Radio beacon, mobile station, processor, system and method for determining location

摘要

A radio beacon ( 105 ( 5 )) is for use in location determination inside a building ( 103 ) or other enclosure. The beacon transmits a RF signal equivalent to a partially coded GPS (Global Positioning System) signal which includes an identity code identifying the beacon but null data in at least one GPS data field. A mobile station ( 101 ) includes a GPS receiver ( 208 ) for receiving GPS signals and a processor ( 202 ) for processing data extracted from signals received by the GPS receiver. The GPS receiver is operable to receive a signal from a transmitting beacon ( 105 ( 5 )). The processor is operable to recognise a beacon identity code from the data extracted from the received signal and thereby detect that the signal is from a radio beacon rather than a GPS satellite and thereby to apply a further procedure to calculate the location of the mobile station based upon a known location of the identified beacon.