Microelectronics sensors enable breakthrough indoor navigation accuracy

GENEVA, SWITZERLAND: STMicroelectronics will be demonstrating the world’s most accurate indoor positioning of a mobile phone at the World Mobile Congress, Barcelona. Comprising a smartphone combining the leading-edge SiRFusion location technology from CSR plc and an optimized MEMS (Micro-Electro-Mechanical-Systems) inertial measurement unit from ST, the demonstration shows that location can be reliably determined to within a few metres even in the absence of GNSS (Global Navigation Satellite Systems) satellite signals.

Accurate indoor location will be the key enabler for future Location-Based Services (LBS), which are widely expected to be the next “killer application” in the mobile world. However, a challenge has been the problem of locating the mobile device with sufficient accuracy and reliability in urban canyons and indoor environments where the signals from the GNSS satellites cannot be received.

In these cases, Wi-Fi and stored databases have been used so far to calculate the approximate location but the resulting accuracy has not been sufficient for many of the LBS services that are envisaged. For example, in the future, visitors in a museum will have the option to download detailed information about an exhibit simply by pointing their mobile towards it but for this to be possible the location of the device must be known to within a few metres, an accuracy not achievable using Wi-Fi alone.

At Mobile World Congress, ST is demonstrating the feasibility of achieving the required order of accuracy by combining the SiRFusion location architecture recently introduced by CSR plc with a sophisticated MEMS inertial module that offers ten degrees of freedom. With the high accuracy of the module, the mobile can be reliably located to within less than a few meters, an order of magnitude better than can be achieved using Wi-Fi alone. The SiRFusion location platform requires no additional infrastructure installations or complex surveys of buildings.

“This solution demonstrates that reliable pedestrian dead-reckoning achieved by combining ST’s industry-leading motion sensors with our SiRFusion location platform is the final piece of the indoor navigation jigsaw,” said Kanwar Chadha, CMO for CSR and founder of SiRF. “This will allow a new wave of location-based services that users will be able to enjoy both indoors and outdoors.”

The sensor used in the demonstration is a multi-sensor Inertial Measurement Unit combining 3-axis sensing of linear, angular and magnetic motion with a pressure reading used to determine the elevation, which enables 3-dimensional location in multi-story buildings. Utilizing motion sensors, Wi-Fi measurements and signals from Global Navigation Satellite Systems (GNSS) satellites, CSR’s SiRFusion solution fuses data from the sensor unit with other data to dramatically improve the accuracy and coverage of the position calculation.

“Our motion sensors enabled the big revolution that allowed people to interact more easily or intuitively with their cell phone. Now we are at the dawn of a new age where optical image stabilization and location-based services will drive the adoption of new high-performance motion sensors. And ST is ideally positioned to drive these two emerging applications,” said Benedetto Vigna.