Method and apparatus to determine mobile user's location in a wireless communication network

A method for determining a location of a mobile station within a wireless communication network, the wireless communication network including a plurality of base receivers coupled to a switch for receiving communication from the mobile station during a specified period of time, the method comprising:

• transmitting a signal from the mobile station for receipt by at least two of the base receivers;
• determining a timing error associated with the transmitted signal for each of the base receivers that received the transmitted signal;
• determining a separation distance between the mobile station and each base receiver that received the transmitted signal based at least upon the timing error;
• and
• determining the location of the mobile station within the wireless communication network based upon the separation distance between the mobile station and the base receivers that received the transmitted signal, wherein the determining the separation distance comprises:
• calculating a difference in the timing errors forwarded by each base receiver for each combination of base receivers that received the transmitted signal, and
• averaging the calculated difference in the timing errors forwarded by each base receiver for each combination of base receivers that received the transmitted signal.

A wireless communication system for determining a location of a mobile station communicating therein, comprising:

• a plurality of base receivers configured to receive wireless communication;
• a controller;
• and
• a mobile station configured to transmit a signal for receipt by at least two of the base receivers, wherein:
• the base receivers configured to receive the transmitted signal are further configured to determine a timing error associated with the transmitted signal, and the controller is configured to determine a separation distance between the mobile station and each base receiver that received the transmitted signal based at least upon the timing error, and is further configured to determine the location of the mobile station within the wireless communication network based upon the separation distance between the mobile station and the base receivers that received the transmitted signal, and
• the controller is further configured to determine a circular region around a location of each base receiver that received the transmitted signal, each circular region having a radius equal to the separation distance between the mobile station and the respective base receiver, and is configured to determine an intersection point of the circular regions, thereby providing the location of the mobile station in the wireless communication network.

A wireless communication system for determining a location of a mobile station communicating therein, comprising:

• a plurality of base receivers for receiving wireless communication;
• a controller;
• and
• a mobile station configured to transmit a signal for receipt by at least two of the base receivers, wherein:
• the base receivers are configured to receive the transmitted signal and to determine a timing error associated with the transmitted signal, and the controller is configured to determine a separation distance between the mobile station and each base receiver that received the transmitted signal based at least upon the timing error, and is further configured to determine the location of the mobile station within the wireless communication network based upon the separation distance between the mobile station and the base receivers that received the transmitted signal,
• the controller is configured to calculate a difference in the timing errors forwarded by each base receiver for each combination of base receivers that received the transmitted signal, and
• the controller is further configured to average the calculated difference in the timing errors forwarded by each base receiver for each combination of base receivers that received the transmitted signal.

A method for determining a location of a mobile station within a wireless communication network, the wireless communication network including a plurality of base receivers coupled to a switch for receiving communication from the mobile station during a specified period of time, the method comprising:

• transmitting a signal from the mobile station for receipt by a subset of the plurality of base receivers;
• determining a timing error associated with the transmitted signal for each of the subset of base receivers that received the transmitted signal;
• and
• determining the location of the mobile station within the wireless communication network as a function of the timing error, wherein determining a timing error further comprises:
• determining a plurality of filter coefficients to match the signal transmitted by the mobile station to a predefined synchronous bit pattern,
• continuously convolving the plurality of determined filter coefficients with the signal transmitted by the mobile station until a predefined recognition pulse is output by the convolution, and
• determining a difference in time that the predefined recognition pulse is output and the specified time period that the mobile station should have transmitted the signal.