Outdoor navigation using GPS receivers installed in various types of consumer electronics
devices, especially smartphones and tablet computers has become very common. However,
indoor navigation can be problematic as GPS signals are blocked by ceilings and building
walls and accuracy is on the order of building dimensions. In present work we propose
using an array of magnetic beacons for localizing a receiver equipped with a magnetic sensor.
A smartphone or a tablet computer with an internal magnetometer can be employed as
a receiver. Exploiting smartphones and tablets for indoor navigation is a great advantage
when considering convenience, simplicity and low cost. The navigation area is covered
by magnetic beacons deployed in known locations. Each beacon generates an AC magnetic
field with a unique signature enabling the receiver to distinguish between beacons. The
signature may feature a specific single frequency tone, a combination of frequencies, or
any other modulated signal.