Localization of external interference in wireless networks
A method for localizing interference uses data available to wireless communication networks to determine probabilities of a source of external interference being located at a plurality of predetermined locations.
1. A method for locating a source of interference external to a wireless telecommunications network, the method comprising:
receiving signal strength measurement data for measurements taken by a plurality of cellular antennas of multi-sector cell sites;
determining that an external interference signal is present in the measurement data;
establishing a grid of pixels that represents an area associated with the plurality of cellular antennas;
determining respective first signal strength values for the pixels in the grid; and
determining respective probability values for the pixels in the grid by comparing the signal strength measurement data to the first signal strength values.
2. The method of claim 1 , wherein determining the first signal strength values comprises:
determining an angle of arrival for a pair of antennas of a cell site for each of the pixels; and
determining an expected interference power for each of the pixels using the associated angles of arrival.
3. The method of claim 1 , wherein determining the respective probability values comprises:
determining differences between values of the signal strength measurement data for antennas in an antenna pair and a hypothetical interference value for each pixel; and
assigning respective probability values to each pixel based on the differences.
4. The method of claim 3 , wherein, when a measured value of a first antenna of the antenna pair is equal to the noise floor and a measured value of a second antenna of the antenna pair is above the noise floor, the first signal strength value of the second antenna is set based on a difference between the measured value of the second antenna and the noise floor.
5. The method of claim 3 , wherein assigning the probability values comprises:
segmenting a normal distribution into a set of binned values; and
assigning one the binned values as the probability value for each pixel for a respective antenna pair.
6. The method of claim 5 , wherein assigning the probability values further comprises:
combining the binned values of antenna pairs of each cell site; and
combining probability values of each cell site,
wherein the respective probability values for the pixels are the combined probability values of each cell site.
7. The method of claim 1 , wherein the grid comprises a plurality of shapes that represent the pixels, and the grid is associated with a geographic area that includes all of the multi-sector cell sites.
8. The method of claim 1 , wherein determining the respective probability values comprises:
determining at least two local probability maxima within the grid, each of the local probability maxima being associated with a respective source of the external interference.
9. The method of claim 1 , further comprising:
providing a heat map indicating probability values of at least a portion of the pixels in the grid.
10. The method of claim 1 , wherein comparing the signal strength measurement data to the first signal strength values includes determining differences between the signal strength measurement data and the first signal strength values to determine the respective probability values.
11. A wireless telecommunications system comprising a spectrum analysis server configured to locate a source of interference external to a wireless telecommunications network, the spectrum analysis server comprising a processor and a non-transitory computer readable medium with instructions stored thereon which, when executed by the processor, perform the following steps:
receiving signal strength measurement data for measurements taken by a plurality of cellular antennas of multi-sector cell sites;
determining that an external interference signal is present in the measurement data;
establishing a grid of pixels that represents an area associated with the plurality of cellular antennas;
determining respective first signal strength values for the pixels in the grid; and
determining respective probability values for the pixels in the grid by comparing the signal strength measurement data to the first signal strength values.
12. The system of claim 11 , wherein determining the first signal strength values comprises:
determining an angle of arrival for a pair of antennas of a cell site for each of the pixels; and
determining an expected interference power for each of the pixels using the associated angles of arrival.
13. The system of claim 11 , wherein determining the respective probability values comprises:
determining differences between values of the signal strength measurement data for antennas in an antenna pair and a hypothetical interference value for each pixel; and
assigning respective probability values to each pixel based on the differences.
14. The system of claim 13 , wherein when a measured value of a first antenna of the antenna pair is equal to the noise floor and a measured value of a second antenna of the antenna pair is above the noise floor, the first signal strength value of the second antenna is set based on a difference between the measured value of the second antenna and the noise floor.
15. The system of claim 13 , wherein assigning the probability values comprises:
segmenting a normal distribution into a set of binned values; and
assigning one the binned values as the probability value for each pixel for a respective antenna pair.
16. The system of claim 15 , wherein assigning the probability values further comprises:
combining the binned values of antenna pairs of each cell site; and
combining probability values of each cell site,
wherein the respective probability values for the pixels are the combined probability values of each cell site.
17. The system of claim 11 , wherein the grid comprises a plurality of shapes that represent the pixels, and the grid is associated with a geographic area that includes all of the multi-sector cell sites.
18. The system of claim 11 , wherein determining the respective probability values comprises:
determining at least two local probability maxima within the grid, each of the local probability maxima being associated with a respective source of the external interference.
19. The system of claim 11 , wherein the computer readable medium further comprises instructions for providing a heat map indicating probability values of at least a portion of the pixels in the grid.
20. The system of claim 11 , wherein comparing the signal strength measurement data to the first signal strength values includes determining differences between the signal strength measurement data and the first signal strength values to determine the respective probability values.