Granted Patent B2

US 6,959,189 · App. 09/929,034 · Granted Oct 25, 2005

Abstract

Claims (57)

1. A method for processing signal strength information from a radio frequency transmitter comprising the steps of:

receiving signal strength information indicating a power for the radio frequency transmitter at one or more first locations;

receiving location information representing a geographic location for one or more second locations;

dividing the received signal strength information into one or more subsets of signal strength information, such that the one or more subsets are determined based on a speed of a receiver of the received signal strength information and a corresponding distance associated with the speed;

determining, for each of the one or more subsets, a local mean, such that the local mean represents an average for one of the one or more subsets;

estimating a location for the local mean based on the received location information;

determining at least one distance between the estimated location and another estimated location based on the speed of the receiver and the signal strength information.

2. The method of claim 1 , further comprising the step of:

interpolating the local mean when the at least one distance exceeds a predetermined distance.

3. The method of claim 1 , wherein said step of determining further comprises the step of:

determining a plurality of local means such that each local mean corresponds to one of the one or more subsets.

4. The method of claim 3 , wherein said step of determining further comprises the step of:

averaging one or more of the plurality of local means to provide a window average.

5. The method of claim 4 , wherein said step of averaging further comprises the step of:

determining a difference value based on one of the plurality of local means and the window average.

6. The method of claim 5 , wherein said step of averaging further comprises the step of:

determining a plurality of difference values.

7. The method of claim 6 , further comprising the step of:

calculating a standard deviation based on the plurality of difference values.

8. The method of claim 7 , further comprising the step of:

determining a signal coverage at a location for a wireless device based on the following equation:

Cp

⁢

(

r

)

=

1

2

-

erf

⁢

w

t

-

LM

⁢

(

r

)

σ

LM

wherein r represents the location, σ LM represents the standard deviation, LM(r) represents the local mean corresponding to the location, w t represents a service threshold for the wireless device, and erf is a normal distribution error function.

9. The method of claim 8 , wherein said step of determining the signal coverage further comprises the step of:

defining the location as at least one of the one or more first locations.

10. The method of claim 1 , further comprising the step of:

defining the one or more first locations as locations that differ from the one or more second locations.

11. A method for processing signal strength information from a radio frequency transmitter comprising the steps of:

receiving signal strength information indicating a power for the radio frequency transmitter at one or more first locations, wherein the signal strength information includes a set of signal strength data based on a signal trace;

receiving location information representing a geographic location for one or more second locations, wherein the received location information for one or more second locations includes one or more of the following: a latitude, a longitude, or at least one of a plurality of first time stamps from a receiver of global positioning system information;

attaching at least one of a plurality of second time stamps to the set of signal strength data;

smoothing the plurality of second time stamps based on the plurality of first time stamps;

dividing the received signal strength information into one or more subsets of signal strength information, such that the one or more subsets are determined based on a speed of a receiver of the received signal strength information;

determining, for each of the one or more subsets, a local mean such that the local mean represents an average for one of the one or more subsets;

estimating a location for the local mean based on the received location information.

12. The method of claim 11 , wherein said smoothing further comprises the step of:

smoothing the plurality of second time stamps based on a slope for the plurality of first time stamps.

Assignments (6)