Terrestrial positioning system calibration
Embodiments disclosed aggregate a plurality of crowdsourced measurement sets for antennas received from a plurality of Mobile Stations (MS) with a Base Station Almanac (BSA), based on a measurement location estimate and a measurement location uncertainty estimate associated with each measurement set. A map comprising a plurality of map layers may be obtained, where each map layer associates locations in the BSA with spatially variable Forward Link Calibration (FLC) values for the antenna derived from the updated BSA data, wherein each spatially variable FLC value is associated with a corresponding location in the updated BSA data. Map layers, which may also include multipath map and/or received signal strength layers, may be provided to MS′ as location assistance data.
1. A method on a Mobile Station (MS) comprising:
obtaining location assistance data comprising a map, the map comprising a plurality of map layers, the plurality of map layers comprising one or more Forward Link Calibration (FLC) map layers, wherein each FLC map layer associates a plurality of entries in a Base Station Almanac (BSA) with corresponding spatially variable Forward Link Calibration (FLC) values for signals transmitted by one or more antennas;
performing, based on the location assistance data, measurements to obtain measurement sets comprising signal measurements for a subset of the one or more antennas, wherein each measurement set corresponds to an antenna in the subset of the one or more antennas;
determining calibrated measurements by applying, based on the location assistance data, a calibration comprising at least one spatially variable FLC value corresponding to a first position estimate of the MS to each measurement in at least one measurement set; and
determining a second position estimate of the MS and a corresponding position uncertainty based, in part, on the calibrated measurements in the at least one measurement set.
2. The method of claim 1 , further comprising:
determining based, in part, on the second position estimate:
one or more refined position estimates of the MS, and
one or more corresponding refined position uncertainties of the MS,
wherein each of the one or more corresponding refined position uncertainties is associated with a distinct refined position estimate in the one or more refined position estimates.
3. The method of claim 2 , wherein, determining each of the one or more refined position estimates comprises:
obtaining, based on a current position estimate of the MS and a corresponding current position uncertainty of the MS, a corresponding refined spatially variable FLC value from a corresponding FLC map layer;
determining refined calibrated measurements by applying a calibration comprising the corresponding refined spatially variable FLC value to each measurement in the at least one measurement set; and
determining a corresponding refined position estimate of the MS and a corresponding current refined position uncertainty, based, in part, on the refined calibrated measurements in the at least one measurement set.
4. The method of claim 3 , wherein, obtaining the corresponding refined spatially variable FLC value comprises:
obtaining the corresponding FLC map layer at a granularity corresponding to the current position estimate and the corresponding current position uncertainty.
5. The method of claim 1 , further comprising:
initiating transmission of the at least one measurement set to a network entity.
6. The method of claim 1 , wherein:
the plurality of map layers further comprise a plurality of multipath map layers, wherein each multipath map layer provides an indication of signal delays due to multipath from the subset of the one or more antennas for entries in the BSA, and wherein each multipath layer comprises exclusion zones indicative of long shadow regions.
7. The method of claim 6 , wherein:
each multipath map layer further comprises statistical parameters associated with signal delays due to multipath for entries in the BSA.
8. The method of claim 6 , wherein each multipath map layer further comprises signal attenuation levels for the subset of the one or more antennas.
9. The method of claim 6 , wherein at least one FLC map layer and at least one multipath map layer include overlapping regions, the overlapping regions including locations corresponding to the first position estimate of the MS and the second position estimate of the MS.
10. The method of claim 6 , wherein the plurality of multipath map layers further comprise at least one of:
a short shadow map layer to indicate short shadow regions for the subset of the one or more antennas, the short shadow layer further to provide an indication absolute signal power information and signal delays due to multipath for the subset of the one or more antennas for entries in the BSA; or
a transmitting pattern map layer to indicate, for each antenna in the subset of the one or more antennas, corresponding unique transmission patterns.
11. A Mobile Station (MS) comprising:
a memory,
a processor coupled to the memory, wherein the processor is configured to:
obtain location assistance data comprising a map, the map comprising a plurality of map layers, the plurality of map layers comprising one or more Forward Link Calibration (FLC) map layers, wherein each FLC map layer associates a plurality of entries in a Base Station Almanac (BSA) with corresponding spatially variable Forward Link Calibration (FLC) values for signals transmitted by one or more antennas;
perform, based on the location assistance data, measurements to obtain measurement sets comprising signal measurements for a subset of the one or more antennas, wherein each measurement set corresponds to an antenna in the subset of the one or more antennas;
determine calibrated measurements by applying, based on the location assistance data, a calibration comprising at least one spatially variable FLC value corresponding to a first position estimate of the MS to each measurement in at least one measurement set; and
determine a second position estimate of the MS and a corresponding position uncertainty based, in part, on the calibrated measurements in the at least one measurement set.
12. The MS of claim 11 , wherein the processor is further configured to:
refine the second position estimate to obtain:
one or more refined position estimates of the MS, and
one or more corresponding refined position uncertainties of the MS, wherein each of the one or more corresponding refined position uncertainties is associated with a distinct refined position estimate of the one or more refined position estimates.
13. The MS of claim 12 , wherein, to determining each of the one or more refined position estimates, the processor is configured to
obtain, based on a current position estimate of the MS and a corresponding current position uncertainty of the MS, a corresponding refined spatially variable FLC value from a corresponding FLC map layer;
determine refined calibrated measurements by applying a calibration comprising the corresponding refined spatially variable FLC value to each measurement in the at least one measurement set; and
determine a corresponding refined position estimate of the MS and a corresponding current refined position uncertainty of the MS, based, in part, on the refined calibrated measurements in the at least one measurement set.
14. The MS of claim 13 , wherein, to obtain the corresponding refined spatially variable FLC value, the processor is configured to:
obtain the corresponding FLC map layer at a granularity corresponding to the current position estimate and the corresponding current position uncertainty.
15. The MS of claim 11 , further comprising:
a transceiver coupled to the processor, wherein, the transceiver is configured to transmit the at least one measurement set to a network entity.
16. The MS of claim 11 , wherein:
the plurality of map layers further comprise a plurality of multipath map layers, wherein each multipath map layer provides an indication of signal delays due to multipath from the subset of the one or more antennas for entries in the BSA, and wherein each multipath layer comprises exclusion zones indicative of long shadow regions.
17. The MS of claim 16 , wherein:
each multipath map layer further comprises statistical parameters associated with signal delays due to multipath for entries in the BSA.
18. The MS of claim 16 , wherein each multipath map layer further comprises signal attenuation levels for the subset of the one or more antennas.
19. The MS of claim 16 , wherein at least one FLC map layer and at least one multipath map layer include overlapping regions, the overlapping regions including locations corresponding to the first position estimate of the MS and the second position estimate of the MS.
20. The MS of claim 16 , wherein the plurality of multipath map layers further comprise at least one of:
a short shadow map layer to indicate short shadow regions for the subset of the one or more antennas, the short shadow layer further to provide an indication absolute signal power information and signal delays due to multipath for the subset of the one or more antennas for entries in the BSA; or
a transmitting pattern map layer to indicate, for each antenna in the subset of the one or more antennas, corresponding unique transmission patterns.
21. A Mobile Station (MS) comprising:
means for obtaining location assistance data comprising a map, the map comprising a plurality of map layers, the plurality of map layers comprising one or more Forward Link Calibration (FLC) map layers, wherein each FLC map layer associates a plurality of entries in a Base Station Almanac (BSA) with corresponding spatially variable Forward Link Calibration (FLC) values for signals transmitted by one or more antennas;
means for performing, based on the location assistance data, measurements to obtain measurement sets comprising signal measurements for a subset of the one or more antennas, wherein each measurement set corresponds to an antenna in the subset of the one or more antennas;
means for determining calibrated measurements by applying, based on the location assistance data, a calibration comprising at least one spatially variable FLC value corresponding to a first position estimate of the MS to each measurement in at least one measurement set; and
means for determining a second position estimate of the MS and a corresponding position uncertainty based, in part, on the calibrated measurements in the at least one measurement set.
22. The MS of claim 21 , further comprising:
means for refining the second position estimate to obtain:
one or more refined position estimates of the MS, and
one or more corresponding refined position uncertainties of the MS, wherein each of the one or more corresponding refined position uncertainties is associated with a distinct refined position estimate in the one or more refined position estimates.
23. The MS of claim 21 , wherein:
the plurality of map layers further comprise a plurality of multipath map layers, wherein each multipath map layer provides an indication of signal delays due to multipath from the subset of the one or more antennas for entries in the BSA, and wherein each multipath layer comprises exclusion zones indicative of long shadow regions.
24. The MS of claim 23 , wherein:
each multipath map layer further comprises statistical parameters associated with signal delays due to multipath for entries in the BSA.
25. The MS of claim 23 , wherein the plurality of multipath map layers further comprise at least one of:
a short shadow map layer to indicate short shadow regions for the subset of the one or more antennas, the short shadow layer further to provide an indication absolute signal power information and signal delays due to multipath for the subset of the one or more antennas for entries in the BSA; or
a transmitting pattern map layer to indicate, for each antenna in the subset of the one or more antennas, corresponding unique transmission patterns.
26. A non-transitory computer-readable medium comprising instructions that are executable by a processor to:
obtain location assistance data comprising a map, the map comprising a plurality of map layers, the plurality of map layers comprising one or more Forward Link Calibration (FLC) map layers, wherein each FLC map layer associates a plurality of entries in a Base Station Almanac (BSA) with corresponding spatially variable Forward Link Calibration (FLC) values for signals transmitted by one or more antennas;
perform, based on the location assistance data, measurements to obtain measurement sets comprising signal measurements for a subset of the one or more antennas, wherein each measurement set corresponds to an antenna in the subset of the one or more antennas;
determine calibrated measurements by applying, based on the location assistance data, a calibration comprising at least one spatially variable FLC value corresponding to a first position estimate of a mobile station (MS) to each measurement in at least one measurement set; and
determine a second position estimate of the MS and a corresponding position uncertainty based, in part, on the calibrated measurements in the at least one measurement set.
27. The non-transitory computer-readable medium of claim 26 , wherein the processor is further configured to:
refine the second position estimate to obtain:
one or more refined position estimates of the MS, and
one or more corresponding refined position uncertainties of the MS, wherein each of the one or more corresponding refined position uncertainties is associated with a distinct refined position estimate in the one or more refined position estimates.
28. The non-transitory computer-readable medium of claim 26 , wherein:
the plurality of map layers further comprise a plurality of multipath map layers, wherein each multipath map layer provides an indication of signal delays due to multipath from the subset of the one or more antennas for entries in the BSA, and wherein each multipath layer comprises exclusion zones indicative of long shadow regions.
29. The non-transitory computer-readable medium of claim 28 , wherein:
each multipath map layer further comprises statistical parameters associated with signal delays due to multipath for entries in the BSA.
30. The non-transitory computer-readable medium of claim 28 , wherein the plurality of multipath map layers further comprise at least one of:
a short shadow map layer to indicate short shadow regions for the subset of the one or more antennas, the short shadow layer further to provide an indication absolute signal power information and signal delays due to multipath for the subset of the one or more antennas for entries in the BSA; or
a transmitting pattern map layer to indicate, for each antenna in the subset of the one
or more antennas, corresponding unique transmission patterns.