Technique for mobile wireless device location
AssigneeInternational Business Machines Corporation
InventorClaudio Anzil
Life of this patent
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Abstract
A method and apparatus of determining the position of a mobile communications device using retransmitted GPS data is described. In the invention, a timing apparatus in the mobile communications device is synchronized with a timing device in the base station. The mobile unit samples and time stamps received GPS signals for retransmission to the base station. The base station uses the time stamp to determine an approximate time when the GPS sample was received allowing a reduction in the amount of GPS sample data needed to compute a position of the mobile communications device.
Claims16
A mobile communications device comprising:
- a timing apparatus to output a time stamp, the timing apparatus synchronized to a base station timing reference;
- an antenna to receive and output GPS data transmitted from at least one GPS satellite;
- a GPS receiving circuit coupled to the antenna and timing apparatus to sample the GPS data and combine a GPS data sample with e time stamp to form a data packet;
- and
- a transmission circuit to transmit a plurality of data packets for periodic determination of the position of the mobile communications device at a sampling rate for correlation with data at a base station, the data at said base station being retrieved from a memory of the base station which data was received at the base station at the same time.
A method of determining a position of a mobile transmitting unit comprising the acts of:
- synchronizing a timing apparatus with a timing signal received from a base station;
- receiving and taking a plurality of samples of a GPS signal from at least one GPS satellite for periodic determination of the position of the mobile transmitting unit;
- associating each sample of the received GPS signal with a corresponding time stamp, the corresponding time stamp based on the timing apparatus and indicating when the sample of GPS data was received;
- and
- transmitting the plurality of samples of the GPS signal each with the corresponding time stamp to a base station for correlation with the data at the base station, the data at said base station being retrieved from a memory of the base station which data was received at the base station at the same time.
A method of determining a position of a mobile communications device comprising:
- receiving GPS signals from at least one GPS satellite at a first station;
- storing the GPS signals as GPS signal segments in a memory;
- indexing each GPS signal segment with a corresponding index indicating a time when the GPS signal segment was received;
- receiving a plurality of GPS samples and each sample associated with a corresponding time stamp from a mobile communications device;
- matching GPS signal segments to corresponding GPS samples having time stamps corresponding to the index of each GPS segment;
- and
- determining what time the GPS sample was received using the matching GPS signal segment.
Dependencies are inferred from the claim text.