Method for estimating signal strengths

• US 6,680,924 B2
• Filed: 12/14/2000
• Issued: 01/20/2004
• Est. Priority Date: 12/14/2000
• Status: Expired due to Fees

• Current Assignee: Carnegie Mellon University
• Original Assignee: Carnegie Mellon University
• Inventors: Hills, Alexander H., Jenkins, Benjamin C., Schlegel, Jon P.
• Primary Examiner(s): TON, DANG T
• Application Number:
  US09/737,184
• Publication Number:
  US 20020075825A1
• Time in Patent Office: 1,132 Days
• Field of Search: 370/328, 370/329, 370/331-334, 370/338, 370/339, 370/341, 370/350, 370/401, 370/901, 370/902, 370/908, 370/910-913, 370/254, 370/252, 370/241, 370/245, 370/247, 370/248, 370/251, 370/255, 370/465, 370/467, 725/123, 725/127, 455/456.1, 455/456.2, 455/456.6, 455/440, 455/452.2, 455/436, 455/441, 455/442, 455/453, 455/69, 375/229, 375/347, 375/345, 375/346, 375/348, 375/349, 375/368, 375/367, 375/227, 375/232
• US Class Current: 370/329
• CPC Class Codes: H04B 17/318 Received signal strength
• CPC Class Codes: H04W 16/18 Network planning tools

Abstract

A method for estimating signal strengths for a wireless environment. The method includes measuring a strength of a first radio signal at a plurality of locations in the environment, wherein the first radio signal is transmitted from a radio transmitter at a first location, estimating the strength of the first radio signal at each of the plurality of locations, and estimating a strength of a second radio signal at the plurality of locations, wherein the second radio signal corresponds to a signal transmitted from one of the plurality of locations, based on a difference between the measured signal strength and the estimated signal strength for the first radio signal.

Claims

1. A method for estimating signal strengths for a wireless environment, comprising:

measuring a strength of a first radio signal at a plurality of locations in the environment, wherein the first radio signal is transmitted from a radio transmitter at a first location;

estimating the strength of the first radio signal at each of the plurality of locations; and

estimating a strength of a second radio signal at the plurality of locations, wherein the second radio signal corresponds to a signal transmitted from one of the plurality of locations, based on a difference between the measured signal strength and the estimated signal strength for the first radio signal.

2. The method of claim 1, wherein estimating the strength of the first radio signal at each of the plurality of locations includes estimating the strength of the first radio signal at each of the plurality of locations based on a distance between each of the plurality of locations and the first location.

3. The method of claim 1, wherein estimating the strength of a second radio signal at the plurality of locations includes:

estimating the strength of the second radio signal at a first set of the plurality of locations; and

estimating the strength of the second radio signal at a second set of the plurality of locations based on the estimated signal strengths of the second radio signal for the first set of locations.

4. The method of claim 3, wherein:

estimating the strength of the second radio signal at the first set of plurality of locations includes estimating the strength of the second radio signal at the first set of plurality of locations based on a difference between the measured signal strength and the estimated signal strength at the first set of plurality of locations for the first radio signal; and

estimating the strength of the second radio signal at a second set of the plurality of locations includes estimating the strength of the second radio signal at the second set of the plurality of locations based on a least difference between the difference between the measured signal strength and the estimated signal strength at one of the first set of plurality of locations for the first radio signal and a difference between the measured signal strength and the estimated signal strength at the second set of plurality of locations for the first radio signal.

5. The method of claim 1, wherein measuring a strength of the first radio signal at the plurality of locations is performed after estimating the strength of the first radio signal at each of the plurality of locations.

6. A method for estimating signal strengths for a wireless environment, comprising:

measuring a strength of a first radio signal at a plurality of measurement nodes in the environment, wherein the first radio signal is transmitted from a first non-measurement node;

estimating the strength of the first radio signal at each of the plurality of measurement nodes; and

estimating a strength of a second radio signal at the plurality of measurement nodes and the non-measurement node, wherein the second radio signal corresponds to a signal transmitted from a first of the plurality of measurement nodes, based on a difference between the measured signal strength and the estimated signal strength for each of the measurement nodes for the first radio signal.

7. The method of claim 6, wherein estimating the strength of the second radio signal at the plurality of measurement nodes and the non-measurement node includes:

generating a graph with the non-measurement node connected to at least one of the plurality of measurement nodes by an edge and with each of the plurality of measurement nodes connected to at least one other measurement node by an edge;

assigning a normalized weight to each edge based on the difference between the measured signal strength and the estimated signal strength for each of the measurement nodes for the first radio signal; and

estimating the strength of the second radio signal at the plurality of measurement nodes and the non-measurement node based on the normalized weights of the edges.

8. The method of claim 7, wherein estimating the strength of the second radio signal at the plurality of measurement nodes based on the normalized weights of the edges includes:

estimating the strength of the second radio signal at a first set of the plurality of measurement nodes; and

estimating the strength of the second radio signal at a second set of the plurality of measurement nodes based on a least sum of normalized weights of edges connecting each of the second set of measurement nodes to one of the first set of measurement nodes.

9. The method of claim 8, wherein estimating the strength of the second radio signal at the first set of the plurality of measurement nodes includes estimating the strength of the second radio signal at the first set of the plurality of measurement nodes based on a distance between each of the first set of the plurality of measurement nodes and the first measurement node.

10. The method of claim 8, further comprising determining the measurement nodes belonging to the first set of measurement nodes and determining the measurement nodes belonging to the second set of measurement nodes.

11. The method of claim 10, wherein determining the measurement nodes belonging to the first set of measurement nodes includes assigning the measurement nodes within a threshold distance from the first measurement node to the first set of measurement nodes.

12. The method of claim 11, wherein determining the measurement nodes belonging to the second set of measurement nodes includes assigning all measurement nodes not assigned to the first set of measurement nodes to the second set of measurement nodes.

13. The method of claim 6, wherein measuring the strength of the first radio signal at a plurality of measurement nodes in the environment is performed after estimating the strength of the first radio signal at each of the plurality of measurement nodes.

14. A computer readable-medium having instructions stored therein which, when executed by a processor, cause the processor to:

determine a first estimated signal strength at a plurality of locations in the environment for a first radio signal, wherein the first radio signal is transmitted from a first location; and

determine a second estimated signal strength at the plurality of locations for a second radio signal, wherein the second radio signal corresponds to a signal transmitted from one of the plurality of locations, based a difference between a measured signal strength at the plurality of locations for the first radio signal and the first estimated signal strengths.

15. The computer-readable medium of claim 14, having further stored thereon instructions which, when executed by the processor, cause the processor to:

generate a graph with a node representative of the first location connected to at least one node representative of one of the plurality of locations by an edge, and with each node representative of the plurality of locations connected to at least one other node representative of one of the plurality of locations by an edge;

assign a weight to each edge based on the difference between the measured signal strength and the estimated signal strength for each of the plurality of locations for the first radio signal; and

estimate the strength of the radio signal at the plurality of locations and the first location based on the weights of the edges for the radio signal transmitted from the first location.