very narrow spaced correlator).

The tracking process could be separated in two main actions. First, a code/carrier tracking error is computed based on correlation information (alternatively based on compressed signal). Then, this instantaneous error is filtered before correcting the local code/carrier generation. The loop filter can be optimised for the considered application (example: pedestrian) but the main work is on the estimation of the tracking error of the LOS signal. The objective is to fight multipath to get accuracies close to one meter. First, classic discriminator (narrow correlator and double delta correlator mainly) are tested with a correlator spacing as narrow as possible to remove a maximum of multipath bias. The high SNR (Signal to Noise Ratio) and high receiver bandwidth of the receiver platform will allow tightening the correlator more than in a GNSS system. If the multipath mitigation of these technique after tightened at the maximum the correlator spacing is still not suitable to reach such a level of performance, then the implementation of other techniques will be considered. Finally, as each PRN suffers more or less from multipath or other degradations, vector tracking will be considered to help poor PRN tracking with other PRN tracking by the mean of the predicted position and clock bias.

In order to increase multipath robustness it is planned to use faster chip rates, from 1 Mchip/s (E1) to 5 Mchip/s (E6).

The deployment of positioning applications requires two components: maps and a positioning engine. In outdoor, positioning relies mainly on Global Navigation Satellite Systems as GPS, GLONASS and the upcoming Galileo, while maps are easily accessible through Google maps, Bing maps, Apple maps and other providers.

Indoor maps have been launched in a few countries a year ago now by Google and Bing Maps, and these have been expanding to many other countries in the last weeks. In particular, selected large venues such as shopping centres, retail stores, airports and museums are already available in France, United Kingdom, United States and Japan, among others.

Recently Google added walking directions for buildings in the United States and Japan.

Indoor navigation technologies are also available but with limited accuracy when in comparison with what is now achieved outdoor. Indoor solutions based on pseudolites such as the solution developed in the i-GOing project will soon be available, and may reach similar performance. Moreover, the potential grey zone of signal losses induced by the outdoor-indoor transition could be avoided by the standardisation approach led in this research project which will allow considering indoor pseudolite networks as an extension of the GNSS.

 An interesting reflection is that the deployment of digital outdoor maps was pushed by the increased performance of GNSS, namely after the GPS Selective Availability was turned off (May 2000). In contrast, regarding indoor positioning, accurate maps are pushing the development of more accurate positioning systems such as pseudolite network systems.

Despite some mature indoor navigation techniques, innovative solutions for indoor and underground environments are still appearing. The project INSIDE, performed by Astri Polska (Poland), aims to “define the most appropriate localisation technique, which could enable better accuracy and positioning in all possible conditions, especially indoor and underground.

The proposed solution makes use of 3 or 4 transmitters located outdoors broadcasting signals in the VLF frequency band (3-30 kHz). Using such frequencies, signals are able to cross walls and be sensed deep indoor and underground.

The positioning technique is based on the angle of arrival method which requires a minimum of 3 three transmitters with a good spatial distribution for an optimum accuracy.

Claimed advantages are a good positioning accuracy, the absence of multipath, diffraction and reflections, and cost-effective transmitters. On the opposite, admitted disadvantages are the large transmitter and receiver antennas.

The size of the required receiver antenna limits the use of such technique in standard portable devices, meaning that it is actually not a technology that may compete directly with pseudolites.

Over the last decade, the growth of applications using positioning systems and location-based services has exploded. Current satellite navigation systems, such as GPS, GLONASS and the future Galileo ensure a large coverage for outdoor positioning. But what’s up for indoor positioning in malls, large buildings or even in area prone to canyoning effects as urban areas?

Solutions using other systems exist: Wi-Fi positioning, inertial navigation… BUT WHAT DO YOU THINK ABOUT AN INDOOR NAVIGATION SYSTEM BASED ON THE SAME POSTIONING SYSTEMS AS IN OUTDOORS?

THE MARKET is already ready:

• MEET YOUR FRIENDS INSIDE A LARGE STADIUM: In Europe, many sportive and entertainment events take place in large covered buildings, such as stadiums, pavilions or halls. The development of the indoor positioning technology would enable the creation of applications that facilitate that friends meet each other during the event;
• FIND YOUR CAR IN A LARGE UNDERGROUND PARKING: In cities it is common that parking lots are indoor, either underground or composed of multiple floors that obstruct the reception of satellite signals. Who has never forgotten the place, including the floor, where the car is? An application for smartphones making it possible to save the place of the car could be very useful;
• FIND YOUR WAY TO YOUR FLIGHT GATE IN EVERY AIRPORT: Examples of large buildings are obviously airports. Often it is not obvious how to get quickly to the boarding gate when departing, or to the conveyor belt when arriving;
• FIND A COMPANY IN A LARGE COMPANY POOL: Fairs that usually occur indoor are also interesting events that might make use of indoor positioning. A guidance application for smartphones similar to car navigations systems would be perfect to help users find the quickest path to the booth of a specific company.
• LET YOU GUIDE FROM ONE SHELF TO ANOTHER IN A SHOPPING MALL: When entering for the first times in a big shopping mall, it might be difficult to find the store one is looking for. Later, after having found the store, the user might be interested in a specific article and do not want being looking for it through many galleries of articles and might make use of an application that guides him or her to the shelf where the article is located. Applications that calculate the shortest path to assemble a set of articles are also enabled with indoor positioning.