Real-time system and method for improving the accuracy of the computed location of mobile subscribers in a wireless ad-hoc network using a low speed central processing unit
First Claim
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1. A method for determining a location of a mobile communication device in a communication network, the method comprising:
- estimating a location of the mobile communication device based on measured data representing respective distances between the mobile communication device and a plurality of reference points;
assigning a respective weight factor to each data of the measured data;
generating a forget factor based on the respective weight factors; and
modifying the estimated location, using a predictive filter including the forget factor which treats older measured data less significantly than newer measured data in estimating the location, to generate a modified estimated location representative of the location of the mobile communication device.
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Abstract
A system and method for improving the accuracy in computing the location of a mobile subscriber device connected in a wireless network. The system and method employ a predictive filter, including a measurement weight algorithm to decrease standard deviation error, to correctly determine a location of a mobile subscriber device. The predictive filter requires lower levels of computation, which allows for real-time processing on low-speed central processing units commonly used in wireless networks.
136 Citations
21 Claims
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1. A method for determining a location of a mobile communication device in a communication network, the method comprising:
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estimating a location of the mobile communication device based on measured data representing respective distances between the mobile communication device and a plurality of reference points; assigning a respective weight factor to each data of the measured data; generating a forget factor based on the respective weight factors; and modifying the estimated location, using a predictive filter including the forget factor which treats older measured data less significantly than newer measured data in estimating the location, to generate a modified estimated location representative of the location of the mobile communication device. - View Dependent Claims (2, 3, 4, 5, 6)
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7. A method for determining a location of a mobile communication device in a communication network, the method comprising:
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estimating a location of the mobile communication device based on measured data representing respective distances between the mobile communication device and a plurality of reference points; modifying the estimated location, using a predictive filter including a forget factor which treats older measured data less significantly than newer measured data in estimating the location, to generate a modified estimated location representative of the location of the mobile communication device; wherein; the modifying step predicts movement of the mobile communication device on three axes of coordinates and uses the predictive filter to adjust the predicted movement to ascertain the modified estimated location; the modifying step predicts the movement using equations including variables representing the starting position of the mobile communication device and variables representing the moving speed of the mobile communication device, as modified by the predictive filter; and the equations include three systems of equations, each system pertaining to a respective axis of movement and employing the forget factor to adjust the estimated starting position coordinate for that respective axis and speed of movement along that respective axis.
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8. A computer readable medium of instructions for enabling a processor to determine a location of a mobile communication device in a communication network, the computer readable medium of instructions comprising:
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a first set of instructions, adapted to control the processor to estimate a location of the mobile communication device based on measured data representing respective distances between the mobile communication device and a plurality of reference points; and a second set of instructions, adapted to control the processor to modify the estimated location, using a predictive filter including a forget factor which treats older measured data less significantly than newer measured data in estimating the location, to generate a modified estimated location representative of the location of the mobile communication device; wherein the second set of instructions is further adapted to control the processor to assign a respective weight factor to each data of the measured data, and to generate the forget factor based on the assigned weight factors. - View Dependent Claims (9, 10, 11, 12, 13)
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14. A computer readable medium of instructions for enabling a processor to determine a location of a mobile communication device in a communication network, the computer readable medium of instructions comprising:
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a first set of instructions, adapted to control the processor to estimate a location of the mobile communication device based on measured data representing respective distances between the mobile communication device and a plurality of reference points; and a second set of instructions, adapted to control the processor to modify the estimated location, using a predictive filter including a forget factor which treats older measured data less significantly than newer measured data in estimating the location, to generate a modified estimated location representative of the location of the mobile communication device; wherein; the second set of instructions is adapted to control the processor to predict movement of the mobile communication device on three axes of coordinates and uses the predictive filter to adjust the predicted movement to ascertain the modified estimated location; the second set of instructions is adapted to control the processor to predict the movement using equations including variables representing the starting position of the mobile communication device and variables representing the moving speed of the mobile communication device, as modified by the predictive filter; and the equations include three systems of equations, each system pertaining to a respective axis of movement and employing the forget factor to adjust the estimated starting position coordinate for that respective axis and speed of movement along that respective axis.
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15. A system for determining a location of a mobile communication device in a communication network, the system comprising:
a processor, adapted to estimate a location of the mobile communication device based on measured data representing respective distances between the mobile communication device and a plurality of reference points, and being further adapted to assign a respective weight factor to each data of the measured data, generate the forget factor based on the assigned weight factors, and modify the estimated location, using a predictive filter including the forget factor which treats older measured data less significantly than newer measured data in estimating the location, to generate a modified estimated location representative of the location of the mobile communication device. - View Dependent Claims (16, 17, 18, 19, 20)
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21. A system for determining a location of a mobile communication device in a communication network, the system comprising:
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a processor, adapted to estimate a location of the mobile communication device based on measured data representing respective distances between the mobile communication device and a plurality of reference points, and being further adapted to modify the estimated location, using a predictive filter including a forget factor which treats older measured data less significantly than newer measured data in estimating the location, to generate a modified estimated location representative of the location of the mobile communication device; wherein; the modifying operation predicts movement of the mobile communication device on three axes of coordinates and uses the predictive filter to adjust the predicted movement to ascertain the modified estimated location; the modifying operation predicts the movement using equations including variables representing the starting position of the mobile communication device and variables representing the moving speed of the mobile communication device, as modified by the predictive filter; and the equations include three systems of equations, each system pertaining to a respective axis of movement and employing the forget factor to adjust the estimated starting position coordinate for that respective axis and speed of movement along that respective axis.
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Specification