Communications system and related method for determining a position of a mobile station

A time division multiple access (TDMA) communications system comprising:

• at least one mobile station;
• a plurality of base stations each transmitting a downlink signal to said at least one mobile station substantially asynchronously from one another in a predetermined sequence and receiving an uplink signal from said at least one mobile station responsive thereto, each base station having a known position and determining a round trip delay between transmission of the downlink signal and reception of the uplink signal;
• and
• a position determiner for determining a position of said at least one mobile station based upon the round trip delays and the known positions of said base stations.

A method for determining a position of at least one mobile station comprising:

• transmitting a downlink signal from each of a plurality of base stations each having a known position to the at least one mobile station substantially asynchronously from one another;
• receiving an uplink signal from the at least one mobile station at each of the base stations responsive to the respective downlink signals;
• determining a round trip delay between transmission of the downlink signal and reception of the uplink signal for each base station;
• and
• determining a position of the at least one mobile station based upon the round trip delays and the known positions of the base stations.

A method for determining a position of at least one mobile station in a time division multiple access (TDMA) communications system comprising:

• transmitting a downlink signal from each of a plurality of base stations each having a known position to the at least one mobile station substantially asynchronously from one another in a predetermined sequence;
• receiving an uplink signal from the at least one mobile station at each of the base stations responsive to the respective downlink signals;
• determining a round trip delay between transmission of the downlink signal and reception of the uplink signal for each base station;
• and
• determining a position of the at least one mobile station based upon the round trip delays and the known positions of the base stations.