Wireless clock synchronization

A system for synchronizing internal clocks of a mobile device locating network, comprising:

• receiving stations having the internal clocks;
• a processor connected to the receiving stations;
• and a beacon adapted for transmitting to the receiving stations a series of reference data packets, the beacon having a known location proximate to a geographical center point of the receiving stations,
• wherein each of the receiving stations is adapted to forward arrival times of the series of reference data packets to the processor, wherein the processor is adapted to compute:
• a linear polynomial fit tB=m tA+b for a pair of receiving stations A and B, where tA and tB are the reception times of the series of reference data packets at receiving stations A and B, respectively, where slope m is function of the difference in the frequencies of the internal clocks of the receiving stations A and B, and where y-intercept b is the offset due to different start times of the internal clocks of the receiving stations A and B;
• and
• a bias for the internal clocks of receiving stations A and B using known difference in distance between the beacon and the receiving stations A and B;
• and
• wherein the processor is further adapted to synchronize the internal clocks of the receiving stations A and B according to the slope m, the offset b and the bias.

A method of synchronizing internal clocks of receiving stations of a locating system, comprising the steps of:

• for a first pair of receiving stations A and B in the location system,
• transmitting a series of reference data packets from a beacon at a known position;
• assuming that the beacon is at the geographical center point between receiving stations A and B;
• correlating first arrival times tA and second arrival times tA by plotting times tA and tB against each other for the series of reference data packets, where a first arrival time tA is a time of reception of the a particular reference data packet by the receiving station A, and corresponding second arrival time tB is a time of reception of the particular reference data packet by the receiving station B, computing a linear polynomial fit tB=m tA+b, where slope m is function of the difference in the frequencies of the internal clocks of the first and second receiving stations and y-intercept b is the offset due to different start times of the internal clocks of the first and second receiving stations;
• determining a bias for the internal clocks using known difference in distance between the beacon and the first and second receiving stations,
• synchronizing the internal clocks for the first pair of receiving stations A and B according to the slope m, the offset b and the bias;
• and
• repeating the preceding steps for a second pair of receiving stations in the locating system.