Wireless user position update using infrastructure measurements

• Main Author: S.S. SOLIMAN
• Format: Patent
• Language: English
• Published: 08.06.2005
• Edition: 7
• Subjects: ANALOGOUS ARRANGEMENTS USING OTHER WAVES; DETERMINING DISTANCE OR VELOCITY BY USE OF RADIO WAVES; ELECTRIC COMMUNICATION TECHNIQUE; ELECTRICITY; LOCATING OR PRESENCE-DETECTING BY USE OF THE REFLECTION ORRERADIATION OF RADIO WAVES; MEASURING; PHYSICS; RADIO DIRECTION-FINDING; RADIO NAVIGATION; TESTING; WIRELESS COMMUNICATIONS NETWORKS

A method and apparatus for tracking the position of a mobile unit in a mobile radio communication system using information from earth-orbiting satellites and information received from the infrastructure of the system, wherein the infrastructure consists of equipment associated with transmitting and receiving voice or data traffic to and from the mobile phone. An initial position of the mobile unit is calculated using measurements from earth-orbiting satellites. Next, one or more range measurements are made using signals transmitted between the mobile unit and the infrastructure. A positional difference between the initial position and a current position of the mobile station is estimated using the one or more range measurements, wherein only range measurements made from signals transmitted between the mobile unit and the infrastructure are used to perform the estimating. An accuracy value is next determined for the estimated positional measurement, and the accuracy value is compared to a threshold to determine whether the estimated positional measurement has an acceptable accuracy. If the estimated positional measurement has an acceptable accuracy, then the initial position of the mobile unit is updated using the estimated positional measurement and the process is repeated using only range measurements made from signals transmitted between the mobile unit and the infrastructure; otherwise, a new initial position is determined from the earth-orbiting satellites and the process is repeated.