Mobile station position determination in a wireless communication system
First Claim
1. A method of determining the position of a mobile station in a wireless communications system, the method comprising the steps of:
- receiving a first time information signal from a base station of the wireless system;
processing the first time information signal in the mobile station to generate a second time information signal; and
transmitting the second time information signal to the system base station using a low-power offset carrier signal, offset in frequency from a mobile-to-base data carrier signal of the system, and having a substantially lower power level than the data carrier signal, wherein the base station utilizes the first and second time information signals in conjunction with range information received from at least one other system base station to determine the position of the mobile station.
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Accused Products
Abstract
Methods and apparatus for determining mobile station position in a wireless communication system are disclosed. A mobile station of the wireless system includes a silent echo generation circuit which receives a transmit time stamp transmitted in a sync channel from a base station, and processes the transmit time stamp to generate a receive time stamp. The silent echo generation circuit transmits the receive time stamp back to the base station on a spurious-like echo carrier which is offset from a data carrier of the wireless system. The base station processes the transmit and receive time stamps to compute a first ranging value, receives corresponding second and third ranging values computed by two other system base stations which receive the echo carrier and its time stamp, and processes the first, second and third ranging values to determine a position vector indicative of the position of the mobile station. The base station then further processes the position vector to determine a bearing for the vector, and converts the result into latitude and longitude coordinates of the mobile station position. The silent echo generation circuit provides mobile position determination capability in the wireless system without significantly increasing the cost, size, weight and power consumption of the mobile station, without requiring a multilayer user interface, and without degrading system voice quality.
62 Citations
29 Claims
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1. A method of determining the position of a mobile station in a wireless communications system, the method comprising the steps of:
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receiving a first time information signal from a base station of the wireless system; processing the first time information signal in the mobile station to generate a second time information signal; and transmitting the second time information signal to the system base station using a low-power offset carrier signal, offset in frequency from a mobile-to-base data carrier signal of the system, and having a substantially lower power level than the data carrier signal, wherein the base station utilizes the first and second time information signals in conjunction with range information received from at least one other system base station to determine the position of the mobile station. - View Dependent Claims (2, 3, 4, 5, 6, 7)
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8. A mobile station suitable for use in a wireless communications system having a mobile position determination capability, the mobile station comprising:
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a receiver for receiving a first time information signal from a base station of the wireless system; and an offset carrier generation circuit having an input connected to receive the first time information signal from the receiver, wherein the generation circuit is operative to process the first time information signal to generate a second time information signal and to transmit the second time information signal to the system base station using a low-power offset carrier signal, offset in frequency from a mobile-to-base data carrier signal of the system, and having a substantially lower power level than the data carrier signal, such that the base station utilizes the first and second time information signals in conjunction with range information received from at least one other system base station to determine the position of the mobile station. - View Dependent Claims (9, 10, 11, 12, 13, 14)
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15. A method of determining the position of a mobile station in a wireless communications system, the method comprising the steps of:
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transmitting a first time information signal from a first base station of the wireless systems; receiving in the first base station a second time information signal generated by the mobile station in response to the first information signal, wherein the second time information signal is transmitted from the mobile station to the first base station using a low-power offset carrier signal, offset in frequency from a mobile-to-base data carrier signal of the system and having a substantially lower power level than the data carrier signal; and processing the first and second time information signals in the first base station in conjunction with range information received from at least one other system base station to determine the position of the mobile station. - View Dependent Claims (16, 17, 18, 19)
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20. A base station suitable for use in a wireless communications system having a mobile position determination capability, the base station comprising:
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a transmitter for transmitting a first time information signal to a mobile station of the wireless system; a receiver for receiving a second time information signal generated by the mobile station in response to the first information signal, wherein the second time information signal is transmitted from the mobile station to the base station using low-power offset carrier signal, offset in frequency from a mobile-to-base data carrier signal of the system and having a substantially lower power level than the data carrier signal; and a processor for processing the first and second time information signals in conjunction with range information received from at least one other system base station to determine the position of the mobile station. - View Dependent Claims (21, 22, 23, 24)
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25. A wireless communication system having a mobile position determination capability, the system comprising:
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at least one mobile station; and a plurality of base stations including at least first, second and third base stations; the first base station including a transmitter for transmitting a first time information signal to the mobile station, a receiver in the first base station for receiving a second time information signal generated by the mobile station in response to the first information signal, wherein the second time information signal is transmitted from the mobile station to the first base station using a low-power offset carrier signal, offset in frequency from a mobile-to-base data carrier signal of the system and having a substantially lower power level than the data carrier signal, and a processor for processing the first and second time information signals in the base station in conjunction with range information received from at least one other system base station to determine the position of the mobile station. - View Dependent Claims (26, 27, 28, 29)
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Specification