Minimum variance location estimation in wireless networks
First Claim
Patent Images
1. A data storage medium encoded with computer executable instructions for acquiring information from a wireless network, the computer executable instructions when executed operable to cause a processor to:
- collect received signal strength data;
compute an aggregate square error surface based on the received signal strength data, wherein the aggregate square error surface corresponds to a matrix of locations each defined by an x-coordinate and a y-coordinate;
compute a probability surface by computing a probability density function from the aggregate error surface, wherein the probability values of the probability surface are normalized such that a sum of the probability values over an entire surface equals one; and
compute a mean x-coordinate location and a mean y-coordinate location of a wireless node based on the probability surface, wherein the mean x-coordinate location is a sum, for all x-coordinates of the matrix, of the coordinate value of x multiplied by the sum of all normalized probability values across all y-coordinate values of the matrix, and, wherein the mean y-coordinate location is a sum, for all y-coordinates of the matrix, of the coordinate value of x multiplied by the sum of all normalized probability values across all x-coordinate values of the matrix.
1 Assignment
0 Petitions
Accused Products
Abstract
In one embodiment, a method includes receiving received signal strength data, computing an aggregate square error surface based on the received signal strength data, computing a probability surface by applying a probability density function to the aggregate error surface, and computing a mean location of a wireless node.
-
Citations
17 Claims
-
1. A data storage medium encoded with computer executable instructions for acquiring information from a wireless network, the computer executable instructions when executed operable to cause a processor to:
-
collect received signal strength data; compute an aggregate square error surface based on the received signal strength data, wherein the aggregate square error surface corresponds to a matrix of locations each defined by an x-coordinate and a y-coordinate; compute a probability surface by computing a probability density function from the aggregate error surface, wherein the probability values of the probability surface are normalized such that a sum of the probability values over an entire surface equals one; and compute a mean x-coordinate location and a mean y-coordinate location of a wireless node based on the probability surface, wherein the mean x-coordinate location is a sum, for all x-coordinates of the matrix, of the coordinate value of x multiplied by the sum of all normalized probability values across all y-coordinate values of the matrix, and, wherein the mean y-coordinate location is a sum, for all y-coordinates of the matrix, of the coordinate value of x multiplied by the sum of all normalized probability values across all x-coordinate values of the matrix. - View Dependent Claims (2, 3, 4)
-
-
5. A method for estimating a location of a wireless node, comprising:
-
collecting, by a computing device, received signal strength data; computing an aggregate square error surface based on the received signal strength data, wherein the aggregate square error surface corresponds to a matrix of locations each defined by an x-coordinate and a y-coordinate; computing a probability surface by computing a probability density function from the aggregate error surface, wherein the probability values of the probability surface are normalized such that a sum of the probability values over an entire surface equals one; and computing a mean x-coordinate location and a mean y-coordinate location of a wireless node based on the probability surface, wherein the mean x-coordinate location is a sum, for all x-coordinates of the matrix, of the coordinate value of x multiplied by the sum of all normalized probability values across all y-coordinate values of the matrix, and, wherein the mean y-coordinate location is a sum, for all y-coordinates of the matrix, of the coordinate value of x multiplied by the sum of all normalized probability values across all x-coordinate values of the matrix. - View Dependent Claims (6, 7, 8)
-
-
9. A system comprising:
-
one or more infrastructure radio transceivers; and a wireless network infrastructure node operable to; collect received signal strength data sensed by the one or more infrastructure radio transceivers;
compute an aggregate square error surface based on the received signal strength data, wherein the aggregate square error surface corresponds to a matrix of locations each defined by an x-coordinate and a y-coordinate;compute a probability surface by computing a probability density function from the aggregate error surface, wherein the probability values of the probability surface are normalized such that a sum of the probability values over an entire surface equals one; and compute a mean x-coordinate location and a mean y-coordinate location of a wireless node based on the probability surface, wherein the mean x-coordinate location is a sum, for all x-coordinates of the matrix, of the coordinate value of x multiplied by the sum of all normalized probability values across all y-coordinate values of the matrix, and, wherein the mean y-coordinate location is a sum, for all y-coordinates of the matrix, of the coordinate value of x multiplied by the sum of all normalized probability values across all x-coordinate values of the matrix. - View Dependent Claims (10, 11, 12)
-
-
13. A data storage medium encoded with computer executable instructions for acquiring information from a wireless network, the computer executable instructions when executed operable to cause a processor to:
-
collect received signal strength data for a wireless node; compute a plurality of aggregate square error surfaces, wherein each of the aggregate square error surfaces corresponds to a matrix of locations each defined by an x-coordinate and a y-coordinate, and wherein one of the plurality of aggregate square error surfaces corresponds to a nominal transmission power, and remaining aggregate square error surfaces each correspond to at least one transmission power above or below the nominal transmission power; compute an unnormalized probability surface for each of the aggregate square error surfaces; compute normalized probability surfaces for each of the unnormalized probability surfaces relative to all the probability surfaces, wherein the probability values of the normalized probability surfaces are normalized such that a sum of the probability values over an entire surface equals one; compute an aggregate probability surface across the normalized probability surfaces at each location bin; and compute a mean x-coordinate location and a mean y-coordinate location to yield an estimated location of the wireless node based on the aggregate probability surface, wherein the mean x-coordinate location is a sum, for all x-coordinates of the matrix, of the coordinate value of x multiplied by the sum of all normalized probability values across all y-coordinate values of the matrix, and , wherein the mean y-coordinate location is a sum, for all y-coordinates of the matrix, of the coordinate value of x multiplied by the sum of all normalized probability values across all x-coordinate values of the matrix. - View Dependent Claims (14, 15)
-
-
16. A method comprising:
-
collecting received signal strength data for a wireless node; computing a plurality of aggregate square error surfaces, wherein each of the aggregate square error surfaces corresponds to a matrix of locations each defined by an x-coordinate and a y-coordinate, and wherein one of the plurality of aggregate square error surfaces corresponds to a nominal transmission power, and remaining aggregate square error surfaces each correspond to at least one transmission power above or below the nominal transmission power; computing an unnormalized probability surface for each of the aggregate square error surfaces; computing normalized probability surfaces for each of the unnormalized probability surfaces relative to all the probability surfaces, wherein the probability values of the normalized probability surfaces are normalized such that a sum of the probability values over an entire surface equals one; computing an aggregate probability surface across the normalized probability surfaces at each location bin; and computing a mean x-coordinate location and a mean y-coordinate location to yield an estimated location of the wireless node based on the aggregate probability surface, wherein the mean x-coordinate location is a sum, for all x-coordinates of the matrix, of the coordinate value of x multiplied by the sum of all normalized probability values across all y-coordinate values of the matrix, and , wherein the mean y-coordinate location is a sum, for all y-coordinates of the matrix, of the coordinate value of x multiplied by the sum of all normalized probability values across all x-coordinate values of the matrix. - View Dependent Claims (17)
-
Specification